Institut für Nutztierwissenschaften

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Wachstum und Wachstumsregulation beim Schwein
(1995) Weiler, Ulrike; Claus, Rolf
The endocrine regulation of growth was studied in wild and domestic pigs by systematic measurements of growth hormone (GH), IGF-I (Insulin-like growth factor-I), insulin and steroid hormones. In some of the studies measurements of osteocalcin were included to monitor the anabolic activity of osteoblasts under different physiological situations. The following results were obtained. Age dependent changes in the secretion of GH- und IGF-I were studied in growing boars, barrows and gilts and compared to growth parameters. IGF-I reflected age dependent changes in the growth potential and were closely correlated with daily gain and protein accretion. Osteocalcin concentrations were always correlated to IGF-I, the age dependent decrease, however, was more pronounced for osteocalcin than for IGF-I, reflecting the allometric predominance of skeletal growth in very young pigs. Osteocalcin concentrations were always correlated to IGF-I, the age dependent decrease was more pronounced for osteocalcin than for IGF-I, reflecting the allometric predominance of bone growth in very young pigs. Additionally a clear rhythm of IGF-I secretion was obvious with a period length of two to three weeks. This rhythm was similarly found for cortisol secretion and peripheral osteocalcin and might be related to allometric growth phenomena, as described for skeletal growth in other species. Regulation of GH-secretion includes interactions with hormones involved in the regulation of reproduction. At the pituitary level such interactions were demonstrated for Gn-RH and GH-RH. Gonadal steroids directly influence the release of GH and IGF-I secretion. The analysis of physiological situations as well as application studies revealed that testosterone had only a minor effect on both hormones. In contrast, low concentrations of estradiol clearly stimulated GH- and IGF-I secretion as well. Further increasing estradiol concentrations were still stimulatory for IGF-I but inhibited GH-secretion. Progesterone tended to lower both, GH and IGF-I secretion. Additionally Large White, Meishan and European wild boar were studied for differences in growth performance and the endocrine regulation during the first year of life. The studies revealed, that the high growth potential of LW is related both, to high levels of anabolic IGF-I and concomitantly low levels of catabolic cortisol. In Meishan and wild boars cortisol levels were high, but in Meishan boars additionally high concentrations of gonadal steroids were measured, which may explain the higher growth rate in MS when compared to wild boars. IGF-I concentrations were even higher in wild boars than in LW. Thus it is assumed that selection for growth potential led to a concomitant change in the level of catabolic glucocorticoids. The influence of the season and photoperiod on endocrine parameter, food intake and growth was investigated in wild and domestic boars. A seasonal influence on IFG-I secretion was obvious in wild and LW boars, but not in Meishan boars. It was further proven by the application of a reverse light programme that the pattern is mainly due to the influence of the photoperiod. In the wild boar three distinct metabolic periods were obvious, which were also found in domestic pigs, but less pronounced. In addition to the photoperiod food intake and food composition modulate GH and IGF-I secretion in the pig. Several experiments revealed, that IGF-I secretion is predominantly influenced by the energy supply and only to a lower extend by protein and tryptophane content of the ration.
Zum Einfluß von mikrobieller Phytase und Calcium auf die Blei-, Cadmium und Zinkretention beim wachsenden Schwein
(1997) Zacharias, Bernhard; Drochner, Winfried
In the present study the influence of microbial phytase and/or calcium supplementation in rations of growing pigs (15 to 30 kg resp. 50 kg) on the retention of lead, cadmium and zinc in kidneys, liver, muscles and bones was investigated. The rations consisted of a barley-soy mixture supplemented with lead, cadmium and zinc either in the form of Pb-, Cd- and Zn-polluted barley or of CdCl2, Pb(CH3COO)2, and ZnSO4. The rations contained an average of 1,45 mg Pb, 0,78 mg Cd, and 55,7 mg Zn per kg dry matter and were given either with or without an addition of 800 U microbial phytase per kg. Compared to the reference group the addition of microbial phytase resulted in diets with a nomal calcium supply (6 g/kg) to a significant increase in the concentration of lead in the phalanx 1 and cadmium in kidneys and liver. The zinc concentration, however, only was increased in tendency in bones and liver. By augmenting the calcium concentration to 12 g/kg it was possible to avoid phytase-induced increase in the retention of lead in phalanx 1 and in the deposition of cadmium in kidneys and liver. For zinc, however, this effect of calcium could not be detected. The higher lead concentration in liver, kidneys and bones after addition of Pb(CH3COO)2 may be due to the 51 higher dietary Pb level as compared to the normally polluted barley rations. The reduced Cd-accumulation in livers and kidneys after feeding CdCl2 supplemented diets with a high calcium level may be explained by an increased formation of insoluble cadmium-calcium-phytate that cannot be hydrolysed by phytase. For the heavy metals lead, cadmium, and zinc the addition of phytase might probably result in an increased metal availability due to phytase-induced hydrolysis of the phytate complex. The effect of a calcium supply exceeding the recommended level may be explained by a reduction in the solubility of phytate which results in a decreased ability of phytate to be splitted by phytase and therefore leads to a reduced
The exocrine pancreatic secretion in pigs and its hormonal regulation as influenced by carbohydrates and fats given per os or infused intraduodenally
(2000) Jakob, Stefan; Mosenthin, Rainer
In the present study the influence of carbohydrates in the form of potato fibre (NSP) and of different fats on the exocrine pancreatic secretion and on the regulative hormonal mechanisms was investigated. When feeding a diet supplemented with 2 potato fibre all measured parameters, e.g. volume of pancreatic secretion, protein output and total trypsin, lipase and alpha-amylase activities increased in pancreatic juice. Simultaneously there was a trend towards a decrease in plasma concentration of CCK. After the intraduodenal infusion of medium chain triglycerol (mct: glyceroltricaprylat), long chain triglycerol (lct: glyceroltristearat) or vegetable oils (olive oil or coconut oil) in all treatments a prandial peak was found as a direct reaction on feed intake for volume of secretion, total protein and colipase contents as well as the total activities of trypsin and lipase. After application of mct the secretion course occured in two phases. In phase 1 a parallel prandial increase in volume of secretion, total protein and colipse content as well as total activities of trypsin and lipase was found. For the same parameters in the second phase 60 min postprandially much lower values were observed compared to the preprandial values. The courses of the curves differed for total lipase activities. The diurnal course of plasma levels of CKK and PYY was not influenced. After coconut oil treatment the course of volume secretion was characterized by 2 phases. After a prandial peak in phase 1 the values decreased by 100 below the preprandial starting values. After the application of olive oil the specific lipase activity was elevated five times. In case of coconut oil there was only a prandial increase by 2.5. It is suggested that the exocrine pancreas responds differently in its secretion to different fat sources. Adaptation is probably regulated through a feedback-mechanism whereas CCK and PYY are of minor importance. Probably other hormones as e.g. secretin have a regulative
Influence of tropical supplemental feeds on the composition and activity of rumen microorganisms, quantified by oligonucleotide probes
(2001) Muetzel, Stefan; Becker, Klaus
This study was undertaken to evaluate the applicability of oligonucleotide probes to unravel the population structure of the rumen flora in vitro. At first a RNA extraction and cell lysis method for rumen fluid samples was optimised. However when tannin containing plants were present in the samples the method failed to recover microbial RNA. The comparison of two rumen fluid sampling sites for inoculation revealed a higher in vitro gas production from samples inoculated with rumen fluid from the feed mat compared to the liquid phase. The higher gas production was not explained by a higher digestibility of the substrates. Changes in the population structure, population density and the kinetic of the fermentation might be responsible for the observed differences. This experiment showed that for interpretation of the results, population structure data have to complemented with metabolic parameters. In a supplementation experiment it was demonstrated that amount, but also the efficiency of the microbial biomass production was positively affected. Comparison of the population structure of the cell wall degrading consortium and cellulase activity revealed that Fibrobacter was mainly responsible for the expression of this enzymatic activity. Such a comparison is a new strategy which will lead to a better understanding of the complex fermentation processes in the rumen. The analysis of the population structure of the cell wall degrading organisms showed a competition for substrate or attachment sites between Fibrobacter and Ruminococcus albus which was independent of the substrate incubated, the time of sampling and the origin of the inoculum.
Entwicklung von spezifischen PCR-ELISA Nachweissystemen für Coxiella burnetii, Francisella tularensis und Orthopockenviren
(2001) Kohlhaußen, Simone; Böhm, Reinhard
In the present work specific systems on the basis of the PCR were developed for the detection of Coxiella burnetii, Francisella tularensis and Orthopoxviruses. The detection of the pathogens is possible without additional cultivation. In order to exclude false-negative PCR results the amplification reaction was established as a competitive PCR in which an internal control DNA is included as an amplification check. With regard to a possible automation the detection-systems were constituted in form of a 'PCR ELISA'. The colorimetric detection of the amplicons takes place thereby in streptavidin coated microtiter plates. For each system biotinylated capture probes for both the internal control DNA (ST) and the pathogen specific DNA (WT) have been developed. For the use of these proof systems in the clinical laboratory, the routine application of the tested decontamination procedure by means of UNG during the execution of the PCR ELISA is recommended. For all three systems a detection of the pathogens is possible within one working day. For the species specific detection of F. tularensis and the genus specific detection of Orthopoxviruses the PCR ELISA systems established here represent the first developments of this type with integrated amplification control and potential for quantification.
Untersuchung der Informativität neuer Mikrosatellitenloci beim Kamel
(2001) Evdotchenko, Dmitri; Geldermann, Hermann
The goal of the investigations was it to use new primers for the representation of polymorphic microsatellite loci in different camel species and to examine new microsatellite loci for Informativity. Some polymorphic loci should be used for the investigation of the genetic differentiation of different dromedary races from Kenya and a bactrian race from Sibiria. For the investigations samples from two species of the old world camels (Camelus bactrianus and Camelus dromedarius) and two species of the new world camels (Llama pacos and Llama glama) were available. As DNA source full blood or leukocyte was used. The representation of the microsatellite loci was carried out with the help of the PCR and following fragment length analysis by means of an automated DNA-Sequencer (A.L.F.). The number of the alleles, their fragment lengths as well as the frequencies of allels and genotypes were computed per locus and taken as original data for estimation of invormativeness. Primer pairs for 34 sequenced loci were tested. 25 of this loci showed specific PCR amplifications with bactrian and dromedary and were therefore included into the further investigations. For instance one third of the loci were found as monomorph, the remaining loci were polymorph. 9 from 17 polymorphic loci showed more than ten alleles in all examined species. The genetic distances between the examined species, computed by means of new microsatellite loci, refer to clear differences between old and new world camels. With the investigations of some dromedary races from Kenya it was shown that the genetic distances estimated on the basis the new marker loci correlated with geographical distances between the races. The investigations supplied thus new informative markers for different genetic analysis in camel. The markers could be also important for the camel breeding (e.g. parentage testing).
Effects of low dietary levels of saponins on two common culture fish - common carp (Cyprinus carpio L.) and Nile tilapia (Oreochromis niloticus (L.))
(2001) Francis, George; Becker, Klaus
Saponins are a group of compounds present in many wild plants and cultivated crops and are commonly found in traditional medicinal preparations. Feeding experiments using saponin-supplemented (commercial Quillaja saponin) feeds were conducted in two commonly cultured fish species, namely common carp (Cyprinus carpio L.) and tilapia (Oreochromis niloticus (L.)). Quillaja saponins (QS) at dietary levels of 150 mg kg-1 and 300 mg kg-1 significantly increased body weight gain in common carp and Nile tilapia compared to controls. When fed to tilapia fry QS (700 mg kg-1) altered the normal 1:1 sex ratio. In separate, in vitro measurements it was found that QS stimulated the release of leutinising hormone (LH) from cultured tilapia pituitary cells, but apparently this did not happen in vivo since serum levels of LH were not found to be elevated in the saponin fed fish. Dietary saponins were also found to affect serum and muscle cholesterol levels. Adult tilapia - but not tilapia fry - fed a dietary level of 300 mg kg-1 QS were found to have significantly higher muscle cholesterol levels than fish fed the control diet. In tilapia fry, the average serum cholesterol levels in males showed a steady increase from dietary QS levels of 0 to 700 mg kg-1, while no such trend existed among the females. Supplementation with 50 and 100 mg kg-1 of Yucca schidigera butanol extract (containing steroidal saponins) did not significantly promote the growth of carp despite showing initial promise. The purified haemolytic fraction of triterpenoid Gypsophila saponin extract (isolated using column chromatography) did not produce any toxic effects in carp at dietary levels up to 250 mg kg-1 in a preliminary feeding trial. A growth promoting effect was however evident at the very low level of about 5 mg kg-1 when the purified fraction was used. More research needs to be done to determine the mechanisms of action of QS and to test whether saponins from other sources have similar effects.
Der Glucocorticoidrezeptor des Schweins: Herstellung und Charakterisierung eines polyklonalen Antiserums, sowie Studien zur Verteilung des GCR im Intestinaltrakt von Ebern und Kastraten
(2002) Gutscher, Monika; Claus, Rolf
Glucocorticoids are well known to be essential for many physiological and developmental processes. Such functions include their effects on carbohydrate and protein metabolism and their regulatory influences on the immune system. In cell regulation they play a dose-dependent key role for differentiation and apoptosis. In rapidly renewing tissues the stringent control of these mechanisms is central to the maintenance of tissue homeostasis. ln the gastrointestinal tract both the adaption to changing nutrients and the presentation with a vast array of different types of antigens, including potential pathogens and harmless dietary antigens requires a granular regulation of cell proliferation, differentiation and cell death. In the pig, the differences in the turn-over rate for instance between skeletal muscle and the gut tissue could be attributed to different GCR concentrations respectively. This explains the tissue specific sensitivty on circulating corticoids. Thus studies on GCR distribution contributes to the clarification of the role of glucocorticoids in the regulation of these mechanisms in the intestinal tract. In the pig, so far receptor detection has been performed by radio ligand binding assays, which only measures steroid unoccupied non-activated receptors in the cytoplasm. Selective GCR antibodies react with both occupied and unoccupied GCR. In addition, antibodies enable celltype specific detection of the GCR in complex tissues by immunocytochemistry. The aim of this investigation was the production of porcine GCR-specific polyclonal antibodies by detailed analysis of the cDNA sequence of the GCR and the recombinant expression of a suitable antigen fragment. A fragment with 2.1 kb of the GCR cDNA (gcr2.1) was sequenced. Based on Blast sequence analysis a GCR antigen fragment for recombinant expression was selected from the modulatory region (GCRmr) and cloned in a T7-expression system as a His-tag fusion protein. After affinity chromatographic und preparative purification The anti-pGCR-antibodies bind the pGCRmr antigen with high affinity, as well as the denatured receptor in western blot analysis. In additon, immunoprecipitation assays demonstrated that cytosolic GCR is recognized regardless of whether it is unoccuppied or occuppied with dexamethasone. Thus, the antiserum is able to bind the native GCR both in its inactivated form as a multiprotein complex in association with HSP90 and in its activated form with shed HSP 90. Our investigations with immunoprecipitation assays support the applicability of the anti-pGCR antiserum in immunohistochemistry. The characterized antibodies were implemented in immunohistochemy for studies of distribution and localization of the GCR in the small bowl and colon of boars and barrows. The intracellular distribution of the GCR was examined by western blot assays. Immunohistochemical studies showed an increased number of immunostained GCR in the colon compared with the small intestine, as has been shown earlier with ligand-binding assays. 32,9 % and 14,5 % of the cells of the lamina propria were GCR immunoreactive in the small intestine of barrows and boars. In the colon 49,3 % and 43,3 % showed immunostaining. Epithelial cells showed a reversed pattern compared to the lamina propria in both groups. The number of GCR immunoreactive cells in barrows and boars decreased from 9,6 % and 9 % in the small intestine to 5,4 and 5,6 % in the colon, respectively. Comparison of both groups ? barrows and boars - revealed significant differences in the number of GCR immunoreactive cells in the lamina propria of the small bowl. Boars showed a decreased GCR expression of 10 % in the duodenum and 30 % in the jejunum. The number of GCR immuostained colonic cells amounts to 36,9 % in the colon ascendens and 49,2% in the colon descendens of boars and 47,5 % and 51 % in barrows. Studies of the subcellular localization by western blot analysis of cytosolplasmic and nuclear proteins demonstrated that in both groups in the ileum a higher amount of GCR was translocated into the nucleus. In the colon the number of cytoplasmic GCR was higher. The different subcellular GCR distribution in the two segments of the intestine can be explained by the increased expression of 11â-hydroxysteroid dehydrogenase 2 in the colon. 11â-HSD 2 inactivates cortisol and thus inhibits receptor activation and thereby translocation to the nucleus.
Seasonal variation in growth, quantitative and qualitative food consumption of milkfish, Chanos chanos (Forsskål 1775), and Nile tilapia, Oreochromis niloticus (L. 1758), in Laguna de Bay, Philippines
(2002) Richter, Hartmut; Becker, Klaus
Laguna de Bay, the largest lake in the Philippines, lies directly southeast of the capital Manila. The lake has a mean depth of only 2.8m and a muddy bottom which is stirred during windy weather, causing turbid conditions (Secchi depth <30cm). In the dry season, the water level drops below that of the nearby sea, leading to a backflow of saline water which clears the water until the return of the monsoon winds (Secchi depth >100cm) and leads to algal blooms. Since the beginning of the 1970s, the lake has been used for culturing milkfish, Chanos chanos (Forsskål), in large netpens (max. 2000ha) and Nile tilapia, Oreochromis niloticus (L.), in smaller cages (max. 200m2). Initially, it was possible during the algal blooms to grow fish from fingerling (ca. 10g) to marketable size (ca. 200g) in three months, making two harvests a year possible. Aquaculture quickly spread until in the middle of the eighties, over a third of the lake was covered with cages. At the same time the growth of the fish declined, which was attributed to the excessive use of primary production. Since then, despite a reduction in aquaculture coverage to the generally recommended level of 10% of the lake, fish growth has never reached the levels of the early days of culture. In the present work, seasonal variation in growth, feeding spectrum and daily ration of these two species was to be investigated in relation to water quality in order to find out more about the interaction between aquaculture and the lake. Between May 1995 and August 1997, milkfish and tilapia were sampled on several occasions at commercial operations over the 24-hour cycle. Since milkfish, unlike tilapia, do not receive supplemental feed, the proportion of their growth derived only from natural food could be determined from the cultured fish. Tilapia were kept in cages without feed specially for this purpose and measured and weighed twice a month between March and November 1997. At the same time, selective water quality parameters (particulate organic and inorganic matter, Chlorophyll-a, zooplankton) were analysed weekly. The growth of unfed fish was significantly faster between saltwater intrusion (mid-May) and the return of the monsoons (late July) than at other times of the year. On the other hand, food consumption was only slightly higher in tilapia when the water was clear than at other times and in milkfish hardly differed over the year. Both species mainly fed on amorphous organic detritus; significant levels of phytoplankton were only found in the stomachs at times of algal bloom. In supplemented tilapia, the daily ration still consisted of 35-75% natural food, suggesting that pelleted feed was used inefficiently. The main factor limiting fish growth therefore seemed to be food quality since detritus has often been shown to be poor quality food. The weekly water samples collected in 1997 demonstrated that the total level of phytoplankton was not necessarily higher at times of rapid fish growth. The main difference was related to algal size, since at times of turbid water, small diatoms dominated but these were replaced by larger blue-green algae after saltwater intrusion. In conjunction with the feeding method of these fish, the strongly seasonal growth of the fish could now be explained. Phytoplanktivorous fish such as milkfish and tilapia can only select their food on the basis of size. Since the organic detritus in the lake consisted of particles smaller than 15µm, it was possible for the fish to selectively filter larger blue-green algae but not smaller diatoms. This could also explain why fish growth rates did not recover after a reduction in aquaculture in the mid-eighties, since the relationship between the level of algae and that of detritus seems to be more important than total algal biomass. In order to increase production to those levels found in the early seventies, the level of detritus in the lake would have to be reduced, for which its origin would have to be investigated first.
Nachweis von luftgetragenen Viren an Standorten der Abfall- und Abwasserentsorgung
(2002) Mayr, Constanze F.; Boehm, Reinhard
In this study, aerosols workers at waste and wastewater treatment plants were exposed to, were examined with regard to the presence of airborne human pathogenic viruses. Besides the detection of hepatitis B virus and hantaviruses the main issue was to detect hepatitis A virus, rotavirus, human enteroviruses and poliovirus. Airborne viruses were sampled in parallel with different bioaerosol samplers, using various physical collection methods. At selected locations, measurements with two special-impingers, the MD 8-sampler and two high-volume-samplers were performed. Personal exposition of waste treatment workers to aerosols was measured using the PGP-GSP-system. Before viruses could be detected, the air samples had to be prepared. Because of the different sampling methods, several protocols had to be established. For the purification and concentration of the collected virus particles the following methods were used: prefiltration, ultrafiltration (100 and 500 KD), density gradient ultrafiltration using a sucrose gradient and the digestion of gelatine with trypsin. After these sampling processing procedures the virus detection and quantification of the samples of the special-impingers, the MD 8-sampler and the high-volume-samplers were assayed for human enteroviruses and rotavirus using four different tissue cultures (VERO, BGM, A549 and MA104) and molecular biological methods (RT-nested-PCR). For all other viruses only molecular biological methods (PCR) were applied. Regarding to the low flow-rate of the PGP-GSP-System only PCR was taken for virus detection. For the detection of viruses using the PCR assay, four different commercially available extraction-kits for DNA and RNA were compared. For all viruses besides hantavirus, several nested-PCR-systems for the qualitative and quantitative (using externe standards) determination with the LightCycler technique were established. To get informations about the attitude of a possible inhibition of the PCR reaction, the prepared samples were seeded with defined amounts of equine rhinovirus and amplified with an external standard on the LightCycler. The established PCR assays for hantavirus, hepatitis A virus, human enteroviruses and poliovirus showed a higher sensitivity (to be more sensitive) than the used cell culture. For detecting rotavirus, the sensitivity of both assays were equal, the detection limit for the nested-PCR of hepatitis B virus was one gencopy per reaction. In none of the 144 aerosol samples (45 PGP-GSP-samples and 99 from the other samplers) rotavirus, hepatitis A virus, hepatitis B virus and hantaviruses could be detected with the PCR technology. Also no rotavirus was isolated with the tissue culture method. In 21 cases the PCR showed positive results for human enterovirus RNA, the calculated concentration ranged from Äq. 100,47 KID50/ml to Äq. 103,74 KID50/ml. Viral infectivity could be demonstrated in 33 out of 99 examined specimens after inoculation on several cell cultures. The virus concentration ranged from 100,7 KID50/ml to more than 103,7 KID50/ml. After plaque purification some of the isolates were sequenced and identified as poliovirus type 1. In conclusion, the results of these studies indicate that at the investigated locations high measurable levels of hepatitis A virus, hantavirus, rotavirus and hepatitis B virus can not be expected. Nevertheless, in some special cases contamination might be possible. The detection of human enterovirus in 21 % of the location-based samples shows that especially bioaerosols at the waste water treatment plants might possibly be contaminated with viruses. Therefore the risk of infections can not be excluded.
Bewertung praxisüblicher Mastschweinehaltungen in Nordrhein-Westfalen hinsichtlich der Tiergerechtheit
(2002) Zaludik, Katrina; Valle Zárate, Anne
The aim of this study was to assess animal welfare in conventional fattening pig systems. Development of means to improve animal welfare shall put the producer in a position to structure the production more in line with consumer requirements. To carry out this assessment the data of 100 fattening pig farms in North-Rhine Westphalia have been analysed. The study comprises of two parts, firstly the collection of operational data and data of housingsystems, and secondly behaviour investigations. In the analysis of the farm data it was found that, particularly in farms with slatted systems important points of the SVHO (1995) were not followed. Deficits were found in space allowance, dimensions of the slatted floors, drinking systems and objects for occupation. Problems apparent in all housing systems were mainly caused by climatic conditions and lighting. In the observational data the most frequent observation was the lying behaviour. This was significantly lower in deep litter systems. The values for the lying behaviour were in line with the figures quoted in the literature for intensively kept pigs. Animals on farms with straw systems, were significantly more active than animals on farms with fully slatted floors, due to the incentives given by the availability of straw. In slatted floor systems the manipulation of penmate and occupational objects were much higher represented in the total behaviour than in straw systems. Abnormal behaviour was found in all housing systems, however only in small amounts. At the end of this study suggestions for ways of improvement were made specific to the relevant husbandry systems, which included housing as well as management factors.
Untersuchungen zur Variation und Rhythmik der individuellen Futteraufnahme bei Pekingenten in Gruppenhaltung
(2003) Bley, Tobias Alexander Georg; Bessei, Werner
Methods to record feed intake in group reared individuals were only available for larger domestic species, such as pigs and cattle. Similar equipment for ducks using an antenna-receiver system had to be developed for the present study. The antenna was fitted nearby the feeder and the transponder was attached to the wing mark. The feeders were connected to an electronic scale and the following characteristics were recorded by a PC continuously: number of the bird, day, time of day, time of visits to the feeder, feed consumption. The system was suitable for duckling from 14 days old onwards. Two experiments were carried out. In experiment 1 a total of 50 male Pekin-type hybrid from 14 to 49 days of age were used. In experiment 2 records were taken from 480 male and female ducks of an experimental line from day 21 to 45. The birds were raised in groups on deep litter (straw). Commercial pelleted feed and water were provided ad libitum. The distance between feeders and drinkers was 1 m in experiment 1 and 5 m in experiment 2. The following traits were extracted from the records: Number of meals per day (defined as visits to the feeder with feed intake) Duration of meals (sec.) Size of meals (grams.) Intensity of feeding (feed intake in grams. per min): feed intake per meal in relation to duration of meal Duration of pauses (sec. or min.) Duration of feed intake per day (min.) Feed intake per day (grams.) Live weight (grams.) Dates of a total of 530 ducks and containing 260000 visits to the feeder were recorded and analysed On the basis of the duration of the frequency of meals per day two distinct groups, birds with large number of short meals (HM), and birds with a small number of big meals (LM), were identified. Comparisons were made between the two meal-type groups for all traits and the circadian rhythms of feed intake. HM ducks were characterised by short duration and small size of meals, and short pauses between meals. There was only a small difference between the meal-types for the total duration of feeding and feeding intensity. HM birds were lighter than LM birds. With increasing age, number of meals per day and duration of feeding per day decreased while daily feed consumption increased. Duration and size of meals, and intensity of feeding increased with age. Changes in feeding activities were most important between 3 and 4 weeks of age. An effect of sex was only noted for the number of meals at seven weeks of age. Differences in the occurrence of pauses were found in response to the experiment, meal-type and age. With regard to the presentation and analysis of pauses the usual procedures using log survivorship functions were discussed. In the present study, however, the differences in the distribution of pauses have been demonstrated using the relative frequency for the pauses of long duration and the cumulative frequency for the pauses of shorter duration. With regard to the high variation of the duration of pauses among individuals and with age the calculation of a single meal criterion, which separates pauses within and between meals, for all individuals and over all ages was not considered useful. On the basis of the distribution of pauses of the different meal-types it seems that the meal criterion is less than one minute in the HM types, and over 35 minutes in the LM types. The circadian rhythm of feed intake was similar in both meal-type groups and shows a biphasic shape with maxima at the beginning and the end of the light period. There was also feed intake during the dark period, the consumption, however, was lower than in the light period. The power spectra of the feed intake showed main components in the 24; 12; 6 and 4.8 hours rhythms and, in addition, various different rhythms in the area of 2-4 hours. The rhythm pattern was more pronounced in the HM types as compared to the LM types. The power of the 24 hours rhythms decreased with age, while a 6 hours rhythm developed at the end of the test period. In general it can be said, that there are distinct types of temporal structures in feeding behaviour in ducks. Age-depending changes appear mainly in the early fattening phase up to 5 weeks of age. There is no general meal criterion in ducks which may be applied to all individuals and at all ages. Feed intake underlies rhythmic processes which are modified with age.
Wohlbefinden von Mastschweinen in verschiedenen Haltungssystemen unter besonderer Berücksichtigung ethologischer Merkmale
(2003) Weber, Ragnhild E. F.; Valle Zárate, Anne
This study aims to compare practice oriented husbandry systems with regard to their effect on the welfare of fattening pigs. This should also contribute to the development of evaluation indicators for pig welfare. A literature review was conducted covering Definition of Welfare, Indicators for Welfare Assessment, Behavior of Fattening Pigs, Ethological Methods for Welfare Assessment, and Husbandry Systems for Fattening Pigs. Insights attained were significantly taken into account when developing and conducting the study. 2 husbandry systems were established, compromising on conventional pig husbandry and currently available knowledge on the welfare of fattening pigs. The investigation emphasizes on ethological traits. This research is part of a comprehensive project investigating prevalent fattening pig husbandry systems in the federal state of North Rhine-Westphalia, Germany, with regard to animal welfare and pig farmers? and consumers? attitudes towards husbandry conditions. The present study was conducted on the experimental station Frankenforst of the University of Bonn, Germany. A total of 256 Piétrain (Pi) x German Landrace (DL) or Pi x (Large White (DE) x DL) fattening pigs were investigated throughout 2 periods of time: middle of June 1998 to beginning of January 1999, and middle of April to end of September 1999. They were kept in two enriched husbandry systems. One system was equipped with heater, forced ventilation and partly slatted floor (TSP: 8 pigs/pen), the other was in an open stable with half the area deep littered (OT: 32 pigs/pen). The enrichments included chains, a wooden chewing bar, and a straw rack in the non-bedded system. Over a period of 10 weeks indirect video observations were conducted once per week between 5:30 and 8:30 a.m. and 1:30 and 4:30 p.m. The behavioral traits observed included feeding, exploration and occupation, abnormal occupation, comfort, aggression and fighting, locomotion, and resting and lying. In the second year direct observations were additionally conducted at specific times to analyse occupation and comfort behavior in more detail. Further traits investigated included: state of health, medical treatments, skin lesions, changes of extremities and claws, general condition, carcass, lung, liver, heart, kidney, and lymph node changes, fattening and slaughtering performance and housing characteristics. The results showed that rooting, which is of utmost importance for the welfare of pigs and which could only be performed in the OT, could not completely be compensated for in the TSP by the enrichment objects and the stable environment. In the TSP the behavioral disorders of pseudo-rooting and manipulation of pen-mates were clearly performed more often. In contrast, the husbandry environment of the OT (straw bedding, enrichment, more overall space, more outside stimuli) had a positive effect on the behavior of the pigs. An improvement of the pigs? welfare in the OT can particularly be concluded from the increased level of rooting, playing, alertness, and walking+standing as compared to the TSP. Comfort+wallowing, the least observed behavior, was also performed significantly more often in the OT. On the other hand, fattening pigs in the OT were also not completely free of behavioral disorders. In both husbandry systems pigs laid (with no other activity) more than 70 % of the observation time. Low lighting in the TSP probably caused a less pronounced endogenously predisposed two-phase daily rhythm of the pigs with less activity in the morning as compared to the pigs in the OT. The forced ventilation in the TSP and the non-bedded area of the OT were not completely sufficient to cool the pigs in summer. The territorial division of the pen by the pigs was disturbed to the point that no clear distinction between lying, defecation and feeding areas could be made. Cardiovascular problems occurred in the OT on some very hot days. Skin lesions, changes in the extremities and claws and the pigs? general condition did not deviate greatly from normal and healthy conditions. No obvious relation of injuries being caused by means of the husbandry system could be found. Carcass inspections showed that lung alterations and pleuritis occurred most frequently. Significant differences between the husbandry systems (OT > TSP) were found for liver and pluck findings. With regard to animal health the pigs in the TSP were better off. It can be presumed that welfare was reduced by the slight Ra. outbreak in the OT in the second year. Differences in daily gain and feed conversion were only due to a substantially lower performance of the pigs in the OT in the first year probably caused by higher thermoregulation efforts. By means of the methods and traits (indicators) used the welfare of the pigs in the two different husbandry systems could be compared. Proposals for further improvements of the methods as well as for the improvement of the husbandry systems were submitted.
Comparison of plant cell wall degrading community in the rumen of N’Dama and N’Dama x Jersey crossbred cattle in relation to in vivo and in vitro cell wall degradation
(2004) Nouala-Fonkou, Simplice; Becker, Klaus
This thesis presents a unique combination of an in vivo feeding trial, the analysis of the microbial community structure in the rumen, and in vitro fermentation studies, in order to assess the impact of breeds and diets on animal performance in a West African production setting. Pure N?Dama and N?Dama x Jersey crossbred cattle were fed two basal diets, baby corn and groundnut hay, supplemented with graded levels of either conventional concentrate or moringa leaf meal, to compare animal responses in productivity. In this context, Moringa oleifera leaf meal constitutes a locally available, potential alternative to commercial concentrate for cattle production. The cell wall digesting community of N?Dama and its crosses was analysed using phylogenetically based hybridisation probes to account for the contribution of rumen microbes to differences in fermentation patterns and animal response. In vitro fermentation studies were carried out using the same diets and supplementation levels as fed in vivo, to test the accuracy of the in vitro gas production technique in predicting the optimum level of supplementation. The in vivo feeding experiment focussed on the comparison of breed performance with diets relevant for local production conditions. Six N?Dama and six N?Dama x Jersey (crossbred) animals were used in a cross over design. They were fed consecutively three combinations of roughage and supplement, baby corn stover and concentrate (BCS:Co), groundnut hay and concentrate (GNH:Co) and groundnut hay and moringa meal (GNH:Mo), each at 5 levels of supplementation (0, 10, 20, 30 and 40%). Results from this study showed that there was a clear difference in animal response to different feeding regimes between the two breeds. When averaged over all diets organic matter intake (OMI) was higher in crossbred compared to N?Dama (94 and 87.6 g/kg 0.75 d-1, respectively). When analyzed for the diets and averaged over the breeds OMI was higher when animals were fed the baby corn based diet compared to groundnut based diets (95 against 88 g/kg 0.75 d-1). Only when the diet consisted of BCS:Co, and at low levels of supplementation, N?Dama ingested more than crossbred, but the difference was not significant. With GNH:Co crossbred ingested significantly more at levels of supplementation less or equal to 20%. With GNH:Mo crossbred ingested more, whatever the level of supplementation. The optimum level of supplementation in vivo, estimated with the single slope broken line model, was 10% and 20% for both breeds when they were fed BCS:Co and GNH:Co respectively, but 30% for N?Dama and 10% for the crossbreds when animals were fed GNH:Mo. Organic matter digestibility (OMD) was higher in N?Dama (64.6% against 60.7% in crossbreds) when animals were fed BCS:Co and supplementation had no effect on OMD of BCS:Co whatever the breed. When animals were fed groundnut hay as basal diet, OMD was also significantly higher in N?Dama at low levels of supplementation, but the differences became insignificant beyond 10% and 20% of concentrate or moringa, respectively. With GNH:Co OMD showed a quadratic response (p<0.001) with increasing level of supplementation when it was fed to crossbreds and was not affected when it was fed to N?Dama. Increasing levels of moringa meal supplementation increased OMD in both breeds up to a peak at 20 and 30% for N?Dama and crossbred, respectively. Average daily weight gain (ADG) was not affected by the breed, however it was higher on BCS:Co compared to other diets. On BCS:Co ADG increased with the level of supplementation, reaching a peak at 30%, whereas supplementation had no effect on ADG when animals were fed groundnut hay based diets. As N?Dama could take in and digest more of the low quality BCS:Co diet, they were less efficient in feed conversion under this feeding regime (FCE: 14 vs. 9 for the crossbreds). On GNH based diets, however, N?Dama surpassed the crossbreds in feed conversion efficiency with ratios of 11 vs. 13 for GNH:Co and 9 vs. 27 on GNH:Mo. Rumen microbes play the key role for the digestibility of a given feed and thus also for feed intake and finally animal performance. Obviously, the community composition and activity is highly dependent on the diet. With the present set-up, however, with identical external conditions and three different, well defined diets fed to both, N?Dama and crossbred cattle, a comparison of the microbial community structure between breeds could be attempted. The in vivo and in vitro data taken in the other parts of the study allow a sensible interpretation of potential changes in microbial composition. Rumen fluid was collected from three fistulated N?Dama and three crossbred animals adapted to the experimental diets at medium supplementation level. The cell wall degrading community was analyzed using the phylogenetically based 16S rRNA hybridisation probes. The results showed that on BCS:Co diet the Fibrobacter and R. flavefaciens RNA concentrations were higher in rumen fluid of N?Dama compared to crossbred. These concentrations were also significantly affected by the diet, such that they were higher on baby corn stover compared to groundnut hay based diets. The results of the microbial community analysis suggested that the differences between breeds observed in digestibility could be partially explained by the composition of the cell wall degrading community. Parallel to the in vivo experiment, in vitro fermentation studies were undertaken to evaluate the predictability of the in vivo response to supplementation by the in vitro data. Rumen fluid from 3 N?Dama and 3 crossbred donor animals was used for 24 hour in vitro fermentations. The donor animals were fed consecutively the same three diets used in vivo (BCS:Co, GNH:Co and GNH:Mo) at 20% level of supplementation. Each of these inocula was incubated with in vitro substrates consisting of all the combinations tested in vivo (i.e. 3 diets, 5 levels of supplementation) plus supplement alone. This design should allow to analyze for both, the impact of donor breed as well as that of the donor diet and to conclude which factors may be varied while maintaining predictability. The breed of the donor animals did not significantly affect 24 hour gas production, but short chain fatty acid concentration was higher with rumen fluid from crossbreds when donors were fed BCS:Co and GNH:Mo. Moringa meal as supplement to donor animals changed the fermentation pattern of all the substrates, such that gas production and SCFA increased substantially in groundnut hay based substrates, whereas gas production of BCS:Co substrates decreased and SCFA did not substantially change. In vitro digestibility was higher with rumen fluid from N?Dama whatever the diet of donor animals and the substrate incubated. GNH:Mo as donor diet also increased IVTD of all the substrates. Even though there was no clear response in vivo, this indicates a general stimulation of microbial activity in the rumen and renders moringa leaf meal a promising supplement. Averaged over all data there was a positive correlation (r2=0.53 p<0.001) between IVTD and in vivo OMD. This correlation was much stronger when calculated for a specific diet (e.g. r2=0.90 p<0.001 for BCS:Co, averaged over the breeds). Analyzing the data for the individual breeds affected correlations only to a minor degree. Thus, when testing a supplementation strategy in vitro, it should be important that donor animals are fed the same components (roughage and supplement) that will be combined at different levels in vitro, whilst the breed of donor animals may be of second importance. This work provides conclusive evidence that in vitro incubations may be used to design supplementation strategies, thus reducing the need for in vivo experiments. Moringa leaf meal is a promising local resource to substitute for conventional concentrate. Differences in productivity between breeds could be correlated to (and may be partially manifested through) a divergent community structure of rumen microbes. That, in turn, indicates that animals of different breeds might have a ?genetic background? that favours the establishment of a certain community, even if the animals are kept under identical conditions. This relationship should be investigated by more advanced molecular techniques.
Erhöhung der Butyratbildung durch Fütterung von Resistenter Stärke beim Schwein: Konsequenzen für die Mitose und Apoptoseregulation der Colonmucosa
(2004) Mentschel, Joachim; Claus, Rolf
Effects of nutrition on health status were examined in numerous studies for human as well as animal species. The interest is mainly focused on those components which are known to exert a beneficial effect on health. Specifically prae- and probiotic substances are discussed to decrease the use of antibiotics in animal nutrition. Moreover epidemiological studies suggest that a higher fiber content reduces the risk for carcinogenesis. The effects seem to be mediated by short chain fatty acids (SCFA). SCFA are major products of microbial fermentation of fiber in the hindgut and are essential for normal colonic function. Butyrate has been shown to have the most significant effects on colonic epithelium. For example colonic recovery after mucosal atrophy is improved due to butyrate supply. To examine the principles of the butyrate dependent effects, in numerous studies the effects of butyrate on mitosis, cell differentiation, and apoptosis of epithelial cells were determined. It has been shown that butyrate increases proliferation of normal cells both in vitro and in vivo, but decreases proliferation in neoplastic cells in vitro. In addition the incubation of adenoma and tumour cell lines with butyrate induced apoptosis whereas the absence of butyrate from the incubation medium triggered apoptosis in guinea pig colonic mucosa. This antiapoptotic function of butyrate has been confirmed in the bovine ruminal epithelium. The reasons for these contradicting results and the regulation of butyrate mediated apoptosis have not been examined so far. In the present study, therefore, the effects of butyrate on colonic epithelium were investigated by feeding resistant potato starch. Effects were verified by determining immunocytochemical parameters. The experiments were performed with 18 castrated male pigs (German Landrace x Pietrain). They were divided into the control group, the resistant starch group (RS), and the realimentation group (RE). At the end of the feeding period the pigs were killed and tissue samples for immunocytochemical studies were obtained. The controls were fed during the whole treatment period (19d) with a ration containing pregelatinized starch with a high ileal digestibility (14,13 MJME and 173,5g XP / kg DM). The RS group received the same diet for 10 days. Thereafter a ration with a lower ileal digestibility containing raw potato starch (11,28 MJME and 138,5g XP/ kg DM) was fed for 5 days in the adaptation period and for 19 d in the treatment period. The pigs of the RE group were fed identically, however after the control diet a starvation period of 3 days was included. Due to the lower energy content of resistant starch compared to pregelatinized starch the average energy and protein content differed between the two rations. To ensure an equal energy and protein supply the RS and RE group received a higher amount of the resistant starch ration. For later analytical determination of pH and SCFA, representative amounts of fresh faeces were collected every morning. They were stored deep frozen (-20°C). At the end of the experimental period pigs were killed and colonic tissue samples were taken for histological and immunocytochemical analysis. Feeding of resistant starch led to a 2.2-fold increase of butyrate in faeces. The morphological results revealed a significant increase of crypt depth (20%) in the resistant starch groups. This difference, however, can not be explained by a different mitotic rate which was nearly identical in both groups. Thus the morphological difference has to be attributed to the differences in the apoptotic activity which was significantly lower (40%) in the groups fed with resistant starch. This decrease of apoptosis was paralleled by an increase of the mucus area of goblet cells which were shown to contain EGF (epidermal growth factor). The difference was about 50%. The results indicate a link between apoptosis and EGF in the colonic epithelium. A reduction of apoptosis by 40% and no change of mitotic rate should lead to higher differences in epithelial development. The low increase of crypt depth can be explained by the shift of apoptosis along the crypt axis. In the group with high butyrate levels 39% of the apoptotic cells were located in the basal compartment of the crypts, in the control-group, however, only 17%. This higher incidence of apoptosis in the stem-cell compartment led to an decrease of average lifespan of colonocytes and consequently to the relative low increase of epithelium. The compartmental distribution of apoptosis is regulated by pro- and antiapoptotic members of the bcl-2 family. Compared to the control group the higher apoptotic rate in the basal compartment of the butyrate group was paralleled by the higher expression (3,5- fold) of the proapoptotic protein Bak. In addition the expression of the antiapoptotic protein Bcl-2 was increased in the luminal compartment by 55%. The results of the RS and RE group did not differ significantly. Due to the treatment-period of 19 days and the high turnover-rate in the colon the effects of starvation seem to be compensated. In conclusion the results demonstrate that under in vivo conditions in the pig butyrate is an inhibitor of apoptosis, but additional mechanisms ensure that the resulting proliferation is limited.
Steuerungsmechanismen der Spermatogenese beim Eber: Auswirkungen einer GnRH-Immunisierung und anschließender Estradiolinfusion
(2005) Wagner, Anna; Claus, Rolf
Whereas the regulation of spermatogenesis is well known in various species, specific differences, however, exist for the boar, which require species-specific investigation. High concentrations of estrogens are synthesized in the boar testis. It is known, that they play a synergistic role for male behaviour and function of accessory sex glands. Additionally, estrogens in the ejaculate reach the female genital tract and contribute to sperm transport and ovulation in the sow. A possible involvement of estrogens in spermatogenesis, however, was not investigated so far. Similarly, high concentrations of glucocorticoids occur in the tubuli of mature boars. Their regulatory function in spermatogenesis so far is unknown. For clarification, boars were actively immunized against GnRH. GnRH stimulates gonadotropin-release from the pituitary. The evaluation of hormone concentrations in blood plasma after GnRH immunization showed unexpectedly, that the gonadotropin FSH is not influenced, whereas LH- and in consequence steroid- (androgen and estrogen) concentrations were abolished. This offers the possiblity to characterize the selecitve function of estrogens in the presence of FSH. Three groups were evaluated: intact boars (n=5), immunized boars (n=5), 17ß-estradiol infused, immunized boars (n=6). All animals were fitted with indwelling cephalic vein catheters on both sides. One of them was reserved for infusion, the other one for uncontaminated blood sampling. All animals were infused with physiological saline over 7 weeks. For the 17ßEstradiol infused, immunized boars, a defined concentration of estradiol was added to the solution. Blood samples were collected over the whole 7-week period for LH, FSH, testosterone and estradiol. Blood samples were later analysed by established radioimmunological procedures. At the end of the 7-week period, all animals were killed. Tissue samples were fixed for histological examination. Morphological criteria included e.g. tubular diameter, seminiferous epithelial height and number of Leydig cells. Imunocytochemical evaluation was performed for mitosis (Ki-67), apoptosis (TUNEL) and the glucocorticoid receptor. The number of germ cell in the tubuli was reduced by 60% in immunized boars compared to the intact controls. These changes were explained by a more pronounced expression of the glucocorticoid receptor in spermatogonia, followed by the appearance of apoptosis in spermatogonia and primary spermatocytes. In consequence these findings demonstrate for the first time an involvment of glucocorticoids in the quantitative regulation of spermatogenesis. They counteract tubular mitosis by reducing the number of germ cells by apoptosis. In the 17ßestradiol infused group of immunized boars, the infusion led to the restoration of physiological estradiol concentrations (230 pg/ml) in peripheral blood plasma. As expected, androgen concentrations were minimal, so that the specific role of estrogens for spermatogenesis could be clarified. Data from the histological evaluation showed, that the expression of the estrogen receptor alpha occured in spermatogonia, selectively in the mitotic active stage of the seminiferous epithelial cycle leading to a 41-50% rise of germ cell numbers compared to immunized boars. The apoptotic rate in the tubuli of the estradiol infused boars however was not changed compared to immunized boars, so that physiological sperm numbers as they are characteristic for intact boars, were not reached. This study shows for the first time that both glucocorticoids and estrogens play an essential role for spermatogenesis in the boar. They are involved in the regulation of sperm yield by influencing the mitosis-apoptosis equilibrium in the tubuli of boars.
Dose Titration, Tolerance and Compatibility of some Feed Additives in Broiler
(2005) Islam, Khan Md. Shaiful; Drochner, Winfried
In two dose titration studies on chicken for fattening growth promoting efficacy and some aspects of safety of fumaric acid (FA), an approved preservative, and humic acid (HA), approved as veterinary drug, were examined. In a third experiment on chicken for fattening the compatibility of the ionophore coccidiostat semduramicin (AVIAX®), also approved at EU level, with the veterinary antibiotic tiamulin should be investigated. In experiment 1 six diets with increasing FA contents were fed for 26 days to 96 newly hatched male chicks per treatment. Final body weight (feed efficiency) amounted to 1,506 (756), 1,597 (767), 1,532 (754), 1,485 (759), 1,342 (738), and 1,378 g (747 g gain kg-1 feed) for the groups with 0, 1.25, 2.50, 3.75, 5.0, and 7.5 % FA, respectively. The 1.25 % FA group showed significantly (p<0.05) better weight gain than all other groups and better feed efficiency than the groups with 5.0 and 7.5 % FA. Body weight of the 5.0 and 7.5 % FA groups was significantly lower than that of the other groups. The relative organ weight was not affected by the treatment. In experiment 2 six diets containing 0, 0.3, 0.6, 1.2, 2.4, and 4.8 g Huminfeed® (74 % humic acid in DM) kg-1, respectively, were fed for 35 days to 80 newly hatched male chicks per treatment. Initially HA depressed weight gain, but recovery started in the third week, so that at the end no significant differences could be observed. But body weight gain was negatively correlated with the HA content of the diets (y (weight gain) = 2327.98 ? 0.0181x (Huminfeed content), r = -.280*). Feed intake was not affected by the treatment. The relative organ weights did not differ among the groups. Experiment 3 (35 days) with a total of 320 female broilers chicks was conducted to study the effect of 25 mg semduramicin kg-1 feed and the potential interference between semduramicin and tiamulin on zootechnical parameters (10 replicates with 8 chicks each), haematology, blood routine biochemistry and health status (1 chick per replicate). Tiamulin medication (250 mg L-1 water) from day 15 to 19 reduced significantly water intake, especially when concurrently given to birds fed semduramicin. Also feed intake was depressed in that period. Body weight gain of the semduramicin/tiamulin group in the third week was affected too. After 35 days, body weight (feed efficiency) was 2,062 (665), 2,067 (669), 2,084 (678), and 2,008 g (679 g gain kg-1 feed) for the control, the tiamulin, the semduramicin and the semduramicin/tiamulin group, respectively. All data obtained form haematology, blood biochemnistry ad pathology did not give evidence for any adverse influence of the coadministration of tiamulin and semduramicin. After a withdrawal period 20 broilers from the control and the semduramicin group were slaughtered and examined for product quality. No treatment effects (P>0.05) on hot carcass weight, viscera, dressing percentage, edible portions (breast muscles, haunch), fat and skin portions were seen. Also the sensory characteristics (juiciness, tenderness, unpleasant pungent aroma, general impression) except the aroma/flavour were not influenced by the treatment.
DIE BEDEUTUNG DER LAUFAKTIVITÄT UND DER GEWICHTSENTWICKLUNG BEI DER ENTSTEHUNG VON BEINSCHÄDEN BEIM MASTGEFLÜGEL
(2006) Djukic, Mirjana; Bessei, Werner
Within the last 50 years, an intensive selection took place in broilers on high growth and therefore there exists a clear reduction of the age at slaughter. Side effects of the selection of faster and higher growth are leg disorders. RUTTEN et al. (2002) tried to reveal the causal relations between weight load, activity and leg disorders by reducing the weight load on legs of fast growing broilers (FB) by a special device. The weight reduced FB showed higher locomotor activity and better bone quality. However, the harness used for the reduction of weight load on the legs impaired the growth rate. In the present study, the experiment of RUTTEN et al (2002) was repeated with an improved device for reduction of weight load of FB. In addition, slow growing broilers (SB) were used, and were brought to the same weight load as weight reduced FB by additional load. In total three experiment were carried out. The first experiment was split in two parts (1a and 1b) so as to incrase the number of replicates. For each experiment, 24 male broilers were used: 12 FG (ROSS 308) and 12 SB (ISA S 257). Load reduced birds weared a harness which was connected to the load reducing device. The load increase of SB weared the same harness with small pieces of led. The chicks of the groups were treated as follows: one with harness and suspension (HS), one with a harness and without suspension ? control bird 1 (C1) and a control bird with no harness and no suspension ? control bird 2 (C2). The load of FB was reduced to the average weight of SB-C2 and FB C2. The load of the SB was increased to the same average value. The following parameters were recorded: body weight, food consumption, weight of breast muscle, thigh, tibiotarsus, femur; length of tibiotarsus and femur; angular deformity of distal femur, distal and proximal tibiotarsus; torsional deformity of femur and tibiotarsus, total area, total density, Corticalis area, Corticalis density, SSI, walking, sitting, standing, eating and ?other behavior?. The weight load reduction in FB led to a significant increase of the locomotor activity. Both the torsional and angular deformities of the Tibiotarsus were clearly reduced, while total area, total density, Corticalis area and SSI were increased. It can be assumed that this was caused by the higher locomotor activity of load reduced FB. The increase of load in the SB diminished the locomotor activity but bone characteristics were not deteriorated. The improvement in the bone conditions of the FB was obviously caused by the increase in activity. In order to determine the influence of decreased load in FB and of increased load in SB the opportunity to move was restricted by reduction of the length of the compartments from 2 to .45 meters. All other experimental conditions remained the same as in experiment 1. Despite the restricted space there was a significant increase in locomotor activity of the load reduced FB. The torsion and angular deformity of the proximal and distal angular deformities of the Tibiotarsus were reduced. There was no significant effect of the increase and decrease of load on the CT-criteria. As in experiment 1, the weight load in the SB diminished the locomotor activity, but the bone characteristics were not influenced significantly. In the third experiment the gait of the load increased SB and load decreased FB was analyzed by a foot print program. For this purpose the length and width of the steps were measured at 4, 5 and 6 weeks of age. The same breeds and the same technique of the modification of the load were used. The load treated birds were kept individually and could use the full length of the test pens. In contrast to the previous experiments the control birds were kept in pens of 1 m² floor space (1 x 1 m). Only the birds without harness (C2) were kept as control. The results of the morphometric and CT- criteria confirmed the results. The FB control birds showed higher step length and greater step width than SB controls. The step length of FB was increased through the load reduction, and decreased through load increase in SB. The treatment had no influence on the step width. SB broilers showed problems to keep their balance under increased weight load. As indicated in the low width of the foot prints the load increased SB broilers tried to place their feet, as usual, under the point of gravity of their body. This seems to impair the stability of gait under increased weight load. FB in contrast, move their centre of gravity above the supporting leg which allows a stable gait under high load. FB did not change the width of their foot prints when the load was decreased, and only the length of the steps increased. The results underline the importance of locomotor activity on the leg conditions of FB. They clearly show that low activity of FB is not caused by lack of motivation but by the high weight load.
Versuche zur Verbesserung der sensorischen Fleischqualität beim Schwein durch nutritive Hemmung der Skatolbildung
(2006) Lösel, Dorothea; Claus, Rolf
Skatole is known to occur in pork carcasses. Due to its pronounced faecal odour, it may have an adverse effect on sensorial quality of pork. Skatole has been associated with boar taint, but is also formed in the large intestine of barrows and gilts by bacterial degradation of tryptophan. As apoptotic cells from the gut mucosa are the main source of tryptophan, skatole formation is partly linked to the degree of cell renewal in the gut. A part of microbially formed skatole is absorbed and stored in adipose tissue due to its lipophilic properties. In earlier studies it has been shown that intestinal butyrate formation increased by feeding resistant potato starch. This short-chain fatty acid reduced the apoptotic activity in the gut mucosa and thus decreased skatole formation and tissue accumulation. Therefore, it was the aim of the present study to investigate whether this method is applicable to improve sensorial quality of pork under routine fattening conditions. In the first experiment the amount of potato starch required for sufficient reduction of skatole was determined. Four groups of pigs received diets containing different amounts of potato starch (0 % as a control, 20 %, 30 %, 40 %) for 2-3 weeks prior to slaughter. Skatole concentrations in gut content (proximal and distal colon, rectum) and adipose tissue (flare fat and ventral fat) were determined by High Performace Liquid Chromatography. An amount of 30 % in the diet reduced skatole concentrations in gut content and adipose tissue compared to the control. The reduction was 98 % in the proximal colon, 93 % in the distal colon and 89 % in the rectum. Skatole concentrations in flare fat decreased by 84 %. Feeding a higher amount of potato starch (40 %) did not result in a significant further reduction. Therefore, in the following experiment (consisting of two replicates) diets of treatment groups contained 30 % of potato starch. In each replicate, 80 Baden-Württemberg Hybrids (barrows and gilts) were fed the diets during the whole fattening period. The control groups received a conventional diet based on grain and soya and a diet with a proportion of 30 % gelatinized starch in replicate 1 and 2, respectively. Skatole concentrations were determined in gut content (proximal and distal colon, rectum), blood plasma and adipose tissue (flare fat, ventral fat and back fat). Apoptosis in the colonic mucosa was determined cytochemically. From each replicate cutlets from 12 control pigs and 12 potato starch pigs were used for sensorial evaluation. The panellists evaluated samples for aroma of meat juice, and aroma and taste of meat according to a 5-point scale. The attributes were from 1 (very unpleasant) to 5 (very pleasant). A trend towards reduced apoptosis was demonstrated in the upper crypt compartment in the proximal colon. Intestinal skatole formation decreased from 50-60 µg/g dry matter to values around the lower limit of detection (0.4 µg/g). Thus, less skatole was absorbed and the mean concentrations in blood plasma were reduced by 45-65 %. In adipose tissue, concentrations in the potato starch group decreased by 57-90 % compared to the controls. Therefore, the variation of concentrations was reduced, so that 90 % of the potato starch pigs had values below 20 ng/g. Concentrations in gut content, blood plasma and adipose tissue were significantly correlated. In replicate 1, sensorial evaluation showed that cutlets containing between 0 and 2.78 ng/g skatole in fat had better ratings for aroma of meat juice and meat than samples with mean (up to 28 ng/g) or high (up to 78 ng/g) skatole concentrations. Also, the overall impression was significantly improved. In replicate 2, there was still a tendency to these differences. In conclusion, this study shows that the reduction of intestinal skatole formation by feeding resistant starch can improve the aroma of pork. For routine application, it would be sufficient to feed the potato starch diet for only a few days prior to slaughter.
Die Regulation der Futteraufnahme beim Schwein - Untersuchung der Wirkungen eines Serotonin Noradrenalin Wiederaufnahmehemmers (Sibutramin) und eines MCH-R1 Antagonisten (Compound B4)
(2007) Sommer, Torsten; Claus, Rolf
The regulation of food- and feed intake is a highly topical investigative area in animal husbandry as well as in human medicine. Here the focus of medicine is primarily on the reduction of food intake and at the same time change of the metabolism to increased energy expenditure in order to counteract the rising number of adiposity and metabolic syndrome. Therefore, substances from pharmacological research are known which act in different nuclei of the hypothalamus and control food intake and energy expenditure. In the present study two of these new substances were examined with regards to their impact on pigs. The results lead to a more detailed understanding of the corresponding mechanisms in pigs, one of the most important animals used in agriculture. In addition, the pig is also a suitable model for human pharmacological research, as it equals the human physiological regulation more than the rat, which is the most common animal model. Study work flow: Two different regulative substances were examined, on the one hand a serotonin noradrenalin reuptake inhibitor (Sibutramine) and on the other hand, a melanin concentrating hormone receptor antagonist (MCH-R1 antagonist; Compound B4). For the evaluation of the effectiveness the following factors were measured; feed intake, water consumption, weight gain, feed conversion rate and the development of body fat content. The changes caused in the regulation of the metabolism were evaluated by anabolic (Growth hormone and IGF-I) and catabolic (cortisol and aldosterone) hormones. In addition, thyroid hormones and urea in the blood plasma were measured as a parameter of protein turnover. The study was divided in three trials, each of them taking six weeks. During the first trial sibutramine was given per os to three animals and three animals were kept as control. During the second trial sibutramine was given intravenously to two animals and two animals were kept as control. During the third trial the MCH-R1 antagonist, Compound B4, was given per os to six animals. The results are described in the following sections. Results of the sibutramine application: The pharmacological effectiveness of sibutramine is mainly explained through its metabolites (desmethyl sibutramine and didesmethyl sibutramine). It was found that for the per os intake of 20 mg/kg LW sibutramine, as well as sibutramine as the first metabolite desmethyl-sibutramine, a lower concentration in the blood plasma existed compared to the intravenous application. Whereas concentration of the second metabolite didesmethyl-sibutramine was higher for per os application than for intravenous application. Since the effectiveness of sibutramine is mainly based on its second metabolite didesmethyl-sibutramine, the way of application was crucial for its effectiveness. This means that the intravenous application was ineffective. After per os application feed intake was significantly reduced, also dependent on the dose applied, but did not lead to a reduced weight gain of the animals. Further, no impact was found on the feed conversion ratio. In contrast, the treatment with sibutramine per os led to significantly increased water consumption. The application of sibutramine had no impact on the growth hormone secretion. However, IGF-1 concentration was increased while feed intake was decreased. The cortisol concentration in blood plasma was not impacted by any treatment. Results of the application of the MCH-R1 antagonist (Compound B4): The application of the antagonist led to a significant reduction of feed intake, dependent on the dose applied. The means derived for daily weight gain show considerable individual differences per animal, hence the reduction of daily weight gain overall was not significant. Further, changes in water consumption were also detected in this trial. However, it could not be clarified if this was caused by the application of the antagonist or the reduced feed intake. Generally, the application of Compound B4 tends to result in energy saving mechanisms, which have an impact on metabolic active hormones. IGF-1 for example, was slightly lower in the control phase. Neither sibutramine nor the MCH-R1 antagonist Compound B4 had any impact on the concentration of thyroid hormones or cortisol. Conclusions: The studies have shown that the MCH-R1 antagonist leads to a significant reduction of feed intake in pigs, whereas the metabolic active hormones, and therefore the energy expenditure, do not seem to be impacted at all. In addition, it was proven that the pig is a useful animal model for such human pharmacological investigations. However, the large amount of substances required can be seen as disadvantageous and as a limiting factor in the investigation of new agents with an initially small amount of substance synthesis.

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