Browsing by Person "Bessei, Werner"

Now showing 1 - 13 of 13

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.
Beiträge zur Ermittlung der P-Verwertung bei der Japanischen Wachtel
(2008) Alfoteih, Yassen; Bessei, Werner
Although there are plenty of studies concerning the metabolism and requirement of phosphorous (P) in poultry, the availability of P from organic and inorganic sources has still to be elucidated. Lacking knowledge on the availability of P has not caused problems in the past since commercial diets have been supplemented with P levels far above the requirement. Only when the excretion of P has been recognized as a source of environmental pollution, and poultry producers were forced to reduce P supplementation in the diet according to the requirement, need more of accurate information on the availability of P has stimulated research in this field. A series of experiments on the utilization of P from different organic and inorganic sources has been carried out using Japanese quail as a model for other poultry species. In addition, the role of the Ca: P ratio on the availability of P was investigated. A total of 6 experiments have been carried out. All experiments were carried out using almost the same methodology. Chicks of a commercial fast growing line of Japanese quail of french origin were hatched at the research station of the University of Hoheheheim and reared up to 3 weeks under standard conditions using a starter diet. Starting from week four, the birds were fed the experimental diets and data for the P-balance were collected for 7 consecutive days (fifth week of age). The components to be tested were added to a basal diet containing all nutrients with the exception of Ca and P. The utilization of P was calculated as difference between P intake and P excretion. The basal diet without supplementation of test-components was included in experiments since P utilization of the basal diet was needed to calculate the partial utilization of P from the test-components. In experiment A1 the utilization of P from summer barley and oats was tested. In Experiment A2 experimental diets comprised three different sources of P, each of plant origin (winter wheat, winter barley and maize) and of inorganic sources mono-calcium phosphate (MCP), di-calcium phosphate (DCP) and mono-sodium phosphate (MNP) were used. Mixtures of P sources tested in experiment A3 (MCP+DCP, MCP+MNP, MCP+maize, Wheat+ barley and wheat+ maize) were examined in experiment A3. The P level in the experimental diets was adjusted to a range of 2 to 3 g/kg and the Ca-level to 3 to 5 g/kg. The Ca:P ratio was restricted to a maximum of 2:1. The supplementation of the different types of grain to the diets was 60.0 to 66.0 %. Calcium carbonate (CaCo3) and sodium bicarbonate (NaHCo3) were used to supplement Ca. The result showed that, there was no significant difference among the experimental diets on weight gain of the birds. P utilization was highest in the basal diet (66.6 %) followed by barley and oats (33.3 and 20.8 % respectively), while the standard diet showed the lowest utilization (7.87 %). In experiment A2 the utilization of P of the basal diet (94 %) was significantly higher than of all other P-sources wheat (60 %), maize (66 %), while diet supplemented with barley showed the lowest value (34 %) and the other sources an intermediate position between 47 and 53 %. The partial utilization was somewhat lower than the overall utilization in all diets. In experiment A3 the utilization of P of the basal diet was 69 % and did not significantly differ from the other diets. The combination MCP+MNP showed the highest utilization (76 %), followed by wheat+barley (53 %) and MCP+maize (50 %). The partial utilization showed the similar values as the overall utilization. The three following experiments (B1, B2 und B3) dealt with the effects of different Ca: P ratios on the utilization of P, feed intake, growth rate and selected bone criteria. Four different Ca levels (0.80; 1.20; 1.60 and 2.20 %) were combined with three P levels (0.30; 0.45 and 0.60 %) in experiment B1. During Experiment B2, experimental diets contained three Ca concentrations at levels higher than in experiment B1 (2.60; 3.00 and 3.30 %) and three P concentrations at levels lower than in B1 (0.10; 0.20 and 0.30 %). Experiment B3 was conducted with the same Ca and P concentrations as in experiment B2, but the duration of the balance period was extended from 1 to 3 weeks. In addition of the P utilization and growth rate Ca and P contents of the tibia bones was analyzed and some bone characteristics were measured by computer tomography. In experiments B1 and B2 neither the P nor the Ca concentration showed a consistent effect on feed intake, growth rate, feed conversion or mortality. The P utilization decreased with increasing P concentration and P intake. The effect of the Ca: P interaction on P utilization was only significant in experiment B1. In the extended balance period in experiment B3, the effects of Ca and P concentration as well as their interaction was significant for body weight in the first week of the experiment. From the second week onwards the effects of the sources of variance decreased and fell under the level of significance. The P utilization was only influenced by the P concentration. As in the previous experiments P utilization decreased with increasing P concentration. Bone characteristics showed tendencial response to Ca and P concentration, whereby with the lowest concentrations of Ca and P in the diet, the highest bone weight, ach content, Ca and P content was found. Elevating Ca supply meliorated the total area and cortical area of the tibia. However, the better tibia quality based on evaluating the Strain Strength Index (SSI) as a criterion for the stability of bone was found in groups fed diets with the highest level of P. The results of these experiments showed that there is an obvious variation in the availability of P from the organic and mineral resources. The utilized P value from mineral resources was underestimated, while the utilized P value from organic resources overestimated. The P utilization of the combinations of different P sources which diverged in their P utilization showed intermediate values. The P concentrations of the diets and the P intake were the main influencing factors on P utilization. This result pointed out that the birds were capable to cover their requirements from P through the diets, although the P contents in the diets were low. The P contents of tested diets have met already the requirement of P with quails or even exceeded. The recommendations of P supply in quail diets need to be reduced accordingly. Should quail be used as model for the study of P requirement in broilers, it is essential either to decrease the P content drastically in the diets, or to conduct the tests at earlier age. The lower requirement of P in quail from 3 weeks of age onwards explains the weak reaction of feed intake and growth rate in response to the low P concentration and to extremely high Ca: P ratios. Some bone characteristics responded to low P concentrations and high Ca: P ratios even at higher ages. This confirms previous findings that P requirement for bone building is evidently higher than the P required for growth. The question posed by this result, weather growth rate or bone characteristics should be used to determine the requirement of P in poultry.
The effect of intensive selection for egg production on foraging related behavior and performance related hormones in laying hens
(2023) Höhne, Anja; Bessei, Werner
The production performance of livestock has increased massively in recent decades. Changing performance levels through intensive selection has played a major role in this. Over the years, a limited number of high-performing lines have emerged. The high performance level of chicken laying lines can only be achieved with optimal feeding and intensive conditions. However, these laying hens are increasingly exposed to changing housing and husbandry systems including changing environmental conditions. Therefore, the aim of the present work was to investigate possible side effects of intensive selection on egg production, such as behavioral and physiological changes leading to a reduced adaptability to alternative environmental conditions. We used four different chicken laying lines: pairs of brown and white layers each with a high (BLA, WLA) and a low (L68, R11) laying performance. All experiments were done before and during the laying period. Foraging strategies and behavior related to foraging were analyzed in groups of 12 hens per pen. The foraging strategy was tested using a contrafreeloading (CFL) paradigm. CFL describes a behavior in which animals prefer food that is laborious to obtain, although it is freely available at the same time. Foraging behavior (number of hens scratching or pecking in the litter area) and the litter area parameter (number of hens in the litter area) were also observed. In addition, hens’ activity in the feeding area was measured using an antenna-transponder system, recording activity around the feeder and time in the feeding area. Because these behaviors lose importance when food is offered ad libitum, we hypothesized that high-performing lines will prefer freely available feed in the CFL and will exhibit less foraging behavior. The peptide hormone ghrelin is related to the regulation of feed intake and feeding behavior. Based on previous studies in chickens and the expected difference in nutrient requirements depending on performance level, we expected lower plasma ghrelin concentration in the high-performing lines compared to the low-performing lines. To investigate the effects of controlled environmental conditions during the intensive selection, plasma ghrelin was recorded both in cages, i.e., in a controlled and barren environment, and in a structured floor housing with 30 hens per compartment. Due to its function in growth and its relationship to ghrelin, the plasma concentration of growth hormone was also analyzed. One of the most important gonadal steroid hormones with various functions in regulating reproduction and, thus, also laying performance is the sexual hormone estradiol-17ß. Egg formation is closely related to its concentration. It was expected that lines with a high ovulation rate would have higher estradiol-17ß concentrations than lines with low performance. Estradiol-17ß was also measured in individual cages and in floor housing systems with 30 hens per compartment. A side effect of the selection on foraging-related behavior was confirmed by the results. High-performing selected hens showed less CFL and foraging behavior, were observed less often in the litter area, and showed less activity in the feeding area compared with non-selected hens. In addition, white hens exhibited more foraging behavior and were observed less frequently in the litter area compared to brown hens. Contrary to our expectations, ghrelin concentration did not differ between the four lines before and during laying period. In adult laying hens, ghrelin does not appear to be involved in the regulation of energy intake associated with laying performance. An influence of selection on plasma estradiol-17ß concentrations during the laying period was confirmed. Hens with high performance showed higher estradiol-17ß concentrations than hens with low performance. The phylogenetic origin showed no effect on the plasma concentration of estradiol-17ß. The increased concentration of estradiol-17ß may affect its further functions. The highest concentration after the laying peak indicates its involvement in calcium and bone metabolism. Especially in high-performing lines, high concentrations of estradiol-17ß have been associated with a reduction in bone strength and an increased risk of bone fractures. Hens in floor housing with more movement opportunities showed lower estradiol-17ß concentrations and, in the growth phase before the start of laying, higher ghrelin concentrations than hens in individual cages. Since this was the same in all lines, it was not an effect of intensive selection, but rather seems to be related to more movement opportunities. Foraging behavior and estradiol-17ß concentration are not used as selection traits, but both traits are associated with performance levels of laying hens. The high level of egg production and controlled environmental conditions during performance testing are associated with behaviors that allow hens to meet their higher energy requirements more efficiently. Energy conservation through reduced activity likely allows them to divert energy to reproduction, i.e., laying performance. Adaptability to husbandry systems including changing environmental conditions is lower in high-yielding selected hens than in non-selected hens. Therefore, adaptation of housing systems should be considered in intensive selection.
Effect of sodium and potassium chloride supplementation in drinking water on performance of laying hens and broilers under high ambient temperature
(2008) Nguyen Van, Dai; Bessei, Werner
It is well known that water intake and maintenance of electrolyte balance play a vital role in the resistance of chicken to high temperature. It was hypothesis that voluntary water intake in response to heat stress may not be sufficient to prevent the reduction of performance in laying hens and broilers, and that stimulation of water intake through supplementation of electrolytes in drinking water may assist the birds to maintain high productivity under heat stress. The present study includes three experiments. Two experiments were carried out with laying hens in controlled ambient temperature conditions to study the effects of sodium chloride (NaCl) and potassium chloride (KCl) supplementation in the drinking water on water intake, feed intake, egg quality, body temperature, body weight and productivity of laying hens under high temperature. The third experiment with broilers was conducted in tropical summer conditions of Viet Nam to find out whether supply NaCl and KCl in drinking water would improve productivity and carcass quality of broilers under tropical summer conditions and which concentration of both minerals should be used. The first experiment was conducted for three weeks (from 26 March to 16 April 2007) at the research station of Hohenheim University, Germany. A total of 48 Hisex hens (76 weeks old) were kept in individual laying cages in climatic chambers and were randomly allocated to three experimental groups of 16 hens each. These groups were given 0; 0.2 and 0.4 % KCl in the drinking water for seven consecutive days of heat stress. Before and after heat stress, birds were given normal drinking water. Water and feed were provided ad libitum. The birds were fed a layer diet containing 11.45 MJ/kg Metabolizable Energy, 16.97 % Crude Protein, 3.73% calcium, 0.62% phosphorus, 0.22% sodium and 0.33% chloride. The room temperature was constant at 21±1°C for 7 days, afterwards, it was cycled from 21±1°C to 34±1°C (from 9 to 22 o?clock) for 7 days, and then constant at 21±1°C for 7 days. Humidity was not controlled. 14-hours lighting schedule was maintained during the experiment. Water and feed intake, water: feed ratio, body weight, body temperature, egg production, egg weight, egg shell thickness, egg deformation, egg shell strength, yolk colour and Haugh Unit (HU) were recorded. In the second experiment, effect of NaCl supplementation (0.2 and 0.4%) in drinking water on laying hens was tested under the same temperature program as in the first experiment. A total of 48 Hisex hens (80 weeks old) were used. The third experiment was carried out on the commercial chicken farm from 26 June to 14 August 2007 (49 days). A total of 240 21-day-old broiler chicks (Lohmann meat) were randomly allocated to 5 treatment groups in a randomized block design. Each treatment consisted of three replicates of 16 chickens each. Both, NaCl and KCl, were supplemented from the beginning of the 4th to 7th weeks of age at 0.2% and 0.4% to drinking town water, and unsupplemented water was used as control. The birds were kept in an open sided poultry house on the rice hull litter. Temperature and humidity of the house were not controlled. Water and feed intake were measured weekly. Body temperature of 15 birds per treatment was measured at 23, 33 and 40 day of age. All birds was individually weighed on day of hatching and afterwards at weekly intervals up to 7 weeks of age. At 49 days of age, one male and one female bird from each replicate (a total of 30 birds) were slaughtered to determine carcass characteristics. The results showed that in laying hens, heat stress increased water intake, water to feed ratio, body temperature and eggshell defects. Feed intake, egg production and egg weight decreased tendentiously during heat stress. Body weight, eggshell thickness, eggshell strength, egg deformation, yolk color and HU were not significantly affected by heat stress. Supplementation of KCl or NaCl in drinking water increased water intake and water: feed ratio. Only KCl supplementation maintained body weight, egg weight and egg production, and decreased eggshell defects. Feed intake, eggshell deformation, yolk color and HU were not significantly affected by either KCl or NaCl supplementation. The results showed that KCl supplementation through drinking water may be a means to maintain egg production and egg quality which are usually deteriorated when the temperature in the layer house increases while NaCl was less effective under these conditions. Supplementation of KCl or NaCl in drinking water enhanced water intake and water: feed ratio of broilers under tropical summer conditions. 0.4% NaCl supplementation in drinking water reduced body temperature, increased body weight, improved feed conversion ratio (FCR) and decreased abdominal fat while feed intake was not affected by both NaCl and KCl supplementation. Therefore, 0.4% NaCl added in drinking water may be a means to improve productivity of broiler under high temperature. 0.4% KCl supplementation increased thigh meat, and improved FCR. However, carcass percentage was reduced by KCl supplementation. Therefore, in the tropical summer conditions, higher levels of KCl concentration and economic aspect should be further studied. It was not clear whether the beneficial effects of KCl and NaCl supplementation in drinking water was caused by the cooling effect of the increased water intake and/or the maintenance of electrolytes balance.
Effects of chronic pesticide and pathogen exposure on honey bee (Apis mellifera L.) health at the colony level
(2018) Odemer, Richard; Bessei, Werner
During the last decade the increasing number of honey bee colony losses has become a major concern of beekeepers and scientists worldwide. Extensive research and cooperation projects have been established to unravel this phenomenon. Among parasites, pathogens and environmental factors, the use of agrochemicals, most notably the class of neonicotinoid insecticides, are suspected to be a key factor for this collapse. Current approaches not only focus on colony collapse but also on the weakening of honey bees by the exposure to sublethal concentrations of such pesticides. Recently, the EFSA temporarily banned three neonicotinoids including clothianidin, imidacloprid and thiamethoxam, for the use in crops attractive to pollinators. Thiacloprid however, likewise a neonicotinoid insecticide, is still tolerated for agricultural use because it is considered less toxic to bees. Nevertheless, some publications indicate sublethal effects of this agent leading to impairments of the colony. A general problem for the study of such sublethal effects is that they often are measurable in individual bees without eliciting clear impact at the colony level. In addition, such effects might only have a consequence in combination with other stressors like pathogens. This thesis presents two new methodical approaches combining the controlled application of stressors to individual bees with an evaluation of the effects under field realistic conditions of free flying colonies. In all approaches, the bees were treated with a combination of different pesticides and/or a combination of pesticides and a pathogen in order to evaluate synergistic interactions. As pathogen, Nosema ceranae, a novel intracellular gut parasite introduced from Asia, was used. This parasite is considered to contribute to “CCD”-like symptoms (“colony collapse disorder”), particularly in Spain. In Retschnig et al. (2015), observation hives at two study sites (Hohenheim and Bern) were used to clarify possible synergistic effects when honey bees are exposed to pesticides of two different substance classes (thiacloprid and tau-fluvalinate), both in combination with an infection of N. ceranae. Mortality, flight activity and social behaviour of individually marked and treated worker bees were monitored. At the Hohenheim site, no impact from any of the treatments could be confirmed except a slightly higher flight activity of the Nosema treated bees. At the Bern site however, the pesticide treatments elicited a significant reduction of worker bee lifespan, whereas the Nosema infection resulted in higher ratios of motionless periods. Importantly and in contrast to several laboratory studies, in neither of the two sites an interaction among the pesticides and the pathogen could be confirmed. The inconsistency of our results suggests that the effects of both, sublethal application of pesticides and infection with N. ceranae were rather weak and that interaction among them may have been overemphasized. To extend this first approach in small observation colonies, Odemer & Rosenkranz (2018) focused on performance parameters such as colony development and overwintering in honey bee colonies, using the same pesticides as in the observation hives. Here, neither the single exposure to thiacloprid or tau-fluvalinate nor their combination had negative effects on the colony performance. However, the chronic application of the tau-fluvalinate significantly reduced the infestation with Varroa mites. In Odemer et al. (2018), a neonicotinoid (clothianidin) with an extraordinary high toxicity to bees was applied alone and in combination with N. ceranae and N. apis. A novel approach was developed with individually marked bees that were infected after hatching with a certain number of Nosema spores and introduced into mini-hives. In order to simulate worst case field conditions, the pesticide was then applied chronically in sublethal concentrations over the whole lifespan of the bees. Again in contrast to previous laboratory studies, no effect of the clothianidin treatment on mortality or flight activity could be observed. However, the lifespan of Nosema infected bees was significantly reduced compared to non-infected bees, but in agreement with the observation hive experiment, the combination of pesticide and pathogen did not reveal any synergistic effect. The results of the three experiments of this thesis indicate that (i) individual honey bees are less impaired by neonicotinoids if kept within the social environment of the colony and that (ii) sublethal concentrations of neonicotinoids in the field are not the main driver for colony losses. These statements refer exclusively to the honey bee colony as a eusocial superorganism that obviously is more resilient to pesticide exposure through mechanisms of “social buffering”.
Einfluss von Beschäftigungs- und Strukturelementen auf das Verhalten und das Beinskelett konventionell gehaltener Mastputen
(2010) Letzguß, Helga; Bessei, Werner
Commercial turkey production in Germany is characterized by the use of heavy strains and intensive management systems with a poor level of environment stimulation. This results in behavioral and health problems, which are not only relevant with respect to animal welfare but do result in substantial financial losses for the farmers. It is assumed that environmental enrichment could be a promising means for improving the locomotor system of turkeys and for reducing cannibalism and feather pecking. The present field study deals with the effects of environmental enrichment under commercial rearing conditions. The major focus was on deducing the impact on (i) cannibalism and featherpecking, (ii) locomotor activity, and (iii) leg conditions. In addition the acceptance and the utilization of the enrichment facilities should be determined. Based on previous work, different enrichment structures were selected. Particular attention was given to choose structures that could easily be integrated into existing stables at low costs. Moreover, the objects should not substantially increase the workload of the farmers. Raised platforms, round bales of straw, baskets filled with hay, and packs of palettes were used as enrichment objects. The latter were substituted with square bales of straw in the second experiment. The enrichment structures occupied 5.3 % of the available area of the houses. The two successive experiments, one in the warm (Durchgang 1) and one in the cold (Durchgang 2) season, were carried out using three commercial turkey houses. Heavy strains of turkeys were kept in houses with more than 4500 animals. Two houses (A1 and A2) were enriched and one house was kept as non-enriched control. Starting from the 6th week of age the animals were observed in 4 week intervals by three observers. In addition, videos were recorded during the same time and evaluated using the commercial software INTERACT (Mangold International GmbH, Arnstorf). The following areas have been observed separately: raised platforms, square bales of straw, round bales of straw, unenriched area, wired basket filled with hay, feeder area, and drinker area. The following behaviours were determined: resting, sitting, locomotion, comfort behaviour, object pecking, environment pecking, feather pecking, aggression, dust bathing, scratching, threat, cannibalism, water intake, and food intake. The duration and the number of animals performing locomotion, sitting, and standing in the individual areas were determined. At 14th weeks of age approximately 150 animals were selected at random and weighted. The conditions of the breast skin, feathering, and foot pads were scored. At slaughter, the scorings of each third breast skin and each fifth food pad were repeated. Furthermore, after slaughter, 50 tibiotaris were randomly chosen for which length, angular distal deformity, torsional deformity were identified. Based on computer tomography the following bone parameters were determined in the middle of the total area, total density, corticalis area, corticalis density and Strain Strength Index (SSI). The enrichment structures were well accepted and used by the turkeys. The structures were mainly used for resting. From the observed extended resting periods it can be concluded that on the enrichment structures the animals could better satisfy their need for resting than in the non-enriched areas. Short resting periods in the non-enriched area are mainly due to frequent disturbances caused by fellow turkeys. From the fractions of locomotion in the unenriched areas it could be shown that the enrichment structures yielded increased locomotor activity. There was no effect of the enrichment structures on animal health. A decreased torsion of the tibiotarsi from the enriched houses were determined. In order to access the raised plarforms, palettes, and square bales of straw, the turkeys in the enriched houses had to wing flap, climb, and jump. This resulted in strengthening of both the leg muscles and the bones. The turkeys used the round bales until the end of the fattening period, where as pecking at the basket filled with hay decreased gradually. The occurrences of threat, aggression, cannibalism, and featherpecking, were very low an all houses. Hence, no effect was found for the enrichment structures on these behaviors. This thesis provided proof that low-cost enrichment of the environment can be advantageous with respect to the bone health of turkeys. In addition, it was demonstrated that it is possible to increase the locomotor activity of heavy strains. Furthermore, the results indicate that even small height differences between object surface and litter level suffice to enable the creation of resting areas. It should be noted that the enrichment structures did not loose attractiveness for the turkeys throughout the complete fattening period.
Der Einfluss von Wirtsfaktoren der Honigbiene (Apis mellifera L.) auf den Reproduktionserfolg der parasitischen Milbe Varroa destructor (Anderson & Trueman) auf die Auswirkungen einer horizontalen Verbreitung des Parasiten auf den Befall der Bienenvölker
(2014) Frey, Eva; Bessei, Werner
The honey bee colony is faced with a huge number of pathogens, including bee viruses, bacteria, fungi and mites. Among these pathogens, the ectoparasitic mite Varroa destructor is considered the most important parasite of the honey bee worldwide. This mite was discovered at the beginning of the last century in South East Asia within colonies of the original host, the Eastern honey bee Apis cerana. From the middle of the last century the mite has been spread worldwide by transports of infested A. mellifera colonies with dramatic consequences for both, feral and managed honey bee colonies. In the meantime this parasite has become the most serious economic problem for global beekeeping. In temperate climates nearly all honey bee colonies are infested and without yearly Varroa treatments these colonies would collapse within a few years. This confirms that a stable host parasite relationship has not been established yet. Therefore the control of V. destructor still represents the main challenge for beekeeping. The main reason for host damages is the dramatic increase of the Varroa population during the season. Our honey bee colonies are obviously unable to control this population dynamic of the parasite. The increase of the mite population is influenced by the reproductive rate of Varroa females within individual brood cells, by host-parasite-interactions on the colony level and by interactions among honey bee colonies on the population level. The dissertation at hand presents experimental approaches and results at all three levels. On the individual level we were able to demonstrate that age-dependent signals of the honey bee larvae not only activate the oogenesis of the Varroa females but even trigger the further course of mite reproduction. Our studies on the activation of the Varroa reproduction revealed that exclusively larvae within 18 h (worker) and 36 h (drones), respectively, after cell capping were able to stimulate the mite’s oogenesis. Furthermore, we were able to confirm for the first time the presence of a signal in the host larvae allowing the reproducing mites to adjust their own reproductive cycle to the ontogenetic development of the host. Under certain conditions such host signals can even stop an oogenesis of the female mite that has already been started. From an adaptive point of view that sort of a stop signal enables the female mite to save resources for a next reproductive cycle if the own egg development is not sufficiently synchronized with the development of the host. My results indicate that age specific volatiles of the larval cuticle are involved in the regulation of mite reproduction. According to preliminary quantitative GC–MS analysis we suggest certain fatty acid ethyl esters as candidate compounds. These host signals – either involved in the activation or in the interruption of the Varroa reproduction – offer possibilities to influence the reproductive success of Varroa females and might therefore be used for biological control in the future. Within an EU cooperation project we could additionally demonstrate that the so called temporary infertility of Varroa females is significantly correlated with three QTL of the host larvae. This confirms a genetic basis for host resistance factors that inhibit the mite reproduction. For this study we made use of the fact that we had access to a honey bee population at the island of Gotland, Sweden that has survived mite infestation without any treatment for more than 10 years. We crossed a queen from this tolerant population with drones from susceptible colonies to rear hybrid queens and produced a mapping population of haploid drones from these hybrids. Because honey bees have a haplodiploid sex determination, the haploid drones provide an extremely simple and highly efficient model system for genetic studies. Subsequently, we mapped three candidate target regions on chromosomes 4, 7, and 9. Although the individual effect of these three QTL was found to be relatively small, the set of all three had significant impact on the suppression of V. destructor reproduction by epistasis. The detection of this epistatic interaction was only possible because we used the simple genetic make-up of haploid drones. For studies on Varroa resistance on the colony level and for selection programs the interactions among the colonies of the local honey bee population have to be considered. In two experimental approaches I was able to prove that the invasion of Varroa mites from neighboring colonies – often called “reinvasion” – significantly influences the population dynamic of the parasite within the colony. First, we quantified the number of mites invading individual colonies in relation to the invasion pressure (= number and distance of infested colonies). For this approach we made use of an isolated military training area near Münsingen at the Swabian Alb not accessible to other beekeepers. We established ten “mite receiver colonies” continuously treated against V. destructor and placed them at distances of 1m to 1.5 km from four heavily infested “mite donor colonies”. In the donor colonies, we estimated the population of bees, brood, and V. destructor at three week intervals. The invasion of mites into the receiver colonies was recorded every 7-12 days. During the measurement period of about two months, between 85 and 444 mites per colony were introduced into the receiver colonies. Surprisingly, there were no significant differences in the invasion rates in relation to the distance between donor and receiver colonies. The second approach was performed under more realistic field conditions of two experimental apiaries established in regions with high and low bee densities, respectively. Additionally, in this experiment we analyzed the multiplication of the invaded mites. Thereby we confirmed that horizontal transmission plus the reproduction of the invaded Varroa mites can cause an exponential increase of the mite population that may exceed the damage threshold within three months. We were further able to show that the invasion rates – and therefore the final infestation – differ significantly according to the number of honey bee colonies in the neighborhood of the apiary: At the site with a high bee density, the average invasion rate per colony over the entire three and a half months period was 462 mites per colony compared to only 126 mites per colony at the site with a low bee density. As a consequence, the colonies of the apiary at the high bee density site revealed an average final infestation in November of 2,082 mites per colony compared to 340 mites per colony at the low bee density site. The highly infested colonies lost about three times more bees compared to the lower infested colonies – obviously a result of Virus infections transmitted by Varroa mites. With my different approaches I was able to add further elements of knowledge for a better understanding of how host factors and ambient conditions influence the Varroa reproduction within individual brood cells and the population dynamic within a honey bee colony. A better knowledge of these host parasite interactions is essential for the selection of mite resistant colonies and further more important for the development of concepts for an effective Varroa treatment.
Environmental enrichment in intensive production systems for farm animals
(2010) Jordan, Dušanka; Bessei, Werner
Barren and space restricted environment of intensive production systems thwarts the expression of numerous behavioural patterns due to inadequate stimulation. Consequently, animals may develop various abnormal and damaging behaviours or may be in general less active, which contributes to the expression of leg disorders, especially in fast growing animals. These problems may be alleviated with appropriate environmental enrichment, therefore the objective of the thesis was to elucidate the appropriateness of selected environmental enrichments in fattening pigs, growing rabbits, laying hens and fast growing broilers. For this purpose, four studies were conducted. In the first study we wanted to examine the effect of small amount of straw or hay (100 g per animal per day) laid daily in a rack on the behaviour, growth rate and carcass composition of fattening pigs of both sexes (castrated males, females) housed in slatted floor pens. In the second study we studied the influence of gnawing sticks made of Norway spruce (Picea abies) on the behaviour of male growing rabbits (Slovenian sire line SIKA for meat production) housed individually in wire-mesh cages. The third study included laying hens with enhanced diet complexity ? instead of only one, hens were fed two diets in sequence. We studied the effect of sequential feeding with wheat on the behaviour, feed intake, feather condition and egg production of non beak-trimmed ISA Brown laying hens housed in standard cages (five birds/cage). The birds were allotted to one of four treatments. The control (C) was fed a conventional complete diet. Three treatments were fed sequentially with whole wheat (SWW), ground wheat (SGW) or ground wheat with a vitamin premix, phosphorus and oil (SGWI). In sequential treatments, 50% of the ration was fed as wheat from 9:00 to 16:00 o?clock and the remaining 50% as a protein-mineral concentrate (balancer diet) from 16:00 to 9:00 o?clock. In the fourth study we examined the effect of environmental enrichment on foraging behaviour, locomotor activity, growth and feed conversion of fast growing broilers (Ross 308). Animals were allotted to three treatments. The control birds (C) were fed with pellets in a trough, the W birds received additionally to pellets in a trough a small quantity of whole wheat scattered twice a day in the litter. In the P treatment the trough was removed at 14 days of age and feed pellets were scattered in the litter five times a day. Environmental enrichment of fattening pigs with small amount of hay or straw increased the proportion of time animals were active on account of increased occupation with substrate. However, increased proportion of total activity was noticed only in females, which also spent more time chewing substrate than castrated males. Both substrates significantly reduced time spent biting pen bars and the frequency of aggressive encounters. Neither hay nor straw negatively influenced pigs? growth rate and lean meat percentage, whereas sex of the animals significantly influenced both traits. Females grew slower and had greater lean meat percentage than castrated males. In contrast to fattening pigs, environmental enrichment had almost no influence on the behaviour of growing rabbits. Gnawing sticks made of Norway spruce did not attract much of rabbits? interest and significantly influenced only the duration of feeding by 2.08 ± 0.87%. In laying hens, SWW birds spent less time feeding and stood still longer compared to birds in other treatments when fed wheat based diet. This influenced the occurrence of feather pecking, because four hours after distribution of wheat diets, feather pecking was the highest in the SWW and the lowest in the SGW treatment. Consequently, the poorest feather condition was recorded in the SWW treatment. Total feed intake was the highest in the C treatment, while birds ate greater amount of balancer diet compared to wheat based diets. In fast growing broilers, the environmental enrichment with scattered whole wheat (W) did not influence any of the observed behaviour. However, scattering feed pellets in the litter (P) significantly decreased time spent lying in the third and fourth week of age. From the third week onwards, P birds also spent more time walking, scratching and pecking compared to the C and W birds. In feed intake, feed conversion and growth rate there was no difference between the C and W treatment, whereas birds in the P treatment grew significantly slower, which resulted in 13% lower slaughter weight. To conclude, small amount of hay and straw proved to be an appropriate and inexpensive environmental enrichment for fattening pigs in intensive housing systems, which improved their welfare. The addition of wooden sticks for gnawing demonstrated to be an unsuitable environmental enrichment for growing rabbits. Sequential feeding with wheat had a detrimental effect on laying hens? behaviour and feather condition when used with whole wheat. Therefore, wheat should be used either grounded or perhaps presented in shorter time periods. In fast growing broilers, scattering feed pellets in the litter proved to be a promising method to enhance broilers? activity and thus to improve their welfare. However, further research is needed to be able to avoid reduction in body weight at slaughter age.
Ontogenetic and individual patterns of volatiles in honeybee queens Apis mellifera and its significance for the acceptance of queens in honeybee colonies
(2008) Al Ali Alkattea, Raghdan; Bessei, Werner
Activities of honeybees Apis mellifera L. colony are coordinated by an effective communication network in which the queen plays a central role by controlling behavior and reproduction of workers through pheromones. Most pheromones are produced in the mandibular (QMP) and tergal gland and distributed over the queen?s cuticle. The acquisition of these pheromones from the cuticular body surface of the queen is performed by antennating and licking of the retinue workers. Workers of a colony are able to recognize their own queen. Foreign queens which are introduced without protection are normally killed by the workers. While a lot of work has been performed on the primer and releaser effect of certain queen pheromones, it is still unknown how the workers distinguish their own queen from foreign ones. The fact that queens can be exchanged successfully by protecting the foreign queen for some days demonstrates that workers are able to ?learn? their queen. It is likely that a certain chemical pattern of the cuticle (odor or taste) is finally responsible for the recognition and acceptance as ?own?. In this context, this work has three different objectives: - To better understand the bees? behavior to ?own? and ?foreign? queens and to quantify certain behavioral traits of the queen-workers interaction. - To study the learning ability for own and foreign queens by the use of the Proboscis Extension Reflex (PER) in order to have a tool for future tests of odorous compounds. - To compare the cuticular pattern of queens of different origin. In all three approaches, virgin and mated queens and queens of different kin relation to each other were reared and established in Kirchhainer nuclei colonies. These queens were compared due to the following hypothesis: If the workers perceive their own queen by a distinct smell and if closely related queens have a more similar chemical pattern on the cuticle, then a related foreign queen should be easier ?learned?/ accepted than a non related one. For this purpose, first a specific bioassay had to be developed and established to enable the record of workers behavior to the queen without an inhibition of the complex social interactions between queens and workers. This ?cage bioassay? consists of a small wooden box with a glass front, a wax comb, 30-40 worker bees and a queen. For the tests, the own queen of this mini-colony was removed and a foreign queen was introduced. For a period of about 2 hours certain aggressive and benign actions, respectively, of the workers toward the queen were recorded. In the first set of tests, queens of different kin relations were compared. The results showed, in general, an aggressive reaction against the introduced foreign queens. However, there were clear lower benign and stronger aggression behaviors against unrelated queens compared to the related ones. Some of the unrelated queens were even killed. However, these differences were only significant when virgin queens were exchanged but not when mated queens were used. Concerning the duration of the aggressive action of workers, aggression generally decreased between the beginning and the end of the test; again, this was significant only in the experiments with virgin queens. This indicates, that at least in virgin queens the individual recognition by the worker bees depends on a kin specific odorous pattern of the queen. The same types of queens used in the cage bioassays were used for the learning experiments. A classical olfactory conditioning (PER) of worker honeybees was applied by using a living queen as the source of odor. Hereby the queen was offered in a way that the worker bees could not touch the body surface. The gradual increase in the learning curves was a good indication that the workers are able to learn the queen?s odor and, therefore, can be used as a kind of ?biosensor?. After having learned a queen?s odor, the conditioned workers were tested by offering virgin and mated queens, respectively, with defined kin relation to the queen used for the conditioning before. The results revealed clear differences in the cues used for the ?learning? of individual mated and individual virgin queens, respectively. The workers could significantly discriminate between the learned odor of a mated queen and any other mated queen irrespective of the relatedness. In contrast, worker bees could not discriminate virgin queens from each other. As the worker could only use volatile substances for the associative learning, one can conclude the following: In virgin queens the volatile ?bouquet? is neither individual specific nor kin specific. In mated queens the bouquet has only an individual specificity. Probably, the huge amount of many volatile gland products (including the main component 9-ODA) makes each mated queen ?unique?. But as in the cage bioassays the worker could recognize whether an introduced virgin queen was related to the own queen or not, these recognition must depend on non volatile substances of the virgin queens cuticle which are perceived by licking. If learned and tested queens were of different mating status the worker bees could significantly discriminate between such individuals (except learned odor of mated queens/ tested odor of related virgin queens). This is not surprising because the GC-MS analysis confirmed the huge differences in the odorous pattern (and here mainly the volatile polar gland products) between virgin (= young) and mated (=elder) queens. From the same types of queens used for the cage bioassays and PER, queens? heads and abdomens were extracted in a solvent and the obtained extracts were analyzed using GC-MS. From the extracts of queen abdomens 32 substances (hydrocarbons and polar compounds) were identified and chosen to calculate the ?chemical distance? between queens of different kin relation (sister vs. unrelated) and between sister queens having different ages and mating status. For that purpose, a matrix of Nei-distances was applied as a measure for the similarity of different patterns. The results showed a significantly higher concordance in the chemical pattern within sister queens compared to non related ones. The ?chemical distance? increased from sister queens over half sister to non-related queens. Cluster analyses of the Nei distance and multidimensional scaling clearly confirmed the differentiation between unrelated queens and the similarity of sister queens. Using the same statistical methods, also a clear differentiation between queens of different ages and mating status could be demonstrated. The results presented in this work confirmed with 3 different approaches that workers are able to learn their own queen with different learning cues depending on the mating status of the queen. In virgin queens it could be demonstrated for the first time that the kin relation between different queens can be recognized, presumably by low or non-volatile substances. The chemical analyses confirmed that the cuticular pattern of queens could be used for the differentiation not only according to age but also according to kin.
Untersuchungen zu den Beziehungen von Federpicken, Exploration und Nahrungsaufnahme bei Legehennen
(2008) Benda, Isabel; Bessei, Werner
First documented in 1873 by Oettel (1873), the problem of feather pecking and feather eating remains a major issue in modern laying hen husbandry. Various motivational models developed in the past years interpret feather pecking as redirected foraging behaviour, pecking while sand bathing or as misdirected exploratory behaviour. The laying hens, however, only show exploratory curiosity in these diverse materials for a short time. It has been shown that diet-related deficiencies elicit increased exploratory behaviour and feather pecking. In the first section of this experiment, we attempted to redirect the exploratory pecking activity of the laying hens to an alternative object (pecking block) for a sustained period of time through offering the animals food and calcium separately. Less feather pecking behaviour was expected to result. Investigations carried out in recent years indicate an association between feather pecking and feather eating. Although almost indigestible, both wood shavings (cellulose) and feathers are eaten by laying hens. Hence, the influence of feathers and cellulose in food on the behaviour of laying hens was tested in the second section of this experiment. The inclusion of feathers or cellulose in food was expected to reduce feather pecking behaviour, since the animals? requirement for these substrates was adequately covered in the food. The goal of the third section of the experiment was to determine if the ingestion of feathers or wood shavings has an underlying physiological background, which consequently initiates a need for these substrates. The effect of substrate ingestion was tested in two different lines. The first experiment comprised three feeding treatments. Group 1 received a calcium-poor ration (0.67% Ca) whereas groups 2 and 3 received a calcium-balanced ration (3.45% Ca). An additional pecking block containing molasses and bran was available to birds in groups 1 and 2. The pecking block available to birds in group 1 had a calcium content of 31%. Each of the 3 treatments was repeated 10 times with 8 laying hens per treatment. Half of the animals were brown, the other half white laying hybrids. The three groups did not differ in their propensity to feather peck. However, animals in group 1 showed a better feather condition than those in groups 2 and 3. Breed origin had a significant effect on pecking activity, whereby brown laying hybrids displayed aggressive and vigorous feather pecking more frequently than their white counterparts. The second section of the investigation likewise comprised three feeding treatments. The first group received pellets with 10% feather grit, the second group pellets with 10% cellulose and the third group received additive-free pellets. Each treatment was repeated 4 times on 15 hens (white laying hybrid). Feed preference with respect to the different pellet variations available was examined and feather eating behaviour was tested after the test rations were discontinued. Birds in both the feather grit and cellulose groups showed less feather pecking behaviour than control animals throughout the entire experiment. Likewise, birds in the feather grit group had a significantly better plumage condition than those in the control group. Animals in the feather grit group also ate more pellets and ingested significantly more feathers than those in both the control and cellulose groups. The third section of the experiment was conducted with animal selected on high (HFP) and low (LFP) feather pecking activity (KJAER et al., 2001); three different feeding treatments were tested. Birds in the first group were offered 70 feathers per week (HF and LF), birds in the second group had access to wood shavings ad libitum (HSp and LSp), and birds in the third group were not offered any additional substrates (H0 and L0). The intestinal passage rate of each group was investigated, whereby animals receiving additional substrates were selected for comparison when the amount of substrate (feathers or wood shavings) ingested was comparable. Animals in the HF group showed the fastest intestinal passage rate, followed by LF and H0 birds. The L0 animals had the slowest marker excretion. Although feather intake in HF and LF groups was similar, only the HF birds had a significantly faster passage rate. HFP birds which had access to wood shavings showed faster marker excretion as LFP birds in comparison. This experiment demonstrates that misdirected exploratory behaviour does not seem to be the primary cause of feather pecking. Rather the ingestion of feathers or wood shavings / cellulose plays a meaningful role in this behaviour. The results of this study show that feather pecking can be classified as feeding behaviour. This is in accordance with previous literature in which feather pecking is identified as feather eating. Furthermore, genetic discrepancies between HFP and LFP animals seem to exist, since the ingestion of a similar amount of feathers or wood shavings had different effects on the intestinal tracts of the animals in the two lines. Further research is necessary to validate the results of this study.
Untersuchungen zur Motivation zum Federfressen bei Legehennen
(2007) Häusler, Kirsten; Bessei, Werner
The focus of this thesis is to unveil the dependency of feather pecking as an expression of explorative behaviour (foraging and activity) and the actual ingestion of feathers. The survey of motivation ratio was realized through conduction a preference test. This was performed by two substrate variations (feathers and feed) at three different grades of accessibility within the trial location. In addition the strength of motivation was measured by force records of pecking impacts vial corresponding gratification in a facility for operant conditioning (Skinner Box). The trials have been conducted with White Leghorn hens, which were selected over six generations on performing high (HFP) and low (LFP) feather pecking activity. At first 20 HFP and 20 LFP individuals were tested in the preference test. The choice presented was displayed as loose feathers (for ingestion), affixed feathers (activity), feed and an empty alternative. Each substrate was provided in equal quantity and frequency at all three grades of accessibility. The findings confirm the HFP type to peck a distinct higher degree of feathers than the LFP. Even affixed feathers were found to be atorn for ingestion mainly by the HFP. The highest grade of substrates displayed by transparent plastic foil remained untouched. 28 individual hens (14 HFP and14 LFP) were selected from the group of hens which were tested in the preference test. The strength of motivation was revealed by the operant conditioning method. The hens were taught tit peck at a pecking device for food and mealworms. They were tested with a fixed (FR)-reinforcement schedule. By using the FR the hens had to peck in the pecking device for a determinate number (1, 5, 10, ...). The number of pecks with had to be fulfilled by the hens where increased after each testing period until twenty by the increments of five. The described experiments were succeeded by a progressive ratio (PR = reinforcement schedule, which includes a successive increase of pecking impacts within a testing period (3x1, 3x3, 3x5, etc.) Mealworms were used to validate the system. Pecking without a reward was checked to pose as reward itself for the conditioned hens. In contrast to the LFP, the HFP (positive and negative evidence) performed a higher motivation expressed by the pecking frequency for feathers. This meets the results of the first preference test. For the second preference test 23 remaining hens (12 HFP and 11 LFP) were tested. Since affixed festhers were ingested and substrate underneath the transparent foil remained unattended in the first preference test, the dispositions of the choises were modified. Affixed feathers were removed and transparent foil was changed into non transparent plastic foil. Visual examination of the covered substrate was disqualified. Furthermore the social partner was moved from the nearby compartment to a place where contact was reduced to an audio exposure. The results of the second preference test provided no further evidence of feather pecking motivation of the conditioned individuals. HFP and LFP results showed no further discrepancy. The results of the present experiments are in contrast to the exisiting hypothesis that describes the motivation of feather pecking mainly as driven by foraging and exploration behaviour, as well as boredom. It is assumed that ingestion of feathers is a relevant issue of the motivation for feather pecking.
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.
Das Verhalten von Mastputen bei unterschiedlicher Besatzdichte und Einstreuart
(2013) Günthner, Pia; Bessei, Werner
There exists at present no legal regulation concerning housing and management of commercial turkey production in Europe. The European Commission is working on a directive of keeping fattening turkeys. In Germany is a voluntary agreement of turkey producers, animal protection societies and governmental authorities, which provides standards and minimum requirements for adequate turkey rearing. These standards, however, are still being debated. Especially the stocking density is considered too high. The present study was carried out to provide scientific information on the behaviour of turkeys under different stocking densities, and thus, to support the revision of the voluntary agreement on turkey keeping. The turkeys (B.U.T. Big 6) were kept in an experimental turkey house. The male and female birds were kept in two separate parts of the same building. Each part contained 16 identical pens. The males were raised up to the 21 weeks of age and received a commercial pelleted turkey diet in 7 feeding phases. The females were raised upt to 16 weeks and received 6 feeding phases. Three different stocking densities were testet: low, intermediate and high. The existing recommendations of stocking density for males and females of the voluntary agreement were chosen as intermediate density. All birds were kept on wood shavings as litter from day-old to 5 weeks of age. From the 6th week of age (which correspond to the 3rd feeding phase) onwards chopped straw was spread as required to maintain good litter quality. In one additional treatment wood shavings instead of straw were spread throughout the fattening period. The intermediate stocking density of males and females was used for this treatment. Hence the experimental setup consisted of 4 treatments within both sexes. Direct behavioural observations were carried out by 4 trained observers. The direct observations started with the 2nd feeding phase and continued untill the end of the fattening period. Feeding, drinking, walking, sitting/lying, standing, litter pecking/scratching, dust bathing, preening, feather pecking, wound pecking and aggressive pecking were recorded using time sampling technique. In addition all pens were video-recorded in the weeks before or after the direct observations. The duration of the different behaviours were measured using the video records. Feed consumption, water consumption, body weight development and temperature inside the stables were recorded continuously. The experiment was repeated with a second batch of birds using the same experimental layout and the same criteria as in the first batch. Litter temperature was additionally recorded in the second batch. In the first batch the frequency and duration of sitting/lying was significantly higher at the lower stocking density as compared to the stocking density. This could by explained by physical disturbance of resting birds at the higher stocking density. The higher litter temperature under high stocking density might also have interrupted the sitting phases of the birds. At the lower stocking density there were significantly more preening, feather pecking and a non-significantly higher level of dust bathing than in the higher stocking density. The opposite result has been expected with regard to feather pecking. This supports the result of other publications which reported an interrelationship of comfort behaviours, such as preening and dust bathing, and feather pecking. The effect of stocking density was not significant for all other behaviours. This shows that stocking density in the tested range has little influence on the behaviour growing turkeys. Feed intake growth rate and the water : feed ratio were lower at the lower stocking density. The lower water : feed ratio indicated that the reduction of feed intake and growth rate with increasing stocking density is influenced by higher litter temperature. The turkeys raised on wood shavings from the 3rd feeding phase onwards showed significantly more feeding behaviour than those kept on straw in the first batch, and a similar tendency in the second batch. They also pecked significantly more the feathers of their pen mates in both batches. The higher feeding behaviour of the birds kept on wood shavings coincided with a significantly higher feed intake only in the second batch. All other performance traits did not significantly respond to the different litter types. The higher feeding behaviour and feed intake of turkeys kept on wood shavings was explained by a compensatory activity to litter pecking: straw as litter obviously presents a higher stimulus for exploratory litter pecking than wood shavings. The lower feather pecking activity of the turkeys kept on straw can be explained by the same effect. Feather pecking as substitute of litter pecking has been reported in the literature for turkeys and other poultry species. Sitting/lying behaviour was consistently higher in male than in female birds in both batches. The causes of this effect can be manifold. The higher body weight may reduce the ability of standing and thus increase sitting/lying. The lower group size and lower stocking density in the males may have led to less disturbances and allowed more resting behaviour. Finally the higher litter temperature observed in the female pens may have reduced the time spent sitting/lying in the females. Males showed significantly more litter pecking and scratching in both batches. Preening was higher and feather pecking was lower in males. This effect was significant in at least one batch. The inverse relationships between litter pecking and feather pecking among males and females are consistent with the effect of litter on these behaviours. In conclusion, the effect of stocking density in the range tested in the present experiment was relatively small as compared to other factors, such as age, season, sex and Litter temperature.