Browsing by Subject "Truthuhn"

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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.
Phytate degradation and phosphorus digestibility in turkeys and broiler chickens fed maize-based diets
(2023) Novotny, Moritz Sebastian Daniel; Rodehutscord, Markus
A growing global human population, stagnation in available land for farming, and an increased interest in sustainable and eco-friendly food production necessitates a highly efficient and environmentally friendly food production. This includes the already very feed-efficient poultry meat production. Currently, using non-renewable mineral phosphate as feed additive is industry standard in poultry nutrition. This can lead to unwanted eutrophication of waterbodies by high faecal concentrations of unutilised plant-based phosphate. Degrading phytate via enzymatic hydrolysation by phytases drastically improves digestibility of plant-based phosphate. With dietary phytase supplementation, a tool is available to reduce necessity of dietary phosphate supplementation. However, predictability of the extent to which phytase supplementation can replace phosphate supplementation is not accurate enough to forego phosphate supplementation entirely. Subject of this doctoral thesis was to study the factors that can influence phytate degradation in the digestive tract of poultry, in order to improve predictability of plant-based phosphate digestibility. The focus was put on maize-based diets, as they are very common worldwide and phytate degradation is challenging due to low intrinsic phytase activity of maize. A literature review on the current state of knowledge on phytate degradation and phosphorus digestibility of chicken fed maize-based diets was conducted. Part of this review was to compare findings for chickens to findings in other poultry species. There is a plethora of studies that investigated the subject in broilers but comparatively little information on turkeys. There were indications of fundamental differences between broilers and turkeys. Consequently, the intention was to identify reasons for these differences and to evaluate to which extent knowledge transfer from chickens to turkeys is possible. Two consecutive trials comparing broilers and turkeys were designed. Factors studied were: supplemented phytase, dietary phosphorus and calcium concentration, age, and endogenous mucosal phosphatase activity. Broilers and turkeys studied were kept simultaneously and under identical conditions, including experimental diets. A total of 480 broiler and 480 turkey hatchlings were obtained at the same day and raised at the experimental facility. Halve of the animals of each species underwent the experiment from day 14 to day 21, the other halve from day 35 to day 42. This set up was chosen to study the influence of physiological development, as species with different maturation rates were compared. In 3-week-old broilers and turkeys, precaecal InsP6 disappearance was the same when no phytase was supplemented and dietary calcium and phosphorus level was low. This coincided with no differences in jejunal mucosal phosphatase activity. Without phytase supplementation, 6-week-old turkeys showed higher precaecal InsP6 disappearance than 6-week-old broilers. This coincided with higher jejunal mucosal phosphatase activity in turkeys than broilers. When phytase was supplemented, precaecal InsP6 disappearance was markedly increased in both species. This increase was always higher in broilers compared to turkeys of the same age. Increased dietary calcium and phosphorus levels led to decreased precaecal InsP6 disappearance in both species. This led to the conclusion that previously reported differences in precaecal InsP6 disappearance between broilers and turkeys were primarily due to the higher dietary calcium and phosphorus concentrations used in turkey diets, and secondly due to more phytate degradation by supplemented phytase in the crop of broilers compared to turkeys. The latter was attributed to more favourable conditions for the supplemented phytase. Although turkeys appeared to have compensated much of that in the more posterior parts of the digestive tract. Jejunal mucosal phosphatase activity was higher in treatments with phytase supplementation than without. As this coincided with high concentrations of lower inositol phosphates in the digesta, these might have triggered increased expression of phosphatases on the brush border membrane. In contrast, an increase in dietary calcium and phosphorus level coincided with a decrease in jejunal mucosal phosphatase activity, numerically in 3-week-old birds, but significantly in 6-week-old birds. This might indicate a downregulation of mucosal phosphatase expression based on phosphate concentration in the small intestine. In conclusion, fundamental mechanisms affecting phytate degradation in the digestive tract of broilers and turkeys seem to be the same. However, there is one big difference in recommended dietary calcium and phosphorus levels and many small differences in important details affecting phytate degradation and phosphate digestibility between the two species. These require dedicated attention to further improve phosphorus efficiency in poultry production.