Browsing by Subject "Turkey"

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Effects of a reduction of dietary levels of calcium and phosphorus on performance, bone minerals and mineral excretion of turkey breeder hens in the rearing and laying period
(2023) Gickel, Julia Maria; Rodehutscord, Markus
Phosphorus (P) is an essential mineral in feed for livestock and has finite resources all over the world. The aim of this study was to obtain an idea about the reduction potential of P in the diets of turkey breeders. As the metabolism of P is interlinked with the metabolism of calcium (Ca), Ca was also examined. Therefore, the requirements of P and Ca were studied using a factorial approach. As data about the requirements of these minerals in turkey breeders is limited, the present study mostly used data from other poultry species. Thus, this study can be viewed as an approach to building new resilient data for turkey breeder hens. The results of the factorial approach were embedded in a feeding program for turkey breeder hens during rearing and laying with two different treatments. One group was fed a standard feed (practical diet used before the trial), while the other group was fed a Ca/P reduced feed. In total, four trials were conducted: trials I and III focused on the rearing period while trials II and IV focused on the laying period. All trials were observed independently but the hens from trial I were used also in trial II afterwards for studying long-term effects. In each trial, body weight and feed intake were measured throughout the trial period. Bone mineralization was studied in trial I, including analyses of bone ash as well as Ca and P in the bone ash from the tibia of fallen and culled animals. The egg components were studied in eggs from trial II, including analyses of the percentages of albumen, egg yolk, and egg shell; Ca in albumen; P in albumen; Ca in egg yolk; P in egg yolk; water in egg shell; Ca in egg shell; and P in egg shell. In trials II and IV, laying performance, egg weights, number (and causes) of culled eggs, fertility, hatchability, as well as body weight and fitness of the hatchlings were additionally observed. At the end of each trial, the concentrations of dry matter, Ca, and P in manure were analyzed and a nutrient balance was calculated to classify the results. Body weight development exhibited significant differences between the treatments in eight out of 30 weeks in trial I (five weeks had a higher mean weight in the group with standard feed; three weeks had a higher mean weight in the group with Ca/P reduced feed); three out of 28 weeks in trial II (two weeks had a higher mean weight in group with Ca/P reduced feed; one week had a higher mean weight in the group with standard feed); four out of 30 weeks in trial III (higher mean weight in the group with Ca/P reduced feed); and two weeks out of 28 in trial IV (higher mean weight in the group with Ca/P reduced feed). The feed intake data also fluctuated, with three out of 30 weeks exhibiting a significant difference in trial I (higher mean feed intake in the group with Ca/P reduced feed) and one week with a significant difference in trial II (higher mean feed intake in the group with standard feed). The observations throughout all of the trials revealed the tendency for a higher mean feed intake in the groups with Ca/P reduced feed. A significant difference concerning bone mineralization was not observed. Moreover, the results of laying performance, fertility, and hatchability exhibited no differences between the treatments. Regarding the egg weight in trial II, there were eight weeks with a significant difference between the treatments (seven weeks with a higher mean egg weight in the group with standard feed; one week with a higher mean egg weight in the group with Ca/P reduced feed). In trial IV, only one week exhibited a significant difference between the treatments (higher mean egg weight in the group with Ca/P reduced feed). Regarding the weight of hatchlings in trial II, three weeks had a significant difference between the groups (higher mean weight in the group with standard feed). In trial IV, no significant difference was observed for any week all throughout the trial period. The analyses of egg components revealed significant differences between the treatments according to the percentages of albumen and egg yolk and the calculated value of total Ca in the egg (including the shell). In trials I and III, significant differences existed between the treatments in the concentration of Ca in manure, with a lower level in the group with Ca/P reduced feed. This study concluded that a reduction in the dietary levels of Ca from 1.00–1.10% to 0.56–0.80% and of P from 0.48–0.61% to 0.35–0.50% (av. P) or 0.70–0.80% to 0.50–0.60% (total P) in rearing and a reduction of the dietary levels of Ca from 2.90% to 2.80% or 2.60% and of P from 0.36% to 0.30% or 0.24% (av. P) or from 0.65% to 0.50% (total P) in laying in the feed of turkey breeder hens are possible and did not result in disadvantages. As the present study also compared the results with required recommendations and target levels from breeding companies, it was also able to conclude that these levels are obsolete and should be adjusted downwards.
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.
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.