During commercial production, turkeys may be exposed to several different types of stressors related to environmental conditions and management practices. Historically, antibiotics have been used to aid in the alleviation of the impacts of stressful situations, and alternatives to antibiotics related to reducing stress are being researched. This study consisted of three rearing trials and had two objectives: (1) Investigate the effects of common U.S. turkey production practices, including environmental and management induced stress, on turkey hens grown to 63 days, and (2) Determine the response of stressed birds to dietary supplementation with fermentation derived functional metabolites. Treatments consisted of a positive control (stressed but not supplemented), a negative control (non-stressed and not supplemented) and two treatment groups that were stressed and supplemented with different products (Original XPC™ or AviCare™). Supplemental products were administered in a dry (feed) and liquid (drinking water) form, and consisted of fermentation derived functional metabolites. Products were evaluated on their effectiveness to mitigate stress responses and turkey performance. Birds were exposed to some combinations of the following stressors: feed and water withdrawal, cold, heat, and crowding. Although the stressors in this study were applied for less than 24 h, they produced significant physiological responses. Blood corticosterone levels, measured immediately after stress, were significantly higher in positive control birds than in negative control birds. In addition, stressed birds had reduced body weights and increased FCR after stress. Stressed birds, supplemented with products had mixed, but generally positive response as measured by bird performance. Based on the response to stress, as observed by alterations in blood corticosterone levels and differences in performance between the two control groups, researchers induced an effective stress model. The use of supplementary products consisting of fermentation derived functional metabolites shows promise for reducing negative impacts of a mixture of stressors.
Industry standards for turkey stocking densities are variable and may not represent the more rapidly growing strains currently available. Therefore, a study was completed to evaluate 4 stocking densities: a nominal density (0.3525 m 2 /bird), 10% tighter density (0.3169 m 2 /bird), 10% looser density (0.3882 m 2 /bird), and 20% looser density (0.4238 m 2 /bird) on the effects on large white, commercial male turkeys with regard to performance from 5 to 20 wk of age. Brooding stocking density was fixed for all pens of birds with 60 birds per replicate pen at 0.46 m 2 /bird to 5 wk of age. Density treatments were applied from 5 to 20 wk by altering pen size with pen population held constant at 60 per pen. There were 4 pens of birds per density treatment. Birds were weighed individually at 0, 5, and 20 wk of age and performance parameters were calculated. There were no differences in bird performance at 5 wk, which was expected because stocking density was fixed. From 5 to 20 wk and at 20 wk, birds that were reared at the nominal standard (0.3525 m 2 /bird) and 10% tighter density (0.3169 m 2 /bird) had significantly lower body weight compared with the 10% looser density (0.3882 m 2 /bird) and 20% looser density (0.4238 m 2 /bird) ( P = 0.03 and 0.01, respectfully). The feed conversion ratio ( FCR ) tended ( P = 0.08) to be improved for birds reared at looser density. In addition, based on linear regression, as stocking density decreased (i.e., m 2 /bird increased), BW ( P < 0.05) increased, and FCR ( P = 0.10) tended to decrease (improve) at 20 wk. It was concluded that birds reared at looser density had improved performance.
The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( < 0.05) in the HEAD/HEART group (45.08 ± 0.72) than the CONTROL group (47.10 ± 0.72). There were no differences ( > 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( < 0.05) than that from the HEAD/HEART group (6,656.4 ± 143.5 g). Overall, the data indicated no difference between the CONTROL and HEAD/HEART groups with regard to animal welfare because the initial stun was effective in all calves. However, longissimus thoracis L* and blood yield were negatively impacted by the HEAD/HEART method. The data in this study suggest that secondary induction of cardiac arrest is not necessary with effective nonpenetrating captive bolt stunning in veal calves.
Lighting is a complex management tool in turkey production, controlled by three parameters; daylength, intensity, and chromaticity. As light-emitting diodes (LED) increase in popularity as alternatives to traditional light sources, research regarding LED impacts on commercial-type turkey production is lacking. Therefore, turkey hens of the same strain were reared under experimental brooding and grow-out conditions with six lighting treatments. An environmentally and light controlled facility (ECF) consisted of 5,000 Kelvin (K) LED or 5,000K + far-red LED (639nm) (RED) with either 12h short or 18h long daylength to test LED spectra. In the remaining treatments, hens were exposed to sunlight in a curtain-sided facility (CSF) as two treatments 1) natural decreasing daylength from September to November (NAT) or 2) natural daylight + 5,000 K LED lighting with an 18h long blocked daylength (BLK). The intensity was 9 footcandles in the ECF and naturally fluctuating in the CSF. Hen's performance was evaluated at 5, 9, and 14 weeks for eye development and feather coverage. Hens brooded and grown-out under NAT light had significantly increased body weight gain compared to BLK hens for the same period. Hens reared with RED LED spectrum had significantly increased eye anterior-posterior distance than birds raised in the NAT treatment. A significant reduction in red heat signature on the breast tissue in the NAT treatment compared to all other 18h treatments indicated improved feather coverage. However, these same results were not observed during serum thyroid hormone analysis. While turkey hens reared under different lighting programs had similar ending performance, lighting parameters significantly affected bird performance during the growing period, bird's eye development, and body feather coverage. Therefore, potential effects on growth patterns and physiology should be considered when choosing a LED lighting program for turkeys
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