Plumage damage (PD) resulting from severe feather pecking (SFP) is a significant problem for animal welfare, performance, and economics in commercial laying hen farms. Genetics, nutrition, and housing conditions are central complexes that contribute to the multifactorial cause of SFP. Practical experience suggests that infestation by the poultry red mite (PRM), which is the most severe ectoparasite of laying hens in cage-free housing systems, may be a risk factor for the occurrence of PD, although evidence-based findings are lacking. The objective of this longitudinal observational field study was to investigate the effects of PRM infestation of commercial laying flocks on the occurrence of PD. Integument scoring (plumage damage and skin lesions) and the quantification of PRM infestation using mite traps were conducted during the laying period of 28 laying flocks, with an average flock size of 12,357 birds in barn (n = 21) or free-range (n = 7) systems. Across all flocks and survey times, the median PRM mass per trap was 0.7 mg (1.-3. quartile: 0.0–19.3 mg/trap), corresponding to a median count of 65.2 mites/trap (1.-3. quartile: 0.0–246.8 mites/trap). Binary logistic regression models revealed an association between PD and skin lesions with hen age, housing system, and hybrid type (p<0.001). The PRM load also affected the plumage condition, where PD increased with increasing PRM infestation (p<0.001). In addition, the PRM load tended to have an effect on skin injuries (p = 0.097). In conclusion, this longitudinal study identified the PRM load in laying hen flocks as a risk factor for PD.
Background/introduction In the absence of evidence‐based findings for Saxonian Chicken (SaChi) and German Langshan bantam (GLB), which are indigenous endangered German fancy chicken breeds, the objective of the present study was to characterise their growth performance and meat potential in an extensive free‐range system Methods A total of 340 hatching eggs from SaChi and 439 eggs from GLB were provided by private breeders, from which 263 SaChi (77.3%) and 174 GLB (39.6%) hatched (p < 0.001) Results By week 20, SaChi reached body weights of 2362.3 ± 315.3 g (mean ± SD; roosters) and 1624.7 ± 158.9 g (hens), while GLB weighed 1089.7 ± 148.3 g (roosters) and 820.4 ± 89.5 g (hens). Fitting the non‐linear regression of growth data to the Gompertz function estimated asymptotic body weights of 3131.4, 2363.9, 1359.2 and 1107.3 g, with inflection point times of 10.5, 10.3, 9.2 and 9.3 weeks in male SaChi, female SaChi, male GLB and female GLB, respectively. Moderate plumage damage was observed on days 18, 35, 53, 70 and 105 in SaChi and on days 53, 70 and 105 in GLB, while all birds presented completely intact plumage on day 140. Using a binary logistic regression model, breed, age and sex were shown to affect the plumage condition (p < 0.001 each). Roosters were slaughtered in week 20. No breed effects were detected in the carcass yield (SaChi: 68.8 ± 1.7%, GLB: 69.7 ± 1.8%) (p = 0.135) or abdominal fat share (SaChi: 0.89 ± 0.15%, GLB: 1.08 ± 0.14%) (p = 0.281). The percentage of valuable cuts (breast fillets and legs) in the carcass was 43.8 ± 1.9% for SaChi and 43.1 ± 3.0% for GLB (p = 0.490) Discussion/conclusions In conclusion, this study provides insights into the performance traits and welfare indicators during the rearing of two endangered German chicken breeds.
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