Effect of four processed animal proteins in the diet on behavior in laying hens

An experiment was performed to investigate the effect of animal versus vegetable protein sources in the diet on the development of behavior in laying hens. A diet containing protein sources of only vegetable origin was compared with four diets, each containing one of four processed animal proteins (PAPs). Two PAPs (Daka-58 and Sonac-60) were classified as meat meals, whereas the remaining ones (Daka-40 and Sonac-50) were classified as meat and bone meals. The impact of a control diet (without PAP) versus four PAP diets (50 g/kg CP of animal origin) on behavior was determined. All diets were isocaloric (AME n = 11.8 MJ/kg) and isonitrogenous (dig. lysine = 6.8 g/kg). Hens were housed in 40 floor pens (12 hens/pen, 8 pens/treatment) from 20 to 40 weeks of age. Supplementation of PAPs did not generally reduce feather pecking behavior. Nevertheless, Daka-40 and Sonac-50 fed hens showed a delay in the development of feather damage and, simultaneously, an increase in litter condition, foraging and walking behavior, and floor pecks compared to hens fed Sonac-60. These shifts seemed to be partly related with the intake of digestible glycine, available phosphorus, calcium, potassium, and sodium.