Influence of Housing System on Growth Performance and Intestinal Health of Salmonella-challenged Broiler Chickens
Abstract
Rearing chickens on litter floors or in cages may influence their performance, especially when they are colonized by enteric pathogens, such as Salmonella. Male Ross 308 broilers were randomly assigned to 32 litter floor (litter) pens in a curtain-sided house or 32 cages (cages) in a total confinement house (25 birds/pen or cage). Birds were orally inoculated with 106 CFU of a cocktail of S. enterica subsp. enterica at three days of age. Salmonella populations (SP), body weights, feed conversion ratio and the weights of spleen and liver relative to body weight were determined at 14, 28 and 42 days of age. At each time point, characteristics of the intestinal segments were scored as an indicator of gut health on 32 birds per house. SP was higher in litter than cages treatment at 14 days of age which corresponded with a higher incidence of mucoid jejunum exudate. In contrast, cages had higher incidence of ileal grain chips than litter at 14 days, indicating inferior gizzard function. At 42 days of age, litter birds had higher breast meat yield, heavier body weight and improved cumulative feed conversion ratio than those in cages. Although, birds raised on litter floors showed greater 14 day Salmonella colonization than cage-reared birds, their digestion capacity appeared superior. Birds reared on litter floors had fewer undigested feed particles in their distal small intestine which correlates with enhanced growth performance and breast meat yield.