Relationship between feed withdrawal and viscera condition of broilers.

This study was conducted to investigate the effects of feed withdrawal on the viscera of commercial broilers. Birds were withdrawn from feed 0, 3, 9, 12, 14, 16, or 18 h before slaughter. Crop and gizzard contents were determined after dissection, and intestinal shape and villi were subjectively scored. Raw liver color was measured colorimetrically. Length of feed withdrawal (time) and its interaction with grower (time by grower) and replication (time by replication) had a significant effect (P < 0.05) on gizzard contents, intestinal shape, and villi; however, time by grower and time by replication did not affect the crop contents or the incidence of bile contamination in the digestive tract. Results also suggested that the integrity of the intestines declined after 12 to 14 h feed withdrawal, as indicated by heavy intestinal sloughing. Color analyses of livers showed that length of feed withdrawal did not affect lightness (L* values), but livers became less red (lower positive a*) as feed withdrawal time increased. It was concluded that length of feed withdrawal significantly affected the gastrointestinal tract; however, variation in the appearance of the liver could not be attributed solely to broiler feed withdrawal time.