The Effect of Extended Holding Time, Temperature, and Dietary Energy on Yields of Broilers

Feed was withdrawn, but water was available, for 12 hr before 8-week-old broilers were held in crates at 10.0 and 32.2 C for 8 and 16 hr or at 26.7 C for 16 hr. The effects of holding time, holding temperature, and dietary energy on shrinkage and processing yields were investigated. The rates of live weight loss were linear with holding time and were .219 and .513%/hr for birds held at 10.0 and 32.2 C, respectively. Male birds tended to have higher weight loss than the females. When based on preholding weight, carcass yields decreased significantly for both holding times at both temperatures; however, yields tended to slightly increase with time when based on the postholding weight. Broilers reared on a 3325 kcal/kg ration lost significantly more than those reared on a 3100 kcal/kg ration after 16 hr of holding at 26.7 C. Eviscerated carcass yields were significantly higher for the birds reared on the low energy diet than for those reared on the higher energy diet. Increased holding time reduced viscera weight and the weight of blood and feathers lost during slaughter.