The Effects of Parent Age and Posthatch Treatment on Broiler Performance

Abstract

The relationship between age of the parent and the quality of the day-old broiler chick were studied in two experiments by examining the loss in egg weight during incubation (percentage of egg weight loss, PEWL). Also, the efficacy of a water-soluble antibiotic and the practice of withholding feed at placement time were examined. Eggs were obtained from two sets of breeders (approximately 30 and 50 wk of age). The eggs were weighed individually and were incubated. Chicks of each parent age group were randomly assigned to one of four treatments: 1) water and feed at placement time; 2) water and Neo-Terramycin and feed at placement time; 3) water at placement time and feed 4 h later; and 4) water and Neo-Terramycin at placement time and feed 4 h later. The chicks were housed in cages for Experiment 1 and in floor pens for Experiment 2.In both experiments, breeder age significantly affected BW. Chicks from old flocks were heavier and exhibited a significantly higher growth rate than the chicks from young flocks. Significant correlations between chick hatch weight and egg weight were observed. Low correlations between PEWL and BW were noted. In Experiment 1, the chicks receiving the Neo-Terramycin were significantly heavier up to 4 days of age than the chicks in other treatments. Chicks allowed access to feed at placement time were significantly heavier at most weigh times, up to 5 wk of age. Male chicks from old flocks that received both Neo-Terramycin and feed at the time of placement had a significantly higher growth rate than did the males of any other treatment in Experiment 1. In Experiment 2, neither the administration of Neo-Terramycin nor the provision of water prior to feeding had a significant effect on BW gain. Male chicks from the young flocks provided with water prior to feed exhibited a significantly higher growth rate than did the males in any other treatment. These data suggest that parent age does influence chick weight. The use of water-soluble antibiotics and the provision of water prior to feed did not benefit chicks that are normally hydrated.