Effects of Rearing Broiler Strains Intermingled Versus Separately and Effects of Placement Time on Broiler Performance

Sixteen chicks of each of four strains were placed in each of three pens: (pen 1) within 4 hours after hatching; (pen 2) 24 hours after hatching; and (pen 3) 48 hours after hatching in 2 experiments. Each of these broiler strains were also reared in separate pens in both experiments. Mortality was progressively higher as more time elapsed before chicks were placed on feed and water. Little difference was found in feed efficiency for the different placement times. In the first experiment chicks placed within 4 hours and 24 hours after hatching were different while in experiment 2 they were similar in 8-week body weight. Chicks placed 48 hours after hatching were lower in 8-week body weight then either of the other placement times in experiment 2, while in experiment 1 they were heavier than chicks placed 24 hours after hatching but were not as heavy as those placed 4 hours after hatching. Broiler strains reared separately were heavier at 8 weeks than those reared intermingled except for one strain in experiment 2. The range of the strain means with their standard errors overlapped except for two strains and the average values in experiment 1. All strains averaged together in experiment 1 were heavier when reared in separate pens.