Extra Dietary Calcium Supplement and Broiler Breeders

The influence of an extra dietary calcium supplement on egg specific gravity and hatchability performance was studied in a commercial broiler breeder flock at 43, 46, 56, and 64 week of age. A breeder flock of 28,000 was divided into two groups: a control group, which didn’t receive the calcium supplement, and a treatment group, which received a coarse limestone supplement (g/hen/day) fed in the afternoon, from 43 wk of age onwards. Egg weight, specific gravity, egg weight loss during incubation, hatchability, and viability (hatchability of fertile eggs) were recorded, and researchers evaluated the influence of calcium supplementation and age of breeders on these traits. Egg specific gravity was significantly improved the coarse limestone supplement, but egg weight loss during incubation was unaffected. Hatchability and viability increased by about 3 percentage points when broilers received limestone in the afternoon, primarily as a result of a reduced incidence of contaminated eggs. As the flock aged, egg weight increased significantly (P < .05) and water loss during incubation showed little variation when expressed as a percentage of the egg weight when set (ca.11.5%). Fertility and viability declined with breeder age.