Effect of different feed restriction programs on the performance and reproductive traits of broiler breeders
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The current experiment evaluated the effect of different feed restriction programs applied during rearing on the performance and reproductive traits of broiler breeder pullets reared on floor pens, isolating the birds' weight effect from the analysis. At 4 wk of age, 1,400 breeder pullets were distributed in a completely randomized design with 4 treatments: daily restriction (DAILY - every day feeding), skip-a-day restriction (SKIP - every other day feeding), 4/3 restriction (4/3-4 days feeding and 3 nonconsecutive fasting days) and 5/2 restriction (5/2-5 days feeding and 2 nonconsecutive fasting days), and 8 replicates. At 11, 18, 25, 32, and 39 wk of age, body weight, feed intake, feed conversion ratio, carcass composition, organs relative weight (liver, fat, oviduct, and ovary stroma), egg production, and egg weight were accessed. At 32 and 39 wk, 12 eggs by experimental unit were collected and incubated to determine hatchability and fertility parameters. Body weight, carcass EE, and FCR were higher for SKIP birds when compared to other feed restriction programs. SKIP birds also showed the lowest number of eggs per bird (NEB) and % of egg production when compared to 4/3 feeding schedule, which provided higher values. Feed conversion ratio per egg mass (FCEM) was also higher in 4/3 schedule in relation to SKIP birds. In regard to incubation parameters, 5/2 treatment showed higher values for hatchability (HAT) and fertility (FERT), similar to results of 4/3 and DAILY treatments, while SKIP birds showed the lowest. In conclusion, 4/3 and 5/2 feeding programs showed best results and should be used by broiler breeder producers to control pullets' body weight. Therefore, the higher number of eggs produced with less feed and statistically not different fertility and hatchability between programs obtained in this study suggest the 4/3 program could be more efficient than 5/2 program. Body weight′|'s effect isolation was important to analyze the effect of feed restriction program per se, and should be applied in future approaches.