The effect of different feed restriction programs on reproductive performance, efficiency, frame size, and uniformity in broiler breeder hens.
Two experiments were conducted to determine the effect of feed restriction programs on breeder reproductive performance. In experiment 1, every day (ED), skip-a-day (SK), 4-3, and 5-2 programs were compared. Diets did not differ, and feed intake was identical in all groups. Four hundred twenty pullets were reared on each program. At 21 wk, 80 breeders from each program were individually housed to record performance parameters. Body weight and frame size were larger in ED pullets than SK, 4-3, or 5-2 despite equal intakes. Hens fed ED reached sexual maturity at a younger age than other groups. Hens fed ED also produced more total and settable eggs than SK hens. Egg weight was heavier in 5-2 hens than in ED with 4-3 and SK intermediate. Efficiency of feed utilization was best in ED hens. In experiment 2 the same programs were tested, but pullets were reared to reach equal BW. One hundred seventy-five pullets were reared on each program, of which 60 were housed. Feed intake was greater for SK, 4-3, and 5-2 than ED pullets to reach the same BW. Frame size did not differ, indicating that BW was the cause of differences in experiment 1. In experiment 2, differences in performance were attenuated but not eliminated by feeding to reach equal BW, suggesting that metabolic factors aside from BW are altered by feeding programs. The 5-2 produced larger eggs than ED with the trend among programs being identical to that in experiment 1. These results suggest that metabolic changes such as increased lipogenesis or alterations in body composition may result in larger eggs in feeding programs that include off-feed days. Mortality, fertility, and hatchability were not affected by feeding programs in either experiment. Body composition analysis indicated the importance of total lean protein mass as a threshold for the onset of sexual maturity. Programs like SK are less efficient than ED and may result in reduced performance.
de Beer
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University of Arkansas, Center of Excellence for Poultry Science, Fayetteville Arkansas 72701, USA.
Coon
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D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition; D001835:Body Weight; D002645:Chickens / Q000033:anatomy & histology* / Q000502:physiology*; D004032:Diet / Q000662:veterinary*; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D012741:Sexual Maturation