Influence of a Low Plane of Nutrition During Sexual Development on Subsequent Reproductive Performance of Small White Breeder Toms

Abstract

Diamond White and Wrolstad breeder toms were reared to 10 weeks of age on a common nutritional regimen. Both strains were subsequently given high and low planes of nutrition to 30 weeks. Low nutrient feeds were ca. 200 kcal of metabolizable energy (ME)/kg less than high nutrient feeds, which paralleled commercial practice. Energy-protein ratio and essential amino acid profiles between nutrient levels were similar. Both planes were phased down ca. 200 kcal ME/kg between the feeds from 10 to 14 weeks to 14 to 30 weeks. All birds subsequently received the same breeder ration.Diamond Whites were heavier than Wrolstads from 2 through 10 weeks of age. Feeding the low plane of nutrition reduced body weight of both strains at 14 weeks. Growth during the 14- to 30-week-period was such that birds given the low plane feeds recovered earlier losses, and Wrolstads became heavier than Diamond Whites. Although no differences in body weight occurred throughout the breeder period that could be attributed to earlier nutrition, the low plane feeds led to significant improvements in semen and sperm yield during the early and late stages. Wrolstads accrued more fat and benefited more from the low plane of nutrition than did Diamond Whites. Results inferred that reducing fat accretion early in sexual maturity improves subsequent reproductive capacity apart from an alteration in body weight.