The Effect of Low Protein Grower Diet on the Reproductive Performance of Turkey Breeder Toms

Sixty Marston Broad White toms were used in each of two experiments (hatched February and late July) and were equally divided among six floor pens (1.5×2.4 m.). All birds were fed a commercial type starter diet through the tenth week of age. From the eleventh through the twenty-fourth week of age, one-half of the birds were fed a low protein grower diet (10.2 percent protein) while the remaining birds were fed the control grower (21 percent protein). Beginning with the twenty-fifth week all birds received a commercial-type breeder diet. At 30 weeks of age one male was placed in each of 18 female pens (ten females per pen). Body weights for the restricted males were 36–38 percent lighter than the controls at 24 weeks of age and changes in conformation were such that males fed the low protein grower diet could be ejaculated more easily than the controls. In general, the semen characteristics of the restricted males were also superior; however, this difference was non-significant. Fertility for the February hatched, naturally mated, birds was more than 100 percent higher for the males fed the low protein grower diet while fertile hatch was numerically, but not significantly, higher than the controls. Fertility and fertile hatch for the naturally mated, July hatch, birds were numerically, but not significantly, higher for the males fed the low protein grower diet. In the artificially inseminated birds, fertility and fertile hatch of the males fed the low protein grower diet were numerically, but not significantly, greater than the controls, in both experiments. It is obvious from these data that increased reproductive efficiency results from nutrient restriction of toms during the growing period.