Large White female turkeys of a commercial variety were used to determine the effects of low dietary protein during the pre-breeder period (12 to 32 weeks of age) on subsequent reproductive performance. Diets containing 10, 12, 14, and 17% protein were fed from 12 weeks or 20 weeks to 32 weeks of age. At 32 weeks of age, all females were fed a 17% protein breeder diet. Reproductive performance was measured for a 24-week production period. Pre-breeder feed consumption and body weight gain from 12 to 32 weeks of age increased with increased dietary protein until diets contained 14% protein. Similar results were obtained when females were fed varying protein levels from 20 to 32 weeks of age. Egg production also showed an increase with increased pre-breeder dietary protein level until diets contained 14% protein. Ten fewer eggs per hen were obtained from females previously fed the 10% protein diet than those fed the 14% (20 to 32 weeks) and 17% protein diets. Pre-breeder dietary protein level did not affect age at sexual maturity, egg weight, specific gravity or shell thickness of eggs, mortality or growth, and feed consumption of progeny. Based upon the results of this study, female breeder turkeys require at least 14% protein to 20 weeks of age and 14% from 20 to 32 weeks of age for optimum egg production.

The effect of low dietary protein during the rearing and breeding periods on the reproductive performance of Large White turkey males was examined. At 12 weeks of age 251 males were randomly divided into two groups and fed either 12 or 17% protein through 56 weeks of age. Body weight gains from 12 to 20 weeks and 20 to 28 weeks of age were significantly reduced for the males receiving the 12% dietary protein. However, after 28 weeks of age, weight differences decreased and by 56 weeks of age body weights of both groups were approximately the same. In addition, a significant reduction in feed consumption was noted for the males fed 12% protein. Males on the high protein diet experienced a higher mortality than those on the low protein diet.Low dietary protein reduced semen volume and spermatozoa concentration at 33 weeks of age, but there were no significant differences thereafter. The percentages of normal, abnormal, or dead spermatozoa were unaffected by dietary protein levels. Feeding 12% protein from 12 to 56 weeks of age to Large White turkey breeder males was adequate for high quality semen production.

Large White turkey breeders of a commercial variety were used to determine the effects of pre-breeder dietary protein, frequency of insemination, and semen volume on subsequent reproductive performance. Treatments included female dietary protein levels of 10, 12, 14, and 17% fed from 12 to 32 weeks of age and 10, 12, an 14% protein from 20 to 32 weeks of age; male dietary protein levels of 12 and 17% fed from 12 to 56 weeks of age; and artificial insemination (AI) treatments of a) .025 ml of semen at weekly intervals, b) .025 ml of semen at biweekly intervals, and c) .05 ml of semen at biweekly intervals in a factorial arrangement of treatments. Male dietary treatment had no significant effect on fertility or hatchability of fertile eggs. Female pre-breeder protein levels also had no significant effect on fertility but resulted in lower hatchability of fertile eggs during the latter part of the production period when females were fed either the 10 or 12% protein pre-breeder diets. Weekly inseminations with .025 ml of semen resulted in the highest average level of fertility during the production year (90%), followed by biweekly insemination with .05 ml (87%) and .025 ml (85%) of semen, respectively. Hatchability of fertile eggs was significantly higher for hens receiving .05 ml of semen biweekly than for the other two AI treatments during the latter half of the production year only. However, weekly inseminations caused a significant decline (6.7 eggs/hen) in egg production when compared to hens inseminated at biweekly intervals. The average number of fertile eggs was greatest for females inseminated with .05 ml semen biweekly (54.3) compared to those inseminated with .025 ml of semen biweekly (53.0) or .025 ml of semen weekly (50.2).