THE REPRODUCTIVE-PERFORMANCE OF 2 GENETICALLY DISTINCT LINES OF MEDIUM WHITE TURKEY HENS WHEN FED BREEDER DIETS WITH AND WITHOUT A YEAST CULTURE CONTAINING SACCHAROMYCES-CEREVISIAE

The suitability of a breeder diet containing a yeast culture as a mean s of improving the hen reproductive performance of two genetically div ergent lines of Medium White turkeys for low (L) and high (H) semen ej aculate volumes was investigated in two experiments. A total of 200 he ns of lines L and H (n = 100 per line) were housed in a curtain-sided breeder house (ten hens per line per pen). Starting at 31 weeks of age (WOA), the hens were fed either corn-soya bean (CS) or com-soya bean plus yeast (CS+Y, 0.5% Diamond V. Mills XP yeast culture, Saccharomyce s cerevisiae) diets. Between 33 and 45 WOA (Experiment 1), the hens we re mated inter se and from 45 to 51 WOA, reciprocal line matings were established (Experiment 2). Hen reproductive parameters measured betwe en 31 and 51 WOA were: body weight (BW) change, feed intake, feed per dozen eggs, egg production, egg size, fertility, embryonic mortality, and hatchability of fertilized eggs from seven biweekly egg settings. Yeast culture supplementation of the diet did not influence (P > 0.05) changes in BW, egg production, egg weight, embryonic mortality, and h atchability of fertilized eggs (n = 5 biweekly hatches) of either line . Significant time by line (P < 0.01) and time by diet interactions we re evident only in feed intake. In Experiment 1 there was an improved (P < 0.05) hen fertility in line H as a result of feeding the dietary yeast culture. In Experiment 2, when the hens of both lines were insem inated with semen of their reciprocal line, the hatch of fertilized eg gs (n = 2 biweekly hatches) was substantially improved (P< 0.05) from hens fed the yeast culture containing diet. The results of this study suggest that there is a genetic factor associated with the feeding of a diet containing a yeast culture to turkey breeder hens.