THE INFLUENCES OF PREINCUBATION STORAGE DURATION AND GENOTYPE ON THE HATCHABILITY OF MEDIUM WHITE TURKEY EGGS FROM HENS FED A DIET CONTAINING A YEAST CULTURE OF SACCHAROMYCES-CEREVISIAE

Two experiments were conducted to determine the effects of feeding tur key breeder hens of different genotypes a diet containing 5 g kg(-1) y east culture (YC) and its effect on preincubation egg storage duration (Experiment 1, eggs stored 0-7 and 8-14 days; Experiment 2, eggs stor ed 0-4, 5-9, and 10-14 days), hen reproductive performance, and the ha tchability of fertile eggs. Wrolstad Medium White turkey hens, represe nting three distinct genetic lines, Low (L), High (H), and Cross (C), were fed pelleted 15.4% crude protein (CP) corn/soya breeder diets wit hout or with 5 g kg(-1) YC (XP yeast culture(R), Saccharomyces cerevis iae, Diamond V. Mills Inc., Cedar Rapids, IA). The results of Experime nt 1 indicated that early embryonic mortality (Days 0-10) of eggs stor ed from Days 0 to 7 was reduced (P<0.01) in the three lines when suppl emental YC was provided in the breeder hen's diet. Hatch of fertile eg gs was increased (P<0.02) in the line C eggs stored from Days 0 to 7 p rior to incubation and there was a significant (P<0.04) genotype-dieta ry YC interaction. The results of Experiment 2 were similar to those i n Experiment 1; early embryonic mortality was reduced in eggs stored f rom Days 5 to 9 in Lines H and C. Significant genotype-dietary YC inte ractions were noted for egg storage times of Days 5-9 (P<0.05) and 10- 14 (P<0.04). A genotype-dietary YC interaction (P<0.01) was also obser ved when the hatch of fertile eggs was increased in eggs stored from D ays 5 to 9 in Lines H and C but not in Line L. These results indicate that the breeder hen's genotype and duration of preincubation egg stor age time are factors to be considered when feeding diets containing a YC to turkey breeder hens.