FACTORS AFFECTING ABORTION, STILLBIRTH AND KID MORTALITY IN THE GOAT AND YAEZ (GOAT X IBEX)

Data on abortions, stillbirths and kid mortality from an experimental herd, used for the development of the Yaez, were analyzed. Total numbe r of embryos was 960. Mortality was divided according to kids' age, to early mortality (during first 48 h), mortality before weaning at 70 d (BWA) and after weaning up to 180 d (AWA). There were more abortions among primiparous does (11%) than among older ones (5.3%). More triple ts were aborted (13.4% vs. 6.2%) and/or born dead (15.5% vs. 5.3%) tha n kids in smaller litters. Season affected mortality of kids before, a s well as after, weaning. Rates were 7%, 25.3% and 12.8% BWA for winte r, spring and summer born kids, respectively. After weaning 8%, 22.6% and 9.5% died out of winter, spring and summer kids, respectively. Day of birth in season was a significant factor of mortality of kids befo re and after weaning. Of the kids born during the first 10 d of season , 7.7% died BWA and 8.9% AWA; out of kids that were born from 11 to 20 days, 17.5% died BWA and 16.5% AWA, while 27.2% of the kids that were born after 20 d died BWA and 20.7% died AWA. Mortality rate before an d after weaning increased corresponding to the percentage of ibex gene s in the dam, the sire and the kid. Combination of low birth weight wi th hybridization of goat and ibex resulted in increased mortality in a ll three ages. During the first 48 h of their life average mortality w as 4.5%; of kids born up to 1.5 kg with 10-30% ibex genes, 17.6% died; and from the group with more than 30% ibex genes, 33.3% died.