Fertility perforrnance in Brown Swiss Herd at Konya Livestock Research Center

The results of the fertility traits were given as Swiss Brown Swiss, German Brown Swiss, American Brown Swiss, Karacabey Brown Swiss and. overall herd respectively. The ages at first insemination were 27.50, 26.98, 25.25, 26.53, and 26.30 months, the ages at first calving were 37.61, 37.82, 35.60, 37.53, and 36.75 months, the conception rates were 73.8, 70.3, 73.1, 72.3 and 72.1 %, anoestrus rates were 1 0.6, 11.8,13.4, 7.1 and 11.4 %, the percentages of abortions, prematurebirths and stillbirths were 2.4, 1.8, 5.9, 3.0 an 3.0 %, twinning rates were 2.9, 2.4, 0.7, 2.9 and 2.3 %, the number of inseminations per conception were 1.45, 1.44, 1.35, 1.68 and 1.44, calving intervals were 12.56, 12.74, 12.79, 12.69 and 12.66 monts, gestation lengths were 287.2, 287.7, 288.9, 289.5 and 287.9 days, service periods were 104.1, 126.1, 123.9, 121.7 and 115.7 days, the intervals from parturition to first insemination were 80.3, 79.7, 83.2, 84.0 and 80.9 days, the intervals from first insemination to conception were 58.7, 40.0, 38.8, 646 and 49.0 days.

The evaluation of some fertility traits of Brown Swiss genetic groups indicated that American groups showed the best reproductive performance among the all groups. The differences among reproductive performances of bulls were found significant. For this reason, the consideration of rnale fertility in the selection programmes would result an increase in reproductiw performance. The evaluation of fertility traits according to the age of cows and the parities showed that 4-year-olds and third parıty cows had hıgher reproductıve performance than the others. The reproductive performance increased until 4-yearolds and the third parity, and decreased with increasing age and parity. Keywords :