Studies on tes years breeding of Holsteins on Karacabey State Farm I. Reproductive efficiney and survival rate

The material of this investigation consisted of 177 female and 166 male Holsteins at different ages which were the total Holstein material on the farm from 1959 to 1968. The characteristics of reproductive efficiency was studied on 93 heifers and cows. They constituted 529 breeding material within ten years. In regard to reproductive efficency number of animals coming to heat, services per conception, number of abortions, stillbirths, calving percentage and twinning were studied. The livability of Holsteins were studied in four stages of life, that is, 0-1 month, 1-3 months, 3-6 months and over six months.

Within the period of ten years 427 conceptions were achieved out of 529 breeding material which constituted a conception rate of 84.3 %. The average number of services per conception was estimated to be 1.73. The abortion rate among pregrant animals was 4.9 %. The cases of abortions were highest in 1959 and 1966 with abortion rates of 28 and 14 %, respectively. The major cause of these abortions was assumed to be the onset of leptospirosis in those years. The rate of stillbirths was very low, about 1.4 %. The calving percentage with in ten years was 93 % among pregrant cows and 75 % in regard to the whole herd.

The ratess of losses within the periods of 0-1, 1-3 and 3-6 months were estimated as 1.4, 2.0 and 1.1 % respectively, which adds up to 4.5 % from birth to sixs months of age. Since the rate of loss above six months of age is 7.2 % the dath loss for the all material makes up to 11.7 %. The major cause of death above six mounths of age was leukemia which was about 40 % of total deats at this age period.

Since the results on reproductive efficiency and surviving ability of Holsteins on Karacabey State Farm are equal to or better than those of Europe and the United States it may be concluded that Holsteins may be succesfully bred and raised in Marmara region. Keywords :