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KMID : 0900919930170010035
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Korean journal of Animal Reproduction
1993 Volume.17 No. 1 p.35 ~ p.41
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Effect of Environmental Factors on Female’s Reproductive Traits of Korean Native Cattle
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Kim Chang-Yup
Kim Kyung-Soo
Kim Ki-Joon
Kim Jong-Bok
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Abstract
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The study was conducted to investigate the effects on environmental factors on the reproductive performance of Korean native cattle based on the data from 13, 588 records which were surveyed from 1983 to 1992. The results obtained in this study are as follows; 1. Mean performaces of the reproductive traits were 510.2days for the age at 1st service, 525.0days for the age at 1st conception, 808.7 days for the age at 1st calving, 102.5 days for the days to 1st conception postpartum and 388.6 days of the calving inverval. The cows of Chunbuk province were tended to be bred and calved at younger age and showed shorter calving interval than those of other provinces. 2. The effect of birth year was significant for the reproductive performances, especially, in 1986~1987 when the cattle prices dropped sharply and reproductive performances were poor. 3. The times of 1st service and 1st conception of heifers calved in spring tended to be delayed. Days to 1st conception postpartum, calving interval and days to 1st service postpartum of cows calved in fall were shorter than other calving season’s cows. 4. Days to 1st conception postpartum, calving interval and days to 1st service postpartum of cow’s were shortened and gestation length was prolonged as the number of parity increases.
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