Studies on the improvement of cheju korea native cattle with brahman and santa gertrudis cattle i. genetic and environmental effects for preweaning growth
Kim, D.C.; Kim, J.K.; Lee, H.S.; Paik, Y.K.
Korean Journal of Animal Science 29(2): 59-71
The primary objective of this breeding project was to study methods for improvement of economically important traits of Cheju Native Cattle with Brahman and Santa Gertrudis that are adaptable to specific climatic conditions, poor quality forage and to make use of some other genetic merits. Data used in this study were ecollected from Cheju Native Cattle (K), Brahman (B), Santa Gertrudis (S) and their crossbreds fed low quality forages throughout the year at Cheju Experiment Station [Korea] during the period from 1974 to 1985. Environmental effects of the experimental animals were estimated by the least square procedures (Harvey, 1960). The results of this study are summarized as follows; 1. The average weights of Cheju Native Cattle at birth (23.0 kg), at 3 months (73.1 kg) and at 6 months (101.8 kg) were lightest among the purebreds. Brahman's birth weight (26.7 kg) were lighter than Santa Gertrudis (29.8 kg) and average body weights of Brahman and Santa Gertrudis were 137.6 kg and 128.7 kg, respectively, at weaning. 2. The live weight of BK (Brahman .times. Cheju Native Cattle) and SK (Santa Gentrudis .times. Cheju Native Cattle) were lighter than any other crossbreds observed. The back crossbreds, B2K (BK .times. Brahman) and S2K (SK .times. Santa G.), grew faster and were heavier at 6 months (B2K; 133.2 kg, S2K; 133.3 kg) than the crossbred .times. back crossbreds (BK .times. B2K and SK .times. S2K), which were 126.3 kg and 133.1 kg, respectively. 3. Male calves (27.4 kg) were on the average 2.4 kg heavier than female calves at birth and the average weight at 6 months was still in favour of the male (P<0.01). 4. Year of calving had a highly significant effect (P<0.01) on the weights of calves. On the other hand, there were remarkable increases in calf weight out of the dams of 4-9 years old and 4th parity cows; but these efects declined as the age of calf increased.