The Use of Radioimmunoassay to Monitor Reproductive Status of Cheju Native Cattle and the Effect of Supplementary Feeding on Reproduction. : Body Weight Changes, Breeding Performances and Progesterone Levels from Weaning until first Calving = 방사선 동위원소 면역기술을 이용한 濟州韓牛 營養給與의 수준이 繁植성적에 미치는 영향

국문 초록 (Abstract)

濟州韓牛의 能力向上을 위하여 營養給與 수준과 Hormone 水準의 相互關係를 규명하였다. 8 頭의 濟州韓牛 未經産牛를 利用, NRC 100%와 70%給與區를 設定 增體量, 繁殖狀況 및 發情期間과 姙娠期間中의 Progesterone의 變化를 調査하였다.
NRC 100%給與區의 增體成績은 6個月에 155kg에 比해 70%區는 137kg 로서 標準區의 發育이 월등하였다. 卵巢의 크기는 標準區에서 2.1×1.6cm(左側)과 2.6×1.8cm(右側) 이였으나 70%區의 卵巢는 이보다 多少 적었다. 初發情은 標準區에서 14.6個月(體重 265kg)이였으며 初産月令은 28.9個月(體重 436kg)이였던 反面 70%區에서는 初發情 23.0個月(體重 250kg), 初産月令 38.9個月로 標準區에 比해 10個月이 지연되고 있었다. Progesterone 水準은 標準區에서 姙娠 14週와 18週에 最高에 達하여 6.4-6.5ng/ml 이였으며 24週까지 이 수준이 유지된다고 姙娠末期에는 2.1ng/ml로 減少하였다. 70%區에서는 16週까지는 標準區와 유사했으나 全 姙娠期間을 通해 Progestone수준은 標準區보다는 떨어지고 있었다.

다국어 초록 (Multilingual Abstract)

Studies were conducted to investigate the relationship between hormone leveles and nutritional levels for improving performance of Cheju native cattle.
In June 1984 a trial was initiated using 8 Cheju native claves after weaning, fed at two supplementary feeding leveles(NRC 100 and 70%). The body weight, breeding performence, change in progesterone level during pregnancy and estrus cycle were evaluated.
Mean body weight at 6 months of age was 155kg when fed 100% NRC ration but it was only 137kg when heifers reveived the 70% NRC ration. At 10, 15 and 20 months of age the body weight was 66, 160 and 115kg, respectively, showing that heifers fed the standard ration gained weight rapidly(p＜0.01).
Average size of the left ovary in the standard group was 2.1 x 1.6cm and right ovary was 2.6 x 1.8cm. However in the restricted feeding group the ovaries were found to be smaller. Diameter of graffian follicles showed a similar tendency to ovarian size in the two groups.
The first oestrus in the standard feeding group appeared at 14.6 months when body weight weight was 265kg. Age at first calving was on average 28.9 months at a body weight of 436kg. On the other hand when heifers were fed the restricted ration the first oestrus appeared at 23.0 months at a body weight of 250kg. Average age at first calving was 38.9 months which was 10 months later than the average in the standard feeding group (p＜0.01).
In standard feeding group the progesterone level was 2.0ng/ml at two weeks after pregnancy and gradually increased up to 14 weeks and peaked at 18 weeks. This peak(6.4-6.5ng/ml) was maintained up to 24 weeks when progesterone level decreased until it reached 2.1ng ml at the end of pregnancy. In the restricted group progesterone level up to 16 weeks followed a similar pattern to the standard group but there was a tendency in the restricted group to have lower progesterone levels (p＜0.01).
The standard and srstricted groups showed similar patterns of progesterone concentration during the oestrus cycle. There were no statistically significant differences in progesterone levels between standard and restricted groups but there was variation between individual animals.