Studies on Early Selection of Excellent Gilts for Improvement of Reproductive Efficiency II. Return of Estrus after the Parturition of Candidate Gilts
종빈돈의 번식효율 증진을 위해 후보종빈돈의 분만후 포유기간, 등지방두께 등이 번식능력에 영향을 미치는 요인을 조사ㆍ분석하여 우수한 후보 종빈돈의 조기선발에 활용코자 수행한 결과는 다음과 같다. 1. 분만모돈의 포유기간이 17∼21일일 때에 등지방두께는 19.19mm였고, 포유기간이 22∼26일 일때에는 16.52mm로 포유기간이 길수록 분만모돈의 이유시 등지방두께는 유의적으로 얇았다.(p<0.01). 2. 분만모돈의 포유기간이 17∼21일인 경우에 발정
These studies were performed to improve the reproductive efficiency of gilts and we investigated the effects of nursing periods after parturition and backfat thickness will adapt to these results for early selection of excellent gilts. The main results were as follows; 1. The backfat thickness in sows nursing for 17∼21 days was 19.19 mm, and 16.52 mm in 22∼26 days and longer nursing period affected significantly the backfat thinner (p<0.01). 2. The recurrence of estrus in sows nursing for 17∼21 days was 5.76 day and 5.62 day in 22∼26 days and there was no difference between nursing periods. 3. The recurrence of estrus in sows had 13∼16 mm backfat thickness was 5.69 day, 5.67 day in 17∼20 mm and 5.75 day in 21∼23 mm and there was no difference among backfat thickness. 4. The concentration of plasma estradiol were 28.49 pg/ in parturition, 12.39 pg/ in weaning and 16.52 pg/ in return of estrous. The concentration ot plasma progesterone were 1.50 ng/ in parturition, 0.69 ng/ in weaning and 0.94 ng/ in return of estrous. The concentration of plasma cortisol were 57.74 ng/ in parturition, 43.01 ng/ in weaning and 47.89 ng/ in return of estrous. There showed the highest level of estradiol, progesterone and cortisol in parturition.