Hormonal Changes of Serum Progesterone and Estradiol-17β on Flushing Feed before Estrus during Estrous Cycle in Sows of Landrace, Yorkshire and F1 (Landrace × Yorkshire)

Hormonal Changes of Serum Progesterone and Estradiol-17β on Flushing Feed before Estrus during Estrous Cycle in Sows of Landrace, Yorkshire and F1 (Landrace × Yorkshire)

This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-17β (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L × Y) (respectively n=3) with excellent ability, and to providea baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or morewere used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushingfeed before estrus. Each pig’s blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analysesof P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-17βwere measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels weresignificantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen betweenthe L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, thetendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a littlehigher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similarto the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swineproduction, these results proved the fact of the methods. And these results suggested that more studies about hormonalchanges in sows according to seasonal and nutritional factors should be needed.

This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-17β (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L × Y) (respectively n=3) with excellent ability, and to providea baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or morewere used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushingfeed before estrus. Each pig’s blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analysesof P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-17βwere measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels weresignificantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen betweenthe L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, thetendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a littlehigher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similarto the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swineproduction, these results proved the fact of the methods. And these results suggested that more studies about hormonalchanges in sows according to seasonal and nutritional factors should be needed.