This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering PGF2α for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone (P4...
This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering PGF2α for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone (P4) concentration against PGF2α compared with conception rate were observed in cows and heifers. The results attained from the studies were as follows.
Significant decreases of CL in size over time after PGF2α administration were detected in both groups (p0.05). In addition, the percentage changes relative to the plasma P4 concentration on day 1 after PGF2α treatment were decreased to below 1ng/ml.
The growth rate of follicle was observed as 31% on day 1 and 42% on day 2 in cows, and 34% on day 1 and 97% on day 2 in heifers resulting that growth of heifers are faster than that of cows (p<0.05).
The conception rate after PGF2α treatment was 60.5% in cows and 64.2% in heifers. It also indicated that the conception rate after estrus observation with PGF2α injection was as high as 66.6% while that with timed-artificial insemination (TAI) regardless of the estrus observation was 56%, which means the pregnancy rate of artificial insemination after estrus observation was higher than that of TAI (p0.05).
The estrus manifestation hours according to the follicle size in cows didn't have any significance each other (p>0.05), though estrus hours was 54 hours (the shortest) with follicle size bigger than 10mm and were made up within 69 hours.
The estrus manifestation hours according to the follicle size in heifers didn't have any significance each other (p>0.05) and took around 46 hours (the shortest) with follicle size of 5mm (the smallest) and were made up within 66 hours.
Follicles after PGF2α injection were ovulated and assigned to many phases as follows; Group 1 (growing phase) - continuously growing into ovulation, Group 2 (growing and static phase) - delaying in growth after the growth of follicles, Group 3 (static and growing phase) - growing after growth delay, Group 4 (regressing and new growing phase) - the follicle is closed and a new follicle grows. In addition, the process of follicle development and estrus hours had no significance each other (p>0.05), though estrus manifestation hours in Group 1 and 2 was relatively short, and in Group 3 and 4 for a relatively long time.
Pregnancy Diagnosis with measuring the CL regression rate was carried out on day 14 and day 20 after artificial insemination by ovarian ultrasonography. Comparing with the result of plasma P4 concentration on day 21 after insemination and the rectal ultrasonography on day 35 after insemination respectively, the result of the diagnostic accuracy and the diagnostic agreement rate were observed as follows.
The diagnosis accuracy rate between ovarian pregnancy diagnosis method and hormonal pregnancy diagnosis method was indicated as 100% of sensitivity, 95% of specificity, and 97.9% of positive predictive value and 100% of negative predictive value respectively. As well, Kappa value presented diagnostic concordance rate between ovarian pregnancy diagnosis method and hormonal pregnancy diagnosis method was 0.96.
The diagnosis accuracy rate between ovarian pregnancy diagnosis method and rectal pregnancy diagnosis method by ultrasonography was indicated as 100% of sensitivity, 70.3% of specificity, and 83.3% of positive predictive value and 100% of negative predictive value respectively. In addition, Kappa value presented diagnostic agreement rate between ovarian pregnancy diagnosis method and rectal pregnancy diagnosis method was 0.72.
In the result of all above, the success of estrus induction didn't depend on the size of CL, plasma P4 concentration, and the largest follicle between cows and heifer. And high pregnancy rate was obtained when administrating PGF2α in follicles more than 5mm. The accuracy rate and agreement rate of the ovarian pregnancy diagnosis method by ultrasonography was so high that it could be available as a new pregnancy diagnosis method and as a way to improve the breed efficiency through diminishing the open days and calving interval.
This study was carried out to develop the useful inducing method of estrus for Korean native cows. Under the condition of estrus induction by administering PGF2α for the cows in which corpus luteum (CL) in ovaries was detected by ultrasonography, ovarian responses and the changes of progesterone (P4) concentration against PGF2α compared with conception rate were observed in cows and heifers. The results attained from the studies were as follows.
Significant decreases of CL in size over time after PGF2α administration were detected in both groups (p0.05). In addition, the percentage changes relative to the plasma P4 concentration on day 1 after PGF2α treatment were decreased to below 1ng/ml.
The growth rate of follicle was observed as 31% on day 1 and 42% on day 2 in cows, and 34% on day 1 and 97% on day 2 in heifers resulting that growth of heifers are faster than that of cows (p<0.05).
The conception rate after PGF2α treatment was 60.5% in cows and 64.2% in heifers. It also indicated that the conception rate after estrus observation with PGF2α injection was as high as 66.6% while that with timed-artificial insemination (TAI) regardless of the estrus observation was 56%, which means the pregnancy rate of artificial insemination after estrus observation was higher than that of TAI (p0.05).
The estrus manifestation hours according to the follicle size in cows didn't have any significance each other (p>0.05), though estrus hours was 54 hours (the shortest) with follicle size bigger than 10mm and were made up within 69 hours.
The estrus manifestation hours according to the follicle size in heifers didn't have any significance each other (p>0.05) and took around 46 hours (the shortest) with follicle size of 5mm (the smallest) and were made up within 66 hours.
Follicles after PGF2α injection were ovulated and assigned to many phases as follows; Group 1 (growing phase) - continuously growing into ovulation, Group 2 (growing and static phase) - delaying in growth after the growth of follicles, Group 3 (static and growing phase) - growing after growth delay, Group 4 (regressing and new growing phase) - the follicle is closed and a new follicle grows. In addition, the process of follicle development and estrus hours had no significance each other (p>0.05), though estrus manifestation hours in Group 1 and 2 was relatively short, and in Group 3 and 4 for a relatively long time.
Pregnancy Diagnosis with measuring the CL regression rate was carried out on day 14 and day 20 after artificial insemination by ovarian ultrasonography. Comparing with the result of plasma P4 concentration on day 21 after insemination and the rectal ultrasonography on day 35 after insemination respectively, the result of the diagnostic accuracy and the diagnostic agreement rate were observed as follows.
The diagnosis accuracy rate between ovarian pregnancy diagnosis method and hormonal pregnancy diagnosis method was indicated as 100% of sensitivity, 95% of specificity, and 97.9% of positive predictive value and 100% of negative predictive value respectively. As well, Kappa value presented diagnostic concordance rate between ovarian pregnancy diagnosis method and hormonal pregnancy diagnosis method was 0.96.
The diagnosis accuracy rate between ovarian pregnancy diagnosis method and rectal pregnancy diagnosis method by ultrasonography was indicated as 100% of sensitivity, 70.3% of specificity, and 83.3% of positive predictive value and 100% of negative predictive value respectively. In addition, Kappa value presented diagnostic agreement rate between ovarian pregnancy diagnosis method and rectal pregnancy diagnosis method was 0.72.
In the result of all above, the success of estrus induction didn't depend on the size of CL, plasma P4 concentration, and the largest follicle between cows and heifer. And high pregnancy rate was obtained when administrating PGF2α in follicles more than 5mm. The accuracy rate and agreement rate of the ovarian pregnancy diagnosis method by ultrasonography was so high that it could be available as a new pregnancy diagnosis method and as a way to improve the breed efficiency through diminishing the open days and calving interval.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.