Thyroid Hormones Concentrations in Relation to Hormonal Estrous Induction, Laparoscopical Insemination and Pregnancy Out of Breeding Seasons

摘要

This study was aimed to determined serum concentrations of Thyroxine (T4) and Triiodothyronine (T3) after induction of estrous out of the breeding season during cold months. This work was carried out on 16 female local breed Iraqi does. Using 20 mg impregnated sponges with Medroxy Progesterone Acetate (MAP) for 13 days and an IM injection of 500 IU Pregnant Mare Serum Gonadotropine (PMSG) 24 h before sponges withdrawal for group A. And 400 IU PMSG for group B and 250 IU of human chorionic Gonadotropine (hcG) IM at the time of estrous appearance for group B. After 24-36 h from estrous sings onset each doe was inseminated laparoscopically with 1 mL of fresh diluted semen contain 100 millions of active fresh sperms directly to the uterine body. Blood samples were collected at the end of progesterone treatment, laparoscpical insemination and during pregnancy. The results were indicated all does showed signs of estrous 100% after 24-60 h with a mean time 46.9±4.90 h after sponges removal. Estrous length was 37.1+1.91 (24-72 h) for group A and 34.7±2-30 h (24-60) for group B. Pregnancy diagnosis was performed by ultrasonography examination at 30, 60 and 90 days post insemination. At insemination time (during laparoscopy) the number of follicles were collected from the right and left ovaries in does and found it was ranged between 3-5 follicles of different sizes on each ovary. Pregnancy was found in 6 does 75% of group A of them 2 does had twine kids 25%, while 6 does 75% of the group B became pregnant and one doe had twinning kids 12.5%. No obstetrical problem was reported except adhesion and tearing of 2 sponges at the time of withdrawal. During the next seasons all does showed normal estrous and each had single kid. The overall average for serum T4 and T3 level during experimental period were 107.61±3.36 and 2.03±0.08 nmol/L, respectively, significantly higher thyroid hormones (p<0.05) levels in progesterone, laparoscopic A.I and first month of gestation.