Gonadotrophin releasing hormone treatment of holstein cows with follicular cysts monitored by skim milk progesterone determination

Progesterone was assayed in skim milk fraction of 38 cystic cows, 26 [68.4%] of which had basal [< 0.5 ng/ml] progesterone concentration and were diagnosed as having follicular cysts. These cows were allotted at random to one of 3 treatments: First, to sham injection of sterile water in 7 cows as controls, second, a single injection [1 mg] of GnRH analog in 8 cows, third, double injections [1 mg] of GnRH analog at 7 day interval in all cows. According to rectal palpation confirmed by skim milk progesterone determination, the double injection group responded well [P <0.05] compared to the single injection and control groups [81.8% vs 62.5% vs 42.9%]. The interval from calving to first insemination, interval from treatment to conception were significantly [P <0.01] shorter in the double- injection group than in the other two groups. Moreover, the conception rate to first insemination was significantly [P <0.05] higher [63.6% vs 37.5% vs 42.9%]. The data provide an evidence for reduction in infertility and reproductive disorders in cystic cows given double injections of GnRH

relationship between plasma progesterone concentration and embryo production in dairy cows superovulated with FSH or PMSG

Fourteen primiparous lactating cows, 3.5 to 4.5 years old in a military dairy farm nearby Cairo [Egypt] were used in this study. Following synchronization, the animals were randomly assigned into two groups; the first group [6 cows] was superovulated with a total dose of 32 mg FSH-P whereas the second group [8 cows] was treated with 3000 iu PMSG. Embryos were collected non-surgically on day 7 [day of estrus = day 0]. Plasma samples were taken from cows of both groups on day-4 [first day of gonadotrophin treatment], day-2 [day of PGF[2] alpha injection], day 0 [day of estrus] days 1,3,5 post-estrus and day 7 [day of recovery] for progesterone assay. The results revealed that FSH was more effective as a superovulatory agent than PMSG. Higher [P < 0.05] ovulalion rate [11.33 +/- 1.85 vs 6.63 +/- 1.14], number of embryos recovered per donor [5.17 +/- 1.20 vs 2.44 +/- 0.45] as well as number of transferable embryos [4.16 +/- 1.01 vs 1.86 +/- 0.42] were obtained from FSH than from PMSG-treated cows. However, more follicles [> 10 mm] were palpated in the PMSG-treated group [2.00 +/- 0.40 vs 0.33 +/- 0.19; P < 0.01]. Coefficients of correlation between progesterone concentration at initiation of superovulalion and each of the ovulation rate, number of embryos recovered and number of transferable embryos were higher in FSH than in PMSG-treated cows. When the data of both groups were pooled, the respective correlations [0.74, 0.69, 0.67] were still highly [P < 0.01] significant. Moreover, significant correlations were estimated between progesterone concentration and the mentioned parameters in FSH group at the day of recovery. This study revealed that measurement of plasma progesterone concentration can serve as a prognostic tool to predict the yield of fertile eggs and quality of embryos