Efficacy of decreasing the dose of GnRH used for synchronization of ovulation and timed artificial insemination in anestrus lactating dairy cows [electronic resource].

Includes references.

To estimate the efficacy of reducing the dosage of GnRH used for synchronization of ovulation with timed-AI, 20 anestrus lactating Holstein cows were randomly assigned to 1 of 2 treatment groups. Additional 10 cows were used as control, without hormonal treatment (G1 ). Ovulation was synchronized for cows in the second group using intramuscular injection ofGnRH and PGF2a as follows: Day 0, 100 ug GnRH; day 7,500 ug PGF2a; day9, 100 ug GnRH. Ovulation was synchronized in the third group of cows using the same manner but only 50 ug GnRH was injected. Pregnancy was diagnosed at 28 and at 65 days post AI by assessment of progesterone concentration in serum and by rectal palpation, respectively.

Summary in Arabic.

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