Physiological principals underlying synchronization of estrus identified 1) hormones naturally controlling the estrous cycle of cattle, 2) hormones commercially available, 3) mode of action of the hormones commercially available, and 4) when/how they might be used to manage estrus and breeding of beef cattle. The products available are progestogens (melengestrol acetate (MGA) and progesterone d...

The objective of this study was to evaluate the efficiency of two doses of PGF associated or not to hCG on the associated reproductive parameters in dairy goats. A total of 29 goats received two doses of 30μg d-cloprostenol latero-vulvar at a 10 day intervals (Day 1 and Day 10). The does were allocated according to body weight and body condition score into two treatments, to receive hCG (250IU)...

The objective of this study was to determine the effect of dietary P concentrations of 0.37 (recommended) or 0.57% (excess; dry matter basis) on reproductive performance. At calving, Holstein cows were randomly assigned to 1 of 2 dietary treatments (n = 134 for 0.37% P and n = 133 for 0.57% P). Cows were fitted with a radiotelemetric transmitter (50 d in milk [DIM]) to record mounting activity ...

Background and Objectives: Strategies that enhance sow estrus detection and the correct time of mating/insemination are critical to reproductive and economic advancement of individual herds and of the swine industry. The domestic pig, whose ancestors were short-day seasonal breeders, still retains some the responsiveness to photoperiod (daylength) change (Claus & Weiler, 1985; Bassett, 1996). L...

The efficacy of two doses of progesterone (P4), i.e. 350 and 300mg was evaluated in acycling crossbred ewes (50) during the autumn breeding season. Ewes were treated with intravaginal progesterone sponges with either 350mg or 300mg for 12 days. At standing estrus, ewes were hand mated (three cycles). Progesterone (350mg) gave a better (P<0.05) estrus response (75%), compared to 300mg dose (42%)...

This study aims at investigating the effectiveness of utilizing barley as a Flushing ration with an energizing source and soybean meal-based diets as a Flushing ration with a protein source the sexual and breeding behaviors in Ghezel sheep. To this end, 36 three and half-year old ewes (51±1.5 kilograms) with the record of giving birth to two lambs and 6 three-year old (89±2.5 kilograms) rams we...

The objective of the present study was to evaluate the feasibility of delivering feed and detecting estrous behavior by computer-controlled equipment in a nonconfinement environment. In Exp. 1, gilts were assigned to treatment when detected pregnant by ultrasound at 30 to 35 d after artificial insemination. They were assigned to be fed individually in stalls once/day (0830) with a scoop (contro...

To investigate the IgG content and its variations in uterine fluid (UF) during the estrous cycle of the cow and to compare them with those of the blood serum (S), six pairs of serum and UF samples for each phase of the cycle selected out of 240 bovine genital tracts and blood samples were collected from Urmia abattoir. The UF samples were collected by gentle scraping of the endometrium using a ...

Forty-five dairy cows were used to compare the enzyme activity of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), α -amylase in the cervical mucus of cows during spontaneous and induced estrus using progestagen or PGF2 α and to determine whether these enzymes affect the fertility in cows with induced estrus, at the time of Al. The animals were assigned to 3 groups (no treatment, a Cres...

We have determined uterine glycogen content, metabolizing enzyme expression and activity in the mink, a species that exhibits obligatory embryonic diapause, resulting in delayed implantation. Gross uterine glycogen concentrations were highest in estrus, decreased 50% by diapause and 90% in pregnancy (P ≤ 0.05). Endometrial glycogen deposits, which localized primarily to glandular and luminal ep...