Sheep with ovarian androgen excess have fibrosis and follicular arrest with increased mRNA abundance for steroidogenic enzymes and gonadotropin receptors.

An androgen excess ovarian micro-environment may limit follicle progression in sheep. Two populations of ewes with divergent follicular fluid androstenedione (A4) were identified in a flock in Jordan: High A4; (A4) ≥ 30 ng/mL, (N = 12) or Control A4 (Control); A4 ≤ 15 ng/mL; (N = 12). We hypothesized High A4 ewes would have increased steroidogenic enzyme mRNA abundance, inflammation, and follicular arrest.

Effects of dietary betaine on body temperature indices, performance, metabolism, and hematological variables of dairy heifer calves during hot summer conditions.

Background And Aim: Heat stress (HS) can negatively impact farm animal productivity and adversely affect animal welfare worldwide, placing a major financial burden on global livestock producers. Dietary betaine (trimethylglycine) has been known to have several biological functions, which may aid in offering beneficial effects on livestock productivity during HS conditions. However, information on the role of dietary betaine in heat-stressed dairy heifer calves is yet to be documented.

Effect of two prostaglandin injections on days 5 and 6 in a timed AI protocol after estrus expression on pregnancy outcomes in dairy cows during cold or hot seasons of the year.

The objective of this study was to test whether prostaglandin (PG) injection on day 30 postpartum (pp) and detection of estrus can affect the efficacy of injecting PG on days 5 and 6 in the timed artificial insemination (TAI) protocol on pregnancy rate in a large dairy herd in hot or cold seasons. Out of 2235 cows, 1998 received an injection of PG at  d pp and estrus was observed. Cows that displayed estrus during the estrous observation period after PG injection were classified as estrus (E), while those that did not show estrus were classified as nonestrus (NE).

Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows.

A study was conducted to evaluate the effect of human chorionic gonadotropin (hCG) administration 4 or 6 days after timed AI (TAI) on P4 concentration and pregnancy outcomes in repeat breeding dairy cows. All cows were treated by Cosynch protocol before being assigned into 3 groups: CON (n=139): did not receive hormonal treatments; D4 (n=136): received 1500 IU hCG 4 days post TAI; and D6 (n=131): received 1500 IU hCG 6 days post TAI. Plasma P4 concentration was evaluated on Day of hCG and 12 days post TAI.

Effect of progesterone (P(4)) intravaginal device (CIDR) to reduce embryonic loss and to synchronize return to oestrus of previously timed inseminated lactating dairy cows.

A study on postpartum dairy cows was done to evaluate the effect of using progesterone intravaginal device (CIDR) to synchronize return to oestrus of previously timed inseminated (TAI) cows and to evaluate embryo survival and pregnancy rate in the return to oestrus cows. All cows were subjected to TAI program. On Day 14 after AI, cows were assigned randomly into two groups: treated group (CTAI; n=126) and control group (TAI; n=172).

Comparison of an oestrus synchronisation protocol with oestradiol benzoate and PGF2alpha and insemination at detected oestrus to a timed insemination protocol (Ovsynch) on reproductive performance of lactating dairy cows.

A total of 226 out of 245 postpartum lactating dairy cows in a commercial dairy farm were allocated to two groups of oestrous synchronisation protocols in order to evaluate reproductive performance. One group was treated with oestradiol benzoate (ODB) and PGF2alpha on day 10 of the oestrous cycle with insemination at the detected oestrus, the second group underwent the Ovsynch (OVS) protocol (GnRH + PGF2alpha + GnRH) with timed AI. Pregnancy was diagnosed by ultrasonography on day 28 after AI and confirmed by rectal palpation on day 45.