The reliability of a Korean black goat (Capra hircus coreanae) to detect estrus in Himalayan tahrs (Hemitragus jemlahicus) for an artificial breeding program was investigated. Estrus in six female Himalayan tahrs was synchronized using fluorogestone acetate (FGA) sponges. Thirteen days later, 200 IU of PMSG and 100 IU of hCG were injected before removing the sponges and simultaneously injecting 5 mg of PGF2alpha the next day. Penetration of the cervical canal and the thickness and location of red crayon marks were examined 40~43 h later. Two females treated with sponges containing 60 or 45 mg of FGA had estrogen levels of 8.7 and 11.1 pg/mL, respectively. No red marks were found on the backs of these two tahrs. The remaining females had higher levels of estradiol, and the red crayon marks were clearly shown. The cervical folds of these tahrs were readily penetrated and the insemination gun was smoothly inserted into the uterine body. In conclusion, a Korean domestic goat with its chest crayon-harnessed was successfully used to detect estrus of Himalayan tahrs. This technique might be utilized as a part of breeding programs for wild goats and avoid the need for a vasectomy of conspecific males.
Animals ; Breeding/methods ; Estradiol/blood ; Estrus/physiology ; Estrus Detection/*methods ; Estrus Synchronization/methods ; Female ; Goats/*physiology ; Male ; Progesterone/blood

This study was conducted to evaluate the influence of category (heifers, primiparous or multiparous cows) on pregnancy rates in a large scale resynchronization ovulation program. Nelore heifers (n = 903), primiparous lactating cows (n = 338) and multiparous lactating cows (n = 1,223) were synchronized using a conventional protocol of estradiol/P4-based fixed-time artificial insemination (FTAI). Thirty days after ultrasonography, females who failed the first FTAI were resynchronized with the same hormonal protocol prior to a second FTAI. The pregnancy status of each cohort was evaluated by ultrasonography 30 days after each FTAI. The average conception rate after the first FTAI and resynchronization was 80.5%. Heifers had a higher conception rate (85%) than primiparous (76%) or multiparous cows (78%; p = 0.0001). The conception rate after the first FTAI was similar among heifers (57%), primiparous cows (51%) and multiparous cows (56%; p = 0.193). After the second FTAI, heifers exhibited a higher conception rate (66%) than primiparous or multiparous cows (51%; p = 0.0001). These results demonstrate the feasibility of resynchronization in large beef herds for providing consistent pregnancy rates in a short period of time. We also demonstrated that ovulation resynchronization 30 days after FTAI is particularly effective for heifers, providing a conception rate of up to 66%.
Animals ; Brazil ; Cattle ; Estradiol/*pharmacology ; Estrus Synchronization ; Female ; Fertilization/*drug effects ; Insemination, Artificial/*veterinary ; Lactation ; *Parity ; Pregnancy ; Pregnancy Rate ; Progesterone/*pharmacology

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 +/- 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.
Animals ; Drug Implants/therapeutic use ; Estrus Synchronization/drug effects/*methods ; Female ; Fertilization/drug effects ; Insemination, Artificial/methods/*veterinary ; Pregnenediones/administration & dosage/*pharmacology ; Sheep

To compare an injectable progesterone (MAD-4) with an intravaginal device (IPD), and natural O17 with synthetic oestradiol (OB) in a synchronisation protocol, 51 cows were divided into four groups. Each group was treated with one of the two sources of progesterone and one of the two oestradiol formulations. Oestrus behaviour, follicle diameter, and pregnancy rates were evaluated. Oestrus behaviour (p = 0.902), numbers of cows in oestrus (p = 0.917), follicle diameter (p = 0.416), and pregnancy rates (p = 0.873) were similar among the four groups. More cows in the group treated with the IPD and OB scored > 200 oestrus behaviour points compared to the other groups (p = 0.038). A longer interval between the end of treatment and oestrus was observed among cows treated with MAD-4 than cows given the IPD (p = 0.030), but no differences were found between animals receiving the two oestradiol formulations (OB and O17). While the use of MAD-4 requires further testing, similar responses to natural oestradiol observed in the present study could allow the use of this formulation in reproductive protocols because it is not associated with the potential human health risks of OB.
Administration, Intravaginal ; Animals ; Cattle ; Estradiol/administration & dosage/*analogs & derivatives/*pharmacology ; Estrus/drug effects ; Estrus Synchronization/*methods ; Female ; Injections, Subcutaneous/veterinary ; Ovarian Follicle/drug effects ; Postpartum Period/drug effects ; Pregnancy ; Pregnancy Rate ; Progesterone/administration & dosage/*pharmacology ; Reproduction/drug effects

The objective of this study was to investigate factors that influence the success of resynchronization protocols for bovines with and without progesterone supplementation. Cow synchronized and not found pregnant were randomly assigned to two resynchronization protocols: ovsynch without progesterone (P4) supplementation (n = 66) or with exogenous P4 administered from Days 0 to 7 (n = 67). Progesterone levels were measured on Days 0 and 7 of these protocols as well as 4 and 5 days post-insemination. Progesterone supplementation raised the P4 levels on Day 7 (p < 0.05), but had no overall effect on resynchronization rates (RRs) or pregnancy per artificial insemination (P/AI). However, cows with Body Condition Score (BCS) > 3.5 had increased P/AI values while cows with BCS < 2.75 had decreased P/AI rates after P4 supplementation. Primiparous cows had higher P4 values on Day 7 than pluriparous animals (p = 0.04) and tended to have higher RRs (p = 0.06). Results of this study indicate that progesterone supplementation in resynchronization protocols has minimal effects on outcomes. Parity had an effect on the levels of circulating progesterone at initiation of the protocol, which in turn influenced the RR.
Animals ; Cattle/*physiology ; Dinoprost/administration & dosage/*pharmacology ; Estrus Synchronization/*drug effects/methods ; Female ; Fertility Agents/administration & dosage/pharmacology ; Gonadotropin-Releasing Hormone/administration & dosage/*pharmacology ; Insemination, Artificial/veterinary ; Ovulation/drug effects ; Pregnancy ; Progesterone/administration & dosage/*pharmacology ; Tromethamine/administration & dosage/*pharmacology

The present experiment aims to examine the efficiency of estrus synchronization using progesterone and equine chorionic gonadotrophin (eCG) and to look at luteal function. During the non-breeding and breeding season, 5 adult female Korean native goats were injected intramuscularly with 2.5 ml of physiological saline as the control. A progesterone impregnated intravaginal sponge was then kept in the same goats for 10 days followed, after a week, by an intramuscular injection of 500 IU eCG. Five adult female Nubian goats were mated with a fertile buck during the non-breeding season. During the non-breeding season 2 of the 5 goats showed a normal estrous cycle (ranging from 18 to 21 days) and 3 a short estrous cycle (ranging from 3 to 6 days). During the breeding season the equivalent figures were 1 and 2. The major axes of the corpus luteum (CL) were measured by means of calipers built into the ultrasonography system, and the concentrations of plasma progesterone (P(4)) were determined by double antibody radioimmunoassay. The mean major axes of the CL in goats showing the short cycle (6.1 +/- 0.5 mm) was significantly smaller than in those showing the normal cycle (8.9 +/- 0.5 mm; p < 0.01) and also the value of P4 in goats showing the short cycle (4.2 +/- 2.1 ng/ml) was significantly lower than for those showing the normal cycle (10.3 +/- 4.3 ng/ml; p < 0.05) at day 3 following ovulation. Three out of 5 Nubian goats became pregnant but only one goat carried to full term. The present experiment indicated that a combination of progesterone and eCG was effective in inducing estrus, although it resulted in a high incidence of short luteal lifespan. The low kidding rate and high incidence of embryonic loss may be due to the instability of the luteal lifespan.
Animals ; Chorionic Gonadotropin/*pharmacology ; Corpus Luteum/*drug effects/*physiology ; Estrus Synchronization/*drug effects/physiology ; Female ; Fertility/*drug effects ; Fertility Agents, Female/pharmacology ; Goats/*physiology ; Horses ; Pregnancy ; Progesterone/blood/*pharmacology