comparative study of estrus induction with long-term and short term progesterone in ewes during non-breeding and breeding seasons

The objective of this trial was to compare the efficacy of long-term and short-term progesterone treatments on induction of estrus and pregnancy rate in Rahmani ewes during non-breeding and breeding seasons. Twenty-four animals were randomly grouped for two treatments with intravaginal progesterone device: Group A] during breeding season and Group B] during non-breeding season. Furthermore, both groups were subdivided into two treatments: Al and BI for short-treatment [7 days] and A2 and B2 for long-treatment [12 days]. The progesterone treatment was a vaginal sponge containing 40 mg medroxy progesterone acetate [MAP]. Equine chorionic gonadotrophin [eCG] and cloprostenol [PGF2 alpha] were intramuscularly administered to all ewes at the time of sponge removal. After the detection of estrus, the animals were hand-mated naturally. During the breeding season, mean percentages of estrus and pregnancy were 100% and 83.33%, respectively in both the short-term and long-term treated groups. During the non-breeding season, the average values of estrus were 100% in short-term and 100% for long-term progesterone treatment, but the pregnancy rates were 66.67 and 50.00% in the short- and long-term treated groups, respectively. The treatment with progesterone for short-term [7 days] was effective to induce estrus in sheep during both breeding and non-breeding seasons

relationship between oxidants / antioxidants imbalance and postpartum fertility in cattle [with 2 tables and 2 figures]

The objective of this study was to determine the relationship of postpartum oxidative stress and the ovarian anestrus in the dairy cows. Sixteen cows showed normal ovarian cyclicity [normal estrous cycle] detected after 56-63 days postpartum and kept as G1. Thirteen cows showed ovarian cycle after 70-84 days postpartum, G2 and other ten animals showed marked delayed in the ovarian cyclicity more than 90 days, G3. Venous blood samples were taken weekly from all animals in the last two weeks of pregnancy and in postpartum period as well as, sera of blood samples were kept for measuring all parameters. Another blood samples from ten non-pregnant cows in diestrus were taken. The oxidative stress [lipid peroxides and nitric oxide], antioxidants [superoxide dismutase, vitamin E and selenium], as well as estradiol-17beta and progesterone were measured in all animals. In prepartum, lipid peroxides as well as nitric oxide were increased in the last week of pregnancy. In postpartum the preoxidative indices were elevated in the animals of G3 while antioxidants were decreased significantly in G3 and to some extend in G2. Estradiol-17 beta hormone levels were increased significantly in animals of G3 and it was negatively significant correlated with LPO and NO. While progesterone levels were positively significant correlated with antioxidants in the animals of G3. The oxidative stress in these animals may be led to follicular damage and failure of maturation and ovulation. It was concluded from this study that excess free radical production may be play a role in the prolongation of the postpartum anestrus in dairy cows. These may be due to exhaustion of antioxidant system in milk production. Therefore, it was advise to supplement the dam with antioxidants during the late stage of pregnancy and in the postpartum period to stimulate the normal ovarian activity

Pregnancy rate in Egyptian buffaloes after synchronization of estrus with PGF2alpha or ovulation by ovsynch program [with 2 tables and 2 figures]

Postpartum in buffaloes plays a great role in delay of the cyclicity in buffaloes that seemed to be anestrous. So, the use of hormones to induct estrus or induct ovulation has an importance to increase pregnancy rate. The present study was designed to evaluate the efficacy of the two methods in inducing high pregnancy rate. The experimental animals [48 lactating buffaloes] were divided into three groups: PGF2alpha group 1[n=16]; Ovsynch group 2 [n=16] and control group [n=16]. Pregnancy rate was significantly [p<0.001]increased in group 2 than group 1 and control group due to higher level of progesterone and more accurate synchronization for ovulation., It is more suitable to use the regimen of ovsynch in postpartum buffaloes especially in multiparous females with good condition score