Objectives were to compare the effect of presynchronization and resynchronization methods on fertility responses of grazing dairy cows at first and second artificial insemination (AI) and pregnancy rate during the entire breeding season. Lactating dairy cows (n = 1,263) in 2 seasonal grazing farms were blocked, within farm, by parity, breed and days in milk. Within each block, cows were randoml...

A 5-yr study involving 45 to 78 pregnant Hereford range cows each year evaluated relationships among prepartum nutrition, body condition scores, BW changes and reproductive performance. Four prepartum nutritional treatments were imposed. One group of cows were fed to maintain (M) their November BW until calving in March and April. The other three groups of cows were fed to lose about 5% of thei...

The present cattle population of Bangladesh is 24.17 million (DLS, 2009). More than 80 percent of this cattle population is indigenous and rests of them are purebreds and crossbreds of different exotic breeds (Friesian, Jersey and Shahiwal) cattle, which is contributing a major share of livestock sub-sector and playing multi-functional roles (supply of milk, meat, skin, manure, carting etc.) in...

The objectives were to characterize repeat breeding in dairy cows, including reproductive performance and risk factors. Data from 613 Holstein Friesian cows in nine dairy herds across Japan were enrolled. A repeat breeder was defined as a cow that did not become pregnant after three inseminations, despite no clinically detectable reproductive disorders. In contrast, cows that became pregnant wi...

Anogenital distance (AGD), defined as the from center of anus to base clitoris, in lactating dairy cows first and second parity, has been reported be inversely related fertility moderately heritable. Thus, AGD may a useful reproductive phenotype for future genetic selection improve fertility. The objectives this study were (1) characterize nulliparous heifers; (2) determine if inverse relations...

Five hundred forty-six postpartum, multiparous and primiparous beef cows at the University of Illinois Dixon Springs Agricultural Research Center (Simpson, Illinois) were used in this experiment. All cows were administered Syncro-Mate B (SMB) for estrus synchronization and were bred from a timed AI about 48 hours after SMB implant removal. Blood samples were collected from all cows on days 0 (A...

A comparative assessment of the reproductive qualities beef-cows Hereford and Kazakh white-headed breeds is given, depending on Body Condition Scoring. In scientific economic experiment in three farms 3 groups cows two breeds, influence Scoring was studied. It found that with a 6 points have significantly shorter service period (by 10-13 days) interval between calving 6-9 days), an increase dur...

Objectives of these studies were to determine the effects of flunixin meglumine (FM) administration on early embryonic mortality and circulating PG and cortisol concentrations in transported and non-transported cows. Cows (n = 483) from 3 locations were used to evaluate the effects of transportation and FM approximately 14 d after AI on the establishment of pregnancy and serum concentrations of...

In postpartum beef cows, GnRH-induced ovulation of small dominant follicles decreased pregnancy rates and increased late embryonic/fetal mortality. In Exp. 1, single ovulation reciprocal embryo transfer (ET) was used to examine the relationship between preovulatory serum concentrations of estradiol at GnRH-induced ovulation in donor and recipient cows and establishment and maintenance of pregna...