In this research genetic and phenotypic parameters were estimated using linear and threshold models, for reproductive traits, data from 6 large industrial dairy herd of East Azerbaijan province collected by Agriculture Jihad Organization during 10 years (2001-2010). Best linear unbiased predictions of traits breeding values were estimated using Restricted Maximum Likelihood method by WOMBAT sof...

In this research genetic and phenotypic parameters were estimated using linear and threshold models, for reproductive traits, data from 6 large industrial dairy herd of East Azerbaijan province collected by Agriculture Jihad Organization during 10 years (2001-2010). Best linear unbiased predictions of traits breeding values were estimated using Restricted Maximum Likelihood method by WOMBAT sof...

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...

two experiments were performed to determine the effectiveness of different progestogens contained in intravaginal devices, different doses of ecg and subsequent hcg treatment on the reproductive performance of estrus-induced mature lori ewes. in the first experiment, 88 ewes were allocated into two groups, and were treated with either fluorogestone acetate (fga) sponges or controlled internal d...

Long-term selection for increased ovulation rate (1984 to 2002) has resulted in a unique ovarian phenotype in the MARC Twinner cattle population. Ovulation rate and frequency of bilateral ovulations were examined by rectal palpation in 29,547 estrous cycles for 3,910 heifers (12 to 18 mo of age) in this population. Bilateral ovulations (one corpus lutuem [CL] on each ovary) were of interest bec...

a selection program is being implemented to improve meat production in makooei sheep. increasing litter size per ewe is the main objective, but possible repercussions on weight traits of lambs should be considered. the aim of this study was to estimate heritability along with genetic and phenotypic correlations between ewe's reproductive vs. weight traits in makooei ewes. data were comprised of...

Delayed conception is defined as an interval of greater than 90 days postpartum before a cow becomes pregnant again. In this study, the risk factors for delayed conception in Korean dairy herds were determined by evaluating several reproductive factors in individual cows. The following data was recorded from 1,012 pregnancies in eight dairy herds (designated A-H) from July 2001 to June 2006: he...

The phosphorus requirements for dairy heifers (0.20-0.35%) and endogenous concentrations (0.20-35%) of P in feeds fed to dairy heifers are similar, suggesting that the need for supplemental P in dairy heifer diets may be minimal. Because long-term P feeding studies on dairy heifers are unavailable, 183 Holstein heifers and 182 backcross Holstein × Jersey heifers were offered diets with (SP=0.40...

p REPARTUM and post-partum energy intake has been shown to influence reproductive performance of beef cows (Wiltbank et al., 1962, 1964). A low level of energy before calving was shown to delay onset of estrus following calving. Marked differences in conception rate were noted in cows on varying levels of energy following calving. Conception rate was decreased by low levels of energy after calv...