The aim of this study was to determine the factors affecting stillbirth and the consequences of stillbirth on longevity, production, and reproductive performance in Holstein cows of Iran. Calving records from March 2000 to April 2009 comprising of 220,043 calvings on 102,199 cows in 33 herds were used. The results showed that 4.06% of the newborn calves died within 48 h of birth. The stillbirth...

Twinning costs the dairy industry an estimated $96 million each year. Twin pregnancy occurrence in high-producing cows is primarily a result of multiple ovulations associated with low circulating concentrations progesterone due to high milk production. The present retrospective observational study aimed identify associations between (1) previous parity yield and subsequent twin birth prevalence...

SUHMARY Genetic and evironmental variability in gestation length (GL), birth date (BD), and time from first day of breeding season to first observed estrus (FE) were analyzed ·using twelve years of breeding and calving records on cows, sired by Simmental, Maine-Anjou, Limous,in and Gelbvieh bulls. All cows were artificially inseminated. Statistical analyses were performed separately on first, s...

The objectives of this study were to estimate genetic parameters for stayability in US organic Holstein dairy cows and correlations with nationally evaluated traits interest. Stayability is the binary trait success or failure remain herd until a given time point. We used birth, calving, cull dates from 16 USDA certified farms recommended by industry personnel as herds maintaining individual cow...

The improvement in porcine embryo preservation and non-surgical embryo transfer (ET) procedures achieved in recent years represents essential progress for the practical use of ET in the pig industry. This study aimed to evaluate the effects of parity, weaning-to-estrus interval (WEI) and season on reproductive and embryonic parameters at day 6 after insemination of donor sows superovulated afte...

A 5-yr study was conducted beginning in 1983 with 460 cows to evaluate the effects of three breeding seasons (30, 45, and 70 d in length) and two times of spring calving, March (early) and April (late), on cattle production under Nebraska Sandhills range conditions. Criteria evaluated included pregnancy and weaning percentages, calving date and distribution, cow weights and body condition at fo...

A 3-yr study was conducted with heifers (n = 170) whose dams were used in a 2 x 2 factorial arrangement of treatments to determine the effects of late gestation (LG) or early lactation (EL) dam nutrition on subsequent heifer growth and reproduction. In LG, cows received 0.45 kg/d of a 42% CP supplement (PS) or no supplement (NS) while grazing dormant Sandhills range. During EL, cows from each l...

A better understanding of changes in plasma amino acid (AA) concentrations during the transition period may help optimize nutrition to improve health, welfare, and production dairy cows. The aim this study was assess AA Holstein cows first-lactation heifers. Blood samples for analysis were collected from tail vein/artery 9 multi- 8 primiparous 3 weeks prior at 1, 2, post-calving. Concentration ...