The objective of this experiment was to compare fatty acid (FA) concentrations in plasma and reproductive tissues as well as hormones and expression of genes associated with pregnancy establishment in beef cows supplemented or not with Ca salts of soybean oil (CSSO) beginning after timed AI. Ninety nonlactating multiparous Nelore (Bos indicus) cows were timed inseminated on d 0 of the experimen...

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...

the intracellular parasite neospora caninumis prevalent in several countries and is increasingly recognized as an important cause of abortion and stillbirth in cattle. for characterizeing the tachyzoite antigens of neospora caninumin aborted cows, sera were obtained from 116 cows which were aborted in the third semester of the pregnancy period and had antibodies to neospora caninumin elisa. to ...

Reproductive performance in young beef cows is often compromised due to a mismatch of physiological demands and suboptimal environmental conditions. Studies conducted at the Corona Range and Livestock Research Center from 2000 to 2007 evaluated 3 postpartum supplement strategies that varied in the amount of glucogenic potential (GP) supplied. Reproductive variables, milk production, and serum m...

Lactating Holstein cows (n = 141) were synchronized to receive their first timed artificial insemination (TAI). Blood and milk samples were collected 25 and 32 d after TAI, and pregnancy status was determined 32 d after TAI using transrectal ultrasonography. Cows diagnosed pregnant with singletons (n = 48) continued the experiment in which blood and milk samples were collected and pregnancy sta...

uterine infection is one of the reproductive diseases that can have disturbing postpartumuterine health in cattle. therefore, identification of resistant genotypes to uterine infection isimportant. lactoferrin (lf) is one of the major antimicrobial compounds in the normal uterinedischarges of cows. we hypothesized that allelic diversity in lf gene may contribute tosusceptibility or resistance t...

the aim of this study was to consider reproductive performance parameters and blood progesterone concentration changes in high-producing dairy cows (39±2 kg per day) after artificial insemination, in summer and winter. 270 heads of holstein dairy cattle were choose in three big dairy farms, and blood samples were collected at days seven, ten and fourteen after artificial insemination. temperatu...

The objective was to compare pregnancy rates and pregnancy losses in lactating dairy cows that were diagnosed not pregnant and re-inseminated following either the Ovsynch or Heatsynch protocols. Also evaluated were the effects of stages of the estrous cycle, ovarian cysts and anestrus on pregnancy rates for both treatments. Non-pregnant cows (n = 332) as determined by ultrasonography on day 27 ...