Cows that exhibit estrus within 24 h of fixed-time AI have elevated concentrations of estradiol and greater pregnancy rates compared with cows not in estrus. Our objective was to determine whether estradiol, estrus, or both had an effect on uterine pH during a fixed-time AI protocol. Beef cows were treated with the CO-Synch protocol (100 mircog of GnRH on d -9; 25 mg of PGF(2alpha) on d -2; and...

Relative effects of Beef Quality Assurance (BQA)-related defects in market beef and dairy cows and bulls on selling price at auction was evaluated during 2008. The presence and severity of 23 BQA-related traits were determined during sales in Idaho, California, and Utah. Overall, 18,949 unique lots consisting of 23,479 animals were assessed during 125 dairy sales and 79 beef sales. Mean sale pr...

The objective of this study was to determine if factors associated with the biostimulatory effect of bulls alter breeding performance of primiparous, suckled beef cows using a progestin-based estrous synchronization protocol. We tested the hypotheses that the estrous synchronization response and AI pregnancy rates differ among cows exposed to bulls, continuously exposed to bull urine, and expos...

BACKGROUND The objective was to evaluate if cortisol concentrations are associated with the resumption of luteal activity in postpartum, primiparous cows exposed to bulls. The hypotheses were that 1) interval from start of exposure to resumption of luteal activity; 2) proportions of cows that resumed luteal function during the exposure period; and 3) cortisol concentrations do not differ among ...

The objective of this trial was to investigate the effects of feeding a soybean oil refining by-product (SORB), made up mainly of sodium salts of long-chain fatty acids, on reproductive performance and productivity of 36 early lactation Holstein cows managed in a free-stall barn or on annual rye-ryegrass pasture. In this 2 x 2 factorial arrangement of treatments, cows consumed 0 or 0.5 kg/d of ...

The objectives of this study were to evaluate the functional properties of immunocompetent cells in dairy cows fed diets enriched in n-3 or n-6 polyunsaturated fatty acids during the transition period. Six weeks before calving, 21 primiparous and 27 multiparous pregnant Holstein dairy cows were randomly allotted to 1 of 3 dietary fat treatments: calcium salts of palm oil (Megalac), micronized s...

Lameness is one of the most important welfare problems in dairy cattle. Most studies on lameness have focused on wide ranging surveys to identify causal factors, but few have considered the welfare implications of this disorder. In this study, we compared the social and individual behavior of 10 lame cows and 10 nonlame cows. The 20 Holstein-Friesian cows calved in the summer and spent the autu...

OBJECTIVE To compare calf weaning weight and associated economic variables for beef cows with serum antibodies against Mycobacterium avium subsp paratuberculosis (MAP) or from which MAP was isolated from feces with those for cows that were seronegative for antibodies against or culture negative for MAP. DESIGN Retrospective study. ANIMALS 4,842 beef cows from 3 herds enrolled in the USDA Na...

The objective of this study was to evaluate effects of a daily oral drench of Propylene Glycol (PG) on fertility in dairy cows experiencing seasonal heat stress. In treatment group, cows (n=9) were treated with drenching 250 ml propylene glycol once daily from 3 to 15 days post-partum following the morning milking. Another group of cows (n=9) was selected as untreated control. The serum beta-hy...

The aim of this study was to determine if, and under what conditions, indoor-housed dairy cows would seek a shelter to calve. Seventy-two Holstein dairy cows were paired by expected calving date and moved into a maternity pen that contained an open area with no cover and a sheltered area that was covered on all sides except for the ceiling and an entrance where cows could freely enter or exit. ...