In a 4-yr study, molasses (M; 6% CP), molasses-urea (MU; 17.5% CP; 92% molasses, 4% urea and 4% water) and molasses-cottonseed meal-urea (MCSM; 17.5% CP; 73% molasses, 25% cottonseed meal, 1% urea and 1% water) were compared as winter supplements for Braford cows (514 matings) consuming low-quality forage. Cows were fed 1.35, 1.50 and 1.27 kg.head-1.d-1 of the respective supplements for 127 d b...

Multiparous beef cows were managed to achieve marginal (BCS = 4.7 ± 0.07; n = 106) or good (BCS = 6.6 ± 0.06; n = 121) body condition (BC) to determine the influence of forage environment on BW and BC changes, intramuscular fat percentage (IMF), rump fat (RF), and serum hormones during 2 yr. Cows within each BC were randomly assigned to graze either common bermudagrass (CB; n = 3 pastures/yr) o...

Postpartum endometritis compromises milk production and fertility in high-producing dairy cows. Infection of the endometrium induces an inflammatory response with secretion of cytokines that lead to polymorphonuclear cells (PMN) influx and bacterial clearance. Considering that only a portion of cows with endometritis is eligible for clinical diagnosis, there is an increasing effort for developi...

BACKGROUND In dairy mixed production systems, maximizing pasture intake and total mixed ration (TMR) supplementation are management tools used to increase dry matter and energy intake in early lactation. The objective was to evaluate metabolic and endocrine profiles and hepatic gene expression of Holstein cows fed either TMR ad libitum (without grazing) or diets combining TMR (50 % ad libitum D...

Nonpregnant Hereford cows (n = 70) were used to determine the effect of nutrient intake and body condition on reproductive and thyroid function. Body condition scores (BCS; 1 = emaciated; 9 = obese) of cows averaged 5.0 +/- .2 on July 1, and cows were fed for 4 mo either to lose weight and BCS (thin; n = 22), to maintain weight and BCS (moderate; n = 24), or to gain weight and BCS (fat; n = 24)...

The objective of this study was to determine the effects of two different time of GnRH injection after artificial insemination (A.I) (d 6 and d 12) on reproductive performances of Holstein cows during the warm season. Cows randomly assigned to treatments 1) No GnRH injection (control, n = 300),2) GnRH injection at day 6 after A.I (G6, n=300) and 3) GnRH injection at day 12 after A.I (G12, n=300...

This study was designed to test the treatment with prostaglandin F2α (PGF2α) plus equine chorionic gonadotrophin (eCG) and GnRH 48 h later (PEG protocol) followed by fixed-time AI (FTAI) in dairy cows with silent ovulation (cows with a mature corpus luteum and no signs of estrus detected in the preceding 21 days). In Experiment I, ovulation following the PEG protocol monitored in 24 cows with s...

In the current study, blood samples from 319 cows and heifers were studied. Antibodies against BVDV infections in serum samples and BVDV antigens in leukocytes were present in 203 (148 cows and 55 heifers) and 56 (28 cows and 28 heifers) samples, respectively. Although no significant difference was detected between seropositive ŠBVDV (Ag-/Ab+)1 and uninfected ŠBVDV (Ag-/Ab-)1 cows and heifers a...

Periparturient cows have been found to reveal immunosuppression, frequently associated with increased susceptibility to uterine and mammary infections. To improve understanding of the causes and molecular regulatory mechanisms accounting for this phenomenon around calving, we examined the effect of an antigen challenge on gene expression modulation on cows prior to (BC) or after calving (AC) us...

To compare 2 strategies for systematically resynchronizing ovulation, lactating Holstein cows (n = 763) at various days in milk and prior artificial insemination services were assigned randomly at timed AI (TAI) to receive the first GnRH injection of Ovsynch 26 (D26) or 33 (D33) d after TAI to resynchronize ovulation (Resynch) in cows failing to conceive. Cows in the D26 treatment received GnRH...