Fourteen anovulatory postpartum (38.0 +/- 1.9 d) beef cows that ovulated after an injection of 250 micrograms gonadotropin releasing hormone (GnRH) in saline were used to examine the influence of indomethacin on luteal function. Beginning the d after GnRH, 6 cows were given intrauterine infusions of indomethacin for 14 d and the other eight cows received vehicle. After GnRH treatment, concentra...

LH release in response to pulsatile administration of small amounts of GnRH analogue in cows with follicular cysts was examined. The pulsatile administration of GnRH analogue induced a LH-surge like peak over 10 hr in both normal cows and cows with follicular cysts. The mean peak value of LH in follicular cystic cows did not differ significantly from that of normal cows. All the cows with cysts...

Cows induced to ovulate small dominant follicles were reported to have reduced pregnancy rates compared with cows that ovulated large follicles. The reason for the presence of small dominant follicles at the time of GnRH-induced ovulation in timed AI protocols is unknown. The objectives of this experiment were to examine the role of day of the estrous cycle at initiation of treatment on ovulati...

Objectives of these studies were to determine the effects of flunixin meglumine (FM) administration on early embryonic mortality and circulating PG and cortisol concentrations in transported and non-transported cows. Cows (n = 483) from 3 locations were used to evaluate the effects of transportation and FM approximately 14 d after AI on the establishment of pregnancy and serum concentrations of...

an experiment was conducted to investigate the effect of different types of ovarian cycles on reproductive indices and blood metabolites in 61 holstein cows. blood samples were taken from each cow between day 12 and day 50 postpartum (pp). serum progesterone concentrations were measured to determine the onset of luteal function and different types of luteal dysfunctions in cows. serum glucose, ...

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=30...

This study explored the effects of a single administration of flunixin meglumine (acting as a non-steroidal antiinflammatory drug) and oxytetracycline combination on the reproductive performance of cows diagnosed with subclinical endometritis during the postpartum period. Cows aged 3 to 9 at 40 to 60 days postpartum were studied. Endometrial samples were collected from cows that had a uterine c...

A 4-year study comparing Hereford × Friesian (HF) and Limousin × Friesian (LF) spring-calving cows and two grass silages on the performance of suckler cows and their progeny was undertaken using 163 cows. Cows were offered, to appetite, grass silage of either low (L) or moderate (M) digestibility in late pregnancy and early lactation. Cows and their calves spent from April until weaning in Octo...

Eighteen multiparous early lactation Holstein cows were assigned to a replicated 3 × 3 Latin square with 28-d periods to evaluate milk protein production potential when corn silage (CS) or small grain silage (SGS) was added to diets based on alfalfa silage (AS). Treatments consisted of all AS, a mixture of AS and CS, or a mixture of AS and SGS. Treatment diets were isonitrogenous, isofibrous, a...

The reproductive ability, milk-producing capacity, survival time and relationships of these parameters with telomere length were investigated in 4 groups of cows produced by somatic cell nuclear transfer (SCNT). Each group was produced using the same donor cells (6 Holstein (1H), 3 Holstein (2H), 4 Jersey (1J) and 5 Japanese Black (1B) cows). As controls, 47 Holstein cows produced by artificial...