Estrus synchronization with an oral progestogen prior to superovulation of postpartum beef cows.

Ovarian follicular dynamics and steroid secretion patterns were monitored in postpartum beef cows that were synchronized for estrus with melengestrol acetate (MGA) or prostaglandin F(2alpha) (PGF) prior to superovulation. Twenty-four muhiparous Angus cows were stratified by number of days postpartum to an MGA or PGF treatment prior to superovulation. Cows in the MGA group were fed 0.5 mg MGA/d for 14 d in a grain carrier. Superstitnulatory treatments began 14 d after withdrawal of MGA from feed or 11 d after administering a single injection of 500 microg cloprostenol (PGF). Supersthnulatory treatments (FSH) were administered twice daily in decreasing doses (7.5, 5, 5, 2.5 mg) over 4 d. Sixty and 72 h after initiating the superstimulatory treatments, all cows were treated with 750 microg and 500 microg PGF, respectively Cows were inseminated at 0, 12, and 24 h from the onset of standing estrus with semen from 2 proven sires. Cows within treatment were inseminated with 1, 2 and 1 (single) or 2, 4 and 2 units (double) of semen at the designated insemination times. Blood sampling and transrectal ultrasonography of ovaries were performed daily beginning 2 d prior to the initiation of FSH treatment and were continued through embryo recovery. Ovaries were examined daily to determine the number and size of follicles. Plasma samples were analyzed for progesterone and estradiol. Follicles were counted and categorized based on a 5 to 9 mm range or >/= 10 mm. At the end of superovulatory treatment there were more (P /= 10 mm among cows that were estrus synchronized with MGA (75 +/- 1.2) than with PGF (3.9 +/- 1.2) These differences were reflected in higher (P

Improved synchrony, conception rate, and fecundity in postpartum suckled beef cows fed melengestrol acetate prior to prostaglandin F2 alpha.

Occurrence of estrus, conception rate, and fecundity were compared between postpartum suckled beef cows fed or not fed melengestrol acetate (MGA) before synchronizing estrus with prostaglandin F2 alpha (PG). One hundred thirty-three purebred Angus cows were stratified by age and days postpartum to one of two treatments. All cows received an injection containing 25 mg of PG; however, one group (MGA+PG) was fed .5 mg of MGA.cow-1.d-1 for 14 d then received PG 17 d after the last feeding of MGA. The other group (PG) received only PG. Cows in both treatments that failed to exhibit estrus within 6 d after PG received a second injection of PG 11 d after the first injection was administered. Cows were checked for estrus from the first PG injection until 6 d after the second PG injection. Cows were inseminated with semen from a 3/4 Brahman bull 12 h after observed estrus. Cows were exposed to Angus bulls after the AI period. Conception date was determined by palpation per rectum and verified by calving date and calf phenotype. Differences in response variables were analyzed by chi-square. A greater proportion of cows (P < .04) that were pretreated with MGA exhibited estrus after the first injection of PG (76%) than of cows that received only PG (60%). Total response did not differ between treatments after both injections of PG. Conception rate among cows that received a first service was higher (P < .007) for the MGA+PG (88%) group than for the PG (67%) group, although the total number of cows that received a first service was not different between groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective evaluation of a peritoneal dialysis catheter system for large volume paracentesis.

Large volume paracentesis is becoming a popular form of therapy for patients with massive ascites and cirrhosis. Although the physiologic effects of the removal of large amounts of ascitic fluid have been well described, the techniques utilized to perform the procedure are either not well documented or not currently available. Over a 13-month period, 52 patients with moderate to severe ascites have undergone 73 large volume paracenteses with a peritoneal dialysis catheter system. The mean volume of ascitic fluid removed was 7.6 L, with a mean time of removal of 129 min. Total paracentesis was accomplished within 1 h in 38% of procedures. The most common site for paracentesis was the left lower quadrant. Complications related to the procedure were few, the most common being a self-limited ascitic fluid leak at the sight of paracentesis. No patient experienced intestinal perforation, peritonitis, or a significant change in serum creatinine after the procedure. The widely available peritoneal dialysis catheter system represents a safe and rapid technique for the removal of large quantities of ascitic fluid.

Effects of nutrition, sex of calf and breed type on response to zeranol: preweaning growth.

An experiment was conducted to evaluate the effects of breed, sex and plane of nutrition on the growth response to zeranol in Angus and crossbred calves prior to weaning. Eighty-eight heifers and 118 steers received either a high or low plane of nutrition using a first and last grazing technique. Half of the calves in each nutrition group received a zeranol implant (36 mg) at an average age of 3.4 mo. Both zeranol and the higher level of nutrition increased (P less than .001) growth rate prior to weaning (7.4 mo of age). Zeranol did not affect hip height at weaning (P greater than .1), but calves on the higher plane of nutrition were taller (P less than .01) than calves on the lower plane of nutrition. The zeranol x nutrition interaction was not significant (P greater than .1) for growth rate or hip height. Steers grew faster (P less than .01) preweaning and were taller (P less than .01) at weaning than heifers. Crossbred calves gained more rapidly (P less than .001) preweaning and were taller (P less than .001) at weaning than Angus calves were. Neither sex nor breed interacted with zeranol to influence any of the traits examined. Based on these results we conclude that preweaning growth was affected by zeranol and this effect was consistent across sexes, breeds and planes of nutrition tested.