Rodolfo Luzbel de la Sota

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Our objectives were to identify stages of the estrous cycle at which initiation of a timed artificial insemination (Ovsynch/TAI) protocol may reduce pregnancy rates and to monitor ovarian follicle dynamics and corpus luteum development after initiation of the Ovsynch/TAI protocol at different stages of the cycle. Cycling Holstein heifers (n = 24) were(More)
Interactions of dietary energy and fat with recombinant bST (sometribove) injections were tested for their effects on ovarian function. Lactating dairy cows were fed one of three diets differing in energy concentration (NEL) and percentage of DM of calcium salts of long-chain fatty acids: diet 1, 1.68 Mcal/kg and 0%; diet 2, 1.68 Mcal/kg and 2.2%; and diet(More)
Studies of ovarian follicular dynamics in cattle may lead to methods for improving fertility, for synchronizing estrus with more precision, and for enhancing superovulatory responses. Within an estrous cycle, two or three large (> 10 mm) follicles develop during consecutive waves of follicular growth. The last wave provides the ovulatory follicle, whereas(More)
The effect of progestin and luteinizing hormone (LH) pulse frequency on dynamics of dominant follicle growth during the first follicular wave after oestrus was examined in non-lactating Holstein cows by ultrasonography. On day 8 of the cycle, cows (n = 8) received a luteolytic dose of prostaglandin F2 alpha (PGF2 alpha; 25 mg) and an ear implant of(More)
Menhaden fish meal, fed at 0.7 kg/d [2.7% of dietary dry matter (DM)], replaced blood meal and meat and bone meal (2.0% of dietary DM) in the diet fed at dairy A (n = 341) and replaced blood, meat and bone, and corn gluten meals (3.2% of dietary DM) in the diet fed at dairy B (n = 300). Cows consumed the experimental total mixed diets from approximately 24(More)
A series of experiments with Holstein heifers was conducted to develop the capability of inducing accessory corpus luteum (CL) with a GnRH agonist (Buserelin, 8 micrograms; GnRHa) or hCG (3,000 IU) to increase plasma progesterone concentrations (Exp. 1, 2, and 3) and to test whether induction of accessory CL with hCG will increase conception rates in(More)
To examine endocrine and biochemical differences between dominant and subordinate follicles and how the dominant follicle affects the hypothalamic-pituitary-ovarian axis in Holstein cows, the ovary bearing the dominant follicle was unilaterally removed on Day 5 (n = 8), 8 (n = 8), or 12 (n = 8) of synchronized estrous cycles. Follicular development was(More)
We wished to compare the effect of summer heat stress on pregnancy rate in cows that were inseminated at a set interval associated with a synchronized ovulation vs those inseminated upon routine estrus detection. The study was carried out on a commercial dairy farm in Florida from May to September 1995. Lactating dairy cows were given PGF2 alpha (25 mg(More)
The objectives of this study were to assess the agreement between endometrial cytology and uterine biopsy for the diagnosis of subclinical endometritis (SEND) in grazing dairy cows, the interobserver agreement of the biopsy's readings, and the bacterial population isolated from the uterus of cows having SEND. In experiment 1, lactating Holstein cows (n=44)(More)
The aim of this study was evaluate the survival ability of canine and feline spermatozoa maintained within epididymides stored at 4 degrees C for 24, 48 or 72 h in sterile isotonic saline solution (SAL) or a Tris-egg yolk (TEY) storage medium. Fifteen domestic dogs and 15 cats were neutered and their testes were placed in TEY or SAL and stored at 4 degrees(More)