Ramses Sala

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Two experiments were designed to evaluate the use of resynchronization (RESYNCH) protocols using a progestin-based timed artificial insemination (TAI) protocol in beef cattle. In experiment 1, 475 cyclic Nelore heifers were resynchronized 22 days after the first TAI using two different inducers of new follicular wave emergence (estradiol benzoate [EB; n =(More)
In Bos taurus cattle, antimullerian hormone (AMH) has been demonstrated to have a high degree of correlation with ovarian antral follicle count and the number of healthy follicles and oocytes. To document the correlation between the plasma concentration of AMH and follicular number in Bos indicus and Bos taurus heifers, Nelore (Bos indicus, n = 16) and(More)
Three experiments were designed to evaluate methods to optimize the use of sex-sorted sperm in timed AI (TAI) programs for suckled beef cows. In all 3 experiments, suckled Bos indicus cows were synchronized using an intravaginal progesterone (P4) device during 8 d and a 2.0-mg injection of intramuscular estradiol benzoate (EB) at device insertion. The(More)
Fertility of in vitro-produced embryos is affected by embryo stage and quality. Embryos quality 1 and stage 7 result in higher fertility than embryos of earlier stages and/or lower quality. The objective was to evaluate the effect of unilateral and bilateral transfer of 2in vitro-produced embryos of earlier stages and/or poor quality on fertility. Heifers(More)
Synchronization protocols for fixed-time embryo transfer (ET) contribute significantly to the overall cost of an in vitro-produced-ET program, primarily through the cost of drugs and the labour required. Optimization of synchronization protocols to reduce cost, while providing high fertility, have the potential to improve overall efficiency and(More)
The present study evaluated the use of sex-sorted sperm upon estrus detection (ED) or following timed artificial insemination (TAI) in lactating dairy cows. Additionally, the effect of the presence of a corpus luteum (CL) at the beginning of the TAI protocol was verified. Cows (539 crossbred Gir × Holstein and 87 Holstein) were classified according to the(More)
The objective was to evaluate the effects of timing of insemination and type of semen in cattle subjected to timed artificial insemination (TAI). In Experiment 1, 420 cyclic Jersey heifers were bred at either 54 or 60 h after P4-device removal, using either sex-sorted (2.1 × 10(6) sperm/straw) or non-sorted sperm (20 × 10(6) sperm/straw) from three sires (2(More)
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