Manipulation of ovarian and uterine function to increase conception rates in cattle.

In cattle, embryonic and fetal losses are the major causes of reproductive failureo Losses associated with failure in the process of maternal recognition of pregnancy can amount to as much as 30%0 Successful establishment of pregnancy depends on a delicate balance between luteolytic mechanisms inherent to the endometrium at the end of diestrus and antiluteolytic mechanisms, orchestrated by the conceptus to change endometrial function and, ultimately, block luteolysis. Antiluteolytic strategies are pharmacological, mechanical, nutritional and management manipulations of the process of maternal recognition of pregnancy that aim to increase the probability of successful gestations. Objective of the present paper is to review the recent literature on antiluteolytic strategies in cattle. Specifically, we focused on strategies to stimulate production of progesterone, strategies to reduce production of estradiol and other sttategies. Future directions for research in this area are proposedo

Embedding of psycho-perceptual-motor skills can improve athlete assessment and training programs

Practitioners in a variety of sports seek unique ways to train athletes to better prepare them for competition. In this position paper, we argue that inclusion of psycho-perceptual-motor skills, from the fields of sport psychology and sport expertise, is crucial, but underutilized in the assessment and training of athletes. First, a brief introduction is provided as to why psycho-perceptual-motor skill is vital for training athletes. Second, examples are discussed relating to key concepts. These include the following: assessment of expertise discriminators such as visual anticipation under pressure contexts, incorporation of sports analytics and performance analysis to aid reflection upon previous experiences of good anticipation and coping with pressure, use of qualitative and quantitative measures to understand processes underlying performance and learning, as well as design of representative tasks for assessment and training anticipation under pressure contexts. Third, some recommendations are made to practitioners of sports teams to assist them in taking advantage of psycho-perceptual-motor skill to better prepare athletes for competition. Collectively, we hope this paper stimulates collaboration between practitioners of sports teams and scientists to create a greater focus upon integrated sport psychology and sport expertise in the training of athletes

Estratégias para reduzir a mortalidade embrionária em bovinos: I. Alternativas farmacológicas para otimizar a função luteínica de vacas de corte.

A mortalidade embrionária precoce é a maior causa de perdas reprodutivas em bovinos europeus criados no hemisfério norte. Uma vez que a eficiência reprodutiva do gado de corte nacional é baixa, conjetura-se que tais perdas também ocorram com bovinos de corte zebu criados no Brasil. Para aprofundar os conhecimentos sobre esse tema e propor possíveis estratégias que minimizem as perdas de prenhez, foi desenvolvido na Embrapa Pecuária Sudeste o projeto ?Mortalidade embrionária em bovinos e estratégias para a sua redução? que, além de ter como objetivo principal a determinação das taxas e da cronologia das perdas reprodutivas em vacas nelore inseminadas artificialmente, estabeleceu como meta o desenvolvimento de uma alternativa farmacológica de otimização da função luteínica de vacas de corte. Para tanto, avaliou-se o efeito de diferentes protocolos de suporte hormonal sobre as funções luteínicas e foliculares de vacas das raças Nelore e Red Angus. O alcance dessa meta, ou seja, o desenvolvimento de um protocolo de otimização da função luteínica de vacas de corte disponibiliza uma prática pecuária inovadora, a qual está descrita detalhadamente no presente Boletim de Pesquisa e Desenvolvimento.bitstream/item/43525/1/Boletim26.pd

Metodologia para obtenção de concepto bovino

bitstream/CPPSE-2009/18334/1/Boletim19.pdfISSN 1517-198

A redução da mortalidade embrionária - estratégia hormonal para otimizar a função luteínica em bovinos

bitstream/item/37273/1/Circular51.pdfISSN 1981-208

Effects of equine chrionic gonadotrophin (eCG) on corpus luteum development and progesterone concentrations in Nelore cows.

This trial aimed to test eCG as an enhancer of the luteal function, as well as to evaluate the ability of eCG to delay or prevent luteolysis mechanism. A group of 32 mature, synchronized (CRESTAR@), lactating Nelore (Bos taurus indicus) cows were randomly allotted to receive either 400 lU of eCG at implant withdrawal (GeCG; n=16) or remain as contrais (GC; n=16). Ultrasound per rectum evaluation of avaries was conducted daily, from implant rem oval up to the following ovulation (a complete estrous cycle). Simultaneously, blood samples were taken to determine plasmatic concentration of progesterone ([P4]). Data were analyzed by GLM of the SAS program. GeCG showed non-significant (P>.05) higher volume of corpus luteum (CL) from day 3 after synchronized ovulation up to lhe rest of lhe luteal phase. In addition, eCG promoted a longer lasting growing period of lhe CL without changing its growing rale (P>.05) as compared to GC. As a result, CI maximum volume was reached later (9.2:t .47 days) and achieved a larger dimension (6927.5:t 405.86 mm3) for GeCG than occurred for GC (respectively, 7.7:t .47 days and 5437.8:t 405.86 mm3). The peak of [P4] was observed at lhe same time for both groups (11.3 t .59 and 11.4 t .59 days for GeCG and GC, respectively). However, maximum [P4] was higher (P.O5) for both groups (17.3 t .45 to GeCG and 17.1 t .45 days of lhe estrous cycle to GC). As a consequence, estrous cycle length did not differ (P>.O5) between treated (21.8 t .57 days) and non-treated cows (21.4 t .57 days). In summary, eCG not only increased CL dimension but also optimized [P4] over the luteal phase ofthe estrous cycle. Therefore, eCG given at implant removal provided a luteotrophic effect, but it was not capable to delay luteolysis