João Carlos Pinheiro Ferreira

• 14th Biennial 4A Conference, AR.BR

• Abstract

  The testicular temperature should remain about 3° to 5° C below body temperature for normal spermatogenesis to occur in cattle. When this situation is lost, and the testicular temperature rises, spermatogenesis is compromised. A series of seminal changes are perceived, markedly characterized by increased abnormal sperm forms and decreased sperm motility and concentration. These seminal ch…

  Heat stress effect on the transcript abundance of testicular tissue, AP.R

• Abstract

  It is well known that a bull's testes must be cooler than body temperature and that increased testicular temperature reduces motile and morphologically sperm and their fertility. Regarding pathogenesis of increased testicular temperature on spermatogenesis, there is a long-standing belief that the bovine testis is almost hypoxic, increased testicular temperature increases O2 use but testi…

  EFFECT OF HEAT STRESS IN BOVINE TESTICULAR BLOOD FLOW AND METABOLISM: IS THERE A DIFFERENCE BETWEEN EUROPEAN BREEDS AND ZEBUIDS?, AP.R

(Only some records are available in English at this moment)

• Abstract

  The effects of heat stress (ET) on testicular gene expression have been attracting more and more interest, however, to obtain testicular samples, it is almost always necessary to castrate the males, thus making it impossible to collect samples and limiting the understanding of the phenomena being studied. Testicular biopsies using Punch, Split and Tru-cut needles have been used to obtain …

  Effect of sequential TRU-CUT needle biopsies on testicular gene expression, BP.IC

• Abstract

  Disputes between confined beef cattle are quite common and can cause injury and stress, impoverishing the welfare state of animals. There are several factors that influence the motivation for the expression of agonistic behaviors. However, it is not yet known whether the decrease in testosterone levels can alter the amount of social interactions, interfering with the social order of a gro…

  The effect of testosterone on the social hierarchy formation of Nelore bulls, BP.IC

• Abstract

  The profile of gene expression of follicles reflects its status of development. After the period of divergence dominant follicle goes through a differentiation process, especially in granulosa cell layer. This process is characterized by an increase in mitotic and steroidogenic capacity of the dominant follicle. However, in heat stress environment the follicular development occurs abnorma…

  In vivo study of the factors involved in the establishment of follicular dominance and atresia in Holstein cows and the effect of heat stress on these phenomena, BP.DR

(Only some records are available in English at this moment)

• Abstract

  The reduced fertility associated with summer is a multi-factorial problem. The hyperthermia can affect cellular function in various tissues of the female reproductive tract. Dairy producers might alter their reproductive program to cope with the negative effects of heat stress. This proposal will aim to study the protein expression of follicular fluid of cows undergoing to heat stress c…

  Proteomics evaluation of the follicular fluid of Holstein cows under heat stress, BE.EP.DR

• Abstract

  This work aims to perform in vitro culture of bovine luteal cells evaluate the effect of PGF2± on gene expression and protein in substances involved in steroidogenesis (StAR), the production of PGF2± intraluteal (PGTS, PTGFS, HPGD) in the induction of apoptosis (CASP-3, Bax, Bcl2) and genes of immune system that have an increased expression during the process of luteolysis and functional …

  In vitro culture of bovine steroidogenic and non-steroidogenic luteal cells: effect of PGF2a on the expression of genes and proteins associated with steroidogenesis and apoptosis, BE.EP.DR

• Abstract

  It is well established that P4 from the CL is essential for maintenance of pregnancy and that the early embryo produces interferon-tau, which is essential for changes in uterine and CL gene expression that results in continued function of the CL during pregnancy (Dorniak et al., 2013, Spencer et al., 2007b). However, there has recently been substantial controversy regarding the precise en…

  Evaluation of the hormonal and molecular pathways involved in maintaining the corpus luteum of pregnancy in lactating dairy cows, BE.EP.DR