Fresh Semen Quality of Bos taurus, Bos indicus and Bos sondaicus Bulls in the Tropical Condition

Effects of scrotal insulation on sperm production, semen quality, and testicular echotexture in Bos indicus and Bos indicus x Bos taurus bulls.

The objectives of the present study were to evaluate the effects of scrotal insulation on sperm production, semen quality, and testicular echotexture in Bos indicus and Bos indicus x Bos taurus crossbred bulls. In one experiment, B. indicus bulls (n=12) were allocated to control and whole-scrotum insulation groups, while in a second experiment, crossbred bulls (n=21) were allocated into control...

Pregnancy rate and birth rate of calves from a large-scale IVF program using reverse-sorted semen in Bos indicus, Bos indicus-taurus, and Bos taurus cattle.

Obtaining sexed sperm from previously frozen doses (reverse-sorted semen [RSS]) provides an important advantage because of the possibility of using the semen of bulls with desired genetic attributes that have died or have become infertile but from whom frozen semen is available. We report the efficiency of RSS on the pregnancy rate and birth rate of calves in a large-scale program using ovum pi...

Growth hormone mRNA expression in the pituitary of Bos indicus and Bos taurus x Bos indicus crossbred young bulls treated with recombinant bovine somatotropin.

The effects of breed and of recombinant bovine somatotropin (rbST) treatment on growth hormone gene expression were studied in young bulls. The experiment was completely randomized in a [2 x 2]-factorial arrangement, using two levels of rbST (0 or 250 mg/animal/14 days), and two breed groups (Nelore and Simmental x Nelore crossbred). A cDNA encoding Bos indicus growth hormone was cloned and seq...

Biological Efficiency Differences Among Bos taurus x Bos taurus andBos indicus x Bos taurus F1-Cross Cows

Logistic regression analysis of pregnancy rate following transfer of Bos indicus embryos into Bos indicus x Bos taurus heifers.

Factors affecting pregnancy rate of 5627 Zebu embryos in crossbred females with unknown proportions of Holstein and Zebu breeding were examined. After evaluation for developmental stage, quality, and viability, embryos were immediately transferred to recipients. Pregnancy diagnosis was conducted approximately 53 d after transfer; pregnancy rate was coded as a binomial event and analyzed using l...