Research
Andrological Points Classification (CAP) Nelore Bulls (Bos Taurus Indicus) Of Different Ages, Kept in Reproduction Central
The objective of this study was to evaluate the reproductive potential of Nellore bulls at different ages, using the Andrological Points Classification system and to analyze the physical and morphological characteristics of the semen, when submitted to the cryopreservation protocol. Thus, 15 Nellore bulls were evaluated, divided into three groups according to age. The first group consisted of bulls aged ≤ 4 years, the second group of bulls aged 5 ≥ to ≤ 7 years, and the third group of bulls aged 8 ≥ to ≤ 10 years. From the evaluations performed, biometrics testicular and semen morphology, were relevant to determine the andrological classification by points (CAP index). For this purpose, the semen was collected using the electroejaculation method. And the results were expressed as mean and standard deviation. The variables were submitted to ANOVA, Tukey and Pearson's correlation tests, with the differences between the groups being significant at the p <0.05 level. The results describe differences between the groups and in the sperm viability between the groups when the samples are submitted to different moments of evaluation (In natura, post-thaw and thermoresistance test). It is concluded that the Nellore breed, presents variation in the sperm quality, with a very small loss on the older ones
Evaluating the Impact of Rapid Thermoresistance (RTT) on Membrane and Chromatin Features in Post-Thawed Bovine Semen
This work aims to evaluate the effects of rapid thermoresistance on the morphofunctional aspects of membranes using flow cytometry, as well as the quality of sperm chromatin using the Toluidine Blue technique, both before and after the thermoresistance test.Six sets of frozen semen from ten bulls were used. The samples were thawed in a water bath at 36ºC and separated into two aliquots. The first aliquot, control group (C), was kept in a test tube previously heated to 36ºC with subsequent evaluationsusingmicroscopy, cytometry, and chromatin analyses. The second aliquot, experimental group (E), underwent the rapid thermoresistance test (RTT) in a water bath preheated at 46ºC for 30 minutes with subsequent evaluations usingmicroscopy, cytometry, and chromatin analyses. For statistical analysis, the paired T test, significance (P<0.05), was used. It was observed that from the results presented, semen samples after the resistance test showed a reduction of approximately 56% for motility and 36% for vigor (P< 0.05) when compared to samples before the test.
