The objective of this study was to determine the minimum representative area to evaluate testicular echotexture parenchyma and to identify the correlations between the intensity of pixels of the testicular parenchyma and the fibrosis score with the physical and morphological characteristics of the ejaculate of Texel rams. The study used 88 Texel rams, aged between 10 and 12 months, and reared in a semi-extensive system. The animals underwent breeding soundness evaluation (BSE) and ultrasound of the testicles. The images were transferred to a computer where they were defined in areas of 400, 1600, 3600, and 6400 mm 2 , after which the average intensity of the pixels of each image of the testicular regions was evaluated. A testicular fibrosis score was assigned in order to quantify the frequency of fibrotic lesions. In relation to the intensity of pixels of the predetermined regions, only the area of 400 mm 2 presented a difference (P < 0.05), with the area of 1600 mm 2 being the smallest area that best represented the testicular parenchyma. There were no correlations between the intensity of pixels of the testicular parenchyma and the fibrosis score with the physical and morphological characteristics of the ejaculate of the rams.

The aim of this study was to characterize the angiotensin-converting enzyme (ACE) in Gir semen before and after cryopreservation. The ejaculate of five sexually mature bulls was used. After collection, one 1-mL aliquot of fresh semen was analyzed immediately, and the rest of the semen was cryopreserved in liquid nitrogen for subsequent analysis. Freshly collected semen and thawed cryopreserved semen were centrifuged twice with Tyrode's albumin lactate pyruvate medium (TALP) to remove plasma and extender, respectively. Samples were then subjected to western blotting, immunocytochemistry, and enzymatic activity techniques. At least one 100 kDa band was observed in every bull analyzed using western blotting with an anti-ACE monoclonal antibody, and band intensity decreased by 70% (p < 0.05) after cryopreservation. Immunocytochemistry showed periacrosomal ACE localization, and the area stained by the fluorescent antibody significantly decreased (p < 0.05) after cryopreservation. Enzyme activity was evaluated using FAPGG substrate hydrolysis, which was significantly lower (p < 0.05) in cryopreserved semen than in fresh semen. Therefore, the process of cryopreservation decreases ACE band intensity and enzyme activity in Gir bull semen, and reduces the stained area in immunocytochemistry.

This study aimed to analyze the effects of semen cryopreservation on seminal proteins. Initially, we analyzed the effects of cold shock and the advent of proteomics and its benefits on the characterization of seminal proteins. Subsequently, studies reporting losses of some sperm proteins and increase in the expression of others during the cooling and freezing of the semen of different species are presented. Finally, some questions were raised to motivate the study of semen proteomics aiming to predict quality losses during the cryopreservation of semen in breeding animals of greater genetic merit.

The aim of this study was to characterize the testicular isoform of angiotensin-converting enzyme (tACE) before and after semen cryopreservation, and in the acrosome reaction of sperm from Nelore bulls in vitro. Ejaculates of 10 sexually mature Nelore bulls were used. After semen was collected, 1.0 mL of the ejaculate was used for the analysis and the rest was subjected to cryopreservation. Fresh semen before freezing, and frozen/thawed semen were centrifuged twice and the pellet was resuspended intyrode's albumin lactate pyruvate (TALP). Thereafter, 100 μL aliquots containing 100 × 10 6 spermatozoa were prepared. Aliquots of samples were used for western blot analysis, subjected to capacitation, and thereafter, acrosome reaction assays were performed in vitro. With the help of an anti-ACE monoclonal antibody, a

The purpose of this study was to evaluate the functional morphology of the spermatogenesis of Gir bulls, with emphasis on the testicular biometry and testicular parenchyma histomorphometry. Testicular fragments from eight Gir bulls were used. The fragments were fixed by tissue perfusion with Karnovsck's solution, and inclusion was subsequently performed using glycol methacrylate. Histological sections of 4 μm were made and stained with a 1% toluidine blue-sodium borate solution. The mean age of the bulls was 8.0 ± 1.3 years and the mean body weight was 467.5 ± 26.7 kg. Testicular weight was 289.2 ± 30.5 g on average, and the average gonadosomatic index was 0.12% ± 0.02%. The seminiferous tubules, Leydig cells, stroma, and intertubular tissue composed 80.9% ± 1.7%, 5.4% ± 1.3%, 13.7% ± 1.1%, and 19.1% ± 1.7% of the total testicular weight, respectively. The mean length of the seminiferous tubule per gram of testicle was 17 ± 0.8 m. Losses during spermatogonia mitosis averaged 75.5% ± 3.22%, while losses were 30.6% ± 8.17% during the meiotic phase, which resulted in an average total loss of 81.49% ± 2.58% of cells during the entire process of spermatogenesis. The average daily sperm production per gram of parenchyma was 28.0 × 10 6 cells. It was concluded that the histometric measurements of testicular parameters in the Gir breed are within the averages reported for other zebu cattle breeds.