The aim of this study was to assess the seasonal effects of the environment on semen quality in bulls, using infrared thermography. Sperm motility (M), mass motion (MM), and vigor (VIG) were evaluated in sperm samples from 17 Bradford bulls aged approximately 24 months at the beginning of the study. Infrared thermography images and data were collected using an infrared FLIR T 300 camera and Quick Report 1.2 SP2 software to determine the temperature of the proximal and distal poles of the testis and to assess the testicular temperature gradient. The seasonal effects on physiological, seminal, and climatic variables were analyzed by the GLM ANOVA and CORR procedures using SAS®. The microclimatic factors were recorded in hourly intervals, and the daily mean temperature and mean relative humidity were calculated to determine the daily temperature-humidity index (THI) every day for 1 year. The temperature gradient (TG) variations of the testes were significantly higher in the autumn (4.5 °C), winter (4.0 °C), and spring (2.9 °C) compared to summer (0.9 °C) (P < 0.05). Ocular globe temperatures were lower in the winter (27.6 °C) and autumn (26.8 °C) compared to summer (33.9 °C) and spring (31.1 °C) (P < 0.05). The average MM (2.58), M (52.64), and VIG (2.70) of the semen decreased in the summer compared to other seasons (P < 0.01). The TG was negatively correlated with THI (-0.44; P < 0.05). For the seminal variables, MaD (-0.45; P < 0.05) and TD (-0.50; P < 0.01) presented a negative correlation with TG. The TG had a positive correlation between M and VIG, which had values of 0.36 and 0.35, respectively (P < 0.05). We have concluded that infrared thermography can be used to assess the testicular temperature gradient and its consequences on physical and quantitative aspects of sperm.

No abstract

The morphology of the accessory genital glands of the male agouti was studied in twenty-three animals that were raised in captivity. Twenty animals had their genital glands dissected in situ for macroscopic description. The samples of each gland were recovered, embedded in paraffin, sliced and stained by Hematoxylin-Eosin technique. It was founded four pairs of glands: the vesicular glands, the coagulating glands, the prostate and the bulbourethral glands. Histological characteristics of the vesicular, coagulating and prostate glands showed similar morphology, within the pseudostratified columnar epithelium. The tubulo-alveolar type of the bulbourethral glands showed a lack of connective tissue among the tubules, a small amount of red stained presented it the cytoplasm, and the presence of vacuoles in the tissue. This study concluded that the agouti showed to have similar morphological aspect described in the others species of rodents.INDEX TERMS: Vesicular glands, coagulating glands, prostate gland and bulbourethral glands.

This study evaluated the thermoregulation and spermatogenic changes by scrotal temperature gradient using infrared thermography in testicular compromised bulls. Bulls were insulated (n = 6) for 72 hr and control animals (n = 3) remained without insulation during all the experimental period. Seminal evaluation was performed prior, at insult removal and once per week for 13 consecutive weeks. Mean temperature gradient in insulated animals was lower at the time of insulation removal compared to the week prior and after the insult (p < .05). Two weeks after insult, sperm motility was lower in insulated compared to control animals (p < .01) and spermatozoa total defects were higher in insulated compared to control animals (p < .05). Two and seven weeks after insult, the major defects were higher in insulated compared to control animals (p < .05). Scrotal temperature gradient showed a positive correlation with sperm mass motion (p < .01) and a negative correlation with ocular globe temperature (p < .01) in insulated animals. The infrared thermography can be used to evaluate ocular globe temperature in bulls; however, it is only effective to detect changes in scrotal temperature gradient at the insult removal.

mRNA for Mas receptor, ACE2, and PEP are differentially expressed in granulosa cells throughout follicular development and the Mas receptor can be involved with the establishment of follicular dominance.

-This study was intended to evaluate body size structure and growth parameters of crossbred heifers fed at four nutritional levels to achieve puberty earlier. Animals were classified depending on their level of crossing between Nelore and Hereford and subjected to four nutritional levels (kg day -1 ) as follows: 0.5 (light; n = 32), 0.75 (medium; n = 32), 1.00 (high; n = 29), and 1.25 (very high; n = 27). Heifers at puberty and at weaning were individually classified for growth parameters. The fat thickness and longissimus muscle area throughout the experimental period were determined by ultrasonography. The height, heart girth, frame, and weight:height ratio were variables used to evaluate body traits. Univariate analysis of variance using the GLIM MIXED procedure os SPSS was performed and the significance level was set at 0.05. Age and body weight at puberty were 388±1.9 days and 331.4±1.3 kg, respectively. Body condition score demonstrated an interaction between nutritional level and crossbred degree. Heifers with the highest degree of Nelore had higher fat thickness and lower weight:height ratio compared with other racial groups at puberty. Pearson correlation coefficient showed a negative association for body condition score (-0.34) and fat thickness (-0.58) compared with age at puberty. The increased fat thickness at younger ages at puberty was observed in all racial groups. The increased weight:height ratio at younger ages at puberty was observed in all racial groups. We observed higher values for a frame in animals at the higher level of supplementation. There is a greater correlation between live weight gain and phenotypic traits during weaning to achieve puberty at an earlier age in crossbred heifers.

The aim of our study was to evaluate the effect of different cooling rates on the post-thawing quality of bovine spermatozoa. Ejaculated semen from a 24-month-old Jersey bull was collected using an artificial vagina and diluted in a commercial extender to evaluate spermatozoan concentration and motility subjectively before cooling and freezing and after thawing. Straws were allocated to four cooling curves: rapid (RD), semi-rapid (SRD), semi-slow (SSLW) and slow (SLW). The temperature was decreased from 25ºC to 4ºC in 10, 50, 110 and 135 min, which represents a cooling rate of 2.06, 0.40, 0.18 and 0.15ºC/min, respectively. Then straws were frozen and stored at -196ºC. After thawing, one aliquot of each straw was used for evaluation. Spermatozoan integrity and mitochondrial function were evaluated using a combination of fluorescent probes containing 100 mg/mL FITC-PSA, 0.5 μg/mL PI and 153 μM JC-1. At the end of cooling, spermatozoan motility did not differ among RD (63.3%), SRD (66.7%), SSLW (66.7%) and SLW (80.0%). However, normal spermatozoan morphology was lower in SRD (84.8%) compared to RD (91.7%), SSLW (91.7%) and SLW (90.3%) (P<0.05). In thawed semen, spermatozoan motility and normal morphology did not differ among RD (40.0%; 88.8%), SRD (43.3%; 82.5%), SSLW (40.0%; 87.2%) and SLW (36.7%; 88.0%). The percentage of damaged spermatozoa, including plasma and acrosome membrane damage and low mitochondrial potential, was higher in RD compared to the others (P<0.05). In conclusion, a rapid cooling curve is detrimental to the spermatozoa and affects the post-thaw spermatozoan integrity of bovine frozen semen

The aim of this study was to evaluate the bioclimatic thermal stress assessed by Equivalent Temperature Index (ETI) and Temperature Humidity Index (THI) on Braford and Nellore bulls sperm quality during the reproductive seasons at the tropical region in the Brazilian Pantanal. We used 20 bulls aged approximately 24 months at the beginning of the study. Five ejaculates per animal were collected using an electroejaculator. Temperature, air humidity, and wind speed data were collected every hour from the automatic weather station at the National Institute of Meteorology. Infrared thermography images data were collected to assess the testicular temperature gradient in each animal. Data were analyzed with ANOVA using MIXED procedure of SAS and means were compared using Tukey's HSD test. The THI and ETI at 12 days (epididymal transit) were higher in January (89.7 and 28.5, respectively) and February (90.0 and 29.0, respectively) compared to other months (P < 0.01). Total seminal defects differ only in Bradford bulls between the months of November and February. Nellore bulls had lower major defects (MaD) and total defects (TD) compared to Braford. Nellore bulls showed correlation between minor defects (MiD) and THI for 30 days (0.90) and 18 days (0.88; P < 0.05). Braford bulls showed correlation for MaD (0.89) in ETI for 12 days (P < 0.05). Infrared thermography showed no difference between animals. Reproductive response to environmental changes is a consequence of Nellore and Braford adaptation to climate stress conditions. Both THI and ETI environmental indexes can be used to evaluate the morphological changes in the seminal parameters in Nellore or Braford bulls; however, more experiments should be performed focusing on larger sample numbers and also in reproductive assessment during the consecutive years to assess fertility potential.