Physiological impact of the environment on the welfare of transgenic goats raised in a tropical climate.

The present study evaluated the general welfare state of two strains of transgenic goats bred in a region with a hot and humid tropical climate. Nine females were used, being three transgenic for human lysozyme (hLZ group), three transgenic for human glucocerebrosidase (hGCase group), and three non-transgenic (control group). The temperature and humidity index (THI) were recorded during the morning, afternoon, and evening. The physiological parameters measured were respiratory rate, heart rate, and rectal and vaginal temperatures. Venous blood samples were collected using Vacutainer® tubes containing 10% ethylenediaminetetraacetic acid (EDTA). Also, analysis of erythrogram, leukogram, and some biochemical parameters of serum was performed. It was observed that the afternoon shift presented the largest THI, being potentially more impactful on the physiology of animals. In general, respiratory and heart rates were higher in transgenic animals, especially in the hLZ group compared to the control group (P < 0.05). Regarding the hematological parameters, the quantification of red blood cells, hemoglobin, and hematocrit was significantly lower (P < 0.05) in the hGCase group compared to that in the hLZ and control. The leukocyte count was considerably lower (P < 0.05) in the hLZ group compared to that in the hGCase and control. Correlation analysis showed that the increase in THI was associated with a change in physiological parameters normally used as indicators of thermal stress. Despite the differences found among the experimental groups, all the physiological parameters remained within the normal limits recommended for the goat species. Further studies involving a larger number of animals from different categories should be carried out to elucidate the impacts that transgenesis can have on animal welfare under different THI conditions.

Rectal temperatures, respiratory rates, production, and reproduction performances of crossbred Girolando cows under heat stress in northeastern Brazil.

This study compared the two breed groups of Girolando (½ Holstein ½ Gyr vs. ¾ Holstein » Gyr) through analysis of the percentages (stressed or non-stressed cows) of rectal temperature (RT), respiratory rate (RR) and pregnancy rate (PR), and means of production and reproduction parameters to determine the group best suited to rearing in semiarid tropical climate. The experiment was conducted at the farm, in the municipality of Umirim, State of Ceará, Brazil. Two hundred and forty cows were used in a 2 × 2 factorial study; 120 of each group were kept under an intensive system during wet and dry seasons. The environmental parameters obtained were relative humidity (RH), air temperature (AT), and the temperature and humidity index (THI). Pregnancy diagnosis (PD) was determined by ultrasonography 30 days after artificial insemination (AI). The milk production of each cow was recorded with automated milkings in the farm. The variables were expressed as mean and standard error, evaluated by ANOVA at 5% probability using the GLM procedure of SAS. Chi-square test at 5% probability was applied to data of RT, RR, pregnancy rate (PR), and the number of AIs to obtain pregnancy. The majority of ½ Holstein cows showed mean values of RT and RR within the normal range in both periods and shifts. Most animals of the ¾ Holstein group exhibited the RR means above normal during the afternoon in the rainy and dry periods and RT means above normal during the afternoon in the dry period. After analyses, ½ Holstein crossbred cows are more capable of thermoregulating than ¾ Holstein cows under conditions of thermal stress, and the dry period was more impacting for bovine physiology with significant changes in physiological parameters, even for the first breed group. Knowledge of breed groups adapted to climatic conditions of northeastern Brazil can directly assist cattle farmers in selecting animals best adapted for forming herds.

Hormonal profiles, physiological parameters, and productive and reproductive performances of Girolando cows in the state of Ceará-Brazil.

This study compared two breed groups of Girolando (½ Holstein ½ Gyr vs. ¾ Holstein » Gyr) through analysis of physiological, productive, and reproductive parameters to determine the group best suited to rearing in a semiarid tropical climate. The experiment was conducted at the Companhia de Alimentos do Nordeste (CIALNE) farm, in the municipality of Umirim, State of Ceará, Brazil. Eighty cows were used in a 2 × 2 factorial study; 40 of each breed group were kept under an extensive system during the wet season and an intensive system during the dry season. The collection of physiological data and blood samples were obtained in the afternoon after milking. Rectal temperature (RT), surface temperature (ST), and respiratory rate (RR) were obtained for each cow after milking. Blood samples were obtained by tail vein puncture and were determined triiodothyronine (T3) and thyroxine (T4) and cortisol. The environmental parameters obtained were relative humidity (RH) and air temperature (AT), and from these, a temperature and humidity index (THI) was calculated. Pregnancy diagnosis (PD) was determined by ultrasonography 30 days after artificial insemination (AI). The milk production of each cow was recorded with automated milkings in the farm. The variables were expressed as mean and standard error, evaluated by ANOVA at 5% probability using the Proc GLM of SAS. Chi-square test at 5% probability was applied to data of pregnancy rate (PR) and the number of AI's to obtain pregnancy. It can be concluded that the breed group ½ Holstein ½ Gyr is most suited for farming under conditions of thermal stress.

Thermal comfort indices of female Murrah buffaloes reared in the Eastern Amazon.

The study aimed to develop new and more specific thermal comfort indices for buffaloes reared in the Amazon region. Twenty female Murrah buffaloes were studied for a year. The animals were fed in pasture with drinking water and mineral supplementation ad libitum. The following parameters were measured twice a week in the morning (7 AM) and afternoon (1 PM): air temperature (AT), relative air humidity (RH), dew point temperature (DPT), wet bulb temperature (WBT), black globe temperature (BGT), rectal temperature (RT), respiratory rate (RR), and body surface temperature (BST). The temperature and humidity index (THI), globe temperature and humidity index (GTHI), Benezra's comfort index (BTCI), and Ibéria's heat tolerance index (IHTI) were calculated so they could be compared to the new indices. Multivariate regression analyses were carried out using the canonical correlation model, and all indices were correlated with the physiological and climatic variables. Three pairs of indices (general, effective, and practical) were determined comprising the buffalo comfort climatic condition index (BCCCI) and the buffalo environmental comfort index (BECI). The indices were validated and a great agreement was found among the BCCCIs (general, effective, and practical), with 98.3 % between general and effective a.nd 92.6 % between general and practical. A significant correlation (P < 0.01) was found between the new indices and the physiological and climatic variables, which indicated that these may be used in pairs to diagnose thermal stress in buffaloes reared in the Amazon.

Cryopreservation of canine epididymal sperm using ACP-106c and TRIS.

The objective was to cryopreserve sperm recovered from the canine epididymal cauda immediately after an orchiectomy. The sperm was stored for 12h at 4 °C using ACP-106c and TRIS as extenders. Sixty adult male dogs were used. The testis-epididymis complex (TEC) was removed, immersed in 0.9% saline and transported to the laboratory. The 60 TEC were divided into groups according to the 4 °C cooling time (0 h or 12 h) and according to the extender used for sperm recovery (ACP-106c or TRIS), forming 4 experimental groups: G0h-ACP, G12h-ACP, G0h-TRIS and G12h-TRIS. The sperm were recovered from the epididymal cauda using the retrograde flow technique. Next, 1.0 mL of ACP-106c or 1.0 mL of TRIS (preheated to 37 °C for 5 min) was added to the sperm of each epididymis. One week later, the sperm was thawed at 37 °C for 1 min, and its morphology, functionality and total and progressive sperm motilities were analyzed. Other parameters were obtained by Computer Assisted Semen Analysis (CASA). The data were submitted to multivariate analysis of variance (MANOVA) (P<0.05). The total motility values were 52.17 ± 1.78 and 49.8 ± 1.93 for groups G0h-ACP and G12h-ACP and 50.7 ± 2.06 and 43.90 ± 2.51 for groups G0h-TRIS and G12h-TRIS, respectively. A decrease in total sperm motility was observed after 12h of cooling for both extenders (P<0.05). ACP-106c can be used as an extender for freezing canine epididymal sperm, and the freezing procedure must be performed immediately after sperm recovery.

Physiological and production response of dairy goats bred in a tropical climate.

The aim of this work was to determine the adaptability of Saanen and ½Saanen × ½Anglo-Nubian (½S½AN) goats bred in tropical climates. The study included 30 goats, 15 Saanen and 15 ½S½AN. The data was collected during the rainy and dry seasons. During the whole experimental period, the environment variables were recorded, as well as rectal temperature (RT), superficial temperature (ST), respiratory rate (RR) and heart rate (HR) and milk production (MP). The adaptability coefficient (AC) was calculated for both genotypes. The averages were evaluated by ANOVA at 5% probability. There was a genotype and period of year effect, as well as the interaction genotype × period of year. Pearson's simple correlation analysis was then carried out between milk production and physiological and environment variables. There was a statistical difference (p < 0.05) between the seasons for RT, ST and RR. RT, RR and HR were lower for ½S½AN than Saanen goats, regardless of the season. MP was greater in the dry season (p < 0.05) (2.52 ± 0.50 kg/day for ½S½AN and 2.41 ± 0.38 kg/day for Saanen) than the rainy season (2.17 ± 0.27 kg/day for ½S½AN and 2.28 ± 0.53 kg/day for Saanen). The MP correlations were very significant (p < 0.05), however low and negative, where it was higher when correlated with RR in Saanen goats. Under the conditions of the present study, it is concluded that the goats were influenced by climatic factors, where the rainy period was more likely to cause thermal stress in the animals.