High environmental temperatures cause heat stress in ewes, resulting in thermoregulatory problems. In this study, the thermoregulatory responses of Blackbelly adult ewes (G1, n = 14) and female lambs (G2, n = 7), during the summer under tropical conditions, in southern Mexico were analyzed. Different physiological variables and skin temperatures (ST) of the ewes were recorded. Breathing frequency (BF) values were similar between groups at 116.73 ± 33.598 bpm (G1) and 113.661 ± 34.515 bpm (G2) (p > 0.05). In the case of skin elasticity (SE), there were no significant differences between the time of day and the age of the ewes (p > 0.05). Significant differences were observed between groups for BF, rectal temperature (RT), and heart rate (HR) values (p < 0.05). All ST values, for both groups, were significantly higher during the afternoon (p < 0.001). In general, all Blackbelly adult ewes and female lambs during the summer present severe heat stress conditions as a result of an increase in physiological constants and ST. It is concluded that all ewes thermoregulate body temperature by modifying different physiological variables to counteract the effect of heat stress.

The aim of this study was to evaluate the intensity of the annual sexual behavior (SB) of Boer bucks under tropical conditions in southern Mexico. For one year, 16 extensively grazing males were evaluated for SB individually with estrogenized goats. From the beginning of the experiment and every 30 days, body weight (BW), body condition (BC), testicular circumference (TC), odor intensity (OI), and SB (nudging, ano-genital sniffing, flehmen, mounting attempts, mounts with intromission, and self-urination) were recorded. The bucks showed more intense SB during the months of November to May than during the months of June to October (p < 0.05). Greater frequencies were found for nudging, ano-genital sniffing, mounting attempts, and self-urination in the months of November to May (p < 0.001). BW was lower during the months of January to August than in the months of September to December (p < 0.05). On the other hand, TC increased from October to December (p < 0.05). Similarly, the OI in males varied over time (time effect; p < 0.001). In fact, an increased odor was found from October to December. The conclusions are that breed male goats from the tropics of Guerrero have a more intense SB during the months of November to May, but TC, OI, BW, and BC correspond to the time of the year when forage availability is the greatest.

Objective. To determine whether Blackbelly ewes are affected by heat stress (HS) during the summer in a tropical climate. Materials and methods. In this experiment, 21 female ewes were divided into two treatments (T1=7 female lambs and T2=14 multiparous ewes) to evaluate the effect of HS through the temperature and humidity index (THI), physiological, and hematological variables. Results. In the experiment, a THI between 77 and 88 U was found. Likewise, respiratory rate (RR) was higher in T2 in the afternoon (117 bpm) than in the morning (114 bpm) (p<0.05). Also, rectal temperature (RT) was found to be higher in T1 in the afternoon (39.3°C) than in the morning (38.9°C) (p<0.05). Finally, it was found that the heart rate (HR) was higher at T2 during the afternoon (p<0.05). The hematocrit (HCT) and hemoglobin (HB) variables were similar between treatments during the study, but there were differences between samples two to seven (higher concentrations) compared to sample 13 (lowest concentration) (p<0.001). Finally, the potential of the Hydrogen variable (pH) showed variations, being higher in samplings three and six, and lowest values in samples four, five, seven, and twelve (p<0.001). Conclusions. Blackbelly ewes showed severe HS during the summer in the tropics of Guerrero.

Using an Ekomilk Bond Total Ultrasonic Milk Analyzer, the physicochemical characteristics of milk from 10 herds and 237 samples were analyzed during the rainy season (July and August; 109 samples) and dry season (January and February; 128 samples), providing the following measures: fat (%), non-fat solids (NFSs; %), density (g/mL), freezing point (°C), acidity (%), temperature (°C), lactose (%), conductivity (mS/cm), pH and water (%). In this study, there was a higher percentage of fat (2.975 vs. 5.001%) and a higher density (1033.692 vs. 1035.45 g/mL) in milk during the dry season compared to during the rainy season (p < 0.05). The rest of the milk characteristics were not significantly different relative to the study season (p > 0.05). The variables of fat and temperature of milk presented higher values in the dry season than in the rainy season, whereas the variables of density, freezing point and conductivity presented higher values in the rainy season than in the dry season (p < 0.001). Regarding the variables of NFSs, protein, acidity, lactose, pH and water percentage, the results were similar in the two study seasons (p > 0.05). Finally, density maintained significant positive correlations with the variables of protein, freezing point and lactose (p < 0.05). However, fat showed significant negative correlations with density, freezing point, acidity and conductivity (p < 0.05). In conclusion, the physicochemical characteristics of raw milk from dual-purpose cows per herd are better during the rainy season.

Two groups of ewes (10 lactating and 10 non-lactating) were used to evaluate the effect of heat stress during summer under tropical conditions. In this study, a temperature and humidity index (THI) was found that ranged between 65 and 79 (morning and afternoon). Likewise, a heat tolerance coefficient (HTC) of 6 units was observed. The highest breathing frequency (BF; 115.46 ± 35.25 breaths per minute (bpm)) and rectal temperature (RT; 38.95 ± 0.51 °C) were found during the afternoon in the group of lactating ewes. The means were compared by group, time of the day, and interaction, and only significant differences were found between groups for RT and udder temperature (p < 0.001). In the case of time of day, all parameters were higher during the afternoon, regardless of the group of ewes (p < 0.001). Likewise, an interaction was found in the parameters RT, right paralumbar fossa (RPF), rump, leg, and udder (p < 0.001). In conclusion, Blackbelly ewes lactating during the summer in the tropics have higher skin temperatures, and also raise BF and RT to tolerate HS in tropical climates.

Objetivo. Conocer la percepción de los habitantes sobre la tarántula “rodillas rojas” (Brachypelma smithi) en la colonia Vista Hermosa, municipio de Técpan de Galeana, Guerrero, México. Materiales y métodos. Se entrevistaron a 51 habitantes de la colonia Vista Hermosa. Las preguntas iban orientadas al conocimiento de la población sobre el arácnido. Resultados. En los habitantes se registró un promedio de edad de 25.23±12.16 años, con una mínima de 16 años y una máxima de 59 años. El 37.2% de la población son originarios de Técpan de Galeana, el 72.5% tienen hijos, el 84% pertenecen a la población católica y el 90% tienen casa propia. La mayoría son mujeres (86.27%), con educación primaria (41.18%), ocupación de amas de casa (49.02%) y 3 a 5 hijos (41.18%). La mayoría de la población encuestada mencionan encontrar a la tarántula una vez al año (76.47%), durante la época de aguas (60.78%) y son de color naranja con negro (62.75%). Por su parte, la mayoría de los encuestados mencionan retirar a la tarántula de su casa (50.98%) y otra parte de la población la mata (43.14%). En este sentido, un alto porcentaje las considera peligrosas y toda la población desconoce la existencia de la tarántula rodillas rojas, así como, que es inofensiva. Conclusiones. La urbanización de la colonia Vista Hermosa municipio de Técpan de Galeana, influye activamente en la extinción de la tarántula mexicana rodillas rojas (Brachypelma smithi).