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Objetivo. Determinar si las hembras ovinas Blackbelly son afectadas por el estrés calórico (EC) durante el verano en un clima tropical. Materiales y métodos. En el experimento, 21 hembras ovinas fueron divididas en dos tratamientos (T1=7 corderas y T2=14 ovejas multíparas) para evaluar el efecto del EC a través del índice de temperatura y humedad (ITH), variables fisiológicas y hematológicas. Resultados. En el experimento se encontró un ITH de entre 77 y 88 U. Asimismo, la frecuencia respiratoria (FR) fue mayor en el T2 por la tarde (117 rpm) que por la mañana (114 rpm) (p

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.

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.

Objetivo. Evaluar el efecto de tres promotores de crecimiento sobre el consumo de alimento (CA) y ganancia diaria de peso (GDP) en corderos de pelo. Materiales y métodos. Fueron asignados aleatoriamente 12 corderos en cuatro tratamientos con tres repeticiones cada uno: Tratamiento 1 control (T1-C; dieta basal), tratamiento 2 (T2; complementación con 0.125 g de clorhidrato de zilpaterol (Zilmax®), tratamiento 3 (T3; complementación con 3 g de Clorhidrato de Ractopamina (LAPI-RACTO®) y tratamiento 4 (T4; 12 mg de zeranol en implantes) (Zearalenona-Ralgro®). Se utilizó un diseño estadístico de bloques completos al azar. Resultados. Se encontró una diferencia significativa en el CA (p0.05). El T4 presentó mayor ganancia diaria de peso (GDP) versus con el T2 (p

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).

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.