The objective of the present study was to evaluate the effects of supplementation of zilpaterol hydrochloride (ZH) to the finishing diets on the feedlot performance and carcass characteristics of hair sheep ewe lambs during hot environmental conditions. Twenty Katahdin × Pelilbuey and Dorper × Pelibuey crossbred females with an average initial liveweight (LW) of 26.2 ± 0.83 kg were blocked by the initial LW, and assigned individually to 20 pens in a closed calf-rearing unit provided with fans. Treatments were (1) control group (basal diet without ZH) and (2) ZH group (basal diet plus 10 mg of ZH/ewe.day). Skin temperatures were measured each 2 days in five ewes by treatment; ambient weather conditions were recorded every day. After a 34-day feeding period, all ewes were slaughtered. Climatic variables during the study showed severe heat stress, with the average temperature–humidity index and temperature 85 units and 34.1°C, respectively. The skin temperature of belly and right flank was greater (P < 0.05) in ZH females than in control lambs. Ewe lambs fed ZH had feedlot performance, carcass length, shear force, body fat and skin percentage similar (P > 0.05) to control ewe lambs. With the exception of peritoneum and head (P < 0.05), all visceral organs had similar (P > 0.05) percentages between treatments. However, hot- and cool-carcass weights, dressing percentage, conformation and rib-eye area were greater (P < 0.05) for ewes supplemented with ZH. Likewise, the weight of hindquarter, legs and ribs expressed as a percentage of hot-carcass weight increased (P < 0.05) with ZH supplementation. Growth and deposition of excessive fat in hair-sheep ewe lambs were not improved with ZH supplementation under heat-stress conditions, whereas carcass-quality traits such as dressing and rib-eye area were increased.

Objetivo: evaluar la respuesta superovulatoria y calidad embrionaria de un grupo de vacas Brahman lactando sometidas a un protocolo de dosis bajas de FSH. Metodología: en el estudio fueron superovuladas 33 vacas de raza Brahman multíparas lactando. Las hembras fueron sincronizadas con CIDR (inserción día 0) y dosis decrecientes de FSH (día 5: 250mg FSH, día 6: 200 mg FSH, día 7: 150 mg), el día 9 y 10 se practicó la inseminación artificial (IA); finalmente el día 17 se realizó el lavado para la recolección de embriones. Los embriones fueron colectados con una sonda Foley, y el contenido fue depositado en una caja de  Petri cuadrada de 100  100 mm con fondo cuadriculado para la posterior búsqueda de embriones en el microscopio provisto de un aumento de 20 a 30 X. Los embriones fueron clasificados de acuerdo a su morfología y estadio de desarrollo en una escala del 1 (estadio de una célula) al 9 (estadio de blastocito eclosionado) y calidad como 1 (excelente), 2 (bueno), 3 (regular) y 4 (degenerado). Resultados: Del 100% de las vacas tratadas se obtuvieron 363 embriones: 41.8% fueron viables; 65% se clasificaron como blastocisto eclosionado de calidad 8 y 34.8% de calidad 7. De los embriones clasificados como blastocisto eclosionado, 60.6% fueron de calidad excelente, 28.28% de calidad buena y 11.11% de calidad regular. El promedio de embriones viables por vaca fue de 2.9% y 1.9% transferibles. Implicaciones: Es difícil superovular vacas lactando, por el control de los becerros durante el proceso experimental, y no es recomendable este tipo de tratamiento por el gasto metabólico y reproductivo a lasque son sometidas las hembras. Conclusiones: Las vacas de raza Brahman lactando tienen una respuesta superovulatoria baja cuando son sincronizadas con un protocolo de dosis bajas de FSH.

Objective: To evaluate the reproductive characteristics of male goats (Capra hircus L.)with habitual management on their herds at Benito Juarez municipality, Guerrero, Mexico.Design / methodology / approach: Ten male Creole goats from seven herds wereevaluated, aged between 2 to 7 years and 2 to 3 body condition (BC). The males wereevaluated regarding their sexual behavior, sperm quality, physical examination andreproductive clinical evaluation.Results: All the assessed male Creole goats displayed sexual behavior (P &lt; 0.05).However, for the males of three of the evaluated herds the sexual behavior was lower (P &lt; 0.05). Of the ten electro-ejaculated males, 20% ejaculated and 80% did not (P &lt; 0.05). From the males that ejaculated, a sperm concentration of 224 x 106 and 16 x 106 spermmL -1 was recorded for the first and second male. Finally, the physical and clinicalreproductive evaluation concurred with the established parameters for the species.Limitations of the study / implications: Under the conditions in which the study wascarried out, it was not possible to evaluate males in the same age conditions andreproductive characteristics. However, this allowed collecting information from fieldconditions so that producers can apply it for herd improvement.Findings / conclusions: The male Creole goats of the evaluated herds showed intensesexual behavior with low sperm characteristics.

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis (PTB), disease that causes a syndrome of bad nutrient absorption, weight loss and eventually death. The intestine is the main target organ where the infection develops; however, there is evidence of infection by MAP in extra-intestine sites of sheep, including mesenteric nodes and semen. The aim of the study was to identify the presence of MAP in reproductive tissue and semen of infected Pelibuey rams in clinical state of PTB. Seven rams were used in clinical PTB state and a non-infected ram by MAP of the Pelibuey breed, confirmed by serology, nPCR and bacteriological culture, with average weight and age of 57.23 ± 1.73 kg and 2.91 ± 0.17 years, respectively. The presence of MAP was identified in different tissue samples: spleen (1/7, 14.3% and 2/7, 28.6%), small intestine (3/7, 42.9% and 4/7, 57.1%) and mesenteric lymph nodes (3/7, 42.9% and 3/7, 42.9%), with nPCR and culture, respectively. It was also identified in epididymis tissue (1/7, 14.3%), Cowper gland (2/7, 28.6%) and prostate (1/7, 14.3%), using nPCR, although without detection in culture. It was identified in testicular tissue in 42.8% (3/7; culture or nPCR technique), but in 28.6% (2/7) with both techniques. Finally, the presence of MAP was identified in 42.9% (3/7) of semen samples with nPCR; however, it was not detected through culture. In conclusion, the presence of MAP was identified in lymphatic, digestive tissue, and semen; the presence of MAP was reported for the first time in epididymis, Cowper gland, prostate and testicles of infected Pelibuey rams.

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.