Influence of gender on carcass yield of twin lambs Blackbelly x Pelibuey at 56 days of age / Influência do gênero no rendimento de carcaça em cordeiros gêmeos Blackbelly x Pelibuey aos 56 días de idade

The aim of this study was to determine the influence of gender on pre-weaning growth, yield and weight of primal cuts of the carcass of Blackbelly x Pelibuey lambs. 16 twin lambs were used. The lamb gender was the fixed factor. The variables evaluated were: body weight at birth and at weaning, average daily weight gain, weight and yield of carcass and primal cuts: neck, arm, thorax, abdomen and leg. Gender did not affect (P>0.05) body weight at birth. However, the pre-weaning average daily weight gain and body weight at weaning were affected (P<0.05) by the gender. Hot carcass yield and weight and primal cuts were not affected (P>0.05) by the gender of the lamb. Nevertheless, the area of the Longissimus dorsi muscle and cavity fat were different between males and females (P<0.05) 11.5±0.73cm2 and 198±0.05 g vs 9.3±0.73cm2 and 282±0.05g, respectively. In conclusion, in twin lambs Blackbelly x Pelibuey males had greater average daily weight gain and body weight at weaning than females. Carcass yield and weight and primal cuts were not affected by the gender of the lamb. However, males had greater area of the L. dorsi muscle than females and these in turn had a greater amount of cavity fat than males.(AU)

Objetivou-se determinar a influência do gênero no crescimento pré-desmame, no rendimento e no peso dos cortes primários de carcaça de cordeiros Blackbelly x Pelibuey. Utilizaram-se 16 cordeiros gêmeos. Os dados foram analisados em um desenho completamente ao acaso, em que o gênero dos corderos foi o fator fixo. As variáveis avaliadas foram: peso vivo ao nascimento e ao desmame, ganho diário de peso, peso e rendimento de carcaças e dos cortes primários: pescoço, braço, tórax, abdômen e perna. O gênero não afetou (P>0,05) o peso vivo ao nascimento. No entanto, o ganho diário de peso e o peso vivo ao desmame foram afetados, sendo esses valores superiores nos machos (P<0,05). O peso e o rendimento das carcaças quentes e dos cortes primários não foram afetados (P>0,05) pelo gênero do cordeiro. Entretanto, a área do músculo Longissimus dorsi e a gordura cavitária foram diferentes entre machos e fêmeas (P<0,05): 11.5±0.73cm2 e 198±0.05g vs. 9.3±0.73cm2 e 282±0.05g, respectivamente. Em conclusão, nos cordeiros gêmeos Blackbelly x Pelibuey, os machos tiveram maior ganho diário de peso e maior peso vivo ao desmame do que as fêmeas. O peso e o rendimento da carcaça bem como os cortes primários não foram afetados pelo gênero do cordeiro. Todavia, os machos tiveram maior área do músculo L. dorsi que as fêmeas e estas tiveram maior quantidade de gordura cavitária que os machos.(AU)

Citología y análisis morfométrico de las células del epitelio vaginal durante el ciclo estral en ovejas de pelo (Ovis aries) / Citology and morphometric analysis of epithelial cells from the vagina of hair sheep ewes (Ovis aries) during their estrous cycle

La citología vaginal puede usarse para caracterizar estados del ciclo reproductivo de la hembra. Sin embargo, no ha sido validada en ovinos de pelo, y ofrece resultados inexactos debido a interpretaciones subjetivas. El objetivo del presente trabajo es tipificar las características morfológicas y morfométricas de las células epiteliales de la vagina durante el ciclo estral en ovinos de pelo. Cinco borregas Santa Cruz se sincronizaron con esponjas intravaginales. Desde el día del 1er celo posterior al retiro de la esponja y hasta el siguiente celo, se obtuvieron muestras diarias del epitelio vaginal de cada oveja, y se cuantificó el número de células parabasales, intermedias y superficiales, y se midió la longitud, perímetro y área de citoplasma y núcleo de cada una. Los resultados muestran que las células superficiales incrementan (P<0,05) durante el estro en comparación con el diestro. En contraste, el número de células parabasales e intermedias es mayor (P<0,05) durante el diestro que en el estro. Las células más grandes (36,11+/-0,38 µm) y núcleos más pequeños (8,46+/-0,12 µm) se encontraron durante el estro, independientemente del tipo de célula, mientras que citoplasmas más pequeños (26,72+/-0,11 µm) y núcleos más grandes (10,48+/-0,02 µm) se observaron durante el diestro. Se concluye que la morfología de las células epiteliales de la vagina de la oveja de pelo coincide con las variaciones encontradas en otras hembras, y que el tamaño de citoplasmas y núcleos presenta un patrón cíclico que puede utilizarse para determinar de manera objetiva la etapa del ciclo estral de la oveja.

Vaginal cytology can be used to characterize stages of the reproductive cycle of the female. However, it has not been validated in hair sheep, and generates inaccurate results due to subjective interpretations. Thus, the purpose of the present work is to typify morphologic and morphometric characteristics of the epithelial cells from the vagina during the estrous cycle of hair sheep. Five Saint Croix ewes were synchronized with intravaginal sponges. Day zero of the cycle was considered the day of first estrus after sponge withdrawal. From this day until next estrus, samples from the vaginal epithelium were obtained daily from each ewe. The number of basal, intermediate and superficial cells was quantified, and length, perimeter, and area from cytoplasm and nucleus were obtained. The results show that the number of superficial cells increase (P<0.05) during estrus and decrease during the rest of the cycle. In contrast, the number of basal and intermediate cells showed an inverse pattern. The largest cells (36.11+/-0.38 µm) and smallest nucleuses (8.46+/-0.12 µm) were present during estrus, regardless of the cell type, while the smallest cells (26.72+/-0.11 µm) and larger nucleuses (10.48+/-0.02 µm) were observed during diestrus. It was concluded that citology of the epithelial cells from the vagina of hair ewes is in accord with changes found in other female spices, and that cytoplasm and nucleus sizes display a cyclic pattern that might be used to objectively determine the specific estrous cycle phase of the ewes.

Prevalencia de parásitos gastrointestinales en ovinos sacrificados en un rastro de Tabasco, México / Prevalence of gastrointestinal parasites in slaughtered sheep at a slaughterhouse in Tabasco, Mexico

The objective of this study was to determine the prevalence of gastrointestinal parasitic nematodes in sheep at necropsy at a slaughterhouse in Tabasco, Mexico. Adult parasites from gastrointestinal tract were recovered and preserved in formaldehyde for their later counting and identification. Adult nematodes were separated by species and the final count was transformed to Log + 1 to decrease the variance. GLM procedure using SAS statistic program was performed for data analysis. Provenance, sex, physiological status, and sampling month were considered as the variation sources. From a total sample of 242 slaughtered animals necropsied for monitoring gastrointestinal parasites, 57.4% including Nematoda, Trematoda or Cestoda classes. The main identified species corresponded to Haemonchus contortus in the abomasum. Cooperia curticei, Trichostongylus colubriformis, Strongyloides papillosus and Bunostomum trigonocephalum were found in the small intestine and Oesophagostomum columbianum, and Trichuris ovis in the large intestine. Fasciola hepatica and Moniezia expansa were the Trematoda and Cestoda parasites found in liver and small intestine, respectively with prevalence lower than 7%. The average of the total count of adult nematodes in the gastrointestinal tract of the infested animals was 2175 ± 445. Among the factors studied, the slaughter month and the provenance of the animals affected the prevalence of parasite infestation in sheep at slaughter. The main adult parasites found were H. contortus, C. curticei and T. colubriformis with average counts higher than 1009, 813 and 335, respectively.

El objetivo de esta investigación fue conocer la prevalencia de parásitos en ovinos sacrificados en un rastro en el estado de Tabasco. Se realizó la recuperación y conservación en formol de parásitos adultos presentes en el tracto gastrointestinal, para su posterior conteo e identificación. Los conteos de nematodos adultos por especie se transformaron a Log + 1 para disminuir la varianza, y se realizó el análisis con el procedimiento GLM del SAS en el cual se incluyeron como fuentes de variación: origen, sexo, estado fisiológico y mes de muestreo. De una muestra total de 242 animales sacrificados, se observó que 57.4% se encontraban parasitados con alguna especie de las clases Nematoda, Trematoda o Cestoda. Las principales especies identificadas correspondieron a Haemonchus contortus en abomaso. Cooperia curticei, Trichostongylus colubriformis, Strongyloides papillosus y Bunostomum trigonocephallum en intestino delgado. Oesophagostomum columbianum, y Trichuris ovis en intestino grueso. De los trematodos se encontró Fasciola hepatica en hígado y de los cestodos Moniezia expansa se localizó en intestino delgado con prevalencia menor a 7%. El conteo total de los nematodos adultos en el tracto gastrointestinal de los animales parasitados fue, en promedio, 2175 ± 445. De los factores estudiados, el mes de sacrificio y el origen de los animales afectaron la prevalencia de parasitosis en los ovinos al sacrificio. Los tres principales parásitos fueron: H. contortus, C. curticei y T. colubriformis, con conteos promedio de adultos, superiores a 1009, 813 y 335, respectivamente.

Crecimiento prenatal y predestete en corderos Pelibuey, Dorper, Katahdin y sus cruces en el sureste de México / Prenatal and preweaning growth of Pelibuey, Dorper, Katahdin lambs and their cross in the south-east of Mexico

Registros productivos de 1.097 pesos de corderos al nacimiento (PN), 543 pesos de corderos al destete (PD) y 543 ganancias diarias de peso predestete (GDP) fueron analizados con el objetivo de comparar la eficiencia productiva predestete de tres razas Pelibuey (P), Dorper (D), Katahdin (K) y dos cruces (PxD, PxK). Los registros productivos estudiados procedían de un rebaño localizado en Huimanguillo, Tabasco, México y correspondían al período enero 2001 y abril 2005. Las variables estudiadas fueron pesos de corderos al nacimiento, pesos de corderos al destete y ganancia diaria de peso predestete. El modelo final que describió el PN contempló los efectos fijos significativos de año (AN) de nacimiento (cinco clasificaciones, 2001 a 2005), grupo racial (P, D, K, PxD y PxK) dentro de año de nacimiento GR (AN), tipo de nacimiento (TN) único y doble, la interacción ANxTN, sexo del cordero (SX) hembra y macho, época climática de nacimiento (E) seca, lluvias y nortes. La edad al destete (EDEST) y PN se consideraron como variables continuas independientes en los análisis de PD y GDP predestete. Con excepción de E, todos los efectos principales afectaron (P<0,01) PN, PD y GDP. Época de nacimiento afectó (P<0,01) el PD. La interacción ANxTN afectó únicamente el PN (P<0,01). La eficiencia productiva predestete de Dorper y Katahdin fue mayor que la de los otros grupos raciales. El cruce PxD mostró un mayor PD (P<0,01) que la raza pura Pelibuey en los años 2001 y 2002. La GDP predestete fue mayor en este mismo grupo que el grupo P en el año 2001. La época de lluvias fue la peor, en términos de PD, con 15,4 kg. Los corderos de TN único y los de sexo macho tuvieron mejor eficiencia productiva que los corderos dobles y hembras. La edad al destete y el peso al nacimiento afectaron (P<0,01) el PD. Los coeficientes de regresión fueron de 0,023 ± 0,005 y 1,023 ± 0,315, respectivamente. Se concluye que bajo las condiciones del presente estudio, en el período...

Data from 1097 lambs’ birth weights (BW), 543 lambs’ weaning weights (WW) and 543 preweaning daily gain weight (DGW) were analyzed in order to compare preweaning performance of three breeds Pelibuey (P), Dorper (D), Katahdin (K) and two crosses (PxD, PxK). The variables studied were from a sheep farm at Huimanguillo, Tabasco, México and were collected from January 2001 until April 2005. The traits included lambs’ birth weights, lambs’ weaning weights and preweaning daily gain weight. The final model which describes BW included the fixed effects of birth year (BY) (five classifications, 2001 to 2005), breed group (P, D, K, PxD and PxK) within the birth year BG(BY), birth type (BT) (single and twin), interaction BYxBT, lambs sex (female and male) (SX), birth season (S) (dry, rainfall and rainfall and winds). Weaning age (WA) and BW were as considered as a continuous independent variable. With the exception of S, all the main effects affected (P<0.01) BW, WW and DGW. The interaction BYxBT affected only BW (P<0.01). Lambs PxD showed higher WW (P<0.01) than Pelibuey bred in years 2001 and 2002. DGW was higher in this group than P group in year 2001. The rainfall season was the worst in WW, with 15.4 kg. Single lambs and male lambs had better performance than twin lambs and female lambs. Weaning age and birth weight affecting WW. Regression coefficients were 0.023 ± 0.005 and 1.023 ± 0.315, respectively. In conclusión that under the present conditions, in the preweaning period, the hybrid breed group seems to be less important than others factors (for example: the weaning age, birth season and birth weight) as determinants of the weight at weaning. The Dorper and Katahdin breeds offer a viable alternative, considering the weight of the lambs at weaning in order to include them in systems of production in a humid, hot climate, such as pure breds or a Dorper x Pelibuey crossbreed.

Fertilidad en ovejas de pelo inseminadas con semen congelado rediluido con plasma seminal / Fertility in hair sheep inseminated with freeze spermatozoa rediluited with seminal plasma

El objetivo del presente estudio fue determinar la viabilidad espermática del semen congelado rediluido con plasma seminal a través de la fertilidad de 146 ovejas de pelo, inseminadas vía cervical e intrauterina. La fertilidad se midió en dos tiempos; retorno a celo a los 17 días postinseminación y diagnóstico de gestación por ultrasonografia a los 45 días postinseminación. Los datos de fertilidad se analizaron mediante el test de Ji-cuadrado. Los resultados obtenidos muestran que la adición del plasma seminal en el semen fresco no mejora la fertilidad (P>0,05) obtenida vía cervical e intrauterina, por el contrario, el semen congelado rediluido con plasma seminal, tanto en su aplicación cervical como intrauterina, mejora (P<0,01) los índices de fertilidad en un 41 vs 20% y un 50 vs 16%, respectivamente, a los 17 días postinseminación, resultados que persisten a los 45 días de gestación. Estos resultados permiten concluir que la redilución del semen congelado con plasma seminal proporciona una mayor recuperación de los espermatozoides dañados por choque frío, lo cual se ve reflejado en un mayor porcentaje de fertilidad.

The objective of this study was to determine the spermatozoa viability of the frozen semen rediluted with seminal plasma through the fertility of 146 hair sheep inseminated cervical and intrauterine way. The fertility was measured in two times; return to estrus to the 17 days postinsemination and pregnancy diagnostic by ultrasound scanning to the 45 days postinsemination. The data of fertility were analyzed by means of the Chi-Square test. The obtained results showed that the addition of the seminal plasma in the semen fresh does not improve the fertility (P>0.05) obtained cervical and intrauterine way, on the contrary, the semen frozen rediluted with seminal plasma, so much in its cervical application as intrauterine, improvement (P<0.01) the fertility in a 41% and 50%, respectively to the 17 days postinsemination, results that persist to the 45 days of gestation. The results permit to conclude that the rediluted of the frozen semen with seminal plasma provides a greater recovery of the spermatozoa damaged by cold shock, which it is seen reflected in a greater percentage of fertility.