Alejandro Córdova-Izquierdo

Breed differences in calving interval in the humid Mexican tropic

The objective of this study was to evaluate the influence of breed, breed and sex of the calf, farm, calving number (CN), type of calving, and their interactions on CI using records from four different beef breeds performing in the humid tropical environment of Mexico. The influence of these factors on CN was also evaluated. CI and CN varied with farm, breed of the dam, and with breed of the dam by calf breed interaction (P<0.001), while CI also varied with CN. Significant differences between Bos indicus and Bos taurus breeds for CI (432 vs. 488 days) and for CN (2.13 vs. 1.92) were observed (P<0.001). The interaction effects observed between breed of the dam by breed of the calf on CI and on CN were due to a favorable F1 calf effect on CI observed only in Angus cows, although with an apparent unexpected negative impact on CN.

Best Practices in Animal Reproduction: Impact of Nutrition onReproductive Performance Livestock

The impact of nutrition on reproduction of livestock is of vital importance and is directly related to body condition of the animals, which reflects directly on reproductive performance, both female and male animals. In this short review, emphasis on the importance of nutrition on puberty, estrous cycle, fecundation, delivery and postpartum period is made.

Efecto de la vacunación de cerdas y lechones contra circovirus porcino tipo 2 (PCV2) en la ganancia de peso y porcentaje de mortalidad en México

El objetivo del presente estudio fue evaluar la eficiencia de tres protocolos de vacunacion (cerdas, lechones o cerdas y lechones), sobre la media de la ganancia diaria de peso y porcentaje de mortalidad en lechones desde el parto hasta la finalizacion, en una granja con Sindrome Multisistemico de Desmedro Postdestete (PMWS). Durante el periodo posterior a la vacunacion (semana 3-22) de lechones, cerdas y lechones, estos mostraron un aumento significativo en la media de la ganancia diaria de peso y una reduccion significativa en el porcentaje de mortalidad. Las cerdas y lechones vacunados contra PCV2 para el periodo de estudio (semana 1-22), tuvieron un aumento significativo en la ganancia diaria de peso y una reduccion significativa en el porcentaje de mortalidad cuando se les comparo con el grupo control. Estos datos demuestran que la vacunacion contra PCV2 fue efectiva en mejorar el crecimiento y reducir el porcentaje de mortalidad en una piara infectada con PCV2.

Efecto del estrés calórico y el estrés oxidativo en la función espermática de los mamíferos

Several studies have reported a decrease in the reproductive capacity of the male due to heat stress and its effect on the production of reactive oxygen species (ROS) in sperm. Therefore, the objective of the present work is to show a general view of the risks of the warm environment, oxidative stress and the mechanisms by which there are an alteration in sperm capacity in the male. Sperm and seminal leukocytes produce most ROS. ROS cause damage to the sperm membrane (containing polyunsaturated fatty acids PUFAs), decreased motility, poor ability to fuse with the oocyte, and alteration of sperm DNA, causing poor embryonic development and low fertility. Therefore, the determination of ROS in sperm could be considered an alternative diagnostic tool to identify the etiology of male infertility.

Effects of Jejunal Manipulation During Surgical Laparotomy Techniques and Its Evaluation Using Physical, Clinical, and Echographic Parameters in Horses

Abstract The laparotomy surgical procedure allows for the identification and correction of intestinal lesions associated with acute abdomen in horses. The clinician relies on various laparotomy techniques to diagnose and treat this syndrome, and to date, the postsurgical effects of these techniques have not been clarified. The aim of this study was to evaluate the effects of jejunal manipulation during three laparotomy techniques through physical and clinical parameters and echography. Fifteen healthy horses were randomly assigned to three groups: animals in G1 (n = 5) were subjected to an exploratory laparotomy, animals in G2 (n = 5) to a laparotomy with an enterotomy, and animals in G3 (n = 5) to a laparotomy with an enterectomy. Degree of pain, jejunal wall thickness, and clinical parameters were evaluated before and after surgery. Horses in G3 had higher heart rates, respiratory frequency, degree of pain, and jejunal wall thickness compared with G1. Clinical variables during the postsurgical period were compared among the laparotomy techniques, and higher values of erythrocytes, leucocytes, neutrophils, and proteins were found in horses belonging to G3 compared to those in G1. Intestinal manipulation during the surgical procedure altered the physical and clinical parameters, as well as the results of the echography evaluation, with more significant effects from laparotomy with enterectomy. In the postsurgical period, the heart rate of horses in G3 was higher (P = .02) than the values obtained in G1 and G2. Upon the evaluation of degree of pain, statistically significant differences (P = .04) were identified between horses in G1 versus G3. G3 animals presented a higher degree of pain. Regarding the erythrocytes (L/L), higher values were measured in G3 (P = .001) in comparison with G1 and G2. These results suggest that meticulous tissue handling is essential to minimize intestinal trauma and inflammation. HighlightsIntestinal manipulation altered physical and clinical parameters in laparotomy with enterectomy.Increases in postsurgical intestinal thickness during jejunal manipulation on enterectomy.Enterectomy shows highest degree of pain and increased heart rate 24 hours postoperatively.

Composición nutricional, consumo e índices de palatabilidad relativa de los frutos de tres acacias en la alimentación de ovejas y cabras

The aim of this study was to determine the nutritional composition of Acacia farnesiana , Acacia macilenta and Acacia cochliacantha fruits and determine...

Identificación de nuevos péptidos de una biblioteca de despliegue en fagos con un anticuerpo monoclonal específico a la proteína N del virus PRRS

El objetivo del estudio fue seleccionar de una biblioteca combinatoria de fagos filamentosos clonas que mimeticen la proteina N del virus del Sindrome Respiratorio y Reproductivo Porcino (PRRS) utilizando un anticuerpo monoclonal (SDOW17). Se utilizo una biblioteca combinatoria de fagos filamentosos (M13) que expone aleatoriamente peptidos de 7 aminoacidos en la region N-terminal fusionado con la proteina III. Para determinar el efecto del enriquecimiento despues de cada ronda de seleccion, los fagos eluidos fueron titulados; estos se incrementaron de 4,8 x 103 unidades formadoras de colonias (ufc) en la primera ronda a 3,2 x 105 ufc en la tercera. Despues de tres rondas de seleccion, 32 clonas fueron picadas al azar, cada clona individual fue amplificada, purificada y titulada. La reactividad de la union de las clonas a los anticuerpos anti-PRRS fue determinado utilizando un ELISA de fagos. El alineamiento de las clonas secuenciadas con la obtenida del GenBank, ubican a estas en la region aminoterminal y porcion media de la proteina N del vPRRS. La secuencia consenso de las 32 clonas seleccionadas fue NYRYQ. Las secuencias de los mimotopos fueron utilizadas para calcular los epitopos de la proteina N, mediante la herramienta bioinformatica del servidor Peptiope con el algoritmo PepSurf. Dos epitopos conformacionales contra el anticuerpo monoclonal antiproteina N fueron identificados, localizados en diferentes posiciones y presentados principalmente como helices a. Los mimotopos seleccionados y epitopos conformacionales podrian ser considerados informativos para el diagnostico de la enfermedad