José Maria Carrera Chávez

• Doctor of Veterinary Science
• Professor at Universidad Autónoma de Ciudad Juárez

Es indiscutible la importancia de los antibióticos (AB) para la salud humana y animal, así como en la producción de alimentos de origen animal. Sin embargo, su uso indiscriminado ha provocado que la resistencia a los AB (RAB) se convierta en una crisis global que puede alcanzar niveles catastróficos. Este uso desmedido es especialmente grave en la...

To evaluate α-tocopherol supplementation on in vitro maturation of oocytes and their embryonic development, maturation, cleavage, blastulation and blastocyst expansion of 1019 high- and low-quality oocytes supplemented with 100, 200, 400 µL of α-tocopherol or ethanol during maturation were evaluated. Maturation rate of high-quality oocytes was simi...

Cryopreservation has adverse effects on the post‐thaw sperm quality due to oxidative stress and the presence of bacteria. To minimize such effects, plant extracts have been included in the composition of the semen diluents. The objective of the present study was to evaluate the antimicrobial and antioxidant effects of Moringa oleifera seed extract...

Resumen: Hoy en día, las biotecnologías reproductivas han hecho posible conservar y aprovechar los recursos zoogenéticos. Una de estas tecnologías son los programas de sincronización de estros, mismos que permiten programar la época para el empadre acorde a la disponibilidad de forraje o el nacimiento de los becerros por fines comerciales. Otra apl...

Cryopreservation induces oxidative stress that has adverse effects on post-thawed semen quality. The objective was to evaluate the effect of adding quercetin to sheep semen cryopreservation medium. Semen was collected from three sheep stallions by artificial vagina, and a commercial diluent was used. Treatments were: control; quercetin 200 µM; vita...

The period of both in vitro maturation (IVM) and incubation with oocyte activators affects the blastocyst yield following parthenogenetic activation (PA). Nevertheless, it is still unknown how these conditions impact the expansion and hatching rates of bovine parthenogenetic blastocysts. The objective of this study was to assess the influence of th...

Influence of both the presence of a corpus luteum on the ovary and semen sex-sorting on development following in vitro fertilization is not yet conclusive. To determine the effect of these factors, 376 bovine oocytes were processed in vitro according to luteal presence on the ovary (CL+ and CL−) and type of semen used (sexed or conventional). Matur...

Tres protocolos reproductivos fueron evaluados: 1) PG: inyección de PGF2α en el día 50 posparto e inseminación (IA) en base a detección del estro. 2) OVS (Ovsynch: día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA); y 3) ROV (GnRH + Ovsynch: día- 7, GnRH; día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA). Además, el efecto de la somatotropina (b...

El tipo de alojamiento como otros factores tales como el manejo durante la vacunación, el pesaje semanal y el corte de pico, puede incrementar la mortalidad en las pollitas de reemplazo durante su crianza. El objetivo fue registrar las causas de mortalidad macroscópicas en granjas de pollitas en fase de crianza de la semana 1 hasta la 16 de edad. L...

Semen cryopreservation damages sperm due to oxidative stress. This study evaluated the antioxidant capacity of Moringa oleifera seed extract in cryopreserved ram semen and the impact of the extract on sperm characteristics. Semen from eight hair rams (four rams per sampling) was allocated into four groups, according to their treatment prior to cryo...

La porcicultura rural ayuda a mitigar la pobreza alimenticia; en condiciones rurales la alimentación de los cerdos se efectúa con residuos orgánicos alimenticios (ROA) que son los desperdicios de los alimentos destinados a la alimentación humana. El objetivo fue evaluar la inclusión de harina de ROA en una dieta iniciador en presentación pellets en...

ABSTRACT. The objective was to determine the association between different risk factors for placental retention (PR) in northern Mexico. Records of 2 492 Holstein cows from a commercial dairy herd located in Ciudad Juárez, Chihuahua, Mexico were used. Variables were analyzed by the chi-square test (χ 2) test and odds ratios (OR) were calculated to...

The objective of the study was to evaluate the phytobiotic activity of Larrea tridentata, Origanum vulgare and Plectranthus amboinicus on Gram positive and Gram negative bacteria of common presence that endanger human health directly or indirectly. Extracts of leaves from each of the three plants under study were prepared in 75% ethyl alcohol, in p...

Abstract Background: Villi morphology and function affect the absorption capacity of the small intestine. Most tissues are fragile and their morphology may change with excessive manipulation and inadequate sampling techniques. Intestinal sampling includes methodologies such as cutting longitudinally or transversely, keeping the intestinal content i...

Trypan Blue (TB) and Brilliant Cresyl Blue (BCB) are used to select and determine viability and competence of oocytes, however, the effects of corpora lutea on cumulus expansion during in vitro maturation are still undetermined. Cumulus-oocytes complexes (COCs) from ovaries with ipsilateral (ICL), contralateral (CCL) and without corpora lutea in ei...

Ruminal acidosis in ruminants is a metabolic disorder of gastrointestinal origin that occurs in animals with a high feed intake of cereal grains diets, which affect the performance. According to clinical manifestations it can be classified as: a) acute lactic acidosis with prolonged exposure to ruminal pH ≤ 5.0, triggering a systemic acidosis, with...

En México la producción avícola se desarrolla en diferentes contextos. La avicultura de traspatio es la actividad pecuaria de mayor tradición y difusión en el País. No se tiene conocimiento sobre las características o de la actividad avícola de traspatio en zonas urbanas con actividad industrial en México, siendo difícil la comprensión y caracteriz...

Ovine epididymitis caused by Brucella ovis is a chronic disease, characterized by testicular and epididymal alterations, which cause loss of fertility in rams. However, infected rams without clinical signs, may have decreased fertility and be excreting the bacteria. The aim of this study was to evaluate sperm quality in serologically positive to B....

En México la producción avícola se desarrolla en diferentes contextos. La avicultura de traspatio es la actividad pecuaria de mayor tradición y difusión. No se tiene conocimiento sobre esta actividad en zonas urbanas con actividad industrial en México, haciendo difícil la comprensión de la posible problemática que permita orientar acciones encamina...

En este estudio se evaluó el efecto de la somatotropina bovina (bST) y la sobrealimentación sobre la calidad y el desarrollo de embriones obtenidos de ovejas superovuladas. Se utilizaron 24 donadoras asignadas a cuatro grupos: 1) Grupo sobrealimentación, sobrealimentación con 250 gr de maíz; 2) Grupo bST-50, administración de 50 mg de bST; 3) Grupo...

Poultry farmers in the southeastern of Mexico consider that the productivity of the hens that comes from rearing on floor has a higher productive performance than reared hens in cages, mainly due to higher percentage of egg laying and lower mortality. The aim of this study was to evaluate the productive performance of the laying hen in relation to...

To evaluate the effects of season on semen, scrotal circumference and testosterone concentration in Corriente and European-breed bulls, 758 samples were analyzed in four years. Comparisons were made between bulls of the same breed in different seasons and between bulls of different breeds in the same season. Scrotal circumference of both breeds was...

This study evaluated whether the administration of 50 and 100 mg bovine somatotropin (bST) at the start of estrous synchronization and at the time of artificial insemination improves lambing rate and prolificacy in hair sheep. Four hundred eighty adult hair ewes (Pelibuey, Blackbelly, Dorper, Katahdin, and their crosses) were synchronized with intr...

In Mexico, poultry production systems are developed under different contexts. Backyard poultry is the livestock activity of most traditional and diffusion in the Country. It has no knowledge about the characteristics or the backyard poultry activity in an urban area with industry activity in Mexico, making it difficult comprehension and characteriz...

This study evaluated whether the administration of 50 and 100 mg bovine somatotropin (bST) at the start of synchronization and at the time of natural mating in ewes improves the ovulation rate, embryonic development and pregnancy rate of transferred embryos. Forty-eight donors were assigned to three treatments: the bST-100 treatment (n = 15) receiv...

El objetivo de este estudio fue evaluar la calidad espermática y las alteraciones testiculares en ovinos naturalmente infectados serológicamente positivos a B. ovis. Se muestrearon 207 sementales en 11 unidades de producción. El examen clínico se realizó a través de palpación, y se obtuvieron muestras seminales utilizando un electroeyaculador manua...

Epididymitis due to Brucella ovis infection lead to a disease with great importance in Mexican sheep industry. In the affected rams produces a low productivity due to a decreased fertility. The objective of the study was to determine the relevance of different possible risk factors (production system, density of sires, population of ewes, ewes:ram...

La productividad de la ovinocultura en el estado de Zacatecas, México Resumen En México, la ovinocultura es de las actividades pecuarias que tiene una de las mejores tasas de rentabilidad y perspectivas de crecimiento. Zacatecas ocupa el cuarto lugar nacional en inventario y el quinto lugar en la producción de carne de ovino. Sin embargo, los nivel...

Epididymitis due to Brucella ovis infection lead to a disease with great importance in Mexican sheep industry. In the affected rams produces a low productivity due to a decreased fertility. The objective of the study was to determine the relevance of different possible risk factors (production system, density of sires, population of ewes, ewes:ram...

Se describe la situación de la ovinocultura en el municipio de Pinos, Zacatecas, el cual está ubicado en el semidesierto del sureste del estado, el propósito del presente estudio fue evaluar las características y factores que intervienen en la producción ovina, este municipio cuenta con el mayor inventario ovino en la República Mexicana, sin embarg...