Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

La neosporosis caprina es una enfermedad abortiva que ocasiona pérdidas económicas a la industria caprina. Se llevó a cabo un estudio enfocado en medir la seroprevalencia e identificar los factores de riesgo asociados a neosporosis mediante un estudio transversal multietápico estratificado en 14 municipios del centro de Veracruz, México. Se muestrearon seis animales por granja, machos y hembras mayores de 3 meses de edad. El diagnóstico se realizó con un kit comercial de ensayo inmunoabsorbente ligado a enzimas (ELISA) indirecto. Se identificaron los factores de riesgo por medio de dos cuestionarios, uno general para cada hato y uno individual para cada animal seleccionado. Los resultados se analizaron mediante estadística descriptiva y la asociación entre las variables mediante razón de momios y regresión logística para buscar posibles relaciones con los factores de riesgo. En el total de 550 muestras hubo una seroprevalencia general de 3.6 %. Entre municipios la frecuencia fue de 64.2 % y entre granjas de 17.2 %. La interacción entre el movimiento de animales y su lugar de origen desde otros estados se identificó como un factor de riesgo (P<0.05). A diferencia de las hembras seronegativas, las seropositivas fueron más susceptibles a los abortos. Si bien fue baja la seroprevalencia general de neosporosis en cabras del centro de Veracruz, México, la enfermedad presenta una amplia distribución entre los municipios y las granjas estudiados, y diversos factores de riesgo contribuyen a su presencia en la región.

The experiment was conducted to determine the effect of adding Bryophyllum daigremontiana to the feed of broiler chickens on their productive performance and their blood concentration of liver enzymes and troponin T. For this purpose, 120 1-d-old Cobb chicks were randomly assigned to two treatments: a control group and the addition of 20 g of B. daigremontiana per ton of feed. The experiment lasted 49 d, and the body weight, feed intake, and feed conversion were recorded. At the end, blood samples were obtained, and the concentrations of troponin T, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase were determined. The data were analyzed in a mixed model of random and fixed components. Chicks fed with B. daigremontiana had higher (P<0.05) daily weight gain and final weight, better feed conversion, and lower (P<0.05) liver enzyme and troponin T concentrations, compared to the control. The authors conclude that B. daigremontiana improves the productive performance and liver indicators in broilers.

Rhipicephalus sanguineus is a tick considered a vector of diseases for both animals and humans. Its life cycle is complex to study under laboratory conditions due to its feeding and reproductive habits, which limits in vitro research. This study aimed to compare two different models of in vivo feeders for ticks by using the biological cycle of R. sanguineus fed on rabbits as an evaluation method. Two artisanal feeding chambers measuring 60 x 40 mm and 25 x 40 mm were designed and placed on rabbits. The results revealed that the 60 x 40 mm chamber provided better reproductive parameters and a higher recovery rate for both nymphs (82.3 %) and adults (26 %), compared to the 25 x 40 mm chamber (34.7 % for nymphs and 10 % for adults) (P≤0.05). The biological cycle had a similar length in both chambers (74.4 days for the large chamber and 74.1 d for the small one), but there were differences (P≤0.05) in the weight of larvae, nymphs, adult females, and the length of the larval feeding period.

This research aimed to analyze the food composition and preferences of bighorn sheep in Sierra Juárez and Sierra Santa Isabel during the wet and dry seasons of 2022-2023. To assess forage availability, 17 100-meter-long Canfield lines were implemented. Dietary composition was determined by micro histology of fecal samples, whereas forage and diet diversity were calculated using Shannon’s index. Forage selection was evaluated with Ivlev’s index. It was observed that the most common biological forms in the habitat of bighorn sheep were trees and shrubs. In Sierra Juarez and Sierra Santa Isabel, 31 and 43 species of plants were identified in their diet, respectively; trees and shrubs were the most consumed. There were no differences in diet between times and sites. Larrea tridentata and Hibiscus denudatus were the most frequent in the diet, whereas the preferred ones included Eriogonum inflatum, H. denudatus, Horsfordia newberryi, Justicia californica, and L. tridentata. These results provide information to establish strategies for conservation and community management of bighorn sheep in Baja California.

This study evaluated effect of bisection of in vitro and in vivo development of in vivo produced bovine whole and demi-embryos after vitrification/warming. Ninety vitrified bovine embryos were distributed in two treatments: CE = Embryo culture (n = 21), with CE1: 11 embryos (22 demi-embryos), and CE2: 10 whole embryos. The embryos were placed in an atmosphere of 5% CO2 in air and 95% humidity at 38.5ºC and checked every 24 hours for 72 hours. For in vivo development (TG), 69 embryos were transferred. TG1: transfer of 31 embryos (62 demi-embryos), and TG2:38 whole embryos. For the analysis of the viability of demi versus whole embryos at 24, 48 and 72 h the model included only the treatment effect, using the probit function and for TG analysis a mixed threshold model with SAS PROC GLMMIX was used. From T1, 77.3 vs 80% viability 72 h post warming were obtained in CE1 and CE2 in demi and whole embryos, respectively (p> 0.05). In addition, in T2 the pregnancy rate was 19.35 vs 31.6% in TG1 and TG2, respectively (p> 0.05). It is concluded that vitrification did not affect the in vitro or in vivo development, nor TG In addition, the same number of pregnancies with fewer embryos was obtained with demi-embryos.

Bovine embryo bisection and vitrification protocols can affect pregnancy and early pregnancy loss rates. It was compared pregnancy rates at 30 d post-transfer and early pregnancy loss rates at 60 d post-transfer using in vitro-produced vitrified bovine embryos and hemi-embryos. Sixty (60), grade 1 bovine blastocysts were randomly distributed into two treatments: (1) Vitrified whole embryos (n= 30), and (2) vitrified bisected embryos (hemi-embryos) (n= 30). Embryo bisection was done prior to vitrification. Whole embryos and hemi-embryos were vitrified, stored, thawed, and transferred to 60 recipients. Pregnancy was diagnosed by transrectal ultrasound at 30 d post-transfer, and pregnancy loss measured at 60 d. Pregnancy and pregnancy loss rates were analyzed as binomial variables (0= not pregnant; 1= pregnant) and compared using Fisher’s exact test. Neither rate differed between the hemi-embryos and whole embryos. Pre-vitrification bisection of in vitro-produced embryos affects neither pregnancy rate nor early pregnancy loss rate. This technique simplifies the transfer process because it removes the need for in-field bisection.

Maedi-Visna disease (MV) is caused by a retrovirus that affects sheep and causes pneumonic, nervous, and arthritic conditions and mastitis. Its distribution is cosmopolitan, notifiable, and endemic in Mexico. An epidemiological study was conducted in sheep farming basins in the state of Veracruz, Mexico, to determine the seroprevalence of MV and identify its risk factors and spatial distribution in the state. The sample size was 386 animals in 55 randomly selected production units (PUs). Blood serum was collected from the ewes, and the diagnosis was performed in series using two commercial ELISA kits in screening and confirmatory modalities. The distribution map was constructed with QGIS® version 3.0. The overall seroprevalence was 9.59 %, the seroprevalence by municipality was 69.23 %, and the seroprevalence by production unit was 32.14 %. Risk factors were identified as pregnant ewes, coexistence with other ruminant species, sheep aged 13 to 24 mo, the intensive production system, animals located in the Totonaca region, and animals from municipalities with an altitude of less than 500 m asl and environmental temperature of more than 15 °C (59 °F).

In order to evaluate the productive efficiency of Brahman cows based on their body size at weaning, the records of 765 Brahman cows were used. All animals were kept in extensive grazing with the same management during the preweaning period. The response variables analyzed were the adjusted 205-d weaning weight of the calf (AW205), the cow weaning weight (CWW), and the weaning efficiency measure used was (AW205/CWW) * 100 (WWR). The analyses of CWW, AW205, and WWR were performed with PROC GLM of SAS. Analyses included the effect of cow weight group (light, moderate, and heavy), the effects of the year (1998–2019) and month (November, December, January, and February) of cow birth, and cow age at calving (2–8). For CWW, there were differences (P<0.01) between the three weight levels of the cows. Cows in the heavy group were 19 and 10 % heavier (P<0.01) than cows in the light and moderate groups. All estimated correlations were significant (P<0.05), except for the correlation between AW205 and CWW in the heavy cow group. The most efficient cows at weaning were those with lighter weaning weights. WWR, as an efficiency measure, should be used cautiously as it does not consider possible increases in feed intake or milk production.

Donkeys Equus asinus are very important in rural Mexican communities for their utility as transport and pack animals. Morphometric and health data were collected for donkeys in a rural municipality in central Veracruz state, Mexico. A participatory workshop on donkey care and use was held with owner families to establish how they cared for their animals, and social perceptions of them. A total of 200 adult donkeys from 200 families were sampled. Morphometric measurements were taken, blood samples taken for hematology analyses, and feces for parasitology. Donkey morphometric data placed them in the small to medium standard size. Average age was six years, and body condition and weight were acceptable. Two thirds of the sampled donkeys had a medium-low parasite load, and all had hematological data within reference indices for healthy animals. Average daily use of the donkeys was six hours, and they were most commonly used for hauling.

El destete es un evento traumático para el lechón, ya que implica cambios que son responsables de alteraciones gastrointestinales, una disminución de la productividad o incluso la muerte. El desarrollo de resistencia bacteriana debido a la inclusión de dosis subterapéuticas de antibióticos en las dietas de inicio se ha convertido en un importante asunto de salud pública, prohibiendo su inclusión en la alimentación animal. El concentrado de proteína de papa (CPP) se ha considerado una alternativa para regular la inflamación y los trastornos intestinales debido a su contenido de péptidos antimicrobianos que tienen efectos beneficiosos sobre la homeostasis intestinal. En este estudio se evaluó el efecto del nivel de inclusión de CPP en una dieta libre de antibióticos sobre la concentración de marcadores inflamatorios como interleucina-12p40 (IL-12p40) y factor de necrosis tumoral alfa (TNF-α) en el tejido ileal y la concentración de ácidos grasos volátiles (AGV) en la digesta colónica. Se asignaron 90 lechones a tres tratamientos: 1, dieta basal (C) (dieta sin antibióticos ni CPP); 2, dieta basal con 6 % de CPP (CPP 6%) y 3, dieta basal con 8 % de CPP (CPP 8%). A los 15 días posdestete, se eutanasiaron seis lechones por tratamiento para la recolección de muestras. El grupo CPP 8% tuvo los niveles más altos de AGV y la concentración más baja de citocinas inflamatorias en comparación con el grupo C, que tuvo los niveles más bajos de AGV y la concentración más alta de marcadores inflamatorios. La inclusión de CPP en las dietas de inicio de lechones destetados puede ser una alternativa eficaz para regular la disbiosis intestinal durante el destete.