Ruminants are highly susceptible to photosensitization caused by the ingestion of hepatotoxic plants. In two adjacent farms in Colima, Mexico, several sheep exhibited signs of depression and crusting dermatitis involving the ears, periorbital skin, eyelids, nostrils, and axillary regions. Results of serum biochemistry were indicative of liver injury. Post mortem examination revealed jaundice, craniofacial edema as well as an enlarged liver having an orange-brown discoloration; on the cut surface, the hepatic parenchyma had a subtle zonal pattern. Histopathological findings were those of severe necrotizing dermatitis, lymphoplasmacytic cholangiohepatitis, and renal tubular necrosis. Acicular crystals were microscopically and ultrastructurally evident in hepatocytes, Kupffer cells, biliary ducts, renal tubules and interstitium. The clinical, gross and microscopic findings were consistent with hepatogenous photosensitization. A field investigation revealed that affected sheep had been grazing Brachiaria spp., a potentially toxic grass originated from Africa and commonly cultivated in Australia and South America. This grass contains hepatotoxic saponins that cause liver injury and secondary hepatogenous photosensitization. Although frequently reported in South America, to our knowledge, this is the first report of Brachiaria spp. toxicity in Mexico.

El objetivo del presente estudio fue determinar las causas e identificar los factores de riesgo asociados a la mortalidad predestete en cuatro hatos bovinos de doble propósito en Colima, México. Se seleccionaron cuatro hatos y se registraron los nacimientos y muertes durante 12 meses. Se recolectó información sobre sobre el número de parto de la vaca y el sexo del ternero. Se realizó la necropsia en los casos de muerte. Los datos fueron analizados mediate la prueba de Chi-cuadrado y por regresión logística. La tasa de mortalidad predestete fue de 4.30%, ocurriendo la mitad de las muertes dentro de las primeras 48 horas del nacimiento, especialmente por distocia (50%) y anormalidades congénitas (25%). Se encontró asociación significativa entre mortalidad con el hato y el número de parto de la vaca (p<0.05), pero no con el sexo del ternero. Los terneros nacidos en el hato C tuvieron 4.60 veces más probabilidades de morir que aquellos nacidos en los otros tres hatos, en tanto que los terneros nacidos de madres multíparas presentaron un riesgo de muerte 72% menor que los nacidos de madres primíparas.

No abstract

Crocodylus moreletii and Crocodylus acutus are two endangered crocodile species endemic to Mexico. In this descriptive cross-sectional study, a total of 58 crocodiles (30 females and 28 males) were examined to determine and evaluate 24 blood biochemical indicators associated with energy, lipid, protein, mineral and enzymatic metabolic processes. Most of the serum biochemistry parameters were similar among sexes by species. However, male crocodiles showed higher triacylglycerol concentration and alkaline phosphatase activity, and lower globulin concentration than females. There were some significant differences between species. Total bilirubin, triacylglycerol, carbon dioxide, and hydrogen carbonate were higher in Crocodylus moreletii, and urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase were higher in Crocodylus acutus. These reference values are very important for the protection of crocodiles. The calculated confidence intervals could be used to detect alert situations when at least 5% of the sampled crocodiles would fall outside of the calculated reference interval for a given parameter.

Efecto del nivel de dióxido de carbono de la incubadora sobre el desarrollo embrionario y parámetros de eclosión en pollo de engorda Effect of incubator carbon dioxide level on embryonic development and hatching parameters in broiler chicken