Abstract: The aims of this study were to investigate whether treatments with zinc edetate (Zn) and diphenyl diselenide ((PhSe)2) enhance performance, immune responses, protein metabolism, and oxidant/antioxidant status in calf serum and muscle. Animals were divided into four groups (n=6 each): control (without supplementation), and groups supplemented on days 50 and 70 of life with (PhSe)2, Zn, and a combination of (PhSe)2 and Zn. Animals treated with (PhSe)2 gained more weight by experimental day 220 than did the control group, but there was no difference by the end of the experiment (day 300). The absolute number of leukocytes and lymphocytes increased in groups Zn and (PhSe)2+Zn on day 20 of experiment, but decreased on day 40 in groups (PhSe)2, and (PhSe)2+Zn. The number of monocytes decreased in all groups compared with control. One of the principal findings was that (PhSe)2+Zn together had beneficial effects on protein metabolism, represented by increases total protein and globulin levels, compared with the control group. The combination of (PhSe)2 and Zn led to low levels of TBARS and ROS in serum and muscle, and stimulated antioxidant enzyme activities. Thus, supplementation with (PhSe)2+Zn may be a compelling approach to augmenting the calf antioxidant system during weaning.

RESUMEN Objetivo. El objetivo de este estudio fue evaluar la influencia de la suplementación subcutánea con diselenuro de difenilo (PhSe)2 en ovejas lecheras infectadas con nematodos sobre la salud animal y posible daño al ambiente cuando las heces de estos animales se utilicen para fertilizar. Materiales y métodos. El experimento se realizó utilizando 16 ovejas lecheras, que se dividieron en dos grupos: el grupo A se usó como control y el grupo B se suplementó con 3 µmol/kg of (PhSe)2 vía subcutánea. Se utilizaron muestras de sangre para determinar la función hepática, así como el metabolismo de proteínas y lípidos en animales. Las heces se utilizaron para determinar el número de huevos por gramo de heces (EPG), así como para las pruebas de ecotoxicología. Resultados . La suplementación (PhSe)2 no afectó la reproducción de helmintos. Los niveles totales de proteína y globulina aumentan (p<0.05) en los animales suplementados, mientras que los niveles séricos de alanina aminotransferasa (ALT) disminuyen (p<0.05) al final del diseño experimental. Los niveles de colesterol aumentan (p<0.05) en los animales suplementados, mientras que los triglicéridos, la albúmina y la urea no difieren entre los grupos (p>0.05). Las heces de ovejas suplementadas no interferían en la reproducción de las colas de caballo. Conclusiones. A la dosis administrada, el (PhSe)2 no es capaz de controlar el parasitismo; sin embargo, aumenta los niveles de globulinas y colesterol, que son importantes para la respuesta inmune y para la reproducción, respectivamente. Las heces de animales suplementados pueden usarse como fertilizantes orgánicos, sin impactos negativos en ambiente.

ABSTRACT Objective. The aim of this study was to evaluate the influence of subcutaneous supplementation with diphenyl diselenide ((PhSe)2) in dairy sheep infected with gastrointestinal nematodes on animal health and possible damage to environment when the feces of these animals will be used for fertilizing. Materials and methods. The experiment was performed using 16 primipara dairy sheep, that were divided into two groups: the group A as control and the group B supplemented with 3 µmol/kg of (PhSe)2 subcutaneously. Blood samples were used to determine the hepatic function, as well as the protein and lipid metabolism in animals. Feces were used to determine the number of helminths eggs per gram of feces (EPG), as well as used for ecotoxicology tests. Results. The (PhSe)2 supplementation not affected the helminths reproduction, since the EPG did not differ (p>0.05) between groups. Total protein and globulin levels increase (p<0.05) in supplemented animals, while the seric alanine aminotransferase (ALT) levels decrease (p<0.05) in the end of experimental design. Cholesterol levels increase (p<0.05) in the supplemented animals, while triglycerides, albumin and urea not differ between groups (p>0.05). The feces of supplemented sheep not interfered the springtails reproduction. Conclusions. At the administered dose, the (PhSe)2 is not able to control the parasitism, however, it did increase the globulins and cholesterol levels, that are important to immune response and for sheep reproduction, respectively. Also, the feces of supplemented animals with (PhSe)2 can be used as organic fertilizing, without negative impacts to environment.