This study evaluated the effect of supplementing increasing levels of L-methionine (L-Met) in the diet for Muscovy ducks from hatch to 21 days of age. A total of 90 male Muscovy ducklings were assigned to 30 pens with 3 birds per pen. A basal diet with corn, soybean and wheat by-product was supplemented with 0, 0.08, 0.16, 0.24, 0.32 and 0.40% L-Met, obtaining 6 diets with increasing concentrations of sulfur amino acids, but constant in energy and other essential nutrients. Analysis of variance and Tukey's mean comparison test were performed. In addition, an effective dose-response model was performed to determine the optimal methionine level. Body weight and feed intake were not influenced (p>0.05) by L-Met supplementation, although a numerical trend towards greater weights was observed as supplementation increased. Feed conversion was significantly better with 0.24 and 0.32% L-Met s...

The objective of the study was to determine the effect of chemical castration using iodine tincture on the productive and behavioral performance of the guinea pig. Twenty four crossbred Peru-Inti guinea pigs from 25 to 35 days of age were used and allocated in two groups: castrated and non-castrated. Iodine tincture at 2%, dose of 0.1 ml per testicle, was used for the castration at the second week of the study. Weekly body weight and at slaughter, daily body weight gain, and number of fights were evaluated using a completely randomized design with covariance for initial body weight. Weekly body weight was higher in castrated animals from the fourth week of the study (706.5 vs 648.8 g) onwards (p<0.05). Body weight at slaughter (837.9 vs 738.40 g) and daily body weight gain (9.06 vs 6.94 g) were higher in the castrated (p<0.01). The number of fights (7.8 vs14.4) was lower in castrat...

El objetivo del estudio fue determinar el efecto de la castración química con tintura de yodo sobre el comportamiento productivo y conductual del cuy. Se utilizaron 24 cuyes cruzados Perú-Inti, de 25 a 35 días de edad, distribuidos en dos grupos: castrados y no castrados. La castración se realizó en la segunda semana del estudio por inyección intratesticular de tintura de yodo al 2% en dosis de 0.1 ml por testículo. Se evaluó el peso semanal y al beneficio, ganancia de peso diaria, y el número de peleas, a través de un diseño completamente al azar con covarianza por peso inicial. El peso semanal fue mayor en los castrados a partir de la cuarta semana del estudio (706.5 vs 648.8 g, p<0.05). El peso al beneficio (837.9 vs 738.4 g) y la ganancia de peso diaria (9.06 vs 6.94 g) fueron mayores en los animales castrados (p<0.01). El número de peleas registradas (7.8 vs 14.4)...