THE EFFECT OF DIETARY METHIONINE LEVELS ON THE PERFORMANCE PARAMETERS OF ARCTIC FOXES (VULPES LAGOPUS)

The objective of this study was to determine the effect of dietary inclusion levels of methionine and cystine on the performance traits and health status of Arctic foxes. The experimental material comprised 60 blue Arctic foxes of the Finnish type. Control group (C) animals were fed diets (CA and CB) with standard concentrations of methionine and cystine. In experimental groups El and E2, methionine content was increased by approximately 2 g per 100 g total protein, relative to the recommended intake. Diets for group El were supplemented with liquid methionine (E1A and E1B), and diets for group E2 were supplemented with crystalline methionine (E2A and E2B). Diets A were offered during the growing period, and diets B were administered during the furring period. During the growing period, methionine+cystine levels in diets El and E2 were 4.19+0.59 g and 4.22+0.53 g per 100 g total protein, respectively. During the furring period, methionine+cystine levels were 4.83+0.68 g in diets El and 4.91+0.61 g in diets E2. The body weights of Arctic foxes were determined, their body conformation was evaluated, and the duration of the rearing period was calculated. Blood samples for morphological and biochemical analyses were collected from animals aged 24 weeks, selected randomly from each group. After slaughter, pelt length and fur quality were determined in accordance with the International Trading System. The results of this study indicate that diets for Arctic foxes should he supplemented with methionine. The experimental diets contributed to improving the performance traits of foxes, in particular fur quality, and they had no adverse influence on the health status of animals. It may be concluded that farm-raised Arctic foxes of the Finnish type show an increased demand for methionine.