Supplemental dietary methionine affects the pelt quality and nutrient metabolism of raccoon dogs (Nyctereutes procyonoides)

Introduction: The Ussuriensis raccoon dog ( Nyctereutes procy-onoides ussuriensis ), also known as the one of raccoon dog, has unique pelt characteristics. Recently, rac-coon dogs have been raised in cap-tivity in China for the economic value of its pelt, and their numbers have in-creased rapidly. To date, the popula-tion of farmed raccoon dogs has reached about 13 million in China, mainly in the northeast and eastern coast area. It has been shown that methionine is the most important es-sential amino acid for mink and fox (Dahlman et al., 2002). Either insuffi-cient or too much sulfur-containing amino acids in the diet of these ani-mals could lead to certain functional disorders (Takahashi et al., 1991). This study was aimed to evaluate the effect of protein-reduced diet with variable amounts of supplemental methionine on the nutrient metabo-lism and pelt quality of raccoon dog. Materials and Methods: All ani-mal procedures were approved by The Wild Animal and Plant Subcom-mittee of the China Association of Agriculture Science Societies (WAPS CAASS), and all experiments were performed according to the animal health and well-being regulations. Animal Care and Management: Seventy-five, 4-month old male rac-coon dogs of similar body weight (5.13 ± 0.25 kg) were randomly as-signed to five dietary treatments as described above. The experimental period encompassed the winter-fur-growing season, from the end of Sep-tember to the end of November, 2008, a total of 60 days. Experimental design and ra-tions: In accordance with the Nutri-tion Requirements of Mink and Foxes (1982), the basic protein level in the experimental diets was 20% crude protein with supplemented methio-nine 0.15%, 0.355, 0.55% and 0.75% and lysine level of 0.65 g/100 g dry matter (DM).The complete diet com-ponents are shown in Table 1. One part diet powder was mixed with three parts water. Table 1 Composition (%) of experimental basal diets (dry matter) and analysis of nu-trient content of diets Ingredient (%) Control Experimental groups receiving supplemental methionine (g/100 g DM) Group 1 Group 2 Group 3 Group 4 Extruded corn 37.750 47.440 47.440 47.440 47.440 Soybean Meal 5.500 4.750 4.750 4.750 4.750 Meat and bone meal 12.000 7.000 7.000 7.000 7.000 Distillers dried grains with soluble 9.500 9.500 9.500 9.500 9.500 Corn gluten feed 15.000 16.500 16.500 16.500 16.500 Fish meal 13.500 6.500 6.500 6.500 6.500 Chicken oil 4.650 6.010 6.010 6.010 6.010 Lysine 0.450 0.650 0.650 0.650 0.650 Methionine (added) 0.150 0.150 0.350 0.550 0.750 Additives