Effects Of Dietary Nutritional Levels On Production Performance And Nutrient Digestion-metabolism In Growing Blue Foxes

The aim of these studies was to investigate the optimal energy and proteinlevels of pellets for growing blue foxes. In the growing period, 72 weanlingyoung blue foxes (about 8 weeks of age) were divided into 6 groupsrandomly,each group included 12 animals (6 ~, 6 ~- ).In the furring period,these selected foxes were redistributed into 6 groups ,taking into their sex andorigin consideration.There was no significant difference among all the groupsin initial average weight (P>O.05).The feeding trials and digestion-metabolismtrials were conducted using 2(ME:13.OMJ/kg and 13.7MJ/kg)x3(CP:28%,32%and 36%)cross-over design in the growing period and 2(ME: 13.2MJ/kg and13.9MJIkg)x3(CP:24%,28% and 32%) in the furring period. All the groupfoxes were fed with one of the pellets. Body weight was researched throughtexperiments, and the blood parameters were examined, pelt evaluation andclassification were carried out in the furring period. The results were asfollows:(1)The cross-over effects of different energy and protein pellets on thedaily weight gains of females were significant in the growing period (P0.05).7 In the furring period,As dietary energy levels increased,males DMintake,DM and energy digestibility significantly decreased(P<0.05 or P<0.0l).Females digestibility-metabolism rate of DM and energy increased as thedietary protein levels increased from 24% to 28%, and further increased to32%, resulted in significantly decreased(P<0.05 or P<0.0 1).8 In the furring period, with increased dietary protein levels,the result of Nintake (gld) increased.As the dietary Energy levels increased, N intakedecreased significantly (P<0.O I ).Males N deposition decreased with energylevels(13.2-13.9MJ/kg).The dietary energy levels had great effects on femalesfaces N, N apparent digestibility (P