Evaluation On Nutritional Value In Common Feed For Blue Fox

As the fundamental element of blue fox farming, the feeding, especially its nutrient value, affectsthe productive performance and products quality directly. However, the evaluation of feed for blue foxis still at an early stage in China. In this study, we tried to evaluate the nutrient values of certainfeedings which are commonly used in blue fox farming using methods of chemical analysis andevaluation in vivo, expecting to provide useful advices for feeding selection of blue fox farmingbusiness.Three tests were conducted in this study:Test1: The nutrient value evaluation of normal feedings for blue foxes in China using methods ofchemical analysis. The test was conducted from December,2009to June,2011, when the utilization offeeding resources in Shandong, Hebei, Tianjin, Liaoning, Heilongjiang, Inner Mongolia et al, whereblue foxes are widely raised.96animal feedstuff samples of51species from6types were collected andanalysed for moisture, DM,EE,CP, crude ash, Ca and TP. Taking the nutrient content as variables, weconducted the principal component analysis and cluster analysis using SAS. The results showed asfollows: The nutrient values of Chicken skeleton, Duck skeleton, Pig bone paste, Soleus bone, Chumsalmon bone, Butterflyfish bone, Head of small yellow croaker, Walleye pollack bone, and Squilla wereclose. Lepidotrigla, Anglerfish, Soleus, Large yellow croaker, Low-value small fish, Gobiidae, Smallyellow croaker, Clamworm had similar nutrient values. Fox oil, Sheep oil, Chicken oil, Duck oil, Lard,Soybean oil had similar nutrient values. Chicken liver, Duck liver, Beef liver had similar nutrient values.Test2: Effects of different dietary protein and fat sources on the blue foxes of growing periodusing evaluation in vivo.80blue foxes of55-day-age with similar body weight were selected andrandomly divided into4groups with10males and10females each. The nutrient levels of different dietswere consistent despite different protein and fat resources. Two dietary protein sources were plantprotein(soybean meal, corn protein meal and corn germ meal) and animal protein (fish meal, chickenmeal and bone meat meal), two dietary fat sources were soybean oil and lard, in four kinds ofexperimental diets (P plant+F plant, P plant+F animal, P animal+F plant, P animal+F animal). Theexperiment included preset period for16days and test period for58days. The results showed as follows:(1) Digestibility coefficients of dry mass, protein and energy, dry matter intake(P<0.05)in P plant groupwere significantly higher than P animal group, BUN and feed-weight ratio of P plant group weresignificantly higher than that of P animal group(P<0.01), but biological value of protein, serum albumin,efficiency of feed utilization in P plant group were extremely significantly lower than P animalgroup(P<0.01).(2) Digestibility coefficients of dry matter(P<0.01),digestibility coefficients of fat andenergy and total serum protein(P<0.05) in F plant group (bean oil group) were higher than F animalgroup (lard group), but nitrogen retention, net protein utilization, biological value of protein, totalcholesterol and daily matter intake(P<0.01) in F plant group were lower than F animal group for maleblue fox. Digestibility coefficients of protein and blood glucose(P<0.05) in F plant group were higher than F animal group, but nitrogen retention, net protein utilization and biological value ofprotein(P<0.01) in F plant group were lower than F animal group for female blue fox.Test3: Effects of different dietary protein and fat sources on the blue foxes of growing-furringperiod using evaluation in vivo.80blue foxes of129-day-age with similar body weight were selectedand randomly divided into4groups with10males and10females each. The trial design was the sameas test2. The experiment included preset period for17days and test period for64days. The resultsshowed as follows:(1) During the growing-furring period, digestibility coefficients of dry matter, proteinand energy(P<0.05),urine nitrogen, blood glucose, blood total protein and feed-weight ratio(P<0.01) inP plant group were significantly higher than P animal group, while fecal nitrogen, nitrogen retention, netprotein utilization, biological value of protein, gain per day, skin length and fur quality(P<0.01),andblood total cholesterol and final body length(P<0.05) in P plant group was extremely significantly lowerthan P animal group.(2) Digestibility coefficients of protein(P<0.05), urine nitrogen and blood totalprotein(P<0.01) in F plant group were higher than F animal group, but blood total cholesterol (P<0.05)in F plant group were lower than F animal group for male blue fox. Digestibility coefficients of proteinand fat(P<0.05), digestibility coefficients of energy, urine nitrogen, blood glucose, total blood protein,and feed-weight ratio(P<0.01) in F plant group was higher than F animal group, while biological valueof protein and gain per day(P<0.01),and final body length and skin length(P<0.05) in F plant group waslower than F animal group for female blue fox.In conclusion, the nutritional contents of common blue feeds were determined. Two mapsdisplaying the similarity among the feeding resources for blue foxes in China were drawn to offer thetheory basis for blue fox farming business to choose their feed resources wisely. Through animalexperiments, we found that animal protein is better than plant protein for blue fox both in growing andgrowing-furring period. Lard is better than soybean oil for female blue fox in growing-furring period.For male blue fox in growing-furring period and blue fox in growing period, lard and soybean oil aresimilar.