| In vitro and in vivo digestibility of different protein sources for mink feed were initially analyzed. Based on this information and the nutritional requirement of growing mink, a series diets were prepared. The feed intakes and nutrient digestibility of the diets were determined.In experiment â… , protein digestibility of white fish meal, Peruvian fish meal, domestic fish meal was investigated in vitro and in vivo of growing mink. The results showed that in vivo protein digestibility of the diets was similar to the corresponding 4~8h in vitro digestibility. This indicated that the time for digesting in the digestive tract or the retention time of feed was about 4~8h. The in vitro digestibility of 4~8h can be used as the index of the protein digestibility of the mink foodstuff. At the same time, the results also showed that white fish meal had a higher protein digestibility, peru fish meal was slightly lower than white fish meal, domestic fish meal was lowest (p<0.05). The digestibility of extruded soybean diets was obviously lower than the diets that were mainly made up of fish meal (p<0.05). White fish meal can be regarded as the best protein source of the mink diets, but peru fish meal had advantages of market availability or lower price, so the peru fish meal can be used for the main protein source of the growing mink diets.In experiment â…¡, dry powder diet prepared with peru fish meal as protein source. Routine fresh diet and commercial pellet diet were fed to mink; Feed intakes and digestibility of the diets were determined. The results showed that the intake and the digestibility of fresh diet were significantly higher than other groups (p<0.05). The digestibility of protein or EE of the dry powder diets was similar with the fresh diet (p>0.05), but its intake was significantly lower than fresh diet (p<0.05), The results indicated that the increasing palatability and the intake of the dry powder diet still need further study.In experimentâ…¢, 4 levels of Bio-lac (0.0%, 0.2%, 0.5%,1%), a compound plant enzyme extracts and of a culture of 5 strains lactobacillus, were added into the dry powder feed used in experiment â…¡ to study the effect of Bio-lac on the utilization of nutrients of the diets. The result showed that there were no harmful effects by adding three amount of Bio-lac, but it did not improve the digestion of the dry matter, organic matter, proteins, EE, or energy of the diets, when 0.5% of Bio-lac was added, only the digestibility of EE improved (p<0.05). The results suggested that the enzymes from the plant could not significantly improve the digestion of the mink diets.It can be seen from above three experiments that digestible nutrient intake of drypowder diet was lower than routine fresh diets. In the situation that it was unable to totally replace the routine fresh diets with the dry powder diets, in order to improve the feed intake and digestion of the diets, the mink was fed diets mixed with different proportions of the dry powder feed and fresh diets In experimentlV. The results showed that DM intake of four kinds of diets which was added 10-20% fresh fish or chicken intestines was close to or significantly higher than the routine fresh diet. The digestibility of the dry matter, organic matter and protein for minks fed fresh diets was the highest (p<0.05). The diets included 20% of fresh fish had a higher digestibility of energy; the diets added 20% of chicken intestines had a higher digestibility of EE. The results showed that the diets mixed with different proportions of the dry powder diets and fresh diets can improve the intake of the diets, and can also improve the digestion of diets. It is recommended that, in places where fresh fish is limited, 20% of fresh fish or chicken intestines could be included in dry powder feed for feeding growing mink and acceptable performance can be expected.
|
PDF Full Text Request