Effects of Four Kinds of Diets on Nutrient Digestion,Metabolism and Blood Biochemical Indexes of One-year-old Yili Horse

Effects of four kinds of diets on nutrient digestion and metabolism and blood biochemical indexes of one-year-old Yili horse were studied in this experiment.16 health horses(all males) with an average body weight of (227.38±16.48)kg and similar age (one-year old) were used in a staging and grouping experiment design.First stage had groupsⅠ and Ⅱ,second stage had groups Ⅲ and Ⅳ.The horses of group Ⅰ were fed with alfalfa 8 kg/d,pelleted concentrate 0 kg/d; The horses of group Ⅱ were fed with alfalfa 7 kg/d,pelleted concentrate 1 kg/d;The horses of group Ⅲ were fed with alfalfa 6.3 kg/d,pelleted concentrate 1.7 kg/d;The horses of group Ⅳ were fed with alfalfa 5.6 kg/d,pelleted concentrate 2.4 kg/d.Each stage lasted for 21 d (15 d pretrial period and 6 d trial period).The results showed that the digestibility of DM,OM,CP and P were increased with increasing of feed levels of pelleted concentrate,while the digestibility of NDF,ADF and Ca showed downtrend.DE and ME were significantly increased with increasing of feed levels of pelleted concentrate (P > 0.05).N retention and retention rate showed an increasing tendency,N retention and retention rate of groups Ⅲ and Ⅳ were extremely significant higher than those in group Ⅰ (P < 0.01).Ca retention and retention rate decreased with increasing of feed levels of pelleted concentrate,and Ca retention and retention rate of group Ⅰ were extremely significant higher than those in groups Ⅱ,Ⅲ and Ⅳ (P < 0.01).P retention was extremely significant increased with increasing of feed levels of pelleted concentrate (P < 0.01).There were no significant difference in the content of TP among all trial groups (P > 0.05),but the content of BUN in groups Ⅱ,Ⅲ and Ⅳ were lower than those in group Ⅰ (P > 0.05).Thus,comprehensive nutrient digestion and metabolism,blood biochemical indicators of four of kinds diets in one-year-old Yili horse,the requirement of crude protein,digestible protein,metabolizable energy,digestible energy were 14.28,9.16 g/(kg·BW) and 1.74,1.41 MJ/(kg·BW),respectively.