Effects Of Protein And Vitamin A Levels Of Concentrate Supplement On Production Performance And Blood Biochemical Indexes Of Male Red Deer (Cervus Elaphus)

Using feeding and digestion experimental methods,this experiment was conducted to study the effects of protein and vitamin A levels of concentrate supplements on the digestion of dietary nutrients,antioxidant,immune and production performance of male red deer,so as to explore the appropriate concentrate protein and vitamin A levels of male red deer during velvet antler growth period and provide theoretical basis for scientific breeding of red deer.Experiment Ⅰ:Twenty-four Tianshan red deers in captivity,aged 4 to 5 years old with similar weight and good health were selected.24 Tianshan red deers were randomly divided into 4 groups,with 6 in each group.And they were fed experimental concentrate supplements containing different protein levels,which were 20%(group Ⅰ),22%(group Ⅱ),24%(group Ⅲ)and 15%(the control group)respectively.The deers were fed with roughage composed of alfalfa hay and straw freely.This experiment lasted 81 days.The results showed that:(1)The effect of protein level on DM,OM,EE,Ca and P intake of red deer was not significant(P>0.05).The CF intake was significantly lower with the higher protein level of concentrate supplements(P<0.01).The nutrient digestibility first increased and then decreased with the increase of the protein level.CP digestibility of group Ⅰ,Ⅱ and Ⅲ was significantly higher than that of the control group(P<0.05),and P digestibility of group Ⅲ was significantly higher than that of group Ⅰ(P<0.05).(2)The effect of concentrate protein level on blood protein metabolism,glycolipid metabolism,AST and ALT in red deer was not significant(P>0.05),and ALP increased with the increase of protein level(P<0.01).A certain level of concentrate protein significantly increased the antioxidant capacity and immunity of red deer.The contents of blood sex hormones,GH,IGF-I,and vitamin A increased significantly with the increase of protein levels(P<0.01).However,high levels of sex hormones and vitamin A inhibited the growth of velvet antler.(3)The antler yield first increased and then decreased with the increase of the protein level of the concentrate supplements.The highest yield was achieved when the protein level of the concentrate supplements was 22%.The effect of protein level on amino acid content of velvet antler was small.Experiment Ⅱ:Eighteen Altai red deers in captivity,aged 5 to 7 years old with similar weight and good health were selected.18 Altai red deers were randomly divided into 3 groups,with 6 replicates per group.And they were fed experimental concentrate supplements containing different vitamin A levels,which were 12 800 IU/kg(group Ⅰ),18 800 IU/kg(group Ⅱ)and 24 800 IU/kg(group Ⅲ)respectively(The CP level was 21.34%).The deers were fed with roughage composed of alfalfa hay and straw freely.This experiment lasted 81 days.The results showed that:(1)The intake of DM,OM,CP,Ca and P were the highest when the level of vitamin A in concentrate supplements was 12 800 IU/kg,and the intake of all nutrients showed a decreasing trend with the increase of the level of vitamin A.P digestibility of group I was significantly higher than that of group II and III(P<0.05).(2)Dietary vitamin A level had no significant effect on blood protein and glycolipid metabolism(P>0.05),and blood ALP content significantly decreased with the increase of vitamin A level of concentrate supplements(P<0.05).As vitamin A level of concentrate supplements rises,blood IgG,SOD,T-AOC and GSH-PX activity increased(P<0.01)and MDA content decreased(P<0.05).The contents of blood GH,IGF-I,E2 and vitamin A content increased with the increase of concentrate supplement vitamin A level(P<0.01)which had no significant effect on T and 25-OH-VD3(P>0.05).(3)The vitamin A level had no significant effect on the yield of velvet antler(P>0.05),and The highest yield was achieved when the vitamin A level of the concentrate supplements was 12 800 IU/kg.The vitamin A level had small effect on the amino acid content of velvet antler.In summary,when the protein content of the concentrate supplement is 22%and the vitamin A content is 12 800 IU/kg,it is beneficial to the digestion and utilization of nutrients of red deer,improve the antioxidant and immune performance of the body and increase the antler production.