Influence Of Nutrition Levels, Flax-seed And Vitamin E On Growth Performance And Beef Quality Of Holstein Bulls

In order to study the effects of different energy and protein levels, flax-seed andvitamin E on performance and beef quality in Holstein fattening bulls, this study made twoparts experiments.Experiment1: Effects of different energy and protein levels in diets on growthperformance and beef quality of3-12month-old Holstein bulls403-month-old Holstein bulls with the weight of98kg were randomly divided intofour groups, each group with10calves. The experiment was divided into five stages. Theexperiment diet included four protein levels and two energy levels. The results showed that:with the increasing of energy and protein levels, group Ⅲ showed the best growth rate,which indicated9.84%(P<0.01) and7.14%(P<0.05) higher than group Ⅰ and group Ⅱ,respectively. The serum aspartate aminotransferase of group Ⅳincreased17.56%(P<0.05)than group Ⅰ, the serum growth hormone of group Ⅲ and Ⅳincreased48.78%(P<0.05)and42.68%(P<0.05)than group Ⅰ, respectively; the apparentdigestibility of crude protein in group Ⅲ was3.92%(P<0.05) higher than that of groupⅠa nd2.85%(P<0.05) higher than that of group Ⅱ, respectively; with increasing ofenergy and protein levels, the PUFA concentration of longissimus muscle improved, groupⅣ increased6.04%(P<0.05）than group Ⅰ. Compared with group Ⅰ, group Ⅱ and groupⅣ, the economic benefits ofgroup Ⅲwas higher1.64Yuan/(d·heads),1.23Yuan/(d·heads) and0.62Yuan/(d·heads), respectively. Therefore, using Holstein bulls produceveal, nutrient levels for each stages suggested were as follows:13.63MJ/kg digestibleenergy,20.00%crude protein of100～150kg stages;13.26MJ/kg digestible energy,18.50%crude protein of150～200kg;13.26MJ/kg digestible energy,17.50%crudeprotein of200～250kg;13.35MJ/kg digestible energy,16.50%crude protein of250～300kg;13.72MJ/kg digestible energy,14.50%crude protein of300～350kg.Experiment2: Effects of Flax-seed and Vitamin E on performance and beef quality inHolstein fattening bulls75BW520kg of Holstein bulls were randomly divided into five groups, each groupwith15bulls, there were no obvious differences in initial weight between the fivegroups(P>0.05). Group Ⅰ was the control group, feeding based diet；group Ⅱwith10% Flax-seed instead a part of the concentrate, group Ⅲ～Ⅴadding Vitamin E with200mg/kg,400mg/kg and600mg/kg, as the basis of group Ⅱ. The results showed that:adding10%Flax-seed, the average daily gain increased significantly; the F/G wasdecreased, shear force, cooking loss, and the antioxidant ability of muscle were decreasedsignificantly; when adding Vitamin E, the antioxidant ability was increased. Comparedwith the control group, the diet adding10%Flax-seed(group Ⅱ～Ⅴ), the percentage ofPUFA increased. The n-3PUFA of group Ⅱ～Ⅴ increasedby24.59%(P<0.01）,28.42%(P<0.01）,42.62%(P<0.01）,39.89%(P<0.01）. The n-6/n-3of group Ⅱ, Ⅲ, Ⅳ,Ⅴincreased18.41%(P<0.01),20.33%(P<0.01),24.18%(P<0.01) and23.08%(P<0.01)thangroup Ⅰ. Based on the analysis of all indicators, when using10%flaxseed to replace partof the diet to fatten Holstein bulls, can be used with Vitamin E. The appropriate level ofVitamin E was400mg/kg to600mg/kg(DM basis).