| In the Anhui province,Wandong cattle is the local variety which has a long history of breeding.Because of its resistance to forage,high disease resistance,good working performance,slaughter rate is high,gradually to the attention of the people.The purpose of this paper is to explore the energy needs of growing cattle,energy levels of different diet on the daily gain,the influence of the wandong cattle growth can maintain the net requirements,the influence of different feed energy level to heat production,the net requirements.1.The influence of different diet energy level to the daily gain of the growing of wandong cattle.Choosing 13 healthy and the growing of wandong cattle with similar weight(295.97±30.52)kg,Feeding trial,daily weight gain of growing Wandong cattle and the energy for maintenances on different levels of dietary energy.Design with single factor random experimental,According to the different dietary energy intake levels have three treatment were T1(92.03MJ/d),T2(68.77MJ/d)and T3(45.53MJ/d).Measured the total weight and increased growth ADG of wandong cattle.The results showed that:three treatment of cattle Wandong ADG significant difference,metabolic per unit body weight of the total energy intake and ADG relation to GE(kJ/kg0.75·d)=353.87 △W+942.70(P<0.01,r=0.82).△W=ADG,when △W=0,the total energy of maintenance requirements is 942.70kJ/kg0 75·d,Each weight 1 kg,the total energy need is 353.87 kJ/kg0 75·d.2.The research on fasting heat metabolism of Wandong cattle in the growth periodBy researching about fasting heat metabolism of Wandong cattle in the growth period can calculate the Net Energy for maintenance.Choosing 3 healthy Wandong cattle with similar weight(315.6±45.8)kg for fasting metabolism experiment,feeding began a hunger strike with a low level(Hay 2kg/d,concentrate 0.5kg/d)in a week,free to drink water.From the 4th day of hunger strike 3 consecutive days using respiratory metabolism headbox measured the heat production when cattle is standing,measured weight of the beginning and the end,the average value as hunger weight.The results showed that fasting heatproduction of Wandong cattle in the growth period is 356.26 kJ/kg0.75·d,Acorrding to NEm=120%FHP,the Net Energy for maintenance of Wandong cattle in the growth period is 427.51 kJ/kg0.75·d.3.The Research on net energy of Wandong cattle in the growth periodThe purpose of this experiment is to explore Wandong cattle net energy requirement in the growth period.Choosing 7 healthy Wandong cattle with similar weight for this experiment.This test is divided into three different energy levels,every part is 15days,three dietary energy levels were T1(92.03MJ/d)、T2(68.77MJ/d)andT3(45.53MJ/d).By three different energy gradient of feeding,to measure test cow weight change and metabolic heat production.The result showed that transformation efficiency of total energy to net energy is 44.66%,the Net Energy for maintenance of Wandong cattle in the growth period is 420.97 kJ/kg0.75·d.Linear regression of HP and ADG is HP(kJ/kg0.75·d)=81.535△W+420.97,(P<0.01,r=0.78).Net energy of Wandong cattle in the growth period is NE(kJ/kg0.75·d)=158.04△W+420.97,Per kilogram of weight need to grow net energy is 158.04 kJ/kg0.75·d. |
