Study On Energy Metabolic Rule And Requirement Of Yimeng Black Pig In Growing Fattening Period

Yimeng black pig was used in the study to research the effects of different dietary energy levels on the growth performance,apparent digestibility of nutrients and slaughter performan ce through feeding experiment,digestion and metabolism experiment and slaughter experime nt.Then,establish the factorial models in each stage.A single factor design was used to the experiment to study the effects of different dietar y energy levels on production performance of Yimeng black pigs.A total of thirty-two Yim eng black pigs were randomly divided into four experimental treatments with eight replicates of one pig each.The feeding period was divided into three periods:15 to 30 kg,30 to 60 kg,60 to 90 kg.Each period own four dietary energy levels and the same digestible amino acid pattern respectively.Results showed that average daily feed intake,average daily gain and f eed to gain was significantly affected by different dietary energy levels?P<0.05?.As the e nergy increase in the diet?80%,90%,100%of the recommended amount?,the average daily feed intake and average daily gain increase,the feed-to-weight ratio decreases at each stage,when raised to the recommended amount of 110%,the average daily feed intake and the aver age daily gain decreased,and the feed-to-weight ratio increased.A single factor design was used to study the effects of different dietary energy levels on nutrients utilization of Yimeng black pigs.The total fecal collection method was used to stu dy the effects of different dietary energy levels on nutrients utilization in 3 period metabolic experiments with ten day each started at 85 d,154 d,and 215 d of age,respectively.The resu lts showed as follows:As the energy level in the diet increased,the apparent digestibility of dry matter,crude fat,organic matter,carbohydrates and total energy digestibility and metab olic energy digestibility was increased significantly in the whole period?P<0.05?,the appare nt digestibility of crude protein was increased in 15-30 kg,30-60 kg?P<0.05?.The net protei n utilization?NPU?at the 15-30 kg and 60-90 kg stages showed a decreasing trend?P<0.1?.A single factor design was used to study the effects of different dietary energy levels on s laughter performance of Yimeng black pigs.After the feeding experiment was over,all pigs were fasted and died of electric shock.Results showed that 100%recommendation increased the carcass length of Yimeng black pigs,and the slaughter rate and fat rate of high energy gr oup?110%and 100%of the recommended amount?were significantly higher than the low-e nergy group?90%,80%of the recommended amount?of Yimeng black pigs,but the lean-lea ning rate was significantly decreased?P<0.05?,with the increase of energy,backfat thicknes s has an increasing trend?P<0.1?.For the organ index,the low-energy group?90%,80%of t he recommended amount?significantly increased the organ index of the digestive organs,su ch as stomach,large intestine,and small intestine,with no significant effect on other organs.For carcass nutrient content,on the basis of fresh samples,with the increase of energy level,the ratio of water,crude protein and crude ash to body composition was significantly reduce d,and the proportion of crude fat was significantly increased?P<0.05?;In the fat-free sampl e,with the increase of energy level,the proportion of crude protein increased?P<0.1?,and th e proportion of crude ash decreased significantly?P<0.05?;in fat-free dry matter sample,wit h energy increased the proportion of crude protein and reduced the proportion of crude ash w as increased significantly?P<0.05?.For carcass energy distribution.,the proportion of energ y in lean meat gradually decreased?P<0.05?,the proportion of energy in fat meat gradually i ncreased?P<0.05?,the proportion of skin and hair energy increased first and then decreased?P<0.05?.The proportion of fat energy has increased?P<0.1?with the increase of energy lev el.Study on energy requirements of Yimeng black pigs.Based on the results of comprehens ive feeding test,digestion and metabolism test and slaughter test,Yimeng black pig energy i ntake?Y?was used as the dependent variable,and the average daily weight gain?X?was use d as the independent variable for linear regression analysis.The regression equation for total energy,digestive energy and metabolic energy at each stage is as follows:15-30 kg:GEI=2980+5716 DG?r=0.9559?DEI=2347+4502 DG?r=0.9991?MEI=2197+4215 DG?r=0.9664?30-60 kg:GEI=3604+8727 DG?r=0.9250?DEI=2825+6839 DG?r=0.9893?MEI=2688+6509 DG?r=0.9314?60-90 kg:GEI=3821+15158 DG?r=0.9541?DEI=2884+11443 DG?r=0.9997?MEI=2759+10944 DG?r=0.9520?According to the measured values of the average body weight in each stage of Yimeng black pigs,they were converted into the corresponding metabolic body weights,resulting in a factorial model of the total energy,digestive energy,metabolic energy,and net energy requirement for each stage of breeding of Yimeng black pigs,and then subjected to a large group verification test.Get the model as follows:15-30 kg:GER=250 W^0.75+5716 DG;DER=197 W^0.75+4502 DG;MER=184 W^0.75+4215 DG;NER=135 W^0.75+3175 DG?30-60 kg:GER=227 W^0.75+7722 DG;DER=178 W^0.75+6052 DG;MER=169 W^0.75+5759 DG;NER=124 W^0.75+3851 DG?60-90 kg:GER=227 W^0.75+12018 DG;DER=171 W ^0.75+9072 DG;MER=164 W^0.75+8677 DG;NER=120 W^0.75+5271 DG?In the formula:GER,DER,MER,NER:kcal/d;W^0.75:kg;DG:kg/d?...