Evaluation And Prediction Model Of Nutritional Value Of Rice Bran Fed To Growing Pigs

The aim of this study was to evaluate the nutritional value of rice bran from different regions of China for growing and finishing pigs,and to construct the prediction equations of digestible energy(DE),metabolizable energy(ME)and standard ileal amino acid digestibility(SID)of rice bran based on available nutrients of rice bran.In experiment 1,the nutrient composition and amino acid content of 10 kinds of rice bran feed samples were analyzed.In experiment 2,the DE and ME of rice bran were measured by digestion and metabolism test and pig feces and urine were collected,and the prediction equations of DE and ME of rice bran were constructed according to their nutritional components.In experiment 3,apparent ileal amino acid digestibility(AID)and SID of rice bran were measured by digestion and metabolism test and ileal digesta of pigs were collected,and SID prediction equation of essential amino acids of rice bran was constructed according to its effective nutrients.Experiment 1 analysis of nutrient composition and amino acid content of 10 rice bran feed samplesThere were significant variations in nutrient and amino acid contents among the 10 rice bran diets from different provinces,among which the contents of EE and Ca were significantly different(coefficient of variation CV-EE=109.82%,CV-Ca=98.50%).Therefore,there was a large variation in nutrient contents among the 10 rice bran feeds from different provinces.Experiment 2 DE and ME of rice bran of growing-finishing pigs were measured and prediction model was established Twenty-two healthy"Duroc×Landrace×Yorkshire"crossbred barrows with the body weight of(30±1.7)kg were fed a basal diet and 10 rice bran diets using two incomplete Latin square designs of 11×3,respectively.The experiment was divided into 3 periods of 12 days(7 days pre-feeding period 5 days total fecal and urine collection).At the end of the experiment,there were 6 replicates in each diet treatment group.The DE and ME values of rice bran for growing and finishing pigs were measured by total manure collection,urine collection and set algorithm,and the prediction equations of DE and ME for growing and finishing pigs based on available nutrient content of rice bran were established by stepwise regression method.The average DE and average ME of 10 rice bran samples for growing-finishing pigs were 12.80MJ/kg and 12.37MJ/kg,respectively.The prediction model of DE for growing-finishing pigs was as follows(air-dried basis):DE=23.608-0.745CP(R~2=0.60),DE=11.903+0.174EE(R~2=0.50),DE=194.724+0.187 Ee-2.071 DM(R~2=0.76),DE=1.815+0.665GE(R~2=0.67),The prediction model of rice bran on ME of growing-finishing pigs(air-dried basis)was as follows:ME=22.146-0.674CP(R~2=0.56),ME=11,508+0.167EE(R~2=0.52),ME=175.417+0.178 Ee-1.856DM(R~2=0.77),ME=0.439+0.928de(R~2=0.98).Experiment 3 Determination of ileal amino acid digestibility of rice bran and establishment of prediction model for growing and fattening pigsThe results showed that the contents of lysine(Lys),methionine(Met),threonine(Thr)and tryptophan(Trp)in rice bran were 1.02%-0.70%,0.16%-0.11%,0.60%-0.43%and0.20%-0.13%,respectively.The AID of Lys,Met,Thr and Trp to rice bran of growing and finishing pigs were as follows:69.29%～63.10%,73.17%～55.96%,57.82%～45.51%,80.10%～60.76%,The SID of Lys,Met,Thr and Trp for rice bran were 84.33%-76.96%,92.07%-76.23%,87.22%-72.72%and96.34%-81.41%,respectively,SIDTRP=94.523-18.056CA(R~2=0.70),SIDTRP=104.116-20.401CA-0.407NDF(R~2=0.84),SIDTRP=94.190-22.773 CA-0.384NDF+0.332ts(R~2=0.92),SIDMET=122.288-2.712CP(R~2=0.51),SIDLYS=97.540-9.608p(R~2=0.50),SIDLYS=421.013-9.617P-3.662DM(R~2=0.822),SIDTHR=30.762+2.974GE(R~2=0.82),SIDTHR=51.859+2.205GE-1.323CF(R~2=0.97),SIDTHR=53.982+2.123GE-2.015CF+0.521ADF(R~2=0.99).In conclusion,the nutrient and amino acid contents of 10 rice bran diets from different provinces were significantly different.The average DE and ME of rice bran samples for growing-finishing pigs were 12.80MJ/kg and 13.27MJ/kg,respectively.The amino acid digestibility of rice bran(air-dried basis)for growing-finishing pigs was higher.Most of AID ranged from 60%to 70%,and most of SID ranged from 80%to 90%.Rice bran has higher effective energy,higher ileal amino acid digestibility and better nutritional value for growing and finishing pigs.It is concluded that the best prediction model of DE for growing and finishing pigs is(dry matter basis):DE=194.724+0.187 Ee-2.071 DM(R~2=0.76),the best prediction model of rice bran on ME of growing-finishing pigs was(air-dried basis):ME=175.417+0.178 Ee-1.856 DM(R~2=0.77).The optimal prediction equation of ileal amino acid digestibility based on nutrient content of raw materials is as follows:SIDTRP=94.190-22.773 CA-0.384NDF+0.332ts(R~2=0.92),SIDLYS=421.013-9.617p-3.662 DM(R~2=0.822),SIDTHR=53.982+2.123GE-2.015CF+0.521ADF(R~2=0.99).