Evaluation Of Available Energy And Amino Acid Digestibility Of Three Types Of Rice Raw Material Growing In Pigs

The shortage of traditional feed ingredients is the key obstacle limiting the development of pig farming industry at this stage,and the development of unconventional feed ingredients has become a key concern in the pig farming industry at present.China is very rich in rice resources,and some rice varieties have poor taste and are not suitable for human consumption,resulting in a large amount of rice extruded for a long time to become aged rice,if this part of rice raw materials can be applied as pig feed ingredients will somewhat alleviate the above problems.The aim of this study was to evaluate the effective energy and amino acid digestibility of three types of rice materials:brown rice,rice grain and aged rice through digestion and metabolism tests and amino acid terminal“T”fistula tests in growing pigs,and to investigate the potential of rice materials as energy feed to replace maize in pig farming.Experiment 1:Twelve crossbred healthy castrated boars with similar weight（25.56±2.13 kg）were selected and randomly divided into 4 groups according to the Euden square design for a total of 2 phases,with 6 replicates per group and 1 pig per replicate.The control group was fed the basal diet,which consisted mainly of corn,and the control group was fed30%of rice as an equal proportion of corn in the basal diet.The results showed that the apparent digestibility of total energy of brown rice,rice grain and aged rice grain were89.39%,86.92%and 83.53%,respectively,and the digestible energy（DM）of raw materials were 3762.65 kcal/kg,3602.22 kcal/kg and 3360.10 kcal/kg,respectively,and the Metabolizable energy（DM）of raw materials were 3542.50 kcal/kg,3463.03 kcal/kg,and3097.01 kcal/kg,respectively,where the nutritional values of brown rice and rice grains were similar to those of corn（P>0.05）.Experiment 2:Fifteen crossbred healthy castrated boars of similar litter size,age and weight（25.40±3.35 kg）were selected for simple“T”fistula installation at the end of the ileum.The test pigs were randomly divided into 5 groups according to the Euden square design and a total of 2 phases were conducted with 6 replicates of 1 pig per group.The control group was fed the basal diet,which consisted mainly of corn,and the control group was fed 30%of rice ingredients to replace corn in the basal diet in equal proportions,and the nitrogen-free group was fed the nitrogen-free diet to calculate the basal endogenous amino acid losses.The standardized ileal digestibility（SID）of growing pigs on rice was determined using an exogenous indicator method（Cr₂O₃）.The results showed that the standardized ileal digestibility of Lysine,Phenylalanine,Threonine,Isoleucine and Alanine in brown rice,rice grain and aged rice grain were significantly better than that of corn（P<0.05）,among which the standardized ileal digestibility of lysine in brown rice,rice grain and aged rice grain were83.56%,82.35%and 81.12%,respectively;the standardized ileal digestibility of the other amino acids were comparable to that of corn（P>0.05）.