Comparative ileal amino acid digestibility of distillers' grains for growing pigs

The objective of the experiment reported here was to investigate and compare the amino acid(AA)digestibility of distillers' dried grains(DDG), distillers' dried grains with solubles(DDGS), high protein distillers' dried grains(HP-DDG), and high protein distillers' dried grains with solubles(HP-DDGS) in growing pigs. Five semi-purified diets consisting of DDG, DDGS, HP-DDG, HP-DDGS, and nitrogen-free diet(NFD) were fed to pigs fitted with simple T-cannula for 5 observations per diet. Endogenous losses of AA at the terminal ileum of pigs that received the NFD were used to calculate standardized ileal digestibility(SID) of AA from apparent ileal digestibility(AID) of AA. The AID of Lys in DDGS was lower(P < 0.05) than that in DDG, which was also lower(P < 0.05) than that in HP-DDG. There were no differences in AID of Met among DDG, DDGS and HP-DDGS, but was greater(P < 0.05) in HP-DDG than in DDG or DDGS. The AID of Thr in HP-DDG was greater(P < 0.05) than that in DDGS but not different from that in DDG or HP-DDGS. The branched-chain AA Ile and Leu had greater(P < 0.05) AID in HP-DDG than in DDG, DDGS or HP-DDGS, and there was no difference among DDG, DDGS, and HP-DDGS. The AID of Trp in DDG and DDGS or HP-DDG and HP-DDGS were not different, but the AID of Trp in HP-DDGS was greater(P < 0.05) than that of DDGS. The greatest SID of the indispensable AA was in HP-DDG. Except for Arg and Lys in which DDG had greater(P < 0.05) digestibility, there was no difference between DDG and DDGS in the SID of the indispensable AA. The SID of Lys in DDG was greater(P < 0.05) than that of DDGS but there was no difference between that of DDG and HP-DDGS. Only His, Ile, and Met had lower(P < 0.05) SID in HP-DDGS than HP-DDG within the indispensable AA. The SID of Ala, Asp, Cys, GIu, Gly,Ser and Tyr were lower(P < 0.05) in DDGS than in HP-DDG. There SID of dispensable AA in DDG was not different from that of HP-DDGS. The current study provided apparent and standardized ileal amino acids digestibility values for traditional and high-protein corn distillers' dried grains coproducts for use in formulating swine diets. Amino acid digestibility was generally higher in HP-DDG than in other tested co-products of the dry grind processing of corn for ethanol.

Progress in ileal endogenous amino acid flow research in poultry

The progress in our understanding of the endogenous protein concept over the past century is reviewed.Nondietary proteins found in the digesta at the terminal ileum of poultry,known as endogenous protein loss,are comprised of digestive secretions,mucus and sloughed gut epithelial cells.The measurement of this loss is of fundamental importance because it is an indicator of gut metabolism and is essential to adjust apparent estimates of ileal amino acid digestibility.The ileal endogenous amino acid losses comprise of two components,namely basal and specific losses.The basal losses are fixed and associated with feed dry matter intake,whereas the specific losses are variable and induced by the presence of dietary components such as fibre and anti-nutrients.Currently there is no methodology available to directly measure the specific endogenous losses and these losses are calculated by determining the basal and total(basal plus specific)losses and,then subtracting the basal losses from total losses.The seminal features,specific applications and shortcomings of available methodologies are briefly outlined as well as the practical challenges faced in using the published endogenous amino acid loss values for true digestibility corrections.The relevance of taurine as a component of endogenous protein flow in poultry is identified for the first time.

Determination of the available energy,standardized ileal digestibility of amino acids of fermented corn germ meal replacing soybean meal in growing pig diets

Three experiments were conducted to compare the digestible(DE),metabolizable energy(ME),and standardized ileal digestibility(SID)of amino acids(AA)in fermented corn germ meal(FCGM)and soybean meal(SBM),and evaluate the effects of FCGM replacing SBM in growing pig diets.In Exp.1,18 barrows with initial body weight(BW)of 60.2±3.40 kg were randomly allotted to 3 treatments with 6 replicates per treatment.The control diet used corn as the only energy ingredient,and 2 test diets were made by replacing 25.8%of corn with FCGM or SBM.The DE and ME of FCGM were less(P<0.01)than those of SBM.In Exp.2,18 barrows(59.3±2.52 kg BW)with ileal T-cannulas were randomly allotted to 3 treatments with 6 replicates per treatment.The SID of arginine,tryptophan and proline were greater(P<0.05)and the tyrosine was less(P=0.01)in SBM compared with FCGM.In Exp.3,144 growing pigs(56.1±5.22 kg BW)were randomly allotted to 4 treatments with 6 pens per treatment(3 barrows and 3 gilts per pen).Four diets(FCGM0,FCGM10,FCGM20 and FCGM30)were formulated using FCGM to replace 0%,10%,20%and 30%of SBM,respectively.The ME and SID values of AA of SBM and FCGM were determined by Exp.1 and 2.Results showed that increasing FCGM inclusion quadratically(P<0.05)increased the average daily gain(ADG),average daily feed intake,and the levels of serum immunoglobulin G(IgG)and urea nitrogen,and linearly(P<0.05)increased the serum IgM,the propanoic acid,butyric acid,total volatile fatty acid(VFA)and the Shannon index of microbiota in feces.Besides,the relative abundance of genus Streptococcus in FCGM0,Lactobacillus in FCGM10 and Lachnospiraceae in FCGM30 were increased(P<0.05)compared with other treatments.In conclusion,we recommend replacing 11.80%of SBM with FCGM to obtain the optimal ADG of growing pigs.Moreover,as the ratio of FCGM replacing SBM increased in diet,the immunity,intestinal microbiota and total VFA composition of growing pigs were improved.