Effects of Coated Methionine on the Growth Performance, Blood Biochemical Indices and Nutrient Apparent Ileal Digestibility in Broilers

[ Objective] This trial was conducted to study the effects of different coated methionines on the growth performance, blood biochemical indices and apparent ileal digestibility of amino acids in broilers. [ Method ] A total of 3 780 Cobb 500 broilers aged 18 days were randomly arranged into 7 groups with 3 replicates per group and 180 broilers per replicate. Control group （A） received the basal diet supplemented with O. 16% DL-me- thionine, and trial groups received the basal diets supplemented with 0.32% （ B）, 0.29% （ C）, 0.26% （ D）, 0.22% （ E）, 0.19% （F） and 0.16% （G） of coated methionine, and broilers were fed to the age of 42 days. ＂[ Result] The final weight, average daily gain and average daily feed intake of groups B and C were higher than those of the control group （ P〈0.05）, and the mortality of group B was lower than that of the control group （ P 〈0.05）, but there was no significant difference in all above indices between the other groups and the control group （P 〉 0.05）. Plasma GSH-Px activity of trial groups （ except group G） was higher than that of the control group （ P 〈 0.05）, and SOD activity of groups B and C were higher than that of group G （P 〈0.05）, but there were no significant differences in other blood biochemical indices among all groups （P 〉0.05）. There were no significant differences in apparent ileal digestibility of dry matter and crude protein between trial groups and the control group （ P 〉0.05 ）, and the apparent ileal digestibility of amino acids of trial groups was increased （P 〈0.05） or no change expect that the apparent ileal digestibility of many kinds of amino acids of group G was decreased compared with the control group （P〈0.05）. [ Concluslon~ The growth performance and apparent ileal digestibility of amino acids in broilers were increased with the rising supplementation of coated methionine, but the supplementation of 0.19% coated methionine can meet the needs of broilers, namely, coated methionine can be substituted for 60% DL-methionine in the diet, so DL-methio- nine can be saved up to 40%.

Effect of protease supplementation on apparent ileal crude protein and amino acid digestibility of over-processed soybean meals in broilers

Background: Nutritional value of proteins in feed ingredients can be negatively affected by hydrothermal processing, which causes large variation in the bioavailability of amino acids(AA) and negatively affects animal productive performance. Supplementation of exogenous proteases could increase the rate of digestion of damaged proteins, thereby increasing overall AA digestibility and bioavailability. The aim was to determine the effect of exogenous protease supplementation on the apparent ileal digestibility(AID) of crude protein(CP) and AA of soybean meals(SBM) with different degrees of hydrothermal processing in broilers.Methods: The experiment involved a 3 × 2 factorial arrangement, with SBM processing time(commercial SBM or autoclaved for 30 or 60 min at 120 ℃) and protease supplementation(not supplemented and supplemented) as factors. Protease was included at three times the recommended dose(0.06%) and the experimental diets were fed from 15 to 21 d.Results: The interaction between the effects of SBM processing and protease supplementation was significant for the AID of CP(P = 0.01), Trp(P = 0.01), Gly(P = 0.03) and Pro(P = 0.03), and also for the average daily gain(P = 0.01)and feed conversion ratio(P = 0.04). Increasing the processing time of SBM decreased(P < 0.0001) the AID of all amino acids, whilst the effect of protease supplementation was only significant for the AID of Phe(P = 0.02) and Tyr(P = 0.01).Conclusions: Exogenous protease supplementation at three times the commercial dose does not seem to offset the negative effects of hydrothermal processing of SBM on the apparent ileal digestibility of CP and amino acids or performance of broilers. Whilst positive numerical improvements of digestibility and performance(ADG and FCR)were noticed with protease supplementation at relatively mild processing levels, negative results were obtained with the harsh-processed meals.

Total amino acid level affects the results of standardized ileal digestibility assays for feed ingredients for swine

It has been demonstrated that the fiber content of oilseed meals and total amino acids(AA)in distillers'grains products affects standardized ileal digestibility(SID)values from swine assays and that total protein concentration affects the AA digestibility in assays using chickens.This analysis was conducted to test the hypothesis that the total AA content of test samples affects the SID assay results.Databases containing total AA profiles and SID values of 20 feedstuffs commonly fed to pigs from 2 sources,AMINODat 5.0(Evonik Industries,2015)and the Nutrient Requirements of Swine,12th edition(NRC,2012)were used to compare AA concentration effects on standardized ileal digestibility coefficients.Databases were compared with AA and SID available in both data sets.The total AA values were similar for the 2 databases with an R2 of 0.979(P<0.001).The linear relationship between digestibility co-efficients from the 2 databases was highly significant,an R2 of 0.810(P<0.001).Both databases had increased SID values with increasing AA contents within and across feed ingredients.The SID=f(AA concentration)relationship was confirmed with an individual paper.Since SID,as typically measured,is a function of both digestion and absorption,both processes following MichaeliseMenten kinetics,SID=f(AA concentration)may simply be a natural phenomenon.Other reasons for the relationship were explored.Methods of estimating endogenous AA losses and misapplication statistical procedures may contribute to variation in results and at least partially explain why SID=f(AA concentration).

Prediction of protein and amino acid composition and digestibility in individual feedstuffs and mixed diets for pigs using near-infrared spectroscopy

Knowledge of the amounts and digestibility of amino acids in pig feedstuffs is essential for calculating the appropriate inclusion level in a complete diet.Wet chemical analysis and in vivo digestibility trials are time-consuming and costly and cannot be used for routine assessment.Near-infrared spectroscopy(NIRS)offers a rapid,cost effective and environmentally friendly method for evaluating feedstuffs.Calibrations models were developed using NIRS to predict the content of crude protein and 18 amino acids from a wide range of feedstuffs used in pig production(n=607).The samples ranged from single feed ingredients(containing amino acids from 0.3 to 129.8 g/kg of dry matter)to feed mixtures(containing amino acids from 1.2 to 53.2 g/kg of dry matter).The predictive ability of the calibrations was tested with an independent dataset(n=150)and with cross-validation.Furthermore,we compare these calibrations with calibrations developed on more narrowly defined groups of samples and with predictions from regression analysis of crude protein.The models were able to predict the concentrations of crude protein and 18 amino acids with good levels of precision and high coefficients of determination for calibration(RSQ^(CAL))from 0.91 to 0.99 and validation(RSQ^(VAL))from 0.87 to 0.97.Calibration models were able to predict all amino acids except tryptophan and valine with greater accuracy than those from protein regression.We also developed calibration models to predict the apparent ileal and total tract digestibility of protein and amino acids.With the exception of tryptophan,RSQ values(>0.7)and standard error of cross validation(SECV)values(<5%)were obtained for the digestibility of most of the amino acids.In conclusion,NIRS can be used to predict crude protein and amino acid concentrations from a wide range of single ingredients and feed mixtures used for pig diets without separate models for each feedstuff.The digestibility of protein and amino acids can be predicted with an acceptable accuracy to be useful in formulating pig diets.