Effects of the Maillard reactions on chemical composition and amino acid digestibility of feed ingredients and on pig growth performance

amino acid;digestibility;heat damage;pig

Almeida, Ferdinando

关键词: amino acid;    digestibility;    heat damage;    pig;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/44249/Ferdinando_Almeida.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Six experiments were conducted to evaluate the negative effects of heat damage on the nutritional composition and AA digestibility of feedstuffs fed to pigs, and also to determine the negative effects of feeding heat-damaged soybean meal (SBM) or heat-damaged distillers dried grains with solubles (DDGS) on growth performance of weanling pigs. In experiments 1, 2, 3, and 4, the primary objective was to determine the effects of heat treatment on the standardized ileal digestibility (SID) of AA in DDGS, canola meal, sunflower meal (SFM), and cottonseed meal (CSM) fed to pigs. The second objective was to develop regression equations that may be used to predict the concentration of SID AA in these ingredients from their nutrient composition. In Exp. 1, the SID of Lys was quadratically reduced (P < 0.05) from 66.8% in the non-autoclaved DDGS to 54.9, 55.3, and 51.9% in the DDGS that was autoclaved for 10, 20, or 30 min, respectively. The concentration of SID Lys may be best predicted by an equation that includes the concentration of acid detergent insoluble N (ADIN; r2 = 0.84). In Exp. 2, autoclaving of canola meal reduced (quadratic, P < 0.01) the SID of CP and all AA. The concentration (%) of SID Lys in canola meal may be predicted by regression equations using the concentration (%) of reducing sugars (r2 = 0.96) as the main predictor variable. Likewise, the concentrations of SID AA for most AA may also be predicted from the nutrient composition of canola meal. In Exp. 3, the SID of Lys in SFM was reduced (linear, P < 0.05) from 83.2 to 63.5% in non-autoclaved SFM or SFM autoclaved for 60 min at 130°C, respectively. The concentrations of Lys and reducing sugars in SFM may be used as good predictors (r2 = 0.85) to estimate the concentration of SID Lys in SFM. In Exp. 4, the SID of Lys in CSM was greater (P < 0.05) in non-autoclaved CSM (66.2%) than in autoclaved (60 min at 130°C) CSM (54.1%). The equation (r2 = 0.68) that best predicted the concentration of SID Lys in CSM includes the concentration ADIN. Conclusions from the first 4 experiments are that the SID of AA decreases as a result of heat damage, but these reductions may be linear or quadratic depending on the type of ingredient. It is also concluded from these experiments that chemical composition may be used to predict the concentration of SID Lys in DDGS, canola meal, SFM, and CSM, but the predictor variables vary depending on the ingredient.Experiments 5 and 6 were conducted to investigate if adjustments in diet formulations based on either total analyzed AA or standardized ileal digestible (SID) AA may be used to eliminate negative effects of including heat-damaged soybean meal (SBM) or heat-damaged distillers dried grains with solubles (DDGS) in diets fed to weanling pigs. In Exp. 5, 4 corn-SBM diets were formulated. Diet 1 contained non-autoclaved SBM and this diet was formulated on the basis of analyzed AA concentrations and using SID values from the AminoDat® (2006) database. Three additional diets were formulated using autoclaved SBM. Diet 2 was formulated similar to Diet 1 except that the non-autoclaved SBM was replaced by the autoclaved SBM. Diet 3 was formulated by adjusting AA inclusion in the diet on the basis of analyzed total AA concentrations in the autoclaved SBM and published SID values (AminoDat®, 2006). Diet 4 also contained autoclaved SBM, but the formulation of this diet was adjusted on the basis of analyzed AA in the autoclaved SBM and SID values that were adjusted according to the degree of heat damage in this source of SBM. The G:F was greater (P < 0.05) for pigs fed Diet 1 compared with pigs fed the other diets. Pigs fed Diet 4 had greater (P < 0.05) G:F than pigs fed Diet 2. In Exp. 6, 4 diets containing corn, SBM (8.5%), and DDGS (non-autoclaved or autoclaved; 22%) were formulated using the concepts described for Exp. 5, except that heat-damaged DDGS, was used in the diets. Pigs fed Diet 1 had greater (P < 0.05) G:F than pigs fed the other diets, but no differences were observed for G:F among pigs fed diets containing autoclaved DDGS. Results demonstrate that the negative effects of heat damage may be ameliorated if the reduced concentration as well as the reduced digestibility of AA in heat-damaged SBM is corrected. Diets for weaned pigs containing up to 22% of heat-damaged DDGS reduces performance of pigs compared with diets containing DDGS that has not been heat-damaged, but correction for the reduced concentration and the reduced digestibility of AA in heat-damaged DDGS may not be of practical importance for weaned pigs.