Effects of bioethanol plant and coproduct type on the metabolic characteristics of the proteins in dairy cattle

Abstract

The dramatic increase in bioethanol production in Canada has resulted in millions of tonnes of different types of coproducts: wheat dried distillers grains with solubles (DDGS), corn DDGS, and blend DDGS (e.g., wheat:corn 70:30). The objectives of this study were 1) to investigate the effect of DDGS type and bioethanol plant on the metabolic characteristics of the proteins and the total truly digested and absorbed protein supply to dairy cattle using the DVE/OEB system and 2) to compare the metabolic characteristics of the proteins of original feedstock grains with their respective derived DDGS samples. The results showed that all types of DDGS are a good source of the truly digested and absorbed protein in the small intestine [DVE; 107 vs. 249 g/kg of dry matter (DM) for wheat and wheat DDGS; 108 vs. 251 g/kg of DM for corn and corn DDGS]. According to the DVE/OEB system, the predicted total DVE supply to dairy cattle differed among wheat DDGS (DVE=249 g/kg of DM), corn DDGS (DVE=251 g/kg of DM), and blend DDGS (DVE=281 g/kg of DM) and, to a lesser extent, between the different bioethanol plants (DVE: 277 vs. 230 g/kg of DM for bioethanol plants 1 and 2). The results indicated the superior protein value of blend DDGS as well as that of the more optimum degraded protein balance (DPB) value for corn DDGS (DPB: 11 g/kg of DM in corn DDGS vs. 72 g/kg of DM in wheat DDGS and 55 g/kg of DM in blend DDGS). In addition, differences in the acid detergent-insoluble crude protein content of wheat DDGS samples were reflected in differing protein DVE values. In conclusion, it is inappropriate to assume fixed protein values for DDGS without considering factors such as DDGS type and bioethanol plant origin.

The energy and protein value of wheat, maize and blend DDGS for cattle and evaluation of prediction methods

“…The general high rumen bypass value for DDGS as compared with that of the grain is explained by the reduction of the protein amide I to amide II ratio during fermentation and drying (Li et al, 2012). Our RBP-values for maize and wheat DDGS are similar to those of Nuez-Ortín and Yu (2010), who obtained on average 66.1% and 54.4%, In our study intestinal digestibility of RBP was determined by incubating small nylon bags with residual material after 12 h of rumen incubation in the duodenum and collection of the bags in the faeces. This is considered as the reference method for determining dRBP in the Dutch protein system (Van Duinkerken et al, 2011).…”

“…This is considered as the reference method for determining dRBP in the Dutch protein system (Van Duinkerken et al, 2011). No other recent studies with DDGS were found where this in situ technique was used and mostly a three-step in vitro procedure with pepsin and pancreatin was applied (Mjoun et al, 2010;Nuez-Ortín and Yu, 2010;Li et al, 2012). Nuez-Ortín and Yu (2010), who obtained similar RBP-values as in our study, estimated a mean dRBP of 81.3%, 82.5% and 93.9% for wheat, maize and blend DDGS, respectively, thus some 10% lower than our values for WDDGS and MDDGS, but surprisingly a similar value for BDDGS.…”

“…Although the efficiency of the bioethanol processes is significantly improved during the last 10 years, upto-date information about the in vivo digestibility and energy value of DDGS is scarce. During the last years more information became available about the protein value and amino acid (AA) availability of DDGS, mainly through rumen incubation and in vitro experiments (Cao et al, 2009;Mjoun et al, 2010;Nuez-Ortín and Yu, 2010;Azarfar et al, 2012;Li et al, 2012;Westreicher-Kristen et al, 2012). All these studies showed great variability in the quality of DDGS, which makes it very difficult for feed compounders to make accurate feed formulations.…”

Spectroscopic impact on protein and carbohydrate inherent molecular structures of barley, oat and corn combined with wheat DDGS

“…DDGS are a key by-product from ethanol industry, and extensively used in animal feed industry. The nutritive value of dried distillers grain solubles (DDGS) from wheat after ethanol production, makes them an excellent source of protein and energy for dairy and beef cattle [17][18][19]. Subsequent to the process of bioethanol production, ethanol fermentation utilizes most of the starch from grain kernels hence concentrates the remaining components, mainly protein, fiber, fat and minerals into DDGS [37].…”

“…Subsequent to the process of bioethanol production, ethanol fermentation utilizes most of the starch from grain kernels hence concentrates the remaining components, mainly protein, fiber, fat and minerals into DDGS [37]. Wheat DDGS provides many compounds which could be categorized as digestible and available nutrients to animals [17][18][19]. DDGS from wheat contains higher amounts of dry matter (DM, 938 g/kg), crude protein (CP, 393 g/kg) and starch (63 g/kg) [17].…”