Nutrient profile and availability of co-products from bioethanol processing

Effects of Dietary Corn Germ Meal Levels on Growth Performance, Serum Biochemical Parameters, Meat Quality, and Standardized Ileal Digestibility of Amino Acids in Pekin Ducks

The study aimed to investigate the effects of dietary corn germ meal (CGM) levels on growth performance, carcass characteristic, serum biochemical indexes, meat physical and chemical quality, and standardized ileal digestibility of amino acids (SIDAA) in Pekin ducks from 10 to 42 d of age. A total of 420 ten-day-old Cherry Valley ducks were randomly allotted to 5 treatments with 6 replicate cages per treatment and 14 ducks per cages based on mean body weight. Five isonitrogenous and isocaloric experimental diets were formulated on a digestible amino acid basis to produce diets containing 0, 3, 6, 9, or 12% CGM. Results showed: 1) Compared with other groups, ducks fed 12% CGM significantly increased (P < 0.05) the feed to gain ratio. 2) Dietary CGM levels had no effect (P > 0.05) on the carcass traits and breast meat physical quality; but the content of crude protein presented a linear decrease (P < 0.05) in breast meat with increasing dietary CGM levels. 3) Serum biochemical indices (e.g., alanine aminotransferase, aspartate aminotransferase, glucose, high density lipoprotein cholesterol, total cholesterol, triglyceride, total protein, and urea) showed no significant differences among all groups (P > 0.05). 4) The levels of CGM had no significant effect on SIDAA of diets (P > 0.05), except for cysteine which showed a quadratic increase (P < 0.05). These results suggested that the optimal levels of CGM in diets for meat duck aged from 10 to 42 d should be below 9% based on feed to gain ratio and the content of crude protein in breast meat.

Effects of distillers dried grains with solubles on amino acid digestibility, growth performance, and carcass characteristics of growing pigs

Two experiments were conducted to compare the standardized ileal digestibility (SID) of AA by growing pigs in European distillers dried grains with solubles (DDGS) produced from wheat, maize, or wheat–maize mixtures and to test the effect of increasing the inclusion levels of wheat DDGS on growth performance of growing-finishing pigs fed diets balanced for NE and SID Lys. In Exp. 1, 12 barrows (initial BW: 23.0 ± 2.2 kg) were surgically equipped with a T-cannula in the distal ileum and randomly allotted to a replicated 6 × 6 Latin square design with six diets and six periods. Five sources of European DDGS were used: wheat DDGS from 2011, wheat DDGS from 2012, wheat-80 DDGS (80% wheat and 20% maize), wheat-70 DDGS (70% wheat and 30% maize), and maize DDGS. Each diet contained one source of DDGS as the sole source of AA and an N-free diet was used to determine basal endogenous losses of AA. Results indicated that the SID of CP was greater (P < 0.05) in maize DDGS compared with wheat DDGS from 2011, wheat DDGS from 2012, and wheat-70 DDGS. The SID of all indispensable AA except Trp was also greater (P < 0.05) in maize DDGS compared with all other DDGS sources used in this experiment. For Trp, the SID in wheat-80 DDGS, wheat DDGS from 2011, and wheat DDGS from 2012 were not different from maize DDGS, but were greater (P < 0.05) than in wheat-70 DDGS. The SID for all indispensable AA except Ile and Trp in wheat-70 DDGS were not different from the values calculated for wheat DDGS from 2011 and wheat DDGS from 2012, and no differences between SID values for AA in wheat DDGS from 2011 and wheat DDGS from 2012 were observed. In Exp. 2, 36 growing pigs (initial BW: 38.3 ± 1.97 kg) were randomly allotted to one of four dietary treatments (one pig/pen and nine replicate pigs/treatment) in a 2-phase feeding program (35 to 65, and 35 to 105 kg BW). The four dietary treatments included diets containing 0%, 10%, 20%, or 30% wheat DDGS. Results indicated that there was no effect of wheat DDGS on pig growth performance or carcass quality. However, addition of wheat DDGS increased linearly (P < 0.015) the indole concentration in the carcasses of the pigs. In conclusion, the SID of AA in maize DDGS produced in Europe is greater than in European wheat DDGS and DDGS produced from mixtures of wheat and maize, but inclusion of 30% wheat DDGS in diets fed to growing-finishing pigs did not affect growth performance or carcass quality.

Changes in carbohydrate and protein fractions during ensiling of alfalfa treated with previously fermented alfalfa juice or lactic acid bacteria inoculants

The effects of previously fermented juice (PFJ) prepared from alfalfa and lactic acid bacteria (LAB) inoculants on the dynamic changes of nutritive components in ensiled alfalfa after various ensiling periods were investigated by using the Cornell Net Carbohydrate and Protein System. The third-cut alfalfa was harvested at the budding stage, exposed to sunlight, weighed occasionally to estimate the dry matter (DM) content until the actual DM finally obtained was 347.8 g/kg fresh weight, and then chopped to 1–2-cm lengths. Chopped forages were treated with (1) distilled water (control), (2) alfalfa PFJ or (3) LAB at 1 mL/50 g fresh weight. The application amounts of PFJ and LAB to the fresh forage were 8.73 log (colony-forming units/mL) and 7.32 log (colony-forming units/mL) respectively. All silages were prepared in mini-silos of 100-mL polypropylene centrifuge tubes and kept in an incubator at 30°C, and triplicate silos from each treatment were opened after 1, 3, 7, 14 and 35 days of ensiling. Results suggested that silage treated with LAB and PFJ was of better quality than was the control silage, as evidenced by lower volatile fatty acid concentrations, as well as higher lactic acid, sugar, starch, soluble fibre and digestible natural detergent fibre production at various ensiling periods (P < 0.05), and a lower protein degradation as suggested by the low non-protein nitrogen production (P < 0.05). The effect of PFJ on alfalfa fermentation quality and protein degradation was greater than that of LAB, as evidenced by the lower pH value and volatile fatty acid content and the higher concentrations of lactic acid (P < 0.05). In addition, the cost of PFJ for 1 tonne of alfalfa silage is ~1/7–1/5 of that of LAB. In conclusion, adding PFJ to alfalfa forages before preservation as silage is a cost-effective way to improve the silage formation quality; in addition, its effect as a fermentation stimulant may be comparable to, or even better than, that of LAB inoculants at various ensiling periods.

Effect of substituting soybean meal and canola cake with grain-based dried distillers grains with solubles as a protein source on feed intake, milk production, and milk quality in dairy cows

The growth of the bioethanol industry is leading to an increase in the production of coproducts such as dried distillers grains with solubles (DDGS). Both corn-based DDGS and grain-based DDGS (gDDGS; defined as originating from grain sources such as barley, wheat, triticale, or a mix, excluding corn) appear to be relevant sources of feed and protein for dairy cows. To date, most of the studies investigating DDGS have been performed with corn-based DDGS. The objectives of this study were to determine the effects of the proportion of gDDGS in the diet on feed intake, milk production, and milk quality. The present experiment involved 48 Holstein cows in a replicated 3 × 3 Latin square design with 3 grass-based dietary treatments consisting of 4, 13.5, and 23% gDDGS on a dry matter (DM) basis (L, M, and H, respectively) as a replacement for a concentrate mix. The concentrate mix consisted of soybean meal, canola cake, and beet pulp. Dry matter intake and energy-corrected milk yield were not affected by the proportion of gDDGS in the diet. Daily milk yield decreased with the H diet compared with the L and M diets. The percentage of fat in milk was higher when cows were fed the H diet compared with the L and M diets, whereas milk fat yield was not affected by dietary treatment. The M diet had a higher percentage of protein in milk compared with the L and H diets. Milk protein yield was similar for the L and M diets; however, it decreased for the H diet. Milk taste was not affected by the proportion of gDDGS in the diet or when milk was stored for 7 d. Linoleic acid and conjugated linoleic acid cis-9,trans-11 in milk increased with increasing proportion of gDDGS. To conclude, gDDGS can replace soybean meal and canola cake as a protein source in the diet of dairy cows. Up to 13.5% of the diet may consist of gDDGS without negatively affecting milk production, milk quality, or milk taste. When gDDGS represents 23% of dietary DM, milk production is reduced by 1.6 kg/d, whereas energy-corrected milk production is numerically reduced by 1 kg.

Optimized utilization of the co-products from bioethanol processing and oat grain: effect of blending on biochemical, biodegradation, and nutritional profiles

The objective of this study was to (1) optimize the utilization of wheat-based dried distillers grains with soluble (wDDGS) by blending with oat ( Avena sativa L.) grain as an alternative feed for beef cattle when the barley price is high and (2) investigate the effect of blending on biochemical, biodegradation, and nutritional profiles. Oat grains were blended with wDDGS produced in western Canada at different levels (4:0, 3:1, 2:2, and 1:3 on %DM basis in two batches, denoted O0, O25, O50, and O75, respectively). The study revealed that increasing the wDDGS resulted in increasing most nutrient contents linearly (P < 0.05) except for starch and cell wall materials, which were linearly decreased (from 43.6 to 12.0% and from 34.5 to 29.1% of DM for starch and NDF, respectively). When wDDGS was increased in the blend/mixture, intestinally absorbable protein and degradable balance of protein increased (P < 0.05). Overall, through blending or combining with the cereal grain, the co-products from bioethanol processing could be optimally utilized. The best combination of oat to wDDGS ratio was 75% to 25%.

Protein structures among bio-ethanol co-products and its relationships with ruminal and intestinal availability of protein in dairy cattle

The objectives of this study were to reveal molecular structures of protein among different types of the dried distillers grains with solubles (100% wheat DDGS (WDDGS); DDGS blend1 (BDDGS1, corn to wheat ratio 30:70%); DDGS blend2 (BDDGS2, corn to wheat ratio 50:50 percent)) and different batches within DDGS type using diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). Compared with BDDGS1 and BDDGS2, wheat DDGS had higher (p < 0.05) peak area intensities of protein amide I and II and amide I to II intensity ratio. Increasing the corn to wheat ratio form 30:70 to 50:50 in the blend DDGS did not affect amide I and II area intensities and their ratio. Amide I to II peak intensity ratio differed (p < 0.05) among the different batches within WDDGS and BDDGS1. Compared with both blend DDGS types, WDDGS had higher α-helix and β-sheet ratio (p < 0.05), while α-helix to β-sheet ratio was similar among the three DDGS types. The α-helix to β-sheet ratio differed significantly among batches within WDDGS. Principal component analysis (PCA) revealed that protein molecular structures in WDDGS differed from those of BDDGS1 and between different batches within BDDGS1 and BDDGS2. The α-helix to β-sheet ratios of protein in all DDGS types had an influence on availability of protein at the ruminal level as well as at the intestinal level. The α-helix to β-sheet ratio was positively correlated to rumen undegraded protein (r = 0.41, p < 0.05) and unavailable protein (PC; r = 0.59, p < 0.05).

Evaluation of the feed value for ruminants of blends of corn and wheat distillers dried grains

Recently, biofuel processing has produced a large amount of biofuel coproducts. However, to date, there is little information on the metabolic characteristics of proteins and energy in biofuel coproduct-based rations. The objective of this study was to study the metabolic characteristics of proteins and energy in biofuel coproduct-based rations in terms of (1) chemical and nutrient profiles, (2) protein and carbohydrate subfraction associated with various degradation rate, (3) rumen and intestinal degradation and digestion kinetics, and (4) metabolic characteristics of proteins. Two sources of grain corn were mixed with two sources of biofuel coproducts (wheat-based dried distillers grains with solubles, wDDGS) in ratios of 100:0, 75:25, 50:50, and 25:75%. The study revealed that increasing the biofuel coproduct inclusion level increased most of the nutritional components linearly (P < 0.05) except starch, which linearly decreased. With increasing biofuel coproduct inclusion level, the rumen degradation rate and the effective degradability of organic matter were not affected (P > 0.05), but the effective degradability of starch was decreased (P < 0.05). Effective degradation of crude protein and neutral detergent fiber as well as predicted truly absorbed protein supply in the small intestine and degraded protein balance were increased (P < 0.05). In conclusion, the inclusion of the biofuel coproduct up to 25-50% in rations improved potential nitrogen and energy synchronization for microbial growth and improved truly absorbable protein supply to the small intestine, without altering energy value.

In-depth study of the protein molecular structures of different types of dried distillers grains with solubles and their relationship to digestive characteristics

BACKGROUND

Dried distillers grains with solubles (DDGS) have been extensively utilised in ruminant rations in western Canada and USA, and it is important to ensure their consistent quality. Traditional chemical methods do not consider the inherent structural changes of feed ingredients. Synchrotron-based Fourier transform infrared microspectroscopy (SFTIRM) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) have been utilised to detect the changes in molecular structure of several feedstuffs (e.g. barley, flaxseed and alfalfa). However, similar structural information is lacking for DDGS. The objectives of this study were to identify differences in protein molecular structures between different grains (wheat, triticale and corn) and DDGS (wheat DDGS, triticale DDGS, corn DDGS and wheat and corn blend DDGS) using SFTIRM and DRIFT and to reveal the relationship between changes in protein molecular structure and the digestive characteristics of the protein in DDGS when fed to dairy cattle.

RESULTS

The protein molecular structure studies showed significant decreases (P < 0.01) in the amide I to amide II ratio and the α-helix to β-sheet ratio between grains and their DDGS. Protein digestive characteristics were correlated with protein molecular structures in grains and DDGS, and prediction equations were established to estimate protein digestive characteristics of DDGS using protein molecular structure parameters. For the DVE/OEB-1994 model, one of the best prediction equations was for truly absorbed protein in the small intestine (DVE) = 296.17 - 38.98 × the amide I to amide II ratio (R(2) = 0.72). For the NRC-2001 system, one of the best prediction equations was for metabolisable protein (MP) = 300.96 - 43.32 × the amide I to amide II ratio (R(2) = 0.76).

CONCLUSION

Protein molecular structure varies between different DDGS and their original grains, and this variation is associated with the digestive characteristics of the proteins in the DDGS and their original grains.

Assessing protein availability of different bioethanol coproducts in dairy cattle

Bioethanol production has led to the production of considerable quantities of different coproducts. Variation in nutrient profiles as well as nutrient availability among these coproducts may lead to an imbalance in the formulation of diets. The objectives of this study were to fractionate protein and carbohydrates by an in situ approach, to determine ruminal availability of nutrients for microbial protein synthesis and to determine protein availability to dairy cattle for three types of dried distiller's grains with solubles (DDGS; 100% wheat DDGS (WDDGS); DDGS blend1 (BDDGS1, corn to wheat ratio 30 : 70); DDGS blend2 (BDDGS2, corn to wheat ratio 50 : 50)) and for different batches within DDGS type using the 2010 DVE/OEB protein evaluation system. The results indicated that all DDGS types are quantitatively good sources of true protein digested and absorbed in the small intestine (DVE values; 177, 184 and 170 g/kg dry matter (DM) for WDDGS, BDDGS1 and BDDGS2, respectively). Rumen degraded protein balances (OEB) values were 159, 82, 65 g/kg DM in WDDGS, BDDGS1 and BDDGS2, respectively. Despite the differences in ruminal availability of nutrients among the different batches of DDGS, the DVE values only differed between the batches of BDDGS1 (194 v. 176 g/kg DM). In conclusion, when DDGS is included in the rations of dairy cattle, variation in its protein value due to factors such as DDGS batch should be taken into consideration.

Use of a dry fractionation process to manipulate the chemical profile and nutrient supply of a coproduct from bioethanol processing

With an available processing technology (fractionation), coproducts from bioethanol processing (wheat dried distillers grains with solubles, DDGS) could be fractionated to a desired/optimal chemical and nutrient profile. There is no study, to the author's knowledge, on manipulating nutrient profiles through fractionation processing in bioethanol coproducts in ruminants. The objectives of this study were to investigate the effect of fractionation processing of a coproduct from bioethanol processing (wheat DDGS) on the metabolic characteristics of the proteins and to study the effects of fractionation processing on the magnitude of changes in chemical and nutrient supply to ruminants by comparing chemical and nutrient characterization, in situ rumen degradation kinetics, truly absorbed protein supply, and protein degraded balance among different fractions of coproduct of wheat DDGS. In this study, wheat DDGS was dry fractionationed into A, B, C, and D fractions according to particle size, gravity, and protein and fiber contents. The results showed that the fractionation processing changed wheat DDGS chemical and nutrient profiles. NDF and ADF increased from fraction A to D (NDF, from 330 to 424; ADF, from 135 to 175 g/kg DM). Subsequently, CP decreased (CP, from 499 to 363 g/kg DM), whereas soluble CP, NPN, and carbohydrate increased (SCP, from 247 to 304 g/kg CP; NPN, from 476 to 943 g/kg SCP; CHO, from 409 to 538 g/kg DM) from fraction A to D. The CNCPS protein and carbohydrate subfractions were also changed by the fractionation processing. Effective degradability of DM and CP and total digestible protein decreased from fraction A to D (EDDM, from 734 to 649; EDCP, from 321 to 241; TDP, from 442 to 312 g/kg DM). Total truly absorbed protein in the small intestine decreased from fraction A to D (DVE value, from 186 to 124 g/kg DM; MP in NRC-2001, from 193 to 136 g/kg DM). Degraded protein balance decreased from wheat DDGS fractions A-D (DPB in the DVE/OEB system, from 245 to 161 g/kg DM; DPB in NRC-2001, from 242 to 158 g/kg DM). The fractionation processing had a great impact on the chemical and nutrition profiles. Total truly digested and absorbed protein supply and degraded protein balance were decreased. The processing relatively optimized the protein degraded balance of the coproducts to dairy cattle. Compared with the original wheat DDGS (without fractionation), fractionation processing decreased truly absorbed protein supply of DVE and MP values. In conclusion, fractionation processing can be used to manipulate the nutrient supply and N-to-energy degradation synchronization ratio of coproducts from bioethanol processing. Among the fractions, fraction A was the best in terms of its highest truly absorbed protein DVE and MP values. Fractionation processing has great potential to fractionate a coproduct into a desired and optimal chemical and nutrient profile. To the author's knowledge, this is the first paper to show that with fractionation processing, the coproducts from bioethanol processing (wheat DDGS) could be manipulated to provide a desired/optimized nutrient supply to ruminants.