Effect of substitution of soybean meal by canola meal or distillers grains in dairy rations on amino acid and glucose availability

Abstract

Canola meal (CM) or by-products of ethanol production (dried distillers grain, DDG) may offer an economical alternative to soybean meal (SBM) in North American dairy rations. These protein supplements can effectively replace SBM and, in 2 recent meta-analyses, CM had a positive effect on milk and milk protein yields compared with SBM. The objective of this study was to determine if the positive responses observed with inclusion of CM in dairy rations could be explained by an increased availability of His, Lys, Met, or glucose. Eight Holstein dairy cows were used in a replicated 4×4 Latin square with 14-d periods. Cows were fed isonitrogenous (17.2% crude protein) and isoenergetic (1.56 Mcal/kg of net energy of lactation) diets formulated to slightly exceed nutrient requirements. Diets contained 38% grass hay and 62% corn-based concentrate including SBM, CM, corn high-protein DDG (HPDDG), or wheat DDG plus solubles (WDDGS) as the single protein supplement. The effect of protein supplements on availability of His, Lys, Met, and glucose was estimated using variations in the whole-body (WB) flux of these nutrients, determined by isotopic dilution. As planned, dry matter intake and milk and milk protein yields were not affected by treatments and averaged 23.7, 31.4, and 1.14 kg/d, respectively. Lactose yield did not differ among diets although milk lactose content tended to be lower with CM and WDDGS diets than with SBM and HPDDG diets. Lysine availability was affected by treatments: the highest WB irreversible loss rate (ILR) was observed for the CM diet (371 g/d) and the lowest for HPDDG diet (290 g/d); values for SBM and WDDGS were intermediate (330 and 316 g/d, respectively). Availability of His and Met did not vary among diets and WB ILR averaged, respectively, 129 and 124 g/d; the CM diet, however, had numerically the highest His and Met ILR. Plasma concentrations of most of the essential AA were higher with the CM diet and lower with the HPDDG diet, the exception being Leu for which the concentration was highest for the HPDDG diet. Glucose WB rate of appearance was altered by diet, with the highest mean observed for SBM (3,036 g/d) and the lowest for CM (2,795 g/d); the 2 diets with the lowest WB glucose rate of appearance (CM and WDDGS) also had the lowest dietary starch concentration. Overall, this study suggested that positive responses in milk and milk protein yields observed with inclusion of CM in dairy rations could be linked to a greater supply of metabolizable protein, including some essential AA, especially His, Lys, and Met, as glucose availability was certainly not increased in cows fed the CM diet.

Reciprocal combinations of barley and corn grains in oil-supplemented diets: Feeding behavior and milk yield of lactating cows

“…Feed intake and lactational responses might be influenced by the given source of protein supplement; however, McCarthy et al (1989) and Casper et al (1999) reported that substitution of 2 different dietary protein supplements in BBD versus CBD resulted in similar DMI, milk yield, and ruminal fermentation parameters. More recently, Maxin et al (2013) replaced canola meal for soybean meal in dairy cow diets and observed no change in nutrient intake, milk yield, and milk composition. Therefore, it is unlikely that our results are influenced significantly by changing additional elements of the diets.…”

Novel coproducts from corn milling and their use in ruminants’ nutrition

“…HPDG was associated with the highest concentration of casein in milk, suggesting that it might have the most desirable amino acids profile for casein production. The authors highlighted, however, that lysine is the first limiting amino acid, as also shown by other studies (28,61), which warns about the potential lysine deficiency of HPDG, especially at high dietary proportions. Moreover, lysine is highly susceptible to heat damage (17), which makes important the influence of processing conditions and highlights the need of specific analysis when large quantities of corn coproducts are involved.…”

“…For example, because a large proportion of corn phosphorous is found in germs, a low level of this mineral is expected in HPDG following the removal of germs. Profiles of minerals and/or amino acids were sporadically reported both for RFDG (23,24) and HPDG (19,(25)(26)(27)(28)(29).…”

Effects of dietary rumen‐protected lysine on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal

“…This result was consistent with a study, in which the ECM did not differ between DLRSM and SBM (Maxin et al . ).…”

“…The result was consistent with other studies, in which the lactose yield did not differ between diets containing DLREM and SBM, although the milk lactose content was lower in diets with DLRSM than with SBM (Maxin et al . ). One theory that may explain the lack of increase in milk fat and milk lactose was the dilution effect caused by increased milk yield (DePeters et al .…”