PSI-3 - Effects of strategic blending of food industry by-products with canola meal on in vitro and in situ fermentation and nutrient degradation

Abstract: Canola meal (CM) has become an increasingly available high protein feed source for beef cattle in North America, thanks to the expansion of the canola crushing industry in Western Canada and the United States. The inclusion of CM in diets has been reported to improve nutrient utilization and the performance of growing beef cattle. However, the energy value of CM was not as high as barley grain finishing diets, resulting in poorer performance of finishing feedlot steers. Pea starch and pea molasses are available as food industry by-products of industrial pea protein extraction. However, the utilization of these food industry by-products as a component of livestock feed has not been well evaluated. The strategic blending of food industry by-products, such as pea starch and pea molasses, with canola meal (CM) is a novel approach to improving the energy density of CM as animal feed. Nutrient synchrony, where the energy and protein availability in the rumen is synchronized to maximize the ruminal microbial fermentation, has been proposed to improve animal performance. The objectives of our study were to evaluate the in vitro and in situ fermentation and nutrient degradability of novel blended CM. Pea starch and pea molasses were added at 5% (CM5) and 10% (CM10) levels in CM (DM basis), with regular CM serving as control (CON). The in vitro study consisted of two runs of 24 h incubations with three replicates per treatment. The in situ study utilized three cannulated beef heifers and used the same number of replicates of samples and time periods as for the in vitro study. Results indicated a numerical improvement in DM degradation for CM5 and CM10 than CON both in vitro and in situ incubations. Total gas production (mmol) was numerically greater, while the proportion of methane (mmol and g/DM) was lower for CM5 than CON. Results indicated that in vitro fermentation of CM5 was enhanced, while greater propionate production from CM5 likely reduced methane production. Further evaluation of these food industry by-products for beef cattle growth performance studies could provide valuable information about rumen fermentation, nutrient digestibility, and energy value of these novel blended CM.