McKinnon: Establishing canola meal as the protein supplement of choice for growing beef cattle and dairy heifers
Date: June 2018
Term: 3 years
Status: Completed
Researcher(s): John McKinnon, Timothy Mutsvangwa, University of Saskatchewan, Timothy McAllister, Agriculture and Agri-Food Canada, Lethbridge AB
SaskCanola Investment: $90,250
Total Project Cost: $163,808
Funding Partners: NSERC
Project Summary
Researchers in Saskatchewan conducted a series of trials to evaluate the value of canola meal in growing/finishing beef cattle diets relative to other common protein supplements such as soybean meal and wheat dried distiller’s grains with solubles (WDDGS). The results the trials indicate that canola meal is at least equal to soybean meal as a protein supplement for feedlot cattle and that the inclusion of WDDGS did not improve feedlot performance, rumen fermentation, or nutrient digestibility. Therefore, based on current economics, canola meal would be the protein supplement of choice for beef producers.
Researchers in Saskatchewan conducted a series of trials to evaluate the value of canola meal in growing/finishing beef cattle diets relative to other common protein supplements such as soybean meal and wheat dried distiller’s grains with solubles (WDDGS). Soybean meal is traditionally viewed by ruminant nutritionists and cattle producers throughout North America and globally as the protein supplement of choice for beef and dairy cattle, therefore these comparisons are important.
The objectives of this three-year project were: to compare the performance of growing and finishing beef cattle fed canola meal (CM) as a protein supplement relative to those fed soybean meal (SBM) with or without WDDGS; to measure rumen degradability characteristics of canola meal relative to soybean meal and WDDGS; and to determine if canola meal supplementation either alone or in combination with WDDGS improves rumen fermentation, microbial protein synthesis and intestinal amino acid supply in growing beef cattle relative to those fed soybean meal based diets.
Two feedlot trials focused on the value of canola meal relative to soybean when fed with or without wheat DDGS in diets for backgrounding and finishing cattle with a specific focus on performance and carcass quality. The first growing trial consisted of a 95-day backgrounding program using 398 steer calves fed one of four barley based backgrounding diets supplemented with either CM, SBM, CM+WDDGS, or SBM+WDDGS. The second growing/finishing trial consisted of a 61-day backgrounding period followed by a 147-day finishing program using 300 head fed one of five barley based finishing diets supplemented with either CM, SBM, WDDGS, CM+WDDGS, or SBM+WDDGS. In addition an in situ degradability trial was carried out to evaluate the rumen degradability of canola meal relative to soybean meal and wheat DDGS in ‘gradual in, all out’ 48-h ruminal incubations. Finally a metabolism trial that focused on site and extent of nutrient utilization in four cannulated beef heifers was run.
From the study, the results of the growing trial showed that cattle fed canola meal exhibited similar performance to those fed soybean meal, with the poorest performance observed with cattle fed a combination of soybean meal and WDDGS. In the subsequent growing/finishing trial, performance was similar between cattle fed canola meal versus those fed soybean meal. In both trials, soybean meal fed cattle had numerically the highest feed cost of gain. With respect to carcass traits, soybean meal and WDDGS fed cattle had the poorest fat deposition compared to cattle fed canola meal and WDDGS. In terms of impact on rumen fermentation and nutrient digestibility, heifers fed canola meal had the highest dry matter, organic matter, and nitrogen apparently digested in the rumen, and the highest nitrogen truly digested in the rumen compared to heifers fed soybean meal. The inclusion of WDDGS tended to decrease N truly digested in the rumen.
The results of the total tract digestibility trial showed there were no treatment differences on dry matter, organic matter, crude protein, acid detergent fibre or neutral detergent fibre digestibility. Overall rumen fermentation including rumen ammonia levels were not affected by protein source, which was to be expected given the similarity in in situ degradability of the protein sources observed in this research.
Overall, the results of the trials indicated that canola meal is at least equal to soybean meal as a protein supplement for feedlot cattle and that the inclusion of WDDGS did not improve feedlot performance, rumen fermentation, or nutrient digestibility. Therefore, based on performance results of this research, canola meal can be considered equal to soybean meal as a protein supplement for beef cattle and based on current economics would be the protein supplement of choice for beef producers.