Since canola meal was bred from rapeseed in the 1970s, dairy nutrition experts have been reviewing canola meal and studying its use as a dairy cow protein source, as well as how to best utilize it. In fact, there have been many studies looking at many different ration formulations that are recognized as official canola meal studies.
That’s a lot of information. In March 2013, the Journal of Dairy Science published a meta-analysis of canola meal, conducted by Agriculture and Agri-Food Canada in Quebec and led by renowned dairy nutrition expert Dr. Helene Lapierre. Not only did the study condense decades of research into one study, it also found that canola meal was being undervalued in dairy nutrition textbooks and formulation models.
Before we dive into the numbers, let’s talk about what a meta-analysis is. When a researcher conducts a meta-analysis, he or she combines results from different studies, and then compares and contrasts the results to find patterns, variations and any interesting trends that might shed light on a new problem or issue. Dr. Lapierre combined 27 studies to find those similarities and differences, and was able to identify that when canola meal was used as a replacement for soybean meal, milk production increased, and in another study was able to discover one potential cause.
Total protein, or crude protein, in soybean meal is higher than in canola meal. However, Lapierre’s most recent research, which focused on protein metabolism, concluded that more of canola meal’s protein was making it past the small intestine, where it can then be absorbed to fuel milk production, than NRC had estimated. This of crude protein is referred to as bypass protein.
“Getting protein to the small intestine is where it actually counts and is useful to the cow,” says Dr. Essi Evans, dairy nutrition expert. The crude protein level in soybean meal beats canola meal, but more of canola meal’s protein can be used for milk production. A comparison can be seen below:
|CANOLA MEAL VS. SOYBEAN MEAL:
BYPASS PROTEIN MATCH-UP
|Soybean Meal||Canola Meal|
|Percent of the Protein|
|Portion of protein degraded in the rumen (RDP)1||57.6||49.6|
|Portion of protein bypassing (RUP)1||42.4||53.1|
|Percent of the Meal Dry Matter|
|Bypass protein (RUP)||20.0||21.7|
1 Heqvist H, Uden P. 2006. Measurement of soluble protein degradation in the rumen. Anim Feed Sci Technol 126: 1-21
2 Ross, DA, Gutierrez-Botero M, Van Amburgh ME. 2013. Development of an in vitro intestinal digestiblity assay for ruminant feeds. Proc Cornell Nutr Conf