Can canola meal offer sound nutrition to your newborn calves? To answer this question, Dr. Greg Penner with University of Saskatchewan recently prevented “Canola Meal in Starter Mixtures for Dairy Calves: Improving Utilization By Focusing on Gut Development,” hosted by AMTS and Canolamaz!ng.
In his studies, Penner looked at the anti-nutritional factors, including glucosinolates, erucic acid, trypsin inhibitors and phytates and other factors like tannins, phenolic acid and high fiber content. These tend to lead to low palatability, low digestibility and lower feed efficiency – not what farmers want in a ration for calves.
Since a calf is a young ruminant or developing into one, “the most important factor is really the high fiber content relative to other protein sources,” Penner said.
He hoped to discover an opportunity to enhance canola meal use in starter mixtures. Currently, feed additives can stimulate greater efficiency of digestion, and sweeteners improve palatability. Canola meal, which is high in glutamine and glutamate, is viewed as an important source of energy. But Penner questioned if it would have a favorable effect on gastrointestinal tract functions.
Heat treatment at 110º C for 10 minutes reduced canola meal’s anti-nutritional factors and increased its bypass protein like amino acids, including glutamate and glutamine. Glycerol inclusion increased palatability, resulted in higher starter intake and promoted rumen development with greater butyrate fermentation in the rumen.
“We don’t need to worry so much about bypassing glutamate and glutamine as it’s a yet undeveloped digestive tract,” Penner said.
Heat treating without adding glycerol reduced rumen tissue weight, likely as a result of palatability, and it reduced jejunal tissue and length, ileal digesta, cecal digesta, colonic length and butyrate molar proportion. It decreased ruminal pH and cecum digesta.
“These are challenging outcomes, but positive results,” Penner said.
Unfortunately, the results didn’t really tell him whether farmers can improve canola meal utilization.
In a separate study, glycerol was incorporated in all of the diets, learning from previous studies.
“All of these substitution effects are not clear on results,” Penner said. “We’re not controlling for starch.”
Using both bull and heifer calves, the researchers saw some support of previous research that shows when replacing 100% of soy with canola meal, they see reduced intake.
With canola meal, calves experienced a negative impact on growth at weaning, but the “calves were able to adapt after weaning,” Penner said. “We did see a tendency of reduced dry matter digestibility, but it’s not perfectly balanced for starch.”
Penner speculated that the slightly lower digestibility of canola meal compared with soybean meal may explain the reduced abomasal and jejunal tissue.
“We also see increased jejunal tissue weights of calves fed soybean meal compared with canola meal,” Penner said.
He also found that the fecal score is fairly positive. “Canola meal calves had fewer days with diarrhea for those with butyrate than those with soybean meal,” Penner said.
When testing pelleted starter intake, calves did not reduce their intake when canola meal replaced soybean meal.
“There was only a numeric reduction and there was a tendency for soybean meal to have lower intake,” Penner said. “But we did see lower daily gains as we replaced soybean meal with canola meal.”
He saw no differences in average daily gains and feed efficiency with partial replacement of soybean meal rather than full replacement. But it does look like there’s a small reduction of starter intake with inclusion of soybean meal.
The overall implications are that canola meal introduced by partial replacement (up to 60%) of soybean meal will not negatively impact the weight of the abomasum and jejunum.
Heat affects the quality of the canola meal. “It was very clear that with heat-treated canola meal, we saw detrimental effects on gastrointestinal function,” Penner said. Adding glycerol helped counteract those effects.
Penner recommended that anyone seeking more information on feeding canola meal to dairy cows should visit canolacouncil.org/canolamazing/feed-guide.