Omega Nutrition Reexamined
Mar 25, 2013
Researchers have updated our understanding of the role that essential fatty acids, particularly omega-3 and omega-6 fatty acids, play in animal health, growth, production and reproduction.
A few years ago, I reported on a new topic that I called "omega breeding" (Omega 3 Breeding, Dairy Today, Fall 2007). Since then, researchers have been adding to our understanding of how essential fatty acids (EFA), particularly omega-3 and omega-6 fatty acids, play a role in animal health, growth, production and reproduction. A recent review of this topic was presented at the 2013 Florida Nutrition Conference.
Here are some things they have learned:
1. Interestingly, calves born from cows fed supplemental fat (both saturated and unsaturated) during the dry period may receive better passive immunity from their dam. IgG absorption was increased when dams were fed about 2% of their prepartum diet from supplemental fat. The calves out of these dams also produced more milk in their first lactation.
2. Calves fed milk replacers fortified with EFA (linoleic acid or omega-6) gained about 6.5 lb. more than controls by 60 days of age.
3. Fresh cows supplemented with 1.5% bypass fat (about 0.7 lb./day) averaged about 9.5 lb. more milk than non supplemented cows during the first three months after calving. When the fat contained EFA, the milk increase was even higher.
4. Recently, University of Florida researchers studied fertility in 1,380 cows fed EFA. Reproduction was significantly improved when cows were supplemented with EFA from safflower oil prepartum and then switched to EFA from fish oil at 30 days after calving. The response was due to fewer early embryonic pregnancy losses. This effect of feeding EFA has been very consistent.
Essential fatty acids (omega-6 and omega-3) need to be protected from rumen degradation for maximum effectiveness. These experiments used Calcium salts of the fatty acids for rumen protection. Even so, some of the fatty acids were still changed by biohydrogenation in the rumen, as evidenced by conjugated linoleic acids (CLA) found in the colostrum. Fresh grass is a good source of EFA. However, the bugs in the rumen hydrogenate or saturate most of it. That’s why they produce butter, instead of... cow oil.
Reference: The Role of Specific Fatty Acids on Dairy Cattle Performance and Fertility. 2013 Florida Ruminant Nutrition Symposium.