Investigation of Ruminal Degradability and Intestinal Digestibility in Soybean and Canola Meals Coated with Different Fat Sources

The aim of this study was to evaluate the in vitro effect of coating soybean meal and canola meal with different fat sources on ruminal degradability and intestinal digestibility, as well as, the in vivo digestibility. For this purpose, calcium salt of omega-3, calcium salts of unsaturated fatty acids and prilled fat were used for coating. To determine ruminal degradability, three lactating Holsteins cows fitted with rumen fistulas were used and ruminal degradability and intestinal digestibility of dry matter and crude protein were measured. In the in vivo experiment, 40 Holstein cows were randomly assigned to five treatments (control, full fat soybean, soybean-omega3, soybean-ca salt and soybean-prilled fat). The results of the present study showed that coating soybean meal and canola meal with different fats reduced the degradability of dry matter and protein in the rumen and increased their digestibility in the intestine (p <0.0001). It was also shown that protection of soybean meal with prilled fat and calcium salts of unsaturated fatty acids was better than omega 3, but coating of canola meal with calcium salt and omega 3 fats was better than prilled fat (p <0.05). The results of in vitro experiment showed that omega-3 coated soybean meal had the highest digestibility (p=0.009). It can be concluded that coating protein meal with fat will transfer protein digestion from rumen to intestine and thus increase the RUP portion of protein meal.