Effect of different unsaturated fatty acids sources on in-vitro fermentability and digestibility of ration in dairy cattle

Abstract

Supplementation of oil rich in unsaturated fatty acids (FAs) such as canola, soybean, and palm oils improved the quality of milk fatty acids. However, the unprotected unsaturated oil might impair rumen fermentation, feed, and fiber digestibility. A study was conducted to determine the best type of oil supplementation (factor A) including canola (A1), soybean (A2), or palm (A3) and level oil supplementation (factor B) including B0 = 0%, B1 = 1%, B2 = 2% or B3 = 3%) on the in-vitro feed fermentation and digestibility. The study used a 3 x 4 factorial block design. Two-stages were used to measure the pH, ammonia (NH3), volatile fatty acids (VFAs), protozoal number, dry matter (DMD), organic matter (OMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD) digestibility. The results showed that oil type did not significantly influence the fermentability (pH, NH3, VFAs, and protozoa) and feed's digestibility (DMD, OMD, NDFD, and ADFD) but oil level influence the fermentability and digestibility significantly. In addition, an increase above 1% in oil levels reduced protein fermentability, protozoal number, DMD, and OMD, but increased VFA. It is concluded that the addition of unprotected canola, soybean, or palm oil in dairy cattle ration could be applied in a concentration not more than 1%.