Effects of ca-soap protected vegetables oil in dairy ration on rumen fermentability and in vitro digestibility

Abstract

Supplementing dairy ration with Ca-soap vegetable oils rich in unsaturated fatty acid components increases the fatty acid profile and conjugated linoleic acid (CLA) levels in dairy milk, but it might reduce fermentability and digestibility. This study aimed to identify the effect of vegetable oil supplementation protected by Ca-soap on rumen fermentability and digestibility. Parameters observed included pH score, protozoa population, total VFA (volatile fatty acid), ammonia concentration, dry and organic matter digestibility (DMD and OMD), neutral and acid detergent fiber (NDF and ADF) digestibility. The results showed that increasing Ca-soap-protected vegetable oil levels in dairy ration significantly decreased (P<0.05) pH score, protozoa population, NH3 concentration, and digestibility. Oil type also significantly influenced all parameters except for microbial fermentation. The interaction effect of oil types and their levels were found in pH score, protozoa population, NH3 concentration, DMD, and fiber digestibility in ADF. Vegetable oils that influenced optimally were corn oil and canola oil. It is concluded that Ca-soap-protected vegetable oil supplementation in dairy ration should be less than 4%. It is suggested to study at the lower level. The type of oil used should consider its linoleic acid content and availability.