Effect of Combination of Protected and Non-Protected Corn Oil Supplementation on in Vitro Nutrient Digestibility

This research was done to study the effect of supplementation of the combination of corn oil (CO) and protected corn oil (PCO) using formaldehyde on in vitro nutrient digestibility in the rumen and post rumen. Protection of corn oil is carried out by mixing skim milk powder and corn oil (2:1) using formaldehyde 1,5. Feed for fermentation substrate consists of Penissetum purpureum and wheat pollard (60:40). The combination of CO and PCO in several rations was added as the supplement to feed substrate (dry matter basis). The ratios of CO: PCO supplementation that given were T0 (0:0) as a control, T1 (5:0), T2 (3.75:1.25), T3 (2.5:2.5), T4 (1.25:3.75), and T5 (0:5). Their effects on dry matter digestibility (DMD), organic matter digestibility (OMD), crude protein digestibility (CPD) and crude fiber digestibility (CFD) digestibility were studied using the two-stage in vitro digestibility method of Tilley and Terry (1963) modified by Utomo (2012). Data were statistically analyzed using oneway analysis of variance continued by Duncan's Multiple Range Test. The results showed that T1 and T2 significantly (P<0.05) decreased DMD, OMD and CFD at 48 h and 96 h incubation and did not affect rumen CPD. In conclusion, the supplementation of corn oil 1.25 combined with protected corn oil 3.75 had no negative effect on DMD, OMD, CPD and CFD on rumen and post-rumen digestibility.