MACRONUTRIENT DIGESTIBILITIES AND ENZYME ACTIVITIES IN RUMEN FLUID SUPLEMENTED BY PROTEIN-ENERGY SYNCHRONIZED INDEX-BASED RATIONS

Abstract

The protein-energy synchronized (PES) index-based rations can optimize microbial protein synthesis (MPS) and will affect enzyme activity and macronutrients digestibility of ration in rumen fluid. The aim of this study was to examine the in vitro effect of a ration based on PES index on macronutrient digestibility and enzyme activity in rumen fluid. The research was carried out experimentally which consisted of 4 treatment rations with different PES indexes (R1: 0.55; R2: 0.6; R3: 0.65; R4: 0.7). Each treatment was repeated 5 times, so there was a total of 24 experimental units. The material used was the rumen fluid of the Jawa Randu Goat which was taken at the Sokaraja Slaughterhouse shortly after the goat were slaughtered. The results showed that the PES index significantly affected (P<0,01) the digestibility of protein (A), fiber (B), and fat (C), as well as the activity of protease (D) and cellulase (E) enzymes. The orthogonal polynomial test showed that the PES index has a quadratic effect on all test parameters with the following equation: A (Y= -1229.5X2 + 1540.6X - 457.57; R2= 0.75), B (Y = -800.95X2 + 955.86X - 264.51; R² = 0.75), C (Y = 868.92X2 - 1038.2X + 325.1; R2 = 0.81), D (Y = -41.4X2 + 51.697X - 14.982; R² = 0.77), and E (Y = -4.8538X2 + 5.927X - 1.6241; R² = 0.84). The study concluded that the best macronutrient digestibility and enzyme activity were obtained in rations with a protein-energy synchronization index at the medium level (0.6-0.63).