Ration to Produce Milk High in Conjugated Linoleic Acid (CLA) at Smallholder Dairy Farm: An In Vitro Reconstruction

: Smallholder dairy farms have shown the best practices for producing milk with high Conjugated Linoleic Acid (CLA). The rations need to be further investigated to explain the digestion process. This study aimed to reconstruct and evaluate the digestion process of five rations that produced milk with high CLA using in vitro method . The rations were collected from five traditional dairy farms (P1, P2, P3, P4, and P5) after screening 260 milk samples from 60 farms at different smallholder dairy cattle farms in West Java Province, Indonesia. Digestibility of the ration was tested using a two-stage in vitro method. The result shows that the five rations consist of different feeds and nutrients. The P4 was better than other rations of its simplicity, nutrient sufficiency, fermentation, digestibility, and microbial synthesis. The P4 ration consists of 40.27% Napier grass and 59.72% cooperative concentrates with the lowest crude fiber (10.20%) and the highest crude protein (12.63%). The high crude protein percentage was in line with the ammonia concentration. The P4 significantly produced the lowest molar proportion of butyrate (12.68%), the highest total digestible nutrient (59.9%), total VFA (132.23 mm), the in vitro dry matter and organic matter digestibility (77.95 and 74.49%), protozoa (6.31 log cell/mL) and with bacteria number 7.19 log CFU. It is concluded that a ration with 40% Napier grass and 60% concentrate is the best smallholder dairy cattle ration to produce high CLA milk.