Fatty Acid Characteristics of Concentrate Containing Fermented <i>Arenga pinnata</i> By-Product on Milk of Dairy Cows

Abstract This study evaluated the impact of a diet supplemented with a concentrate containing fermented Arenga pinnata by-product, inoculated with Pleurotus ostreatus, on the fatty acid profiles of concentrates, milk, and feces in lactating dairy cows. The purpose of this study was to comply with the 15th side of SDG, which is about life on land. Four different ratios of fermented A. pinnata by-product to rice bran were tested: CA0 (0% fermented A. pinnata , 35% rice bran), CA10 (10% fermented A. pinnata , 25% rice bran), CA15 (15% fermented A. pinnata , 20% rice bran), and CA20 (20% fermented A. pinnata , 15% rice bran). The remaining 65% of the concentrate composition consisted of ground corn, soybean meal, palm oil, mineral mix, Curcuma xanthorrhiza , yeast, NaCl, CaCO 3 , and TSP, which remained constant across all treatments. The study employed a 4x4 Latin Square design using four lactating cows. The results demonstrated improvements in long-chain fatty acids (31.15%), medium-chain fatty acids (17.32%), monounsaturated fatty acids (32.15%), and the polyunsaturated-to-saturated fatty acid ratio (0.28%) in milk, alongside with an improvement in total fatty acids. A similar pattern was observed in fecal fatty acid profiles. Based on these findings, a concentrate containing 20% fermented A. pinnata by-product and 15% rice bran is optimal for enhancing milk fatty acid composition in lactating dairy cows.