 Udo, HMJ, Animal Production Systems Group, WIAS-Wageningen University, Wageningen, The Netherlands NetherlandsUlrikus, RLUlupi, Niken, Department of Animal Production and Technology, Faculty of Animal Science, Bogor Agricultural University, Indonesia IndonesiaUmami, Nafiatul, Faculty of Animal Science, Universitas Gadjah Mada IndonesiaUmami, Nafiatul, Faculty of Animal Science Universitas Gadjah Mada IndonesiaUntu, Ivonne Maria, Department of Nutrition and Feed Sciences, Faculty of Animal Husbandry, Sam Ratulangi University, Jalan Kampus Unsrat, Manado 95115, Indonesia IndonesiaUsman, Yunasri, Animal Husbandry Department, Agricultural Faculty, Syiah Kuala University, Banda Aceh IndonesiaUsman, Yunasri, Laboratory of Animal Nutrition, Animal Husbandry Department, Agricultural Faculty IndonesiaUtama, CS 