Produktivitas itik yang tinggi dapat dicapai dengan memberikan ransum berkualitas dalam jumlah sesuai kebutuhan. Diantara upaya peningkatan kualitas ransum adalah pemberian aditif, berupa prebiotik, probiotik atau campurannya. Penelitian dilakukan untuk mengkaji pengaruh level sinbiotik ekstrak umbi porang dan Labactocillus casei (CEPL) dengan lama pemberian berbeda terhadap retensi nitogen dan kalsium, serta produktivitas itik Tegal. Sebanyak 180 ekor itik Tegal, bobot badan rata-rata 42,33±2,54 g diacak dan ditempatkan pada 18 pen percobaan, menurut rancangan acak lengkap pola faktorial 2 x 3, 3 ulangan. Faktor pertama : level CEPL (1 dan 2%), faktor kedua : lama pemberian CEPL (2, 3 dan 4 minggu). Parameter pengamatan meliputi retensi nitrogen dan kalsium, bobot daging dan bobot tulang. Data dinalisis ragam dan dilanjutkan uji wilayah ganda Duncan. Hasil pengamatan menunjukkan terdapat interaksi nyata (P<0,05) antara level dengan lama pemberian CEPL terhadap retensi nitrogen dan bobot daging. Namun, tidak terdapat interaksi antara level dan lama pemberian CEPL terhadap retensi kalsium dan bobot tulang. Simpulan penelitian bahwa pemberian campuran ekstrak umbi porang dan Lactobacillus casei (CEPL) pada level 1% selama 4 minggu menghasilkan bobot daging paling tinggi tanpa perbedaan retensi kalsium dan bobot tulang.

The study aimed to evaluate fish meal substitution with black soldier fly larvae supplemented with 2% Trichoderma culture on female grower performance and carcass traits quail. The materials used were 200 two-week-old female quails with an average body weight of 51.5 ± 7.3 grams. The study used a completely randomized design with five treatments and four replications. The treatments were: BSF0 (100% fish meal), BSF25 (75% fish meal + 25% BSF meal), BSF50 (50% fish meal + 50% BSF meal), BSF75 (25% fish meal + 75% BSF meal) ), BSF100 (100% BSF meal). The BSF meal used was added with 2% Trichoderma culture. The rations were iso-calorie and iso-protein, formulated from yellow corn, soybean meal, fish meal, BSF meal, mineral mix, and Trichoderma culture, with metabolic energy of 2,900 kcal/kg and 24% protein. The data were analyzed using variance analysis to determine if it had a significant effect, then continued with Duncan's Multiple Range Test. The results showed that the treatments were insignificant to the FCR, percentages carcass, and ovaries. Nevertheless, significant to (p<0.05) feed intake, live weight, average daily gain and abdominal fat. The substitution of fish meal with BSF + 2% Trichoderma culture was more than 75% decreased feed consumption which caused a decrease in quail's life weight. According to the carcass traits, the BSF + Trichoderma sp 2% could be used up to 100%. However, based on quail performance, it can be concluded that BSF + 2% Trichoderma sp can be used up to 75% in quail rations without harmful effects.