Karakteristik Pakan dan Reformulasi Ransum Sapi Perah Berbasis Rumen Degradable Protein (RDP) dan Non Fiber Carbohydrate (NFC)

Abstract

Rumen degradable protein (RDP) diperlukan pada ransum sapi perah sebagai penyedia nitrogen untuk sintesis protein mikroba. Namun, di Indonesia informasi RDP pada bahan pakan sapi perah belum tersedia, dan diperlukan reformulasi ransum berbasis RDP dan kecukupan karbohidrat melalui penyediaan non fiber carbohydrate (NFC) untuk meningkatkan efisiensi pakan sapi perah. Penelitian ini bertujuan untuk mengestimasi RDP dan rumen undegradable protein (RUP) bahan pakan konsentrat sapi perah serta mengevaluasi reformulasi ransum sapi perah berbasis RDP dan NFC. Penelitian terdiri atas dua tahapan, tahap pertama adalah karakterisasi bahan pakan konsentrat sapi perah. Penelitian tahap kedua yaitu reformulasi dan evaluasi ransum sapi perah berbasis RDP dan NFC dengan metode in vitro. Penelitian dilaksanakan di Laboratorium Lapang A Nutrisi Ternak Perah dan Laboratorium Nutrisi Ternak Perah, Fakultas Peternakan, IPB. Bahan pakan konsentrat terdiri atas sumber energi (jagung, dedak padi, gaplek, onggok, gandum, dan pollard); sumber protein impor (kedelai, kedelai sangrai, bungkil kedelai, DDGS, CGM, dan CGF); dan sumber protein lokal (bungkil kelapa, bungkil sawit, ampas tahu, ampas tempe, ampas kecap, ampas bir, kulit kopi, dan ampas habbatussauda). Estimasi RDP dilakukan dengan metode in sacco menggunakan dua sapi fistula jantan Frisian Holstein. Reformulasi ransum sapi perah dilakukan dengan Rancangan Acak Kelompok pola Faktorial 3x3 dan dievaluasi dengan metode in vitro dengan 4 ulangan. Faktor pertama yaitu level NFC (30%, 35%, 40%) dan faktor kedua yaitu imbangan RDP RUP (50:50; 55:45; 60:40). Parameter yang diamati meliputi kecernaan bahan kering dan bahan organik, fermentabilitas (pH rumen, NH3, VFA total), VFA parsial, populasi bakteri dan protozoa, serta sintesis protein mikroba (SPM). Data yang diperoleh dianalisis ANOVA menggunakan program SAS. Hasil penelitian menunjukkan bahwa bahan pakan yang memiliki imbangan RDP:RUP yang tinggi (RDP>60) adalah a) sumber energi: dedak padi, onggok, gandum, dan gaplek, b) sumber protein impor: biji kedelai dan CGF; c) sumber protein lokal: ampas tempe, ampas bir, dan ampas habbatussauda. Bahan pakan yang memiliki rasio RDP:RUP (RDP<60) adalah a) sumber energi: jagung; b) sumber protein impor: CGM, kedelai sangrai, bungkil kedelai, dan DDGS; c) sumber protein lokal: kulit kopi, ampas kecap, bungkil sawit, bungkil kelapa, dan ampas tahu. Evaluasi ransum secara in vitro menunjukkan kecernaan bahan kering dan bahan organik dipengaruhi oleh level NFC (P<0.05). Parameter fermentabilitas dan populasi mikroba rumen berada dalam kondisi normal. Terdapat interaksi antara faktor imbangan RDP RUP dan level NFC terhadap proporsi molar asetat, iso-butirat, n-valerat. Nilai SPM meningkat seiring dengan meningkatnya imbangan RDP RUP dan level NFC (P<0.05). Kandungan NFC yang tinggi cenderung meningkatkan rasio asetat propionat (P<0.05). Informasi degradasi protein pakan menjadi acuan dalam formulasi ransum sapi perah. Imbangan RDP RUP 60:40 dan level NFC 35% dapat dievaluasi lebih lanjut secara in vivo.

Rumen degradable protein (RDP) is needed for dairy cattle as nitrogen supply to microbial protein synthesis. However, in Indonesia the information of RDP in dairy cattle feed is unavailable, and it is necessary to reformulate the ration based on RDP and carbohydrate adequacy through non fiber carbohydrate supply to improve dairy cattle feed efficiency. The objective of this study was to estimate RDP and rumen undegradable protein (RUP) and to evaluate the reformulation of RDP and NFC-based rations. This study consisted of two stages, the first was the characterization of dairy cattle feed, and the second study was the reformulation and evaluation of RDP NFC-based ration with in vitro method. This research was conducted at Field Laboratory A of Dairy Nutrition and Laboratory of Dairy Nutrition, Faculty of Animal Science, IPB University. Feed concentrate consisted of energy feed (corn, rice bran, cassava meal, cassava waste, wheat, and pollard); imported feed protein (soybean, roasted soybean, soybean meal, DDGS, CGM, and CGF); and local feed protein (copra meal, palm kernel meal, tofu waste, tempe waste, soy-sauce waste, brewer waste, coffee husk, and habbatussauda waste). The estimation of RDP was conducted by in sacco method using two ruminal fistulated Frisian Holstein bulls. Reformulation of dairy ration was follow out with a 3 x 3 factorial randomized block design and was evaluated by in vitro method. The first factor was NFC level (30%, 35%, 40%), and the second factor was proportion of RDP:RUP (50:50; 55:45; 60:40). Parameters observed included dry matter and organic matter digestibility, fermentability (rumen pH, NH3 concentration, total VFA, concentration, partially of VFA, bacterial and protozoa populations, and microbial protein synthesis (MPS). The data obtained were analyzed with ANOVA using SAS program. The result showed that feed concentrate that had high RDP:RUP ratio (RDP>60) were a) energy source: rice bran, cassava waste, wheat, and cassava meal; b) imported feed protein: soybean and CGF; c) local feed protein: tempe waste, brewer waste, and habbatussauda waste. Feed concentrate that had low RDP:RUP ratio (RDP<60) were a) energy source: corn; b) imported feed protein: CGM, roasted soybean, soybean meal, and DDGS; c) local feed protein: coffee husk, soy-sauce waste, palm kernel meal, copra meal, and tofu waste. In vitro evaluation of the ration showed that dry matter and organic matter digestibility were affected by NFC levels (P<0.05). The parameters of fermentability and rumen microbial population were in normal conditions. There was an interaction between proportion of RDP:RUP and NFC levels on molar proportion of acetate, iso-butyrate, nvalerate. MPS increased with increasing RDP:RUP proportions and NFC levels. High-NFC tends to increase acetate propionate ratio (P<0.05). Information on feed protein degradation can be used as a reference to formulate dairy rations. Proportion of RDP:RUP 60:40 and NFC level 35% can be evaluated with in vivo.