PENGARUH ARAS UNDEGRADED PROTEIN DAN ENERGI TERHADAP KINETIK FERMENTASI RUMEN DAN SINTESIS PROTEIN MIKROBA PADA SAPI [Effect of Undegraded Protein and Energy Level on Rumen Fermentation Parameters and Microbial Protein Synthesis in Cattle]

Abstract

ABSTRAK Penelitian dilaksanakan dengan tujuan untuk mengkaji pengaruh pemberian aras undegraded protein dan energi terhadap parameter fermentasi rumen dan sintesis protein mikrobia pada sapi perah. Manfaat dari penelitian ini adalah memberikan informasi tentang pemberian aras undegraded protein dan energi untuk meningkatkan efisiensi penggunaan nutrien pada sapi. Penelitian ini dilaksanakan selama 4 bulan di Jurusan Nutrisi dan Makanan Ternak Fakultas Peternakan Universitas Gadjah Mada. Penelitian menggunakan 4 ekor sapi Peranakan Friesian Holstein (PFH) betina yang difistula bagian rumennya, berumur 3 - 3,5 tahun, bobot badan 350 – 400 kg. Masing-masing ternak mendapat 4 macam perlakuan ransum yaitu T1: Undegraded protein 20% dan energi memenuhi 70% dari kebutuhan, T2: Undegraded protein 20% dan energi memenuhi 120% dari kebutuhan, T3: Undegraded protein 30% dan energi memenuhi 70% dari kebutuhan dan T4: Undegraded protein 30% dan energi memenuhi 120% dari kebutuhan, dengan menggunakan rancangan bujur sangkar latin. Variabel yang diamati meliputi pH, NH3 dan volatile fatty acids (VFA) serta sintesis protein mikrobia cairan rumen. Data yang diperoleh dianalisis variansi dan terdapat perbedaan pengaruh perlakuan dilanjutkan uji kontras orthogonal. Hasil penelitian menunjukkan bahwa konsentrasi NH3 cairan rumen pada ransum T1, T2, T3 dan T4 (25,32; 24,99; 24,31 dan 23,41 mg/100 ml) mencapai titik optimal pada 1 jam setelah pemberian pakan dan tidak menunjukkan perbedaan nyata. Aras UDP dan energi tidak mempengaruhi konsentrasi VFA cairan rumen. Kinetik konsentrasi VFA pada ransum energi tinggi (T2 dan T4) cenderung lebih tinggi dibanding energi yang terbatas (T1 dan T2). Kinetik pH cairan rumen sapi perah yang diberi ransum aras UDP tinggi lebih rendah (P<0,01)dibanding pada ransum UDP rendah pada 3, 4 dan 5 jam setelah pemberian pakan. Suplai N mikrobia pada ternak yang diberi ransum dengan level energi tinggi lebih tinggi (P<0,05)dibanding pada aras energi terbatas yaitu 38,37 vs 28,29 g/ekor/hari. Disimpulkan bahwa suplementasi aras UDP dengan level energi yang tinggi dapat meningkatkan parameter fermentasi rumen dan sintesis protein mikrobia. Kata kunci : Undegraded protein, nitrogen, energi, suplementasi ABSTRACT An experiment was conducted to determine the effect of undegraded protein and energy level on rumen fermentation parameters and microbial protein synthesis in cattle. The benefit of the research was to inform about optimation of undegraded protein and energy level to increase nutrient utilization in dairy cows.The experiment was conducted in 4 month in Department of Animal Nutrition and Feed Science, Faculty of Animal Science Gadjah Mada University. The experiment used 4 female rumen fistulated Friesian Holstein Crossbred (FHC) of 3.0 – 3.5 years old and 350 – 400 kg body weight. The treatment of this experiment wereT1: undegraded protein 20% and energy 70% of requirement, T2 : undegraded protein 20% and energy 120% of requirement, T3: undegraded protein 30% and energy 70% of requirement and T4 :undegraded protein 30% and energy 120% of requirement with Latin square design. Variables observed were ruminal pH, NH3, volatile fatty acids (VFA) concentration and microbial protein synthesis. Collected data were analyzed statistically by analysis of variances, and this is report among treatments, then they were tested further by orthogonal contrast. The results showed that NH3 concentration for T1, T2, T3 and T4 (25.32; 24.99; 24.31 dan 23.41 mg/100 ml) were not significantly different and optimally after 1 h post feeding. Undegraded protein and energy level did not influence of VFA concentration rumen fluid. Kinetic concentration of VFA of ration with high energy (T2 and T4) disposed higher than restricted of energy (T1 and T3). Kinetic pH of ration with high UDP was lower (P<0.01) than ration with low UDP (3, 4 and 5 hours post feeding). N microbial supply of ration with high energy level was higher (P<0.05) than restricted energy (38, 37 Vs 28, 29 g/animal/day respectively). It was concluded that high level of UDP and energy could increasing rumen parameters fermentation and microbial protein synthesis in dairy cattle. Keywords : Undegraded protein, nitrogen, energy, supplementation