Pengembangan metode estimasi sintesis protein mikrobia rumen menggunakan ekskresi derivat purin dalam urin berbagai ternak ruminansia Indonesia

YUSIATI, Lies Mira, Promotor Prof.Dr.Drh. Mohamad Soejono, M.Sc.,MS

2005 | Disertasi | S3 Ilmu Pertanian (Peternakan)

Serangkaian penelitian telah dilakukan untuk mendapatkan model estimasi pada ruminansia di Indonesia. Sapi Bali, sapi Peranakan Ongole (PO), sapi Peranakan Friesian Holstein (PFH) dan kerbau masing-masing 6 ekor digunakan untuk mengetahui kontribusi ekskresi basal purin dalam urin. Kontribusi ekskresi basal purin terhadap ekskresi total diperoleh dengan mengukur ekskresi derivat purin (DP) saat ternak diberi pakan King Grass secara ad libitum dan saat ternak dipuasakan selama 1 minggu. Sampel pakan dan feses diambil untuk perhitungan bahan organik tercerna (BOT). Untuk mengetahui pengaruh level pakan terhadap ekskresi DP dalam urin dan proporsi ekskresi DP lewat jalur renal: non-renal, digunakan sapi Bali, sapi PO dan kerbau masing-masing 4 ekor. Ternak diberi pakan King Grass dengan aras 95%, 80%, 60% dan 40% Voluntary Intake, berdasar rancangan 4 X 4 Latin Square. Voluntary Intake ditentukan berdasarkan konsumsi ad libitum terendah diantara kelompok ternak. Sampel pakan dan feses dikoleksi untuk menentukan bahan organik tercerna, sedangkan sampel urin untuk mengetahui ekskresi DP. Untuk mengetahui proporsi DP yang diekskresikan lewat jalur renal : non-renal, ternak diinjeksi dengan 14-C asam urat intra vena sebanyak 280mCi dan dilakukan pengukuran recovery 14-C dalam urin. Untuk mengetahui rasio N-purin dengan N-total mikrobia rumen, digunakan 5 ekor sapi Bali, 6 ekor sapi PO dan 6 ekor kerbau sebagai donor cairan rumen. Ternak diberi pakan rumput Raja secara ad libitum, selama 3 minggu. Cairan rumen diambil untuk penentuan kadar bahan kering (BK), N-purin dan N-total. Untuk mengetahui distribusi dan profil enzim xanthin oksidase dan uricase digunakan sampel plasma, hati dan mukosa usus sapi Bali,sapi PO dan kerbau. Sampel darah diambil dari ternak lewat vena jugularis. Sampel hati dan usus didapat dari rumah potong hewan. Penentuan aktivitas xanthin oksidase dihitung berdasar kemampuan enzim dalam menghasilkan asam urat dari degradasi substrat xanthin, sedang aktivitas uricase dihitung berdasarkan kemampuan enzim dalam mendegradasi substrat asam urat. Penggunaan metode spot sampling dalam estimasi sintesis protein mikrobia rumen berdasar ekskresi DP dalam urin diujikan pada sapi Bali dan PO, masing-masing 6 ekor. Ternak diberi pakan tunggal King Grass secara ad libitum. Koleksi harian urin dilakukan untuk analisis DP, sehingga diketahui total ekskresi per hari. Disamping itu juga dilakukan koleksi sampel urin tiap 3 jam untuk analisis DP dan kreatinin (C). Kemudian diuji korelasi antara ekskresi spot sampling dengan ekskresi total. Hasil ini dikoreksi dengan ekskresi kreatinin lewat urin. Hasil dari penelitian menunjukkan bahwa ekskresi DP sapi Bali, sapi PO, sapi PFH dan kerbau saat diberi pakan ad libitum sebesar 460, 541, 646 dan 179 mmol/kgW0,75/hari dengan perbedaan yang nyata (P< 0,05) diantara keempat macam ternak. Ekskresi basal DP sapi Bali, sapi PO dan kerbau sebesar 145, 132 dan 132 mmol/kgW0,75/hari dengan perbedaan yang tidak nyata antara ketiga macam ternak, sedangkan ekskresi DP endogen sapi PFH sebesar 263 mmol/kgW0,75/hari yang secara nyata (P £ 0,05) lebih tinggi dibandingkan yang lainnya. Setelah dikoreksi dengan DP endogen, ekskresi DP pada kerbau jauh lebih rendah dibandingkan ketiga bangsa sapi yaitu 0,24 dibandingkan 9,82; 12,64 dan 9,80 mmol/g per BOT berturut-turut untuk sapi Bali, sapi PO dan sapi PFH. Ekskresi DP pada sapi Bali dan sapi PO menurun secara nyata dengan menurunnya konsumsi pakan, sedangkan pada kerbau tidak berpengaruh secara nyata. Ekskresi DP pada sapi Bali rata-rata sebesar 12,58 mmol/ kg BOT, pada sapi PO sebesar 11,30 mmol/ kg BOT sedangkan pada kerbau sebesar 2,08 mmol/ kg BOT. Ekskresi DP endogen hasil ekstrapolasi pada sapi Bali dan sapi PO tidak jauh berbeda dibandingkan DP endogen saat ternak dipuasakan (153 dan 121 dibandingkan 145 dan 132 mmol/ kgW0,75/hari), sedangkan pada kerbau jauh lebih kecil yaitu 39 dibandingkan 163 mmol/ kgW0,75/hari. Proporsi DP plasma yang diekskresikan lewat jalur renal sebesar 0,86 untuk sapi Bali dan 0,85 untuk sapi PO. Hasil penelitian menunjukkan bahwa rasio N-purin : N-total mikrobia rumen sapi Bali, sapi PO,sapi PFH dan kerbau sebesar 0,195; 0,200 , 0,180 dan 0,180 dengan perbedaan yang tidak nyata. Aktivitas enzim xanthin oksidase plasma sapi Bali, sapi PO dan kerbau berturut-turut sebesar 3,48; 1,34 dan 0,54 U/l. Pada jaringan hati sapi Bali, sapi PO dan kerbau aktivitas enzim xanthin oksidase sebesar 0,191; 0,131 dan 0,139 U/g jaringan, sedangkan aktivitas xanthin oksidase mukosa usus sebesar 0,001; 0,015 dan 0,020 U/g jaringan. Aktivitas enzim uricase plasma semua ternak sangat rendah, demikian pula aktivitas uricase pada mukosa usus dan hati sapi Bali, sapi PO dan kerbau tidak dapat secara nyata teramati. Korelasi antara kadar DP dalam urin spot sampling dengan ekskresi total DP sangat bervariasi diantara waktu sampling. Hubungan antara DP dalam urin spot sampling yang dinyatakan dalam rasio DP : C dan dikoreksi dengan berat badan metabolik (Y) dengan ekskresi total DP ditunjukkan dengan persamaan regresi Y= -7,28 + 1,30 X (R2= 0,99; n=6) untuk sapi Bali dan Y= 17,64 + 0,87 X (R2= 0,61; n=6) untuk sapi PO dengan waktu koleksi pukul 4.00-7.00. Dari hasil penelitian dapat diambil suatu kesimpulan bahwa, untuk estimasi sintesis protein mikrobia rumen diperlukan persamaan yang berbeda. Besarnya pasokan N mikrobia (EMNS) yang diestimasi dari ekskresi total DP (Y,mmol/hari) untuk sapi Bali, EMNS (g/hari) = (X x 70)/(0,83 x 0,195 x1000), dengan nilai purin terabsorbsi (X,mmol/hari) didapatkan dari persamaan Y =0,145 W 0,75 + 0,86 X mmol/hari, untuk sapi PO, EMNS (g/hari)=(X x 70)/(0,83 x 0,200 x1000), dengan Y =0,132 W 0,75 + 0,85 X mmol/hari , untuk sapi PFH, EMNS (g/ hari)= (X x 70)/(0,83 x 0,195 x1000), dengan Y=0,263 W 0,75+ 0,85 X mmol/hari, untuk kerbau, EMNS (g/hari) = (Xx 70)/(0,83 x 0,180 x1000), dengan Y=0,163 W 0,75 + 0,85 X mmol/hari. Metode spot sampling dapat digunakan dengan pengambilan urin pagi hari antara pukul 4.00-7.00.

A series of experiments were conducted to obtain the estimation model applicable for Indonesian ruminants. Two years old Bali cattle, Ongole cattle and Friesian cattle as well as buffaloes, six each were used in the first experiment to find out the contribution of the endogenous purine derivatives (PD) to the total PD excretion in the urine. The animal were fed ad libitumly for a two weeks period. Feed and uneaten feed material as well as faecal samples were taken during the last week period and were used for digestible organic matter intake (DOMI) measurement. Daily urine collection was done for PD determination. After one week collection period, feeding was reduced gradually within two days to 60 and 30%, followed by fasting for 6 days. During the fasting period, daily urine collection was done for similar analysis purposes. Four males each of two year old Bali cattle, Ongole cattle as well as buffaloes, were used in the second experiment for the examination of the response of PD excretion to feed intake and to define the renal: non-renal partitioning of plasma PD excreted in the urine. The animals were fed with King grass at four levels namely 95%, 80%, 60% and 40% of voluntary intake. The voluntary intake was determined in the preliminary period. It was the lowest intake among the animals of the same species/ breed when they were fed ad libitum. The feeding treatment was allocated according to a 4x4 Latin Square design. Each feeding period lasted for 3 weeks. On the third day of each collection period, each animal receiving voluntary intake would also receive a single dose of 14C-uric acid. Samples were collected during the last 10 days of each feeding period. Urine and blood samples were taken for PD and 14C analysis. Feed and faeces were collected for determination digestible organic metter intake (DOMI). The third experiment was conducted to determine the ratio of N-purine: total-N in the mixed rumen microbial population of Bali and Ongole cattle as well as buffaloes. Five Bali cattle, six Ongole cattle and six buffaloes being used in this experiment were fed with King Grass ad libitumly. Rumen fluid was taken once a week, 3-6 hours after morning feeding, for determination of dry matter (DM), nitrogen (N) and purine content. Tissues of Bali and Ongole cattle as well as buffaloes were used in the fourth experiment for activity of xanthine oxidase and uricase measurement. Six animals from each group were fed with King grass ad labitumly for 3 weeks. The blood samples were taken every week for enzyme assays. Liver and intestine samples were taken from slaughter house and were used for similar analysis. Bali and Ongole cattle, six each were used in the fifth experiment to evaluate the use PD to Creatinine ratio (PD:C) as an index of total PD excretion in the urine to assess the prediction of rumen microbial protein synthesis. The animals were fed with King Grass ad libitumly. The experiment lasted for 3 weeks. During the last 10 days, 24- h urine was collected for PD and creatinine analysis. Urine samples of day 3,4 and 5 were taken periodically, with 3 hours interval times for PD and creatinine analysis. Feed, uneaten feed material as well as faeces were collected daily for determination of DOMI. Correlation analysis between the ratio of PD: C obtained from spot urine sampling with the total PD excretion was done to get the prediction equation. Result showed that daily excretion of PD had everage values of 460 ± 33; 541± 21; 646 ± 9 and 179 ± 7 mmol/kgW0.75/day for Bali, Ongole and Friesian cattle and buffaloes respectively. Purine derivatives excretion decreased significantly when the animals were fasted. The daily PD excretion in the urine of fasted Bali, Ongole and Friesian cattle were 145 ±17; 132±8 and 263±17 mmol/kg W0.75/day respectively, while in the urine of buffaloes was 163 ± 20 mmol/ kgW0.75/day. There were not significant differences in the endogenous PD excretion of Bali cattle, Ongole cattle and buffaloes, while the respective values were lower than the endogenous PD excretion in the urine of Friesian cattle. Daily PD excretion in the urine of Bali and Ongole cattle increased when the level of feed intake was increased. The level of feeding didn’t affect significantly the PD excretion in the urine of buffaloes. The linier relationship between daily PD excretion in the urine (Y, mmol/day) and DOMI (X, kg/day), lead to the rate of PD excretion in the urine of Bali cattle, Ongole cattle and buffaloes as much as 10.67; 8.89 and 3.29 mmol/kg DOMI. Recovery of 14C in the urine of cattle fed at the level of 95% voluntary intake were higher than that in the urine of cattle fed at 60% voluntary intake (86% vs.75% and 85% vs. 56%, respectively for Bali and Ongole cattle). The result showed that there was no significant difference in the RNA and protein content of the microbe in the rumen of Bali cattle, Ongole cattle and buffaloes. The ratio of N-purine: total-N in the rumen microbes of Bali cattle, Ongole cattle and buffaloes were 0.195; 0.200 and 0.180. The activity of the xanthine oxidase in the intestinal mucous of Ongole cattle, Bali cattle and buffaloes were 0.015, 0.001 and 0.020 mmol/min/g tissue..Its activity in plasma of Bali cattle, Ongole cattle and buffaloes were 3.48 , 1.34 and 0.54 U/l plasma while in the liver were 0.131 and 0.139 U/g tissue.The activity of uricase in the plasma of all groups of animal were hardly detectable, even in the intestinal mucous were not found. The activity of uricase in the liver of Bali, Ongole cattle and buffaloes were 0.001, 0.001 and 0.010 U/g tissue.The concentration of PD in the spot urine samples of Bali and Ongole cattle were 4.60 ± 0.42 and 4.16 ± 0.20%, while concentration of creatinine were 7.89 ± 0.38 and 5.00 ± 0.27%. The relationship between PD: C (Y) and total PD excretion (X) was shown as Y = -5.48 + 1.46 X (R= 0.99, n=6, sampling time 4.00-7.00 am.) for Bali cattle, and Y =17.64 + 0.87 X (R= 0.61, n=6, sampling time 4.00-7.00 am.) for Ongole cattle. It could be concluded that estimation model of protein microbial supply for ruminants based on the urinary PD excretion were different among the breed and species of animals. The estimated Microbial Nitrogen Supply (EMNS), could be calculated by these models. For Bali cattle, EMNS (g/day) =(Xx70)/(0.83x 0.195x1000), while X could be calculated by equation Y=0.145 W 0..75 + 0.86 X mmol/day, for Ongole cattle, EMNS(g/day)=(Xx 70)/(0.83 x 0.200 x1000), Y=0.132 W 0.75 + 0.85 X mmol/day, for Friesian cattle, EMNS (g/day)=(Xx70)/(0.83x0.195x1000), Y=0.263W0.75+0.85X mmol/day, while for buffaloes: EMNS(g/day) =(Xx70)/ (0.83 x 0.180 x 1000 ), Y=0.163W0.75+ 0.85X mmol/day. The morning urin (4.00- 7.00 a.m.) was suggested for spot sampling methode

Kata Kunci : Peternakan,Ternak Ruminansia,Ekresi Basal Purin,Urin