4
Figure 1. Rumen Mechanical Stimulator by Smith study 1969; left and Rumenfibe® by Meiwa Co. Ltd. present; right.
Table 2. Nutrient Composition of Formulated Rations
Nutrient Composition
GW1 GW2
GW3 FN1
FN2 FN3
Dry Matter 81.60
81.85 87.61
79.35 79.60
85.36 Organic Matter
83.76 83.27
90.26 88.32
87.84 94.83
Crude Fiber 17.94
18.21 20.41
16.65 16.92
19.11 Crude Protein
13.42 12.81
13.30 14.12
13.52 14.01
Ether Extract 3.96
3.87 4.08
4.46 4.37
4.58 TDN
62.28 61.13
65.36 67.85
66.70 70.93
GEI Kal kg
-1
DM 22.52
22.10 23.63
24.53 24.12
25.65
Notes: GW1= Grower feed + King Grass; GW2= Grower feed + Green cut corn; GW3= Grower feed + Rice Straw; FN1=Finishing feed + King Grass; FN2= Finishing feed + Green cut corn; FN3=
Finishing feed + Rice Straw; NFE=Nitrogen free extract ;TDN=Total Digestible Nutrient; GEI Gross Energy Intake; = National Research Council 1984.
Nutrient intake was analyzed based on dry matter DM in feed rations. Steer was weighed each month 31 days a month with weighing machine since the
beginning of this study. The performance parameters such as nutrient intake, final body weight and average daily gain of each steer were then calculated. Feed conversion ratio
FCR and income over feed cost IOFC were also calculated.
a. Nutrient intake evaluation Nutrient intake was quantified by difference between offered feed and feed
residual in each pen. The model to quatified dry matter intake was :
Nutrient Intake kg head
-1
day
-1
= Σ intake x nutrient in ration
93 days The nutrient intake was calculated since the beginning of this research after RF
installment. Nutrient intake such as dry matter, organic matter, crude fiber, crude protein, ether extract, nitrogen free extract, total digestable nutrient TDN and gross
energy intake GEI; Kal kg
-1
day
-1
were also calculated with the respective model.
5
b. Performance evaluation
Performance of feedlot steers that quantified in this study was total gain and average daily gain ADG. The model used to quatify the total gain:
Total Gain kg head
-1
= Final weight kg head
-1
– Initial weight kg head
-1
Meanwhile, for the average daily gain was according to that model divided by total days of rearing 93 days.
c. Gain : Feed evaluation
The Gain : Feed evaluation in this study was calculated by total DM intake kg head
-1
day
-1
per total gain kg head
-1
. The model used to quatify feed efficiency was :
Feed efficiency = total DM intake kg head
-1
Total Gain kg head
-1
d. Income over feed cost IOFC
Income over feed cost was calculated after steers were sold to describe the bruto income by the difference on total price of bodyweight BW gain and total feed
cost in Rupiah. The model used to quantify feed efficiency was :
IOFC Rp head
-1
= Total price of BW gain – Total feed cost
Rumen Fermentation Study
Each item of the rumen fermentation profile was measured in order to determine the feedlot steer rumen fermentation whether good or poor with and without
administered the RMS brush fed high concentrate diet. Rumen fermentation profile of experimented steer was measured by its biochemical content analysis such pH,
oxidation reduction potential ∆EH, ammonia concentration, lactic acid concentration, volatile fatty acid concentration totally and partially, methane production and
hydrogen recovered potencies of each steer.
Rumen liquor of each steer was storaged into thermos bottles 2 bottles head
-1
; 2 litres bottle
-1
by squeezed the rumens content with sterylized hand. The rumen liquor then
filtered and separated into small bottles at Feed Quality Testing Laboratory, IPB’s Faculty of Animal Science as soon as possible after storaged to partially analyzed in
several laboratory with difference sample bottle. Feed resources were analyzed by proximate analysis at IPBs General Laboratory PAU. Rumen fermentation profile
analysis was measured partially into several indicators, below:
a. pH and ORP ∆EH
The pH and reduction and oxidation p otential redox potential ∆EH were
analyzed with digital pH and ORP kit analysis used electrodes and callibration test solutions at Land Chemistry and Fertility Laboratory, Faculty of Agriculture of IPB.
pH status was measured as soon as possible after storaged. The portable electrodes then pulled in a small bottle. Normal pH indicates around +
7,00 and normal ∆EH of the rumen measures about -330 to -220 mV Wang et al., 2012.
6
b. Ammonia
Ammonia NH
3
was analyzed with conway micro-diffusion method General Laboratory Procedures, 1996 used the conway cup. Conway cup was smeared with
vaseline on both lips. one ml supernatant of rumen liquor then dropped in the left side of Conway cup and saturated with an indicator of Na
2
C0
3
solution at another side of chamber. Before mixed, one ml of boric acid indicator was dropped into the middle of
the conway cup. The conway cup then sealed in order to prevent oxidation. Furthermore, the Na
2
CO
3
then saturated with the supernatant and mixed by slow- shaking the Conway cup. Sample then left at normal room temperature +25
o
C until boric acid were showed a blue color, then opened. In the next 24 hours, cup were
opened then titrated into the midle of chamber with 0.06 N HCI until showed a pink color as same as boric acid indicator. NH3 concentration mM then calculated by the
formula:
Amount of NH 3 mM = ∆H
2
SO
4
titrated ml x N H
2
SO
4
mM x 1000 c.
Lactic acid concentration Lactic acid concentration in the rumen liquor was determined by Baker and
Summerson’s method 1941 with spectrophotometer analyzer. Rumen liquor sample plus 10 TCA were filtered and putted in the centrifuge tube in order to get 10 ml
filtrate. Then, sample was centrifuged at 2750 rpm speed for 15 minutes. The supernatant was poured and aligned round and round with one ml TCA 10. About
20 CuSO
4
solution was added into the tube and was diluted with 10 ml distilled water. Then, 2 grams CaOH powder was added. All tubes were closed with Parafilm in
practical case was closed with marbles then homogenized for more than 30 minutes, then centrifuged again. The supernatant was taken and pulled into a tube test, then were
dried and cleaned φ 18-23 mm. Each tube was diluted and added with 0.05 ml of
CuSO
4
4, then was added with six ml of H
2
SO
4
burette. Tube was heated about 5 minutes 80°C then refrigerated in a few minutes 20
C. At the next step, 0.1 ml of reagent p-hydroxyphenyle was added drop by drop until shown the white color. Tube
then homogenized with mixer before pulled into the water bath 30 C for more than
30 minutes then reinserted into boiling water for 90 seconds before cooled the tube. While liquid in tube turned into a violet color, the tube was moved into the cuvet in
order determined the wavelength each liquids with OD spectrophotometer valued at 20 amplitude and 560 nm of wavelength Good reading transmition around 20-80
amplitude. After wavelength was measured in spectrophotometer machine, lactic acid content was determined with the formula:
Lactic acid content mM = 0,006347 + 15,266 OD Molecular weight g
d. Partial VFA
Partial VFA was analyzed at the Nutritional Laboratory of Technology Agriculture Gadjah Mada University with gas chromatography machine GC 8-
Schmidzu: 10GP-SP-12001 H3PO4 on Chromosorb WAW 80100. One ml of each sample standard VFA liquid indicator and one ml of rumen liquid were inserted
