2.1. Study site
The experiment was conducted at Haramaya University goat farm. Haramaya University is located at 9o 26’N latitude and 42o3’ E longitude. The site is situated at about 1980 meters above sea level (m.a.s.l.) and located at 520 km east from the capital city, Addis Ababa. The mean annual rainfall of the study area is about 870 mm with a range of 560–1260 mm and the mean maximum and minimum temperatures are 23.4oC and 8.25oC, respectively (Mishra et al., 2004).
2.2. Treatment preparation, experiment design and layout
Trichoderma viride (Tv.) was obtained from plant protection section of the school of plant sciences of Haramaya University, Ethiopia. The sample of Tvkept under 4oC was taken and grown on petridish to activate the microorganisms. Three days old slant culture samples of Tvwas inoculated on petridish (9 cm) containing 25ml potato dextrose agar (PDA) for seven days. The seven days old culture was used to inoculate plastic bottle containing the following substances per one liter of distilled water: 4% molasses, 0.4% urea, 0.2% KH2PO4 and 0.03% MgSO4(7H2O) per one liter of water and the inoculate was kept for seven days under room temperature. The Rice husk and sugarcane bagasse were inoculated by the solution to prepare spawn. Then the untreated sugarcane bagasse and rice husk were moistened at 55% and inoculated with 10% of the respective spawn fungi of SCB and RH (Abdel-Azim et al., 2011). The treatment was made on clean room padded with plastic sheet chemically disinfected by Dettol and Formalin. After the spawn and feeds were mixed, it was covered by plastic sheet and left for 21 days to ferment; then the treated materials were opened and placed under the sun for 8 h/days to about 10% and packed and stored until used in the feeding trials.
Adequate quantities of an inert form of EM (EM-1) packed in plastic bottles was obtained from Weljijie PLC (Debrezeit). Molasses was added and mixed with EM at equal proportion in order to initiate multiplication and metabolism activities of the microorganism. The mixture of EM and molasses was diluted with chlorine free water at a ratio of 18:1 per liter, respectively (Higa and Wididana, 2007). After stirring, the solution was stored in 200 liters capacity barrel for seven days to activate the EM solution. Then the EM solution was uniformly sprayed on to the sugarcane bagasse and Rice husk at a proportion of one liter EM to one kg dry matter feed, thoroughly mixed and packed in an airtight plastic bag of 100 kg capacity and stored in a large barrel of 200 to 250 kg capacity, covered with plastic sheet and kept at room temperature for 21 days for feeding.
Six experimental ration were prepared from concentrate feed mixture (CFM) and the two roughages (Rice husk and Sugarcane bagasse). The treatments had 50:50 ratios of the roughages to concentrate as shown in Table 1.The treatments were randomly allocated to thirty six yearlings Hararghe highland rams housed individually in a Randomized Complete Block Design (RCBD), thus each treatment were replicated six times. The rations were offered as a total mixed diet ad libitum at a rate of 20% refusal adjusted at interval of four days based on previous day’s intake of the individual animal. The daily offer was given in two meals at 8:00 AM and 2:00 PM. The amount of feed offer and refusal was recorded daily for each animal to determine daily intake of the individual animal as a difference between the two. Feed samples were taken on batches of feed prepared, but that of the refusal were taken for each animal daily, recorded, and pooled per animal. Feed offer and refusal samples were bulked across the experimental period and sub-samples were taken for determination of chemical composition.
Table 1
Ingredients (%) and chemical composition (%DM basis) of the experimental Treatments
Ingredients (%)
|
Treatments
|
Rice husk(RH)
|
Sugarcane Bagasse(SCB)
|
U
|
EM
|
Tv
|
U
|
EM
|
Tv
|
Untreated RH
|
50
|
-
|
-
|
-
|
-
|
-
|
EM treated RH
|
-
|
50
|
-
|
-
|
-
|
-
|
Tv treated RH
|
-
|
-
|
50
|
|
-
|
-
|
Untreated SCB
|
-
|
-
|
-
|
50
|
-
|
-
|
EM treated SCB
|
-
|
-
|
-
|
-
|
50
|
-
|
Tv treated SCB
|
|
|
-
|
-
|
|
50
|
Maize
|
11
|
11
|
11
|
11
|
11
|
11
|
Wheat bran
|
11
|
11
|
11
|
11
|
11
|
11
|
Noug seed cake
|
23.5
|
23.5
|
23.5
|
23.5
|
23.5
|
23.5
|
Molasses
|
3
|
3
|
3
|
3
|
3
|
3
|
Salt
|
1
|
1
|
1
|
1
|
1
|
1
|
Pre.mix
|
0.5
|
0.5
|
0.5
|
0.5
|
0.5
|
0.5
|
Chemical composition of diet (% DM basis)
|
|
DM
|
89.6
|
66.6
|
89.5
|
89.8
|
61.1
|
89.6
|
OM
|
85.8
|
85.1
|
84.6
|
92.5
|
91.5
|
90.5
|
CP
|
13.7
|
13.8
|
15.6
|
11.4
|
11.9
|
13.2
|
NDF
|
50.3
|
45.7
|
43.7
|
60.2
|
57.6
|
55.7
|
ADF
|
30
|
25.8
|
24
|
38.1
|
35.6
|
35.7
|
ADL
|
9.7
|
9.5
|
8.8
|
10.2
|
9.6
|
9.3
|
ME MJ/kg DM
|
10.59
|
11.37
|
12.05
|
10.4
|
11.2
|
11.14
|
U = Untreated; EM = effective microorganism; Tv = Trichoderma viride; DM = Dry matter; OM = Organic matter; CP = Crude protein; NDF = Neutral detergent fiber; ADF = Acid detergent fiber; ADL = Acid detergent lignin; ME = metabolizable energy;premix contained: 500000IU vitamin A, 100000IU vitamin D3,100mg vitamin E,190g Ca,90g Mg, 50g Na, 2g Mn, 3g Fe, 0.3g Cu,3gZn, 0.1g Co and 1 mg Se |
2.3. Animals and management
A total of thirty six yearling intact Hararghe highland sheep were purchased from Chelenko and Kulubi markets. The animals were transported to Haramaya University and quarantined for 3weeks, at the end of which the animals were treated against internal parasites and ear-tagged for ease of identification. The lambs were placed in an individual pen furnished with feeding and watering equipments. After overnight feed withdrawal, animals were weighed for two consecutive days and the mean weights were taken as an initial body weight. Clean tap water was provided in a bucket twice daily and feed was offered in feeding trough.
2.4. Growth trial
The fattening study lasted for 90 days. The amount of total mixed ration (TMR) offered and refused were recorded daily throughout the study period using digital balance having a sensitivity of 0.02 kg. Animals were weighed at an interval of 10 days after overnight feed withdrawal and before the daily feed was offered using hanging scale graduated in 0.2 kg interval. Total weight gain (TWG) was calculated as the difference between final and initial weights. Average daily weight gain (ADG) was determined by regressing body weight against time. Feed conversion efficiency (FCE) of the animal was determined as the proportion of daily weight gain to the daily DM intake.
2.5. Laboratory analysis of feeds
Chemical analysis of samples was done in Haramaya University Animal nutrition laboratory. Representative samples of feeds and refusals were dried at 60°C for 72 hours. The dried samples were ground using laboratory mill to pass through 1 mm screen and stored for subsequent analyses of dry matter (DM), crude protein (CP), ash (AOAC, 1990), acid detergent fiber (ADF), neutral detergent fiber (NDF) and acid detergent lignin (ADL) (Van Soest and Robertson, 1985). The CP was calculated as N*6.25.
2.6. Carcass evaluation
At the end of the feeding trial, all the sheep were fasted overnight, weighed and slaughtered. The animals were killed by severing their jugular vein and carotid artery with knife. During slaughtering process, data were carefully recorded on total edible offal components (TEOC) that include the sum of weight of blood, heart, liver with gall bladder, tail, kidneys, empty gut and fat (omental, intestinal and kidney); and total non-edible offal components (TNEOC) as the sum of the weight of head, lung with trachea, skin, spleen, penis, testis, gut content and feet. The empty body weight (EBW) was calculated as the difference between slaughter weight (SW) and gut content. Dressing percentage was calculated as HCW divided by SWB and/or HCW divided by EBW. Both the right and left rib-eye area (REA) were cut between the 12th and 13th ribs perpendicular to the backbone to measure the cross section of the rib-eye muscle. The rib-eye muscle was traced first on transparency paper then the left and right REM area were traced onto a square paper which was placed on the transparency and the area of the squares (0.25 cm2 each) that fell within the traced area was counted and those partially fell outside was estimated and the average of the two sides was taken as the REM area.
2.7. Partial budget analysis
The profitability analysis was performed to evaluate the profitability of feeding sugarcane bagasse (SCB) and rice husk (RH) treated with EM and Tv incorporated into the concentrate mixture containing maize, noug seed cake, molasses and salt to Hararghe highland sheep. The analysis was performed considering the main input costs such as sheep price, feed price and labor expenses. The average price was taken as purchasing price of sheep for all treatments. The cost of feed treatements was estimated and added on feed cost. The selling price of each animal was estimated by three experienced individuals involved in sheep trading in the area. The difference in average selling and purchase price of each animal was taken as total return (TR). The calculations for the following economic parameters were done according to Upton (1979) as follows:
NR = TR-TVC; MRR=∆NR/∆TVC; Where NR = net return; TR = total return; TVC = total variable cost; MRR = marginal rate of return.
2.8. Statistical data analysis
The results of weight changes and carcass characteristics for respective treatment diets of sheep were analyzed using SAS software 9.1.3 (SAS, 2008). Where there is significant difference between means, the mean separation was made adjusted Tukey honestly significant difference test.The model employed for the analysis was: Model: yijkl = µ + ai + bj + cl + b*cij + εijkl; Where:Yijkl = the dependent variables, µ = overall mean, ai = The ith block, bj = The jth feed type, cl = The lth treatment method, c*b feed type = The jlth interaction (between feed type and treatment method), εijkl = random error.