EFFECT OF REPLACEMENT OF CONCENTRATE WITH Lablab purpureus HAY ON FEED INTAKE, DIGESTIBILITY, LIVE WEIGHT GAIN AND CARCASS CHARACTERISTICS OF HORRO SHEEP FED NATURAL PASTURE HAY AS BASAL DIET

Abstract

The study was conducted at Ambo University using twenty five Horro sheep with initial body weight of 16.84±0.23kg (mean±SD). The objectives of the experiment was to evaluate effect of replacing concentrate mix with Lablab purpureus hay on feed intake, digestibility, live weight gain, and carcass characteristics of Horro sheep fed natural pasture hay as basal diet as well as to assess the economy of replacing concentrate mix with Lablab purpureus(LP)hay. At the end of feeding trial, digestibility trial and carcass parameters evaluation were carried out. The experimental sheep were blocked into five blocks of five animals based on their initial body weight and randomly assigned to one of the five treatment diets within a block. The treatments were natural pasture hay fed ad libitum to all treatments plus 100% CM/day (T1, CM supplemented), 75%CM:25%LP/day(T2), 50%CM:50%LP/day (T3), 25%CM:75%LP/day (T4), 100%LP/day (T5). The experiment consisted of 7 days digestibility and 90 days feeding trials after quarantine and adaptation period to the environment and experimental feed. Feed offered and refused and feces voided were recorded throughout the respective study period; while body weight change was recorded at 7 days interval. The CP contents of NSC, LP, WB, MG and NGH were 31.1, 21, 18.7, 8.2 and 7.4%, respectively. Organic matter ranged from 87.8% (NGH) to 98.1% (MG). The mean intake of basal DM in T5 (523.4±3.13 g/d) was greater (p<0.001) than in T1, T2, T3 and T4 by 86.2, 63.2, 49 and 24.6% respectively. The supplemented animals had higher (p<0.001) total DM intake (860.2-923.4g/d; SEM±3.07) than the CM supplemented (837.2±3.07g/d) and the higher (p<0.001) total CP intake of 117.58, 118.79, 120.75 and 122.73 g/d (SE±0.23) for T2, T3, T4 and T5, respectively were recorded than T1 (115.7±0.23 g/d). LP Supplementation significantly improved digestibility of DM, OM, CP, ADF, NDF (p<0.001) and higher digestibility was recorded for all parameters in T5 while the lowest was recorded in T2 among LP supplemented groups. LP Supplementation improved (P<0.001) final body weight (FBW) and average daily gain (ADG). Lambs fed T5 diet displayed higher (P<0.001) FBW (22.52±0.074kg) and ADG (63.5±0.76g/d) as compared to T1 (20.78±0.07kg) and (41.76±0.76/d) for FBW and ADG, respectively. LP Supplementation significantly increased (P<0.001) slaughter weight, empty body weight, hot carcass weight, rib-eye muscle area and weights of most of the edible and non-edible offal than T1. Sheep supplemented with sole 400g/d LP (T5) showed the highest rate of return. Therefore, supplementation with 400 g/d LP improved body weight of sheep and correspondingly increased the net income from the sale of sheep at the end of the feeding trial as compared to the CM supplemented and the combination of LP and CM. Therefore, in the present study supplementation of Lablab purpureus to natural grass hay at 400 g appears to be the best feeding practice for Horro sheep both biologically and economically.