Effect of supplementing grazing Arsi-Bale sheep with molasses-urea feed block on weight gain and economic return under farmers management condition

Sheep fattening with Molasses-urea feed block (MUB) was undertaken in Adami Tulu Jido Kombolcha District at Aneno and Arba villages for 87 days during both dry (from 22 March to 17 June) and during wet season (from 19 August to 10 November, 2009). A study was conducted to determine the performance and profitability obtained from MUB supplemented grazing sheep. Molasses, urea, wheat bran, finely ground haricot bean haulm, salt, and bindinder (cement and termite mould) were used as ingredients to produce three different MUBs; Treatment two (T2), Treatment three (T3) and Treatment four (T4) with 17.72, 20.96 and 24.6% CP, respectively. Six sheep were randomly allotted to each of T1, T2, T3 and T4 during both dry and wet seasons at each village. Sheep in T4 had higher overall average daily weight gain (ADWG) (74.8 ± 11.13 g/head/day followed by T2, T3 and T1 (72.88 ± 9.27, 58.5 ± 12.98 and 33.67 ± 3.03) g/head/day, respectively. Over all total body weight gain (TBWG) of T4 was higher (6.26 ± 0.53) kg, followed by T2, T3 and T1 (6.13 ± 0.46, 4.92 ± 0.64 and 2.83 ± 0.39) kg, respectively. Differences (P 0.05). ADWG (67.96 ± 10.31) g/head/day and TBWG (5.91 ± 0.87) kg of sheep at Aneno village was significantly (P<0.05) higher than the ADWG (51.79 ± 9.41) g/head /day and TBWG (4.51 ± 0.75) kg of sheep at Arba village. Significant difference (P<0.05) in ADWG and TBWG was observed between seasons with the higher gain during wet season ( 67.33 ± 11.43) g/head/day growth rate and 5.86 ± 0.43 kg total weight gain as compared to dry season ( 52.07 ± 8.3) g/head/day growth rate and 4.53 ± 0.39 kg total weight gain. The interaction of season by village was not significantly influenced both ADWG and TBWG of sheep. Marginal rate of return of T2 is higher (123.46) followed by T3.77.16) and T4 (65.64). From the biological and economic data analysis, we can conclude and recommend that MUB with 17.72% CP could be used as supplement for sheep fattening in mid rift valley of Ethiopia.   Key words: Feed block, crude protein, weight gain, growth rate, return.