Substitution of dried mulberry (Morus indica L.) leaf meal for concentrate mix on feed intake, digestibility, body weight gain and carcass characteristics of Abergelle sheep

The study was conducted at Abergelle Agricultural Research Center, Ethiopia using 24 yearling intact male Abergelle sheep with initial body weight of 17.52 ± 1.13 kg. The objectives were to evaluate substitution of dried mulberry (Morus indica L.) leaf meal (DMLM) for concentrate mix (CM) on feed intake, digestibility, body weight gain and carcass characteristics, and to determine cost benefit analysis of the supplementary regimes. The study comprised 90 days of feeding trial, 7 days of digestibility trial and carcass evaluation at the end. Six sheep were randomly assigned to each treatment using randomized complete block design. The treatments included feeding of ad libitum natural grass hay and supplementation with 100% CM (T1); 75% CM + 25% DMLM (T2); 50% CM + 50% DMLM (T3) and 25% CM + 75% DMLM (T4) on DM basis. The supplements were prepared iso-nitrogenous and they were offered to meet daily CP requirements of 80.4, 95.7 and 108 g for rams with body weight of 15, 20 and 25 kg, respectively. At beginning of experiment, amount of supplements provided were 439.49, 440.51, 440.75 and 440.50 g on DM basis for T1, T2, T3 and T4, respectively. The CM contained noug seed cake (NSC) and wheat bran (WB) at ratio of 19.28: 80.72, 14.14: 60.86, 9.04: 40.96 and 3.92: 21.08 for T1, T2, T3 and T4, respectively. The CP content of grass hay, WB, NSC and DMLM were 7.20, 16.80, 33.40 and 20.20%, respectively. The OM, CP, NDF, ADF and ADL intakes and digestibilities were similar among treatments but, hay and total DM intakes as well as DM digestibility were significantly higher (p<0.05) in T3 than T1. Calculated ME was greater (p<0.01) in T3 and T2 than T4 but similar in T1, T2 and T3. There was no significant differences among treatments for feed conversion efficiency, final body weight, ADG and most carcass parameters measured. The partial budget analysis showed that T4 had highest economical gain. Therefore, T4 is recommended on both biologically and economically efficient supplementary regime for Abergelle sheep.   Key words: Economical gain, feed conversion efficiency, isonitrogenous, noug seed cake, wheat bran.