Substitution of concentrate mixture with dried brewery spent grains improved biological and economical performance of 50% Dorper × Menz crossbred sheep.

The study aimed to investigate the potential of dried brewery spent grains (DBG) to substitute concentrate mixture (CM) in a diet of growing 50% Dorper × Menz crossbred ram lamb. Randomized complete block design (RCBD) was used for this study, and experimental animals were stratified into 7 blocks based on their initial body weight and age. Ram lambs from each block were randomly assigned to one of the five treatments. Native pasture hay (NPH) was fed to all experimental animals as a basal diet (ad libtum at 20% refusal) and supplemented with 400 g CM (T1) or 300 g DBG + 100 g CM (T2) or 200 g DBG + 200 g CM (T3) or 100 g DBG + 300 g CM (T4) or 400 g DBG (T5). Natural pasture hay and total dry matter (TDM) intake were not affected (P > 0.05) by the inclusion of DBG in the CM; however, supplement intake was greater (P < 0.0001) for DBG than CM alone-supplemented group. Metabolizable energy intake was decreased (P < 0.0001) as CM was substituted with DBG, whereas apparent digestibility was comparable (P > 0.05) among treatments. The treatments with the substitution of 50%, 75%, and 100% of CM with DBG were superior (P < 0.001) in body weight gain to the 100% CM-supplemented group, and the substitution of 25% CM with DBG had an intermediate growth rate. The partial budget analysis revealed that the substitution of 50% and 100% CM with DBG gave greater net returns of Birr 881.19 and 854.91 per head, respectively. Based on MRR, 200 g CM + 200 g DBG is the best treatment, and using this treatment, a farmer can benefit from ETB 8.94 for every 1 ETB investment. Hence, sole DBG or a mixture of DBG with a CM can be used for supplementation in growing 50% Dorper crossbred ram lambs.

Genetic evaluation of growth rate and efficiency-related traits in Dorper × local crossbred sheep population.

The present study was carried out to estimate genetic and phenotypic parameters for growth rate and efficiency-related traits in Dorper crossbred sheep population. Data on body weight collected from 2012 to 2021 at Debre Birhan Agricultural Research Center, Amhara Regional State, Ethiopia, were used to estimate phenotypic and genetic parameters for daily gain from birth to weaning (DG0-3), daily gain from weaning to 6 months (DG3-6), and daily gain from 6 months to yearling (DG6-12) and corresponding Kleiber ratios (KR0-3, KR3-6, KR6-12), efficiency of growth (GE0-3, GE3-6, GE6-12), and relative growth rate (RG0-3, RG3-6, RG6-12). Genetic parameters were estimated by restricted maximum likelihood (REML) procedure fitting six different univariate animal models and the most appropriate model for each trait was determined by log-likelihood ratio test. Multivariate analysis was carried out to estimate correlations between traits. Year and season of birth had a significant effect (p<0.001) in all studied traits. Direct heritability estimates for DG0-3, DG3-6, DG6-12, KR0-3, KR3-6, KR6-12, GE0-3, GE3-6, GE6-12, GR0-3, GR3-6, and GR6-12 were 0.45±0.15, 0.04±0.06, 0.15±0.11, 0.30±0.08, 0.13±0.11, 0.14±0.12, 0.34±0.15, 0.39±0.17, 0.31±0.14, 0.25±0.08, 0.23±0.13, and 0.23±0.13 respectively. Genetic correlation estimates between DG3-6 and other traits were positive and high in magnitude to their respective growth phase (0.95, 0.86, and 0.91 for KR3-6, GE3-6, and GR3-6 respectively). As the Dorper crossbred sheep are reaches market weight at about 6 months of age, focusing on improving traits measured during weaning to 6 months of age is more feasible. Selection based on DG3-6 is recommended to improve efficiency-related traits.