SHEEP AND GOAT HUSBANDRY PRACTICES IN EASTERN TIGRAY, AND EFFECTS OF SUBSTITUTION OF MULBERRY (Morus alba) LEAF MEAL FOR CONCENTRATE MIX ON GROWTH AND CARCASS TRAITS OF TIGRAY HIGHLAND LAMBS IN BARLEY STRAW BASED FEEDING
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Date
2018-06
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Abstract
The purpose of this study was to assess the existing husbandry practices of sheep and goats in Eastern Tigray and evaluate effects of partial or full substitution of mulberry leaf meal for concentrate mix on in vitro organic matter digestibility, in sacco dry matter degradability and on performances of Tigray highland lambs fed barley straw based diet. 299 Households who owned at least two adult sheep and goats and at least two years of experiences in small ruminant production were interviewed using structured questionnaire to assess the husbandry practices and major constraints hindering sheep and goat production in highland (HL), midland (ML) and lowland (LL) agro-ecological zones. Thirty intact yearling Tigray highland male lambs (average initial body weight of 17.8±0.95 kg) were grouped into six groups based on their live weight, which were then assigned to one of the five treatment diets, that were: T1: 300 g concentrate mix alone, T2: 225 g concentrate mix + 86.6 g mulberry leaf meal, T3: 150 g concentrate mix + 173.1 g mulberry leaf meal, T4: 75 g concentrate mix + 259.7 g mulberry leaf meal and T5: 346.2 g mulberry leaf meal alone. The mix was prepared from noug seed cake and wheat bran at 1:2 ratio, respectively. After three weeks of quarantine, lambs were adapted to experimental diets for 15 days, and after adaptation period, digestibility as well as feeding trials were conducted. Survery results indicated that the source of household income was the most important purpose of keeping sheep and goats across all agro-ecologies. Results revealed that 56.5% respondents from the HL and 58.9% from ML agro-ecological zones sourced their foundation stock from markets/purchasing while the rest was home born. On the other hand, home born (67.3%) followed by purchasing (16.4%) accounted sources of sheep and goats in the LL. The proportion of respondents who made use of crop-residues, improved forages and the commercially purchased feeds in wet season was higher in the highland than in the lowland. The importance of crop aftermath becomes prominent during the dry season next to grazing on natural grazing land particularly in both HL and ML agro-ecological zones. However, browses remain the second most important feed sources for the LL farmers during the dry season. Unlike the respondents from HL and ML, respondents in LL did get water from distant during the dry season. The proportions of respondents who provided water once a day were higher (p<0.05) in HL (58% and 59.4%, respectively for dry and wet seasons) and ML (48.2% and 58.9%, respectively for dry and wet seasons) than the LL (30.9% and 45.5%, respectively for dry and wet seasons). Majority of the (65.2%, 64.3% and 54.5% for HL, ML and LL, respectively) respondents across the study area indicated that own rams were the main sources of breeding males followed by breeding rams from neighboring households. However, own breeding bucks accounted the higher proportion in ML (51.8%) and LL (67.3%) whereas neighboring bucks in the HL (55.1%) agro-ecological zones. The majority of respondents (89.9%, 91.1% and 94.5% for HL, ML and LL, respectively) used uncontrolled mating. The results of the experiment revealed that chemical composition of mulberry leaf meal compared favorably with that of the concentrate mixture in most of the nutrients. The ash content of mulberry leaf meal (15.7%) was more than double to that of the concentrate mixture (7.7%). Similarly, the calcium value of mulberry leaf meal (2.1%) was more than threefold to that of calcium content of concentrate mixture (0.6%). Mulberry leaf meal alone had the highest values for slowly degradable fraction (b) than the diets with less proportion of mulberry leaf meal. Whereas, mulberry leaf meal alone (T5) and 75g concentrate mix + 259.7g mulberry leaf meal (T4) had significantly (p<0.05) less soluble fraction (a), and effective degradability (ED) values as compared to the diets with less proportion of mulberry. All the treatment diets accorded more than 66% DM degradability at 24 hours, which implied that they were all highly degradable in the rumen. Sole mulberry leaf meal showed higher (p<0.05) total dry matter, organic matter, NDF and ADF intake than the sole concentrate mix. The growth performance parameter results were comparable across all the treatment diets. The slaughter weight (24.3 vs 23.0 kg) and empty weight (20.5 vs 19.3 kg) were higher (p<0.05) in sole mulberry leaf meal as compared to whole concentrate mix supplemented lambs, respectively. Higher (p<0.05) weights of total edible offal components (5.30, 5.31 and 5.31 kg, respectively for T3, T4 and T5 vs 5.15 and 5.10 kg for T1 and T2) and rib-eye muscle area (9.9, 9.8 and 9.6 cm2, respectively for T3, T4 and T5 vs 9.0 and 9.3 cm2 for T1 and T2) were observed as a result of a higher level of mulberry leaf meal supplementation than the sole concentrate mix, respectively. Feed shortage was the top ranked constraint of sheep and goat production across all the surveyed agro-ecologies. Respondents (42.0, 44.6 and 20% for HL, ML and LL, respectively) showed a great deal of interest to supplement their sheep and goats with concentrates. However, less accessibility and high cost were the most important restraining factors that impeded them from purchasing the supplements. The results of the present study indicated that substitution of mulberry leaf meal for concentrate mix could be used effectively without affecting the growth performance as well as the carcass parameters that could be achieved by sole concentrate mix supplementation. Hence, the finding revealed that mulberry leaf meal alone could potentially be used to substitute the costly and even less accessible commercial concentrate mix in feeding Tigray highland lambs fed a barley straw based diet by smallholder rural farmers.
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PhD Thesis
Keywords
Concentrate mix, Digestibility, Feed intake, Growth performance