Abstract：
An exploratory survey (i) to investigate livestock production system, reproductive and production performance of Irob cattle and (ii) to recognize constraints to cattle production was conducted in eastern Tigray zone, northern Ethiopia. Six tabias (the smallest administrative unit consisting of several villages) were chosen using purposive sampling method and households from each tabia were randomly selected. Mixed crop-livestock farming system dominates the study area. Overall herd size was 5.3 ± 2.7, with each herd comprising of 1.7 ± 1.2 cows, 1.4 ± 0.9 oxen, 0.5 ± 0.7 heifers, 0.5 ± 0.7 bulls and 1.2 ± 0.9 calves. Cattle are kept for draught power (index = 0.43), milk (index = 0.32), income (index = 0.15), manure (index = 0.06) and crop threshing (index = 0.04). Major feed resources in the study area were natural pasture, crop residue and cactus pear (Opuntia ficus-indica). Overall mean (± SD) for age at first services (AFS), age at first calving (AFC), calving interval (CI), days open (DO), daily milk yield (DMY) and lactation length (LL) was 28.3 ± 3.9 months, 37.4 ± 5.5 months, 15.5 ± 4.1 months, 6.5 ± 1.8 months, 1.7 ± 0.4 L and 7.4 ± 2.0 months, respectively. There was no significant (p > 0.05) difference in performance traits between districts. Well-known cattle production constraints in order of significance were feed, disease and parasites, AI, water and veterinary service. In conclusion, the study shown importance of taking into account the production environment in developing breed improvement program and recommends fit management system.
摘要：
探索性调查(I)调查畜牧业生产系统，Irob牛的繁殖和生产性能，以及（ii）在提格雷东部地区进行了对牛生产的限制，埃塞俄比亚北部使用目的抽样方法选择了六个塔比亚（由几个村庄组成的最小行政单位），并随机选择了每个塔比亚的家庭。混合作物-牲畜养殖系统在研究区域占主导地位。总体牛群大小为5.3±2.7，每只牛群为1.7±1.2头，1.4±0.9牛，0.5±0.7母牛，0.5±0.7头公牛和1.2±0.9头小牛。保持牛的牵引力(指数=0.43)，牛奶（指数=0.32），收入（指数=0.15），粪肥(指数=0.06)和作物脱粒(指数=0.04)。研究区主要饲料资源为天然牧草,作物残渣和仙人掌（仙人掌-indica）。首次服务年龄（AFS）的总体平均值（±SD），第一次产牛年龄（AFC），产卵间隔(CI)，开放天数(DO)，日产奶量(DMY)和泌乳长度(LL)为28.3±3.9个月，37.4±5.5个月，15.5±4.1个月，6.5±1.8个月，1.7±0.4升和7.4±2.0个月，分别。各地区间表现性状差异不显著(p>0.05)。众所周知，牛的生产限制按重要性排序为饲料，疾病和寄生虫，AI,水和兽医服务。总之,研究表明，在制定品种改良计划时，考虑生产环境的重要性，并建议采用合适的管理体系。
