Mwangi Felista Waithira, Savage Darryl, Gardiner Christopher Peter, Charmley Edward, Malau-Aduli Bunmi Sherifat, Kinobe Robert Tumwesigye, Malau-Aduli Aduli Enoch Othniel
Animal Genetics and Nutrition, Veterinary Sciences Discipline, College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, James Cook University, Townsville, QLD, Australia.
North Australian Pastoral Company, Brisbane, QLD, Australia.
Front Vet Sci. 2022 Oct 4;9:898325. doi: 10.3389/fvets.2022.898325. eCollection 2022.
Feedlot performance and carcass characteristics of tropical beef steers backgrounded on buffel grass () only or buffel grass oversown with desmanthus ( spp. ; 11.5% initial sward botanical composition) were evaluated. It was hypothesized that tropical beef cattle steers backgrounded on buffel grass only or buffel grass oversown with desmanthus with similar backgrounding growth performance will not differ in feedlot growth performance and carcass quality. Three hundred and twelve × tropical composite steers, 20-23 months old and weighing 413 ± 24 kg, previously backgrounded on buffel grass only or buffel-desmanthus mixed pastures for 147 days were finished on a concentrate diet in the feedlot for 110 days before slaughter. Buffel-desmanthus backgrounded steers had a slightly higher average daily gain (ADG; 1.8 kg/day) than the buffel grass backgrounded steers that had 1.7 kg/day ADG ( < 0.01). However, the final live weight and dry matter intake were not different ( ≥ 0.59). All the carcass traits measured were not different ( ≥ 0.18). Only 4% buffel grass and 8% buffel-desmanthus backgrounded steers fell short of the Meat Standards Australia (MSA) index, a level that is within the 4-9% reported for cattle produced in Queensland and slaughtered between July 2019 and June 2020. These findings indicate that desmanthus can be used to background beef cattle in northern Australia vertosol soil regions, where there is a paucity of adapted pasture legumes, with no negative impact on feedlot performance and carcass quality. The hypothesis that tropical beef cattle steers backgrounded on buffel grass only pastures or buffel grass oversown with desmanthus with similar backgrounding growth performance will have similar feedlot growth performance and carcass quality was accepted.
评估了仅以水牛草（）为背景或播种有澳洲刺槐（澳洲刺槐属植物；初始草地植物组成的11.5%）的水牛草育肥场育肥牛的育肥性能和胴体特征。研究假设是，仅以水牛草为背景或播种有澳洲刺槐的水牛草育肥且具有相似育肥前期生长性能的热带肉牛，其育肥场生长性能和胴体品质不会有差异。312头20 - 23月龄、体重413±24千克的热带杂交阉牛，此前仅以水牛草或水牛草 - 澳洲刺槐混合牧场为背景饲养147天，然后在育肥场以精料日粮育肥110天，之后屠宰。以水牛草 - 澳洲刺槐为背景的阉牛平均日增重（ADG；1.8千克/天）略高于以水牛草为背景的阉牛（其ADG为1.7千克/天，P<0.01）。然而，最终活重和干物质摄入量并无差异（P≥0.59）。所测量的所有胴体性状均无差异（P≥0.18）。仅4%以水牛草为背景和8%以水牛草 - 澳洲刺槐为背景的阉牛未达到澳大利亚肉类标准（MSA）指数，这一水平在2019年7月至2020年6月间于昆士兰饲养并屠宰的牛所报告的4 - 9%范围内。这些研究结果表明，在澳大利亚北部变性土土壤地区，澳洲刺槐可用于肉牛育肥前期饲养，该地区适合的豆科牧草匮乏，且对育肥场性能和胴体品质无负面影响。关于仅以水牛草牧场或播种有澳洲刺槐的水牛草育肥且具有相似育肥前期生长性能的热带肉牛将具有相似育肥场生长性能和胴体品质的假设得到了验证。
