ABSTRACT The objective of this study was to determine the profit-maximising feeding period (PMFP) of different breeds of beef cattle. The differentiation between breeds according to their genetic growth potential was identified and used to increase feedlot profitability and sustainability. The unique growth and feed intake data of different breeds was generated through a feedlot feeding experiment. The PMFP model was developed to incorporate the variable economic value and the unique production data of each breed into a model. The PMFP model can determine alternative PMFPs for any price scenario. The results indicate that breeds can be differentiated in terms of genetic production potential. The seven breeds used in this study can be divided into three groups in terms of their estimated PMFPs for the specific scenario. The Brahman, Bonsmara, and Afrikaner can be grouped together with a PMFP of 16 weeks for the Brahman and Bonsmara, and 15 weeks for the Afrikaner. The second group included the Simbra and the Angus, which have a PMFP of 21 and 22 weeks respectively. The Simmentaler and Limousin have a PMFP of 27 and 26 weeks respectively, which groups them together in the final group. In conclusion, additional Gπ can be generated by each breed by feeding them according to their unique PMFP. According to the case study the additional gross profit that can be generated by the implication of the PMFP-model was 6%.

中文翻译：

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不同品种肉牛的利润最大化饲养期

摘要 本研究的目的是确定不同品种肉牛的利润最大化饲养期 (PMFP)。根据遗传生长潜力确定品种之间的差异，并用于提高饲养场的盈利能力和可持续性。不同品种的独特生长和采食量数据是通过饲养场饲养实验产生的。PMFP 模型的开发是为了将每个品种的可变经济价值和独特的生产数据整合到一个模型中。PMFP 模型可以为任何价格方案确定替代 PMFP。结果表明，就遗传生产潜力而言，可以区分品种。本研究中使用的七个品种可以根据特定场景的估计 PMFP 分为三组。婆罗门、邦斯马拉、和南非荷兰语可以组合在一起，婆罗门和邦斯马拉的 PMFP 为 16 周，南非荷兰语的 PMFP 为 15 周。第二组包括 Simbra 和 Angus，它们的 PMFP 分别为 21 和 22 周。Simmentaler 和 Limousin 的 PMFP 分别为 27 和 26 周，这将它们归为最后一组。总之，每个品种可以通过根据其独特的 PMFP 喂养它们来产生额外的 Gπ。根据案例研究，PMFP 模型的含义可以产生的额外毛利润为 6%。Simmentaler 和 Limousin 的 PMFP 分别为 27 和 26 周，这将它们归为最后一组。总之，每个品种可以通过根据其独特的 PMFP 喂养它们来产生额外的 Gπ。根据案例研究，PMFP 模型的含义可以产生的额外毛利润为 6%。Simmentaler 和 Limousin 的 PMFP 分别为 27 和 26 周，这将它们归为最后一组。总之，每个品种可以通过根据其独特的 PMFP 喂养它们来产生额外的 Gπ。根据案例研究，PMFP 模型的含义可以产生的额外毛利润为 6%。