Duplessis Mélissa, Fadul-Pacheco Liliana, Santschi Débora E, Pellerin Doris
Agriculture et Agroalimentaire Canada, Centre de Recherche et Développement de Sherbrooke, 2000 rue College, Sherbrooke, QC J1M 0C8, Canada.
Department of Animal and Dairy Sciences, University of Wisconsin, 1675 Observatory Drive, Madison, WI 53706, USA.
Animals (Basel). 2021 May 5;11(5):1320. doi: 10.3390/ani11051320.
This analysis is performed to obtain information on the current situation regarding phosphorus (P), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) concentrations in cow diets of commercial dairy herds in Québec, Canada, and to compare them with National Research Council recommendations. Data are collected on 100 Holstein dairy herds in Québec, Canada, and 4430 cows were involved. Rations are analyzed for selected minerals and cow requirements relative to the recommendations were calculated. Median percentages of mineral recommendations fulfilled by forage were 55%, 196%, 54%, 776%, 181%, and 44% for P, Co, Cu, Fe, Mn, and Zn, respectively. Daily dietary concentrations of P, Cu, Mn, and Zn decreased as lactation progressed, whereas Co and Fe were stable throughout lactation. Phosphorus was the mineral fed the closest to the requirements, cows below 21 days in milk were even underfed by 11%. All studied trace minerals were fed in excess for the majority of cows. Cobalt was fed on average 480% above requirements regardless of the stage of lactation. For Cu, Fe, Mn, and Zn, rations for cows below 21 days in milk were fed 23% (95% confidence interval: 15-32), 930% (849-1019), 281% (251-314), and 35% (22-47) above the recommendations, respectively, and were closer to the requirements than after 21 days in milk. These results show that most nutritionists are aware that precision feeding regarding P is important to minimize detrimental environmental impacts of dairy production. However, some efforts should be made to limit trace mineral overfeeding to ensure environmental resiliency.
进行该分析是为了获取加拿大魁北克省商业化奶牛场奶牛日粮中磷（P）、钴（Co）、铜（Cu）、铁（Fe）、锰（Mn）和锌（Zn）浓度的当前情况信息，并将其与美国国家研究委员会的建议进行比较。收集了加拿大魁北克省100个荷斯坦奶牛场的数据，涉及4430头奶牛。对选定矿物质的日粮进行分析，并计算相对于建议值的奶牛需求量。牧草满足矿物质建议值的中位数百分比，磷、钴、铜、铁、锰和锌分别为55%、196%、54%、776%、181%和44%。随着泌乳期推进，日粮中磷、铜、锰和锌的每日浓度降低，而钴和铁在整个泌乳期保持稳定。磷是喂养量最接近需求量的矿物质，产奶21天以内的奶牛甚至缺喂11%。大多数奶牛的所有研究微量元素都过量喂养。无论泌乳阶段如何，钴的喂养量平均比需求量高480%。对于铜、铁、锰和锌，产奶21天以内奶牛的日粮分别比建议值高23%（95%置信区间：15 - 32）、930%（849 - 1019）、281%（251 - 314）和35%（22 - 47），并且比产奶21天以后更接近需求量。这些结果表明，大多数营养学家都意识到精准喂养磷对于将奶牛生产对环境的不利影响降至最低很重要。然而，应该做出一些努力来限制微量元素的过量喂养，以确保环境适应能力。
