CowNflow: A dataset on nitrogen flows and balances in dairy cows fed maize forage or herbage-based diets

Diet and animal characteristics have a significant impact on the nitrogen (N)-use efficiency by dairy cows. A dataset was built that compiles 28 N-balance experiments with Holstein dairy cows from 1983-2019, corresponding to 414 individual N flows, on a wide range of diets and animal characteristics. This dataset is composed of six Microsoft® files that correspond to six levels of information. The main file, “CowNflow_6_Cows_measurements” reports individual weekly measurements of dry matter intake, daily faeces and urine excretion, milk production and composition, cows characteristics, and chemical composition of diets, faeces, urine and milk. These raw data were used to calculate the N-balance, N-use efficiency and nutrients' in vivo total-tract digestibility. The experiments, conducted under standardised conditions, had multiples aims and offered a wide range of diets, including maize forage or herbage-based diet. The other five Excel files provide supplementary information at larger scales and describe experiment characteristics, experimental treatments, offered feeds along with their chemical composition, ingredients composition of compound feeds and cow characteristics.

日粮与动物生理特征对奶牛的氮（N）利用效率具有显著影响。本数据集整合了1983年至2019年间针对荷斯坦奶牛（Holstein dairy cows）开展的28项氮平衡试验，涵盖414组独立氮流量数据，涉及多样化的日粮类型与动物生理特征。本数据集包含6份微软（Microsoft®）文件，分别对应6个层级的信息维度。主文件"CowNflow_6_Cows_measurements"记录了每周采集的个体数据，包括干物质采食量（dry matter intake）、每日粪便与尿液排泄量、产奶量及乳成分、奶牛生理特征，以及日粮、粪便、尿液和牛奶的化学成分。基于这些原始数据，可计算得到氮平衡、氮利用效率以及养分的体内全消化道消化率。这些试验均在标准化条件下开展，兼具多重研究目标，涵盖多样化的日粮类型，包括玉米青贮日粮或牧草型日粮。其余5份Excel文件则提供更大尺度的补充信息，涵盖试验基本特征、试验处理方案、饲喂饲料及其化学成分、配合饲料的原料组成以及奶牛生理特征。