Energy, protein, dry matter and water gap analysis in dairy cows kept under cut and carry fodder based feeding system.

There is a gap in dry matter, water, energy and protein intake of dairy cows kept in cut and carry fodder-based feeding systems in Sub-Saharan countries, Rwanda included. Data on feed characterization were computed using the FarmDESIGN models by Groot and Oomen (2016), while data on cows’ production requirements were calculated using LIGAPS dairy models. Data were analyzed using a general linear model (GLM) in SPSS. Results on feed characteristics showed that the average nutritive value of the offered fodder was 25% dry matter (DM), 58.5% neutral detergent fibre (NDF), 9.8% crude protein (CP), and 6 MJ of metabolizable energy (ME) per kg DM. The average daily feed intake was 9 kg DM, 35 litres of water, 898 g of CP, and 55 MJ of ME, resulting in milk production of 8.8 litres per day across both sites. However, the average requirement for maintaining a dairy cow with a body weight of 430 kg and a target milk production of 16.5 litres per day was 15 kg of DM, 57 Litres of water, 1907 g of CP, and 137 MJ of ME. This resulted in daily deficits of 6 kg DM, 21.6 litres of water, 1,094 g of CP, and 83.7 MJ of ME, along with a 7.6-litre shortfall in daily milk yield. Available fodder in the dry season is low in quantity and quality for sustaining maintenance and milk production and measures of storing enough fodders that are of good quality are much needed. These findings will be used by researchers in developing dairy diet models at the household level. For dairy feed manufacturers, this analysis will guide proper rationing of high-concentrate ingredients rich in energy and protein, in line with cows’ nutritional requirements. Identifying the gap in available feed resources will encourage farmers to adopt effective feeding management practices that enhance energy, protein, and water intake leading to improved milk production包括卢旺达在内的撒哈拉以南非洲国家中，采用刈割带回饲喂型饲草饲养体系的奶牛，其干物质（DM）、水分、能量及蛋白质摄入存在缺口。饲粮特性相关数据通过Groot与Oomen（2016）提出的FarmDESIGN模型计算得到，而奶牛生产营养需求数据则采用LIGAPS奶牛模型进行测算。本研究采用SPSS软件中的一般线性模型（GLM）对所有数据进行分析。饲粮特性分析结果显示，供试饲草的平均营养成分为：干物质（DM）占比25%，中性洗涤纤维（NDF）58.5%，粗蛋白质（CP）9.8%，每千克干物质含代谢能（ME）6兆焦。两个试验点的平均每日饲粮摄入量为：干物质9千克、水分35升、粗蛋白质898克、代谢能55兆焦，对应日均产奶量8.8升。然而，体重430千克、目标日均产奶量16.5升的奶牛，其维持生长与产奶所需的平均营养摄入量为：干物质15千克、水分57升、粗蛋白质1907克、代谢能137兆焦。由此产生的每日营养缺口为：干物质6千克、水分21.6升、粗蛋白质1094克、代谢能83.7兆焦，日均产奶量缺口达7.6升。旱季可用饲草的数量与品质均无法满足奶牛维持生长与产奶的需求，因此亟需建立优质饲草足量储备的相关措施。本研究结果将供研究者用于开发家庭农户层面的奶牛饲粮模型。对于奶牛饲料生产商而言，本分析可指导其根据奶牛的营养需求，合理配比富含能量与蛋白质的高精料原料。明确现有饲粮资源的缺口，可推动养殖户采用高效饲养管理方案，提升奶牛的能量、蛋白质与水分摄入量，进而改善产奶性能。