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, 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

在包括卢旺达在内的撒哈拉以南非洲国家，采用刈割饲喂型饲草喂养系统的奶牛，其干物质、水分、能量与蛋白质摄入存在显著缺口。本研究中，饲粮表征数据通过Groot与Oomen开发的FarmDESIGN模型计算得到，奶牛生产需求数据则借助LIGAPS奶牛模型测算。数据分析采用SPSS软件中的一般线性模型（General Linear Model，GLM）完成。饲粮特性分析结果显示，供试饲草的平均营养价值为：每千克干物质（Dry Matter，DM）中含干物质占比25%、中性洗涤纤维（Neutral Detergent Fiber，NDF）58.5%、粗蛋白质（Crude Protein，CP）9.8%，代谢能（Metabolizable Energy，ME）6兆焦。试验两地的平均每日饲料摄入量为：干物质9千克、水分35升、粗蛋白质898克，代谢能55兆焦，对应的日均产奶量为8.8升。然而，体重430千克、目标日均产奶量16.5升的奶牛，其维持代谢所需的营养摄入量为：干物质15千克、水分57升、粗蛋白质1907克、代谢能137兆焦。由此导致每日营养缺口分别为：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。旱季可用饲草在数量与质量上均无法满足奶牛维持代谢与产奶的需求，因此亟需建立优质饲草的足量储备措施。本研究结果可用于研究者开发家庭牧场层面的奶牛日粮模型；对于饲料生产商而言，本分析可指导其依据奶牛营养需求，合理配比富含能量与蛋白质的高浓缩饲料原料。明确现有饲粮资源的缺口，将有助于鼓励养殖户采用高效饲喂管理措施，提升能量、蛋白质与水分摄入量，进而改善奶牛产奶性能。