Energy, protein 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 fodder-based diets undercut and carry feeding systems in Sub-Saharan countries, Rwanda included. A study was conducted in two contrasting areas of Rwanda: Eastern Savana and Volcanic highlands. The objective was to determine dry matter, water, protein, and energy intake in comparison to their requirements for meeting the potential milk production of lactating dairy cows. Ninety households, including 66 from the lowlands and 30 from the highlands, were randomly selected, and a total of 96 cows were included in the data collection process. About 96 samples that corresponded to different fodder mixtures fed to lactating dairy cows in surveyed households were analyzed for their dry matter (DM), crude protein (CP), neutral detergent fibre (NDF), and metabolizable energy (ME). Data on NDF intake, ME and CP intake, water, DM intake, body weight, and milk performance were also collected. Data on feed characterization were computed with Farm DESIGN Manual models by Groot and Oomen, while data for the production requirement of dairy cows under lactation were computed using LIGAPS dairy models. Data were analyzed using a general linear model with univariate analysis of the statistical package for social sciences (SPSS). Results on feed characteristics showed that the average nutritive value of offered fodder was 25% DM, 58.5% NDF, 9.8% CP, and 6 megajoules (MJ) per kg DM of ME. Results on production management showed that the average daily intake was 9kg DM; 35 litres of water; 898g of crude protein (CP) and 55 MJ ME, resulting in milk production of 8.8 litres per day in both sites. However, the average requirement for both maintenance and a target milk production of 16.5litres per day were 15kg of DM; 57 Litres of water, 1907g of CP, and 137 MJ of ME. This indicated daily deficits of 6kg DM, 21.6litres of water, 1094g of crude protein, and 83.7 MJ of ME, along with a 7.6-litre shortfall in milk yield per day. The results of the present study demonstrate the hypothesis previously posed. Findings from this analysis will serve as instruments for researchers in developing dairy diet models to improve dairy cow productivity at the household level. Demonstrating the gap in available feed resources would trigger the uptake of new feeding technologies by farmers. For dairy feed manufacturers, this would serve as a guide for proper rationing of high-concentrate ingredients rich in energy and protein in consideration of their requirements. This would contribute to improved milk production resulting in better remuneration to farmers, increased national milk pool, and per capita milk consumption.