Energy and protein gap analysis in dairy cows kept under fodder based diet with cut and carry feeding system.

There is a gap in dry matter, water, energy and protein intake of dairy cows kept in fodder- based diet under cut and carry feeding system in Sub- Saharan countries, Rwanda included. A study was conducted in two contrasting areas of Rwanda: Eastern Savana (altitude of 1,566 m, latitude is 1o56’55’S and longitude 30o26’5’’E; rainfall average of 900 mm, with temperatures of 25oC) and Volcanic highlands (altitude of 2250 m, latitude is -1o 29’59.42’’S and longitude is 29o 38’5.89’’E; the rainfall average is 1,845 mm; the average annual temperature is 15.9oC). The objective was to determine dry matter, water, protein and energy intake in comparison to their requirements for meeting the potential milk production. Ninety households, including 60 from lowlands and 30 from highlands, were randomly selected, and a total of 96 cows were included in the data collection process. About 90 samples which corresponded to different fodder mixture fed to lactating dairy cows in surveyed household were analysed 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 well also collected. Data on feeds 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 analysed using general linear model with univariate analysis of statistical package for social sciences (SPSS). Results on feed characteristics showed that the average nutritive value of offered fodder was 25% of dry matter (DM), 58.5% neutral detergent fibre, 9.8% crude protein and of 6 mega joules (MJ) per kg DM. 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 a 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 7.6litres shortfall in milk yield per day. 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 household level. Demonstrating the gap of available feeds resources would trigger the uptake of new feeding technologies by farmers. For dairy feeds manufacturers, this would serve as a guide for proper rationing of high concentrates 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.