An Assessment of the Status and Factors Influencing Utilization of Brewery Byproducts as Feed to Dairy Cows Under Smallholder System in Northern Tanzania

A cross-sectional survey study was conducted in Arusha City and Hai districts in northern Tanzania to assess the status and factors influencing the usage of brewery byproducts as feed for dairy cows. A total of 110 respondents were interviewed using a structured questionnaire. The information collected included gender, educational background, farm size, main occupations, dairying experience, types of concentrates fed to dairy cows and factors affecting the use of brewery byproducts as feed to cows. The body weights of 76 selected cows were estimated using heart girth tape, along with secondary data collected from the farm record books on milk yield. Key informant interviews were made with industry supervisors in two beer processing industries in the two locations. Samples of different types of brewery waste and concentrates used in the study area were collected and chemically analysed, and the two-stage in vitro digestibility was estimated. The study found that farmers with formal education, dairy experience of 10 to 20 years, small farm sizes and herd sizes of more than 15 cows had a greater (P<0.05) likelihood of using brewery byproducts as a supplement to dairy cows. The values of crude protein (23.0%, CP) and nitrogen detergent fibre (51.8%, NDF) contents of wet spent grain byproduct (WSGB) were higher (P<0.05) compared to those of concentrates (12.5 and 28.8%, respectively) commonly used in the study area. The values of in vitro dry matter (63.6 - 65.1%, INVDMD) and organic matter (60.0 - 61.5 INVOMD) digestibility of WSGB were lower (P<0.05) than those of common concentrates with 81.5 and 80.4% for INVDMD and INVOMD, respectively. Cows supplemented with brewery waste had higher (P<0.05) values of milk yield (11.7 litres/cow) and body weight (363.5 kg) compared with those supplemented with common concentrates (9.4 and 341.6, respectively). The usage of brewery byproducts was reported to be influenced by insufficient supply in Hai District (58.82%), while in Arusha city, price fluctuations (29.4%), capital requirements (20.6%) and transportation (8.8%) were the most limiting factors. In conclusion, brewery byproducts are potential feed resources for improving milk production from the dairy cows under a smallholder farming system in Northern Tanzania. Further assessments of the economic profitability of utilizing brewery byproducts as feed supplements for lactating dairy cows managed by smallholder dairy farmers are recommended.