Current Dairy Herd Management Practices and their Influence on Milk Yield and Subclinical Ketosis in an Intensive Dairy Production Region of Uganda

1 Graduate School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyodai Midorimachi, Ebetsu, Hokkaido 069⊖8501, Japan 2 Rakuno Gakuen University, 582 Bunkyodai Midorimachi, Ebetsu, Hokkaido 069⊖8501, Japan 3 College of Agriculture, Food and Environment Sciences, Rakuno Gakuen University, 582 Bunkyodai Midorimachi, Ebetsu, Hokkaido 069⊖8501, Japan 4 Mbarara District Veterinary Office, Mbarara District Local Government, Galt Road plot 5 Boma Hill, P.O. Box 1 Mbarara, Uganda (Received 22 Nov, 2019/Accepted 8 Apr, 2020) Summary Dairy production in Uganda has recently shown steady growth. Development and intensification of dairy production may bring about the issue of negative energy balance (NEB) followed by ketosis in cattle. However, the current dairy herd health and management status in the southwestern region of Uganda has not been reported. The objective of this study was to identify current herd management status in this area by describing herd management practices and production status, and by investigating relationships between feeding management practices, nutritional status, and daily milk yield of dairy cows. Thirty farms participated in this study. Herd attributes, management practices, nutritional and production status of the cows were collected by interviews and inspections from October 2016 to March 2017. In order to estimate the total effects of feeding management on blood β-hydroxybutyrate (BHB) and milk yield, a causal diagram was created. Multivariable analyses were performed using linear mixed-effects models, setting BHB of cows within 21 days after calving and milk yield as response variables, feeding management factors as exposure variables, potential confounders as covariates, and herd as a random effect variable. The mean herd size of adult cows on participating farms (n = 30) was 35.5 and average milk yield 9.8 L/cow/day. The proportion of exotic breeds was 74.5% of 506 adult cows. Supplementary concentrates and fodder were used in 40% and 70% of farms, respectively; grazing was conducted at 93.3%. The prevalence of ketosis including subclinical ketosis (SCK) for cows within 21 days after calving was 10.8% (4/37, 95% confidence interval (CI): 3.0⊖25.4%). From the multivariable models estimating the total effect, cows fed concentrates had higher milk yield (9.20 L/cow/day) than cows not (5.95 L/cow/day, ratio between groups: 1.55, 95% CI: 1.02⊖2.34, p=0.041). Cows in the farm where rotational grazing was conducted had higher milk yield (5.78 L) than those in the farms where rotational grazing was not (3.46 L, ratio between groups: 1.67, 95% CI: 1.11⊖2.51, p=0.017). No significant effect of feeding management on BHB was estimated (p=0.092). Exotic dairy cattle breeds are dominant on dairy farms in southwestern Uganda. This study revealed that exotic and cross-breed cows have the potential to produce higher milk yields, given sufficient nutrition. SCK cows were observed in this study area. Cows with high ketone concentrations require special precautions. In order to increase milk yield without nutritional disorders in Uganda where the dairy industry is fast developing, introduction of adequate feeding management is important.