Degree Name

BS in Dairy Science


Dairy Science Department


Stan Henderson


Heat stress has a major effect on management decisions for a dairy operation because of the decrease in the cows productivity. Dairy cattle loose efficiency of economic production due to lower milk yields and decreased pregnancy rates. Milk loss due to heat stressed cows in California averages a loss of 293 kg of milk/cow/year(St.-Pierre et al., 2003), and with milk prices reaching record highs, dairies are losing out on increased revenue opportunity. Increases in reproductive infertility from heat stress also affect revenue for a dairy operation by reducing conception rates (Hansen 1997) and pregnancy rates, which causes the average days open per cow to increase and less milk throughout the cows lactation This special project is guided by research in: the physical and economical effects of heat stress on dairy cattle, and the reduced physical and economical effects of heat stress through heat abatement systems. The goal of this special project is to establish an economically feasible cooling system, that efficiently reduces loss due to heat stress. Establishing cooling systems on the feed lines, and the wash pens on Oostdam Dairy resulted in $10,324.57 of extra income a month from increased milk production and reproductive fertility.