Relationships among Rates of Milk Flow, Machine Time, Udder Conformation, and Managemental Aspects of Milking Efficiency: A Review

Indirect selection for improved labor economy in milking by direct selection for highly heritable milk flow rate has been suggested by many. However, progress in milk yield from selection will be constrained-by including flow rate among selection 'criteria. Additional costs of improved flow rate such as more udder disease are also likely to rise. This and the absence of direct evidence on how much true milking costs and other production costs are lowered by faster milking cows suggests that more knowledge is needed before implementing such a selection program. The evolution of work on milk flow rate, machine time, udder conformation, and management aspects of milking efficiency that have bearing on the selection decision is reviewed and discussed. Research needs relating to genetic and environmental influences on the economics of milk harvest are suggested.