Studies on pre‐milking preparation 1. Half minute wash and stimulus compared with machine milking action alone

Twelve sets of identical twin cows of Jersey and Jersey cross breed were used in a split‐twin design trial to compare lactation production using the 2 following milking regimes: 30 s of cold water washing and manual stimulation of the udder before machine milking; and milking machine alone. Manually stimulated cows, on average, outproduced their non‐stimulated mates by 657 litres of milk and 33 kg of milkfat, which was about 32% of the average production of the non‐stimulated group. Milkfat yield of the non‐stimulated twin was significantly related to the duration of the milk ejection response. Correlations of within‐set milkfat yield difference with lactation length and milkfat production level of the non‐stimulated twin mate were highly significant.