Double Cupping and Machine Stripping Optimise the Yield and the Composition of Sheep Milk

Two experiments were conducted to compare techniques to maximise the amount of milk harvested mechanically from Poll Dorset ewes. The treatments were double cupping, machine stripping, Sagi hook, a negative control (no extra stripping applied) and a positive control (residual milk withdrawn after injecting 5 IU of oxytocin). In the first experiment it was shown that the amount of milk collected did not differ between treatments, but the fat content in milk was higher for all treatments compared to the control (P c 0.01). A second experiment was conducted in which the fractions of milk were kept separate and residual milk was measured after each of the treatments by injecting oxytocin and hand stripping the ewes. The total amount of milk harvested was the same for all treatments, but there was a significant difference in the amount of milk obtained by machine milking0 and hand stripping after the different treatments. The amount of milk obtained by machine milking after double cupping or mechanical stripping was 13% and 12% more than that obtained after the control. Ewes machine milked with a Sagi hook yielded slightly, but not significantly, more milk than the controls. The residual milk obtained after double cupping and mechanical stripping was about 60-70 g, but after the Sagi hook and the control it was about 200 g. The concentrations of fat and total solids in the milk were significantly higher after the mechanical stripping and double cupping0 treatments. The residual milk was higher in total solids after the mechanical stripping and Sagi hook treatments. It was concluded that double cupping or machine stripping are necessary to optimise the quantity and quality of milk harvested from sheep.