The effect of spring shearing on milk yield and milk composition in Tsigai ewes

Abstract

Milk yield and milk composition responses to shearing were assessed in Tsigai ewes kept indoors. Sheep was offered 700g/head daily concentrate and chopped hay administered ad libitum and was milked twice daily - at 08:00 and at 18:00 h. Average for the two weeks post-shearing, daily milk yield dropped by 7.2 % due to the 8.2 and 2.2 %, respectively, reduction in the morning and in the afternoon milk yields. Fat and protein concentrations in the morning and in the afternoon milk on day 1, day 7 and day 14 after shearing surpassed vastly pre-shearing values whilst milk lactose concentration showed a trend towards postshearing reduction. On the three sampling post-shearing days daily output of different milk constituents exceeded the corresponding mean pre-shearing values by 16.2, 11.6 and 9.1 % in milk fat, 1.6, 3.5 and 6.2 % in milk protein, and 4.1, 7.2 and 2.2 % in total solids. The increase in daily output of milk constituents occurred despite the decline in daily milk yield. Lactose daily output, on the contrary, dropped by 6.9, 7.7 and 9.3 % relative to the mean pre- shearing value. Postshearing adaptive adjustments including changes in nutrient partitioning appear to underlie the alterations in milk yield and milk composition. It may be concluded that post-shearing changes in milk composition makes for the improvement of milk processing characteristics.