A consideration of the techniques for estimation of milk yield by suckled sheep and a comparison of estimates obtained by two methods in relation to the effect of breed, level of production and stage of lactation

Abstract

SummaryThree techniques, lamb-suckling and test-weighing, hand- or machine-milking following administration of oxytocin, and measurements of body-water turnover, used for the estimation of milk yield in suckled sheep are discussed in relation to sources of error and comparability of estimates.Results are presented from an experiment in which the lamb-suckling and the oxytocin techniques were compared. The mean daily milk production of Scottish Blackface and East Friesland × Scottish Blackface ewes suckling single and twin lambs was measured by both methods at weekly intervals for 6 weeks. All ewes were well nourished to ensure full expression of milking capacity. Additional information from a similar experiment on Merino ewes is also presented.The oxytocin method gave higher estimates of mean daily milk yield in the first week of lactation, especially in the groups of ewes rearing single lambs and in the Blackface breed. By the second week in most groups and the third week in all groups there were no significant differences between estimates made by the two methods and the relative values of the estimates were not affected by level of milk production, number of lambs suckled or genotype of ewe and lamb.