The effect of two management systems of dairy ewes on milk production.

Most of Brazilian breeds present capability for meat or wool production, but it is possible to find animals with dairy properties. Bergamasca ewes, for example, introduced in Brazil in 1940, are raised in the Northeast for meat production. Considering their Italian origin, they could be used for milk production; however, the amount of milk produced by lactation and its characteristics are not well known. In view of this, the objective of the present work, carried out at the Ewe Milk Production Research Unit of the College of Veterinary Medicine and Animal Science of the São Paulo State University (UNESP), is to evaluate the effect of the different management systems on milk production of Bergamasca ewes. Eighty seven ewes were used and submitted to two milk production systems. In the group without lambs, these were separated from their mothers 48h after birth, while, in the mixed group, lambs were kept with their mothers until to 60 days of age, when they were weaned. Both ewes from the group without lambs and from the mixed group were machine-milked for a period of 90 days and milk production was daily measured during the whole experimental period. The statistical analysis was performed by means of the GLM procedure of the Statistical Analysis System (SAS, 1985). Ewes managed in the group without lamb presented higher (P<.05) daily average milk production in comparison to the mixed group. This difference may be explained, in part, by milk injection inhibition during machine-milking. In the beginning of lactation, the absence of a proper sign during machine-milking, which is usually present when females are nursing their lambs, inhibits the release of ocytocin and milk ejection reflex. [ABSTRACT FROM AUTHOR]