Effects of short-term maternal separation on behaviour and milk yield of dairy goats under grazing condition in abandoned cultivated land

Abstract

It is considered that extensive milking by grazing-dairy goats is effective for utilizing the abandoned cultivated land in the urban area, since the practitioner is a non-farmer citizen. In order to evaluate the extensive milking methods under grazing condition on abandoned cultivated land in Japan, the behaviour and milk yield were analyzed when 4 dyad of Saanen does and their kids were briefly separated according to their suckling behaviour under natural condition. In the “normal day” when kids could suck their does’ udder freely and the “separation day” when kids are separated from their does during 2-6 h according to their age, total 18 times of 11-hours continuous observations were conducted during 0.8-6.2 month old of kids. Additionally, milk yield was measured immediately after the observation in separation day. The milk yields in separation day were relatively stable (180-350mL/doe) through experiment because separation time was extended from 2 h to 6 h according to kids’ age. However, more than 4 h separation concentrated the does’ grazing-site on the surrounding area of kids’ isolated shelter. From the results of vocalization rate, the rate of attempt to escape from isolated shelter and the concentration of salivary cortisol, it was suggested that kids’ stress was induced by short-term maternal separation in spite of the resemblance between the duration and that one of maximum suckling interval under natural condition. It was concluded that the extensive milking methods with short-term maternal separation was not recommended in grazing goats on abandoned cultivated land.