A note on the use of odor manipulation to facilitate the adoption of alien lambs by ewes bearing twins

Abstract

Adoption of alien lambs by ewes bearing single natural offspring has been facilitated by the use of artificial odorants such as neatsfoot oil to establish a common odor for own and alien young and by the use of cloth stockinette jackets to exchange natural odors between lambs. The objective of the present study was to determine the extent to which a combination of these odor modification techniques would facilitate the acceptance of an alien lamb by ewes bearing natural twin lambs. Neatsfoot oil and cloth stockinette jackets were placed on the twin lambs of 13 East Friesian×Targhee cross ewes and 13 alien lambs within 12 h of birth. On the day following birth, jackets were exchanged between own and alien lambs and the alien lambs were fostered. Daily 10-min acceptance tests were conducted to determine the incidence of acceptance and rejection behaviors exhibited by the ewes. In 5 days, 11 of 13 ewes (85%) had met the acceptance criteria of no butts or butt attempts directed at the alien lamb and sucking time of 20 s or more by the lamb in each of two successive daily acceptance tests. Four of the 11 ewes (36%) adopted alien lambs immediately. It was concluded that alien lambs can be successfully fostered on East Friesian×Targhee cross ewes with natural twin lambs using a combination of neatsfoot oil to establish a common odor between own and alien lambs and cloth stockinette jackets to exchange natural odors between natural and alien lambs.