Martin N L, Price E O, Wallach S J, Dally M R
J Anim Sci. 1987 May;64(5):1378-83. doi: 10.2527/jas1987.6451378x.
Lamb-specific odor is used by ewes to discriminate between their own and alien offspring. Recent studies have demonstrated that fostering can be facilitated by transferring own-lamb odor to alien lambs via cloth stockinettes. The objective of the present study was to investigate the effectiveness of the odor-transfer technique in enticing ewes with a single lamb to adopt an additional lamb ("add-on" procedure). Shortly after birth, nylon stockinettes were placed on the single offspring of 49 ewes and 49 additional alien lambs designated for fostering. Approximately 20 h following parturition, stockinettes were removed from 41 natural lambs and placed on alien lambs (experimental treatment). In the control treatment (eight ewes) own and alien lambs retained their own stockinettes. Four acceptance tests were conducted, 24 h apart, starting at the onset of fostering. Successful adoptions were attained for 21 of 31 experimental ewes (68%) exposed to add-on lambs similar in facial coloration to their own lambs. Only 2 of 10 experimental ewes (20%) with whiteface natural lambs adopted blackface add-on lambs. One of eight control ewes (12.5%) adopted an add-on lamb. Of the 24 ewes that adopted alien lambs 10 (41.7%) demonstrated immediate acceptance and 20 (83.3%) had adopted lambs by the second test day. A higher proportion of primiparous than multiparous ewes adopted alien lambs. The presence of own-lamb odor on stockinettes worn by add-on lambs appears to facilitate fostering. However, the presence of own-lamb odor may not be a significant-enough cue to override obvious differences in facial coloration between own and add-on lambs.(ABSTRACT TRUNCATED AT 250 WORDS)
母羊利用羔羊特有的气味来区分自己的后代和外来羔羊。最近的研究表明，通过布制长袜将自己羔羊的气味转移到外来羔羊身上，可以促进寄养。本研究的目的是调查气味转移技术在诱使单羔母羊收养额外羔羊（“添加”程序）方面的有效性。出生后不久，将尼龙长袜套在49只母羊的单只后代以及49只指定用于寄养的外来羔羊身上。分娩后约20小时，从41只自然出生的羔羊身上取下长袜，套在外来羔羊身上（实验处理）。在对照处理中（8只母羊），自己的羔羊和外来羔羊保留各自的长袜。从寄养开始，每隔24小时进行四次接受测试。暴露于面部颜色与其自己羔羊相似的添加羔羊的31只实验母羊中，有21只（68%）成功收养。有白面自然出生羔羊的10只实验母羊中，只有2只（20%）收养了黑脸添加羔羊。8只对照母羊中有1只（12.5%）收养了一只添加羔羊。在收养外来羔羊的24只母羊中，10只（41.7%）立即接受，20只（83.3%）在第二个测试日之前收养了羔羊。初产母羊比经产母羊收养外来羔羊的比例更高。添加羔羊所穿长袜上有自己羔羊的气味似乎有助于寄养。然而，自己羔羊的气味可能不足以成为克服自己羔羊与添加羔羊面部颜色明显差异的重要线索。（摘要截短至250字）
