Use of birth fluids and cervical stimulation in lamb fostering.

Jackets soaked in birth fluids (BF) and cervical stimulation (CS) were used in a 2 X 2 factorial arrangement of treatments to determine their usefulness in fostering lambs. Subjects were 39, 3-d-old to 14-d-old lambs to be adopted by 39, 2-d to 7-d postpartum ewes rearing their own single lambs. Birth fluids were collected by drying newborn lambs with cloth jackets. Jackets were frozen for storage and were later thawed and placed on experimental alien lambs. Cervical stimulation was applied by attempting to insert a hand into the cervix of the ewe for 5 min immediately before presentation of an alien lamb. Maternal behavior tests, in both the absence and presence of the ewe's own lamb, were conducted twice daily in a small pen for 2.5 d. On d 3 and 4, lambs were tested in a large pen with three to four other ewes and their lambs. Aggression toward the alien lamb was greater during the first exposure in all treatments. Avoidance and nosing behaviors toward aliens were significantly less, and alien lambs were able to suckle more, when the ewe's own lamb was also present. Lambs receiving BF suckled more and were accepted more often. Cervical stimulation, in the absence of BF, improved acceptance compared with controls. The proportion of ewes accepting alien lambs were 100, 80, 60 and 10% for BF, BF-CS, CS and control treatments, respectively. Alien lambs that were accepted had similar growth rates to weaning as the ewe's own lamb. We conclude that fostering is facilitated by use of jackets soaked in BF and by CS.