|LEWIS, GREGORY - Retired ARS Employee|
|Taylor, Joshua - Bret|
Submitted to: Western Section of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/2/2017
Publication Date: 6/1/2017
Citation: Lewis, G.S., Wang, S., Taylor, J.B. 2017. Response of pregnant ewes to ovalbumin inoculation, antiovalbumin antibody transfer to lambs and temporal changes in antiovalbumin antibody. Western Section of Animal Science Proceedings. 68:192-196. Available: https://www.asas.org/docs/default-source/western-section/asasws_western_book_060217.pdf?sfvrsn=e72946d1_0
Technical Abstract: Factors that affect the decay of maternally-derived IgG and the ability of neonatal lambs to produce protective amounts of their own IgG are not well understood. Three experiments were conducted to evaluate colostral transfer of antiovalbumin IgG (OV-IgG) from ewes to lambs and responses of young lambs to ovalbumin inoculation. In Exp. 1, pregnant ewes (n = 10/group) were inoculated with either ovalbumin or control (saline) suspensions at approximately 42 (primary) and approximately 14 (secondary) d before lambing. In Exp. 2, lambs (n = 20/group) born to and nursing ewes that had been immunized against ovalbumin were inoculated with either ovalbumin or control suspensions at age 1 (primary) and 15 (secondary) d. In Exp. 3, lambs (n = 20/group) born to ewes that were naive to ovalbumin received 1 of 2 inoculation types, control or ovalbumin suspension, according to 1 of 2 inoculation schedules, at age 1 and 15 d or 28 and 42 d. According to original inoculation type, lambs also received a booster inoculation at age ˜ 159 d. In Exp. 1, ovalbumin inoculation increased (P < 0.001) ewe serum OV-IgG. Serum OV-IgG was greater (P < 0.0001) throughout the sampling period in lambs born to and nursing ovalbumin-treated ewes than in lambs from control ewes. In Exp. 2, ovalbumin inoculation of lambs at age 1 d reduced (P < 0.04) maternally-derived serum OV-IgG through age 15 d compared with saline inoculation. However, after age 15 d, serum OV-IgG was greater (P < 0.001) in ovalbumin-treated than in control lambs. In Exp. 3, in lambs that received ovalbumin inoculations at age 1 and 15 d, serum OV-IgG increased through age 21 d but declined after age 28 d (P < 0.004). In lambs that received ovalbumin inoculations at age 28 and 42 d, OV-IgG increased (P < 0.001) steadily through age 21 d and stabilized thereafter. In lambs that received ovalbumin inoculation at age 28 and 42 d, serum OV-IgG in blood samples collected just before the booster was greater (P < 0.006) than observed in lambs in the other 3 treatment groups. Inoculating lambs within 24 h after birth may reduce circulating maternally derived antibodies, but it can induce an immune response. The results of this study support vaccinating ewes against common pathogens during late pregnancy and to ensure that lambs receive adequate colostrum soon after birth.