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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Reproduction Research » Research » Publications at this Location » Publication #320001

Research Project: IMPROVING SOW LIFETIME PRODUCTIVITY IN SWINE

Location: Reproduction Research

Title: Assessment of the immunocrit ratio assay for evaluation of colostrum quality in sows induced to farrow and inseminated using single dose fixed time insemination

Author
item Hanson, Andrea - Swine Veterinary Center
item Vallet, Jeffrey - Jeff
item Johnston, Mike - Swine Veterinary Center
item Yeske, Paul - Swine Veterinary Center

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/27/2016
Publication Date: 2/27/2016
Citation: Hanson, A.R., Vallet, J.L., Johnston, M.E., Yeske, P.E. 2016. Assessment of the immunocrit ratio assay for evaluation of colostrum quality in sows induced to farrow and inseminated using single dose fixed time insemination [abstract]. In: Proceedings of 47th Annual Meeting of the American Association of Swine Veterinarians (AASV), February 27-March 1, 2016, New Orleans, Louisiana. Poster #47.

Interpretive Summary:

Technical Abstract: Problem Statement: Sufficient intake of quality colostrum is essential for the success of newborn piglets. Relatively high levels of immunoglobulins (Ig) generally indicate colostrum of high quality. IgG is the predominant Ig in colostrum. The immunocrit ratio assay has been developed as a simple method for assessing concentrations of IgG in porcine serum (Vallet et al., 2013), but it is unknown if this assay has similar utility for colostrum or milk. Objective: Evaluate the relationship between concentrations of IgG and the results of the immunocrit ratio (ICR) assay in sow milk. Materials and Methods: One hundred fifty one sows (parity 2 to 13) were stratified by parity and breeding group and randomly assigned to be either induced on d 113 post insemination (2 ml intramuscular injection of Lutalyse®) or not induced. All sows were administered Ovugel® (JBS-United) on d 4 post weaning and inseminated using single dose fixed time insemination on d 5 post weaning. Milk samples were collected and serum obtained from 3 pigs/litter within 18.25 h of farrowing (range = 0 to 18.25 h; median = 3 h). Milk was analyzed for IgG using a commercial ELISA (Immunology Consultants Laboratory, Inc.; Kit E-5G) and the ICR assay described by Vallet et al. (2013) with duration of centrifugation extended to 15 min. Serum samples were evaluated for ICR as described by Vallet et al. (2013). Relationships between continuous variables were assessed using linear regression in JMP 7.0 (SAS Institute, Inc.). Evaluation of treatment effects was conducted using ANOVA procedures in JMP 7.0, and the model included effects of parity, sample collection time, and farrowing group. Results and Discussion: Three milk samples were omitted because a Cook’s distance test indicated they were outliers. Treatment did not significantly affect pig serum or milk ICR or IgG levels in milk (P > 0.20). Litter mean serum ICR had weak negative associations with milk ICR and IgG (R**2 = 0.03 and 0.03, respectively; P <= 0.05). Both ICR and IgG declined as the time of sample collection post farrowing increased (R**2 = 0.20 and 0.16, respectively; P < 0.01). There was a moderate relationship (R**2 = 0.40; P < 0.01) between ICR and IgG concentration. Absence of a strong relationship indicates that components in milk in addition to IgG react in the ICR assay. Samples with low IgG also had low ICR indicating that the assay could be used to screen for colostrum quality. Furthermore, the immunocrit is considerably less expensive and easier to conduct than alternative techniques to assess specific Ig. References: Vallet, J. L. 2013. A simple novel measure of passive transfer of maternal immunoglobulin is indicative of preweaning mortality in piglets. Vet. J. 195. 91-97.