Evaluation of assay procedures for prediction of passive transfer status in lambs.
OBJECTIVE
To compare 4 assay procedures for prediction of passive transfer status in lambs.


METHODS
Thirty-one 1-day-old Sardinian lambs.


METHODS
Serum IgG concentration was determined by use of single radial immunodiffusion. The following were determined: serum total protein concentration as measured by refractometry (ie, refractometry serum total protein concentration), serum total protein concentration as determined by the biuret method (ie, biuret method serum total protein concentration), serum gamma-globulin concentration as determined by serum protein electrophoresis, and serum gamma-glutamyltransferase (GGT) activity as measured by spectrophotometry. Accuracy of these assays for estimation of serum IgG concentration in 1-day-old lambs was established by use of linear regression analysis.


RESULTS
Refractometry serum total protein concentration, biuret method serum total protein concentration, and serum gamma-globulin concentration were closely and linearly correlated with serum IgG concentration. The natural logarithm (ln) of serum GGT activity was closely and linearly correlated with serum IgG concentration (ln). Refractometry serum total protein concentration, biuret method serum total protein concentration, and gamma-globulin concentration accounted for approximately 85%, 91%, and 95% of the variation in serum IgG concentration, respectively. Serum GGT activity (ln) accounted for approximately 92% of the variation in serum IgG concentration (ln).


CONCLUSIONS
For prediction of passive transfer status in 1-day-old lambs, serum GGT activity or biuret method serum total protein concentration determination will allow for passive transfer monitoring program development. Immediate refractometry serum total protein concentration determination is beneficial in making timely management and treatment decisions. Serum gamma-globulin concentration determination can be used as a confirmatory test.
Massimini
Genesio
G
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, University of Teramo, Viale F. Crispi 212, I-64100 Teramo, Italy.
Peli
Angelo
A
Boari
Andrea
A
Britti
Domenico
D
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D007116:Immunization, Passive / Q000662:veterinary*; D007074:Immunoglobulin G / Q000097:blood*; D007558:Italy; D012756:Sheep / Q000276:immunology*; D005723:gamma-Glutamyltransferase / Q000097:blood
D001798:Blood Proteins; D007074:Immunoglobulin G; D005723:gamma-Glutamyltransferase