Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #79021
Title: ASSESSMENT OF IMMUNOCOMPETENCE OF HOLSTEIN DAIRY BULLS AS MEASURED BY NEUTROPHIL IODINATION CAPACITY DURING AN IMMUNOSUPPRESSION MODEL

Author
item KELM, S - IOWA STATE UNIVERSITY
item KEHRLI JR, MARCUS
item FREEMAN, ALAN - IOWA STATE UNIVERSITY
item BURTON, JEANNE - MICHIGAN STATE UNIVERSITY
item KUCK, A - SHAWANO WISCONSIN

Submitted to: American Dairy Science Association Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: We are investigating indirect selection criteria for increased disease resistance in dairy cattle, including immunocompetency measures. The neutrophil iodination assay (NI) is a measure of neutrophil function. The objective of this research was to establish immunocompetency rankings of dairy bulls using NI before (NI-B), during (NI-D), and after (NI-A) glucocorticoid-induced immunosuppression. Dexamethasone was used as an immunologic stressor. Sixty Holstein bulls were tested in 5 groups of equal size. Four control bulls were used in each group with results expressed as percent of controls. Days relative to dexamethasone treatment defined NI-B (days -5, -4, and -3), NI-D (days 2, 3, and 4), and NI-A (days 5, 9, 10, and 11). Neutrophil function was assessed each day and arithmetic means were calculated within time period for each bull. Phenotypic means for NI-B, NI-D, and NI-A were 95.7, 70.9, and 80.5%, respectively, with standard deviations of 19, 17, and 17. Breeding values for the three NI measures were estimated using single=trait animal models. The model included in fixed group effect and a random animal effect. Bulls were ranked by breeding value in each measure, and overall rank was determined by the sum of the individual ranks.