title: Immune function in dairy cows related to energy balance and metabolic status in early lactation.
abstract: Two feeding experiments were carried out in 2 successive years with 28 cows of the Norwegian Red Cattle (NRF) in each experiment. The cows were randomly distributed into 4 groups and subjected to different feeding regimens from 1 month prior to calving until 12 weeks after calving. The experimental design was factorial (2 x 2) with respect to protein content of the concentrate (17.5% digestible crude protein (DCP) v.s. 12.5% DCP) and concentrate allowances (standard v.s. substandard allowances after calving). Silage was offered ad libitum. Samples for estimation of serum immunoglobulin-G, white blood cells and lymphocyte responses to the mitogens phytohemagglutinin, concanavalin A and pokeweed mitogen were collected 4 weeks prior to expected calving, and 2, 4 and 8 weeks after calving. The levels of milk immunoglobulin-G were estimated at calving and 2, 4 and 8 weeks after calving. A significant positive relationship was found between the estimated energy balance and the lymphocyte response to mitogens. Little evidence was found for the existence of a significant relationship between the immunologic parameters and plasma indicators of metabolic status. The lymphocyte response to phytohemagglutinin and levels of serum immunoglobulin-G increased, while levels of milk immunoglobulin-G decreased during the period from calving to 8 weeks after calving. Increased milk somatic cell counts were associated with a significant decrease in the lymphocyte responses to mitogens.
authors.forename: E
authors.initials: E
authors.lastname: Ropstad
authors.forename: H J
authors.initials: HJ
authors.lastname: Larsen
authors.forename: A O
authors.initials: AO
authors.lastname: Refsdal
mesh_terms: D000818:Animals; D002417:Cattle / Q000276:immunology*; D004734:Energy Metabolism; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis; D007774:Lactation / Q000378:metabolism*; D008213:Lymphocyte Activation; D008892:Milk / Q000166:cytology; D011247:Pregnancy; D011897:Random Allocation
chemical_list: D007074:Immunoglobulin G