|Carroll, Jeffery - Jeff Carroll|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 7/11/2010
Publication Date: 10/11/2010
Citation: Martel, C.A., Mamedova, L.K., Minton, E.J., Jones, M.L., Carroll, J.A., Bradford, B.J. 2010. Effects of continuous infusion of tumor necrosis factor-alpha (TNF) into adipose tissue on glucose and fatty acid metabolism in lactating dairy cattle [abstract].2010 American Society of Animal Science Meeting, July 11-15, 2010, Denver, CO. Journal of Animal Science. 88(E-Supplement 2):529. Interpretive Summary:
Technical Abstract: Late-lactation Holstein cows (n=9/treatment) were used to evaluate effects of TNF-alpha administration on glucose and fatty acid (FA) metabolism. Cows were blocked by feed intake and milk yield and randomly assigned within block to 1 of 3 treatments: control, TNF-alpha, and pair-fed control. Treatments (4 mL saline or 14 micrograms/kg TNF-alpha in 4 mL saline) were infused continuously over 7 d via 2 osmotic pumps in the adipose layer in the tailhead region. Plasma, milk samples, milk yield, and DMI data were collected daily. On d 7, pumps were removed and liver and contralateral tailhead adipose samples were collected. Results were modeled with fixed effect of treatment and random effect of block; P values > 0.10 were considered non-significant. TNF-alpha did not alter adipose or liver TNF-alpha mRNA abundance, plasma TNF-alpha, IL-4, IL-6, or interferon-gamma concentrations, DMI, or rectal temperature. Milk fat and lactose concentrations decreased with TNF-alpha (P<0.05), but milk yield was unchanged and treatments did not alter the proportion of short vs. long-chain FA in milk on d 7. Treatments did not alter plasma NEFA concentration, liver triglyceride content, or adipose mRNA abundance for hormone-sensitive lipase or perilipin. Plasma glucose turnover rate, as measured by disappearance of U-13C-glucose bolus, was not altered by treatment, nor was liver mRNA abundance for phosphoenolpyruvate carboxykinase or pyruvate carboxylase. However, TNF-alpha tended to decrease adipose TNF-alpha mRNA abundance (P=0.09) and increase liver IL-10 mRNA abundance (P=0.05) compared to controls. This TNF-alpha delivery protocol may have allowed for an adaptive anti-inflammatory response to suppress systemic inflammation, which may account for the lack of metabolic responses, in contrast with previous responses to daily subcutaneous TNF-alpha injections.