Free Access
Reprod. Nutr. Dev.
Volume 46, Number 5, September-October 2006
5th annual INRA-Meeting: Mammary gland and milk
Page(s) 503 - 514
Published online 23 September 2006
Reprod. Nutr. Dev. 46 (2006) 503-514
DOI: 10.1051/rnd:2006035

Combined effect of salinomycin and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet

Tadahisa Fujita, Hiroya Majima, Takahiro Itoh and Hiroaki Sano

Department of Agro-bioscience, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka 020-8550, Japan

(Published online 23 September 2006)

Abstract - The aim of this study was to investigate the effects of salinomycin (SL) and feeding on whole body glucose kinetics in sheep fed a high-concentrate diet (25% orchardgrass hay and 75% commercial concentrate). Four adult sheep were fed the diet with or without 20 mg$\cdot$kg-1 diet of SL once daily for each 3 wk. The rates of glucose entry and utilization were determined before and during 3 h after feeding using a [ 13C6] glucose dilution approach. Ruminal characteristics and concentrations of blood volatile fatty acids (VFA) and plasma glucose and insulin were also measured. Metabolizable energy intake was unaffected (P = 0.22) with SL. Salinomycin decreased (P = 0.06) the ratio of acetate to propionate in rumen fluid. Salinomycin increased (P = 0.01) both rates of entry and utilization of glucose, but did not affect (P > 0.10) concentrations of blood VFA or plasma glucose or insulin. Feeding caused gradual increases in concentrations of blood acetate (P < 0.01) and propionate (P = 0.01), a transient increase in plasma insulin concentration (P = 0.05), a transient decrease in plasma glucose concentration (P < 0.01), and persistent increases in both rates of glucose entry (P < 0.01) and utilization (P < 0.01). No SL $\times$ feeding interaction was observed (P > 0.10) on any measurements. We conclude that SL and feeding would have an additive effect on both rates of glucose entry and utilization without modifications with SL to feeding responses of peripheral concentrations of blood VFA, plasma glucose and insulin.

Key words: feeding / glucose metabolism / insulin / ionophore / propionate / sheep

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© INRA, EDP Sciences 2006