The regulation of glycogen level in the muscle of ruminants by nutrition
D.W. Pethick, L. Cummins, G.E. Garner, R.H. Jacobs, B.W. Knee,
M. McDowell, B.L. McIntyre, G. Tudor, P.J. Walker and R.D. Warner
Division of Veterinary and Biomedical Sciences, Murdoch
University, South St., Murdoch, Western Australia, 6150
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Proceedings of the New Zealand Society of Animal Production.
2000, 60: 94-98
This paper discusses recent work by the authors which has
investigated the nutritional regulation of glycogen concentration in
skeletal muscle of sheep and cattle. Several experiments are summarised
which show a clear relationship between the level of glycogen in muscle
and the intake of metabolisable energy. This translates into strong
seasonal effects on the level of muscle glycogen in pasture fed cattle
that correlate with live weight change. The clear message is that
animals destined for slaughter should be on a high plane of nutrition as
this will contribute to an increased level of muscle glycogen at
slaughter and so help alleviate the problem of dark cutting meat. Acute
regulation of glycogen is more problematical since the rate of glycogen
repletion in skeletal muscle is relatively slow and the scope for rapid
dietary change in ruminants is constrained by the need to allow rumen
adaptation to high starch/sugar diets. However the sudden introduction
of a high energy diet (based on cereal grain) in the presence of a
'rumen modifier' to reduce ruminal acidosis can increase muscle glycogen
concentration within 1 week of feeding. The ability to further modify
glycogen level in skeletal muscle using carbohydrate and electrolyte
products is discussed. In particular the possibility of using oral
glycerol/ propylene glycol as a means for increasing blood glucose and
so glycogen synthesis is proposed. Experiments to examine the
effectiveness of MgO as a means for reducing the stress response are
also discussed.
Keywords: NZSAPAB;
energy intake; muscle glycogen; ruminants
Last Updated 12-07-2000
