PAROTID SALIVARY SECRETION IN SHEEP: ITS MEASUREMENT AND INFLUENCE ON PHOSPHORUS IN RUMEN FLUID

¹ Commonwealth Scientific and Industrial Research Organization, Division of Nutritional Biochemistry, Adelaide, South Australia

The establishment and maintenance of permanent parotid duct fistulas in sheep is described. With appropriate cannulation of the fistulas the saliva flow can be measured and sampled at successive points in time over long periods without the loss of saliva to the sheep. When saliva flow rate is not being determined the saliva flows directly to the mouth via a ‘closed loop’. By this means saliva flow was measured periodically over 3-12 months in nine sheep receiving a variety of treatments. Saliva flow rates varied from 3 to 10 1/day and were reproducible within sheep. The surgical procedure is simple and sheep can be held in ordinary pens when saliva flow rate determinations are not required. Data relating to the influence of parotid saliva on the rumen fluid phosphorus concentrations by use of the described technique are presented and discussed. Inorganic phosphorus concentrations in rumen fluid are determined principally by the salivary phosphorus secretion.

Note:

I wish to thank Professors E. J. Underwood and R. J. Moir and Dr M. Somers for their support and encouragement during the initial development of the surgical technique at the Institute of Agriculture, University of Western Australia, Thanks are also due to Mr V. A. Stephen of the CSIRO Division of Nutritional Biochemistry, Adelaide, for his construction of the tilting bucket mechanism.

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