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Stocking intensity and pastoral production: II. Herbage intake of Merino sheep grazed at different stocking rates

Published online by Cambridge University Press:  27 March 2009

J. P. Langlands
Affiliation:
C.S.I.R.O., Pastoral Research LaboratoryArmidaleN.S.W., 2350, Australia
I. L. Bennett
Affiliation:
C.S.I.R.O., Pastoral Research LaboratoryArmidaleN.S.W., 2350, Australia

Summary

Estimates were made at monthly intervals between January and December 1965 of the intake and nutritive value of the diet of unmated Merino ewes grazed continuously at stocking rates ranging from 2·5 to 37·1 sheep/ha. Oesophageally fistulated sheep were used to estimate intake and nutritive value.

Drought conditions existed during the experiment. Digestibility declined linearly with increasing stocking rate. The intercepts of the relationship between digestibility and stocking rate differed between months, being at a maximum in spring. Nitrogen content was also greatest in spring but did not change consistently with increasing stocking rate. Organic-matter intake declined linearly with stocking rate and increased asymptotically with total herbage available, the asymptotic relationship being the more precise. Neither relationship differed significantly between months. Organicmatter intake/ha increased continuously with increasing stocking rate and the maximum intake was predicted to occur at a stocking rate greater than that at which the sheep survived.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1973

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