Journal of the Department of Agriculture, Journal of the Department of Agriculture, Western Australia, Series 4 Western Australia, Series 4
Volume 11
Number 2 1970 Article 2
1-1-1970
Sheep : experimental basis for urea feeding recommendations Sheep : experimental basis for urea feeding recommendations
Department of Agriculture, Western Australia
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Recommended Citation Recommended Citation
Department of Agriculture, Western Australia (1970) "Sheep : experimental basis for urea feeding
recommendations," Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 11: No. 2, Article 2.
Available at: https://library.dpird.wa.gov.au/journal_agriculture4/vol11/iss2/2
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SHEEP
EXPERIMENTAL BASIS FOR UREA FEEDING RECOMMENDATIONS
Recent scientific reviews have concluded that in spite of the great number of experi- mental observations recorded throughout the world there is no evidence yet to prove that urea can be used profitably for sheep on low quality roughages in genuine graz- ing conditions.
Experimental sheep fed in pens can use urea as a substitute for protein in the right conditions. With continued research and experience we are getting a better understanding of the things that decide whether penned sheep will respond to urea. This could lead eventually to the profitable use of urea supplements for grazing sheep in some particular circum- stances.
Current recommendations, based on the results of experiments throughout Aus- tralia, are that urea mixtures should not be fed to sheep because the chances of a response are slight.
The Western Australian Department of Agriculture has done six trials to test the value of urea supplements for grazing sheep. In none of these has a response to urea been demonstrated.
The first two experiments were on stubbles from 24-bushel-an-acre crops of Gamenya wheat at Chapman Research Station in 1963-64 and 1964-65. The crops were grown on clover ley land.
In 1963-64 the stocking rates were two and four sheep an acre. The sheep grazed selectively to eat feed that contained more protein and less fibre than the stubble as a whole. There was little difference in the amounts of stem and leaf material present before and after grazing but no grain or
"cocky chaff" could be found after grazing.
In 1964-65 the stocking rate was four sheep an acre, with half the sheep on clean and half on weedy stubble. The
weeds—capeweed with some annual herbs and grasses—did not affect liveweights or wool production.
Urea/molasses/salt blocks were fed in both these experiments and no response to these could be measured. The sheep, at four sheep an acre, selected a fairly good diet from these abundant stubbles until late March, when they lost weight rapidly after wet weather.
Two experiments carried out on farmers' properties in the summer of 1966-67, tested urea/molasses/salt blocks as supplements to wheat stubble, one at Mullewa on land that had never grown improved pasture and one on old pasture land at Wagin.
Sheep did not respond to urea in either of these trials.
Another experiment in 1966-67 tested a grain/urea/fermented molasses/additives mixture in comparison with oats to supplement an improved pasture on a farm at Beverley. Both supplements gave better results than pasture alone but the oats gave better results than the urea mixture.
The response to this mixture was probably due to the grain it contained.
The sixth experiment, on a farmer's property in 1968, tested a liquid mix of urea and molasses as a supplement to stubble feed. There was no response to the urea/molasses mixture and the experiment was stopped in March because the sheep were doing poorly on the stubble after wet weather.
An experiment is in progress at Merredin Research Station this season, especially designed to demonstrate a response to urea by sheep grazing wheat stubbles, if such a response is possible. The site, stock- ing rates, mineral mixture and method of feeding urea have been chosen to fulfil as many as possible of the conditions known to favour a response to urea.
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Journal of Agriculture, Vol 11 No 2, 1970
