Reproductive Performance of Merino Ewes Dosed with Selenium Prior to Mating
G.H. Scales
Tara Hills High Country Research Station, Omarama
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Proceedings of the New Zealand Society of Animal Production. 1974, 34: 103-113
Dosing Merino ewes with 5 mg selenium approximately 17 days
before mating significantly reduced the proportion of barren ewes by 12%
in three out of four trials. The reduction in barrenness associated with
pre-mating selenium administration was greater for ewes grazing
ryegrass/clover pastures (15.0%) than for ewes grazing lucerne pasture
(8.9%). The application of selenium to the pasture via superphosphate
prior to mating significantly reduced the proportion of barren ewes by
8% relative to control ewes, but was not as effective as oral dozing
(14.3%) under the experimental conditions imposed.
Dosing ewes with 5 mg selenium prior to lambing in addition to mating,
significantly reduced lamb mortality from birth to weaning. Little
additional response was obtained by dosing lambs with selenium at
tailing, although in the absence of selenium at lambing, substantial
reductions in lamb mortality and improvements in weaning weights were
made.
Keywords: NZSAPAB;
Last Updated 24-08-2000
