The effect of exogenous melatonin, administered in summer, on
wool growth and testis diameter of Romneys
P.M. Harris, Z.Z. Xu, H.T. Blair, D.W. Dellow, S.N. McCutcheon,
J. Cockrem
Biotechnology Division, DSIR, Palmerston North; Department of
Animal Science, Massey University, Palmerston North; Ecology Division,
DSIR, Taita
Proceedings of the New Zealand Society of Animal Production.
1989, 49: 35-38
To study the influence of melatonin on seasonal changes in wool
production of crossbred sheep, a pharmacological dose of sustained
release melatonin was administered over a month in early summer to both
fleeceweight-selected and control rams from the Massey university
Progeny Test lines. Wool growth and testis diameter were compared with
those of untreated animals during the period of melatonin treatment and
for a further 2 month period.
Melatonin treatment did not significantly change either greasy or clean
fleeceweight production. However, the testis diameter of the melatonin-
treated animals was significantly greater than in untreated animals
during the period of melatonin treatment and significantly smaller
during the recovery period. Hence, although the melatonin treatment was
sufficient to produce a change in reproductive characteristics, it was
not sufficient to induce a measurable change in the pattern of wool
production.
Keywords: NZSAPAB;
Melatonin; wool; sheep; testis size
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Last Updated 18-03-1997
