New Zealand Journal of Agricultural Research abstracts
Effect of hogget nutrition in pregnancy on lamb birthweight and
survival to weaning
S. T. Morris
P. R. Kenyon
D. M. West
Institute of Veterinary, Animal and Biomedical Sciences
Massey University
Palmerston North, New Zealand
Abstract The effect of hogget nutrition during
pregnancy on birthweight and survival of lambs has not been thoroughly
examined under pastoral conditions in New Zealand. The aims of the
present study were to examine the effect of three hogget nutrition
levels during pregnancy on both lamb birthweight and lamb survival, and
hogget performance. Hoggets were offered either a “low”, “medium” or
“high” level of nutrition of herbage during pregnancy, which resulted
in total liveweight increases of 12, 21, and 30 kg, respectively
over the period from 13 days after the average day of mating to average
day 130 of pregnancy. Hogget nutritional treatment failed to affect
either lamb birthweight or lamb survival. Nutritional treatment also
failed to consistently affect ewe metabolic status. However, “low”
group hoggets weaned significantly (P < 0.05) lighter
lambs and were themselves significantly (P < 0.05)
lighter at weaning and produced significantly (P < 0.05)
less wool. The results of this study indicate that offering pregnant
hoggets a level of nutrition that increases their liveweight gain above
that of the expected conceptus growth will not benefit lamb birthweight
or survival rate to weaning, but will increase hogget fleece weight and
lamb weight at weaning. On the other hand, and in contrast to some
earlier research, an even higher level of nutrition in pregnancy did
not reduce birthweight or survival rate to weaning. This suggests that
when farmers are aiming to achieve heavy lamb weaning weights and
two-tooth mating weights, they need not avoid offering hoggets a high
level of nutrition in pregnancy.
Keywords hogget; nutrition; lamb birthweight; lamb
survival; sheep; pregnancy
A04047; Received 12 May 2004; accepted 21 February 2005; Online
publication date 30 May 2005
New Zealand Journal of Agricultural Research, 2005, Vol. 48:
165–175
0028–8233/05/4802–0165 © The Royal Society of New Zealand 2005
PDF file of entire paper: Print-quality
(288K) | screen-quality (496K)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
