The effect of pre-natal nutrition and type of birth and rearing
of lambs on vigour, temperature and weight at birth, and weight and
survival at weaning
R.W. Moore, C.M. Millar, P.R. Lynch; and B.W. Dow
Whatawhata Hill Country Research Centre, Ministry of Agriculture
and Fisheries, Hamilton; and Ruakura Agricultural Research Centre,
Ministry of Agriculture and Fisheries, Hamilton
Proceedings of the New Zealand Society of Animal Production.
1986, 46: 259-262
Two hundred and thirty 5-year-old Romney ewes were synchronised
with progestagen intravaginal sponges and injected with dexamethasone
142 or 143 days after the median mating day of the first and second
cycles of oestrus. Seventy-one % of the lambs were born 30 to 50 h
after injection. The ewes were offered 2 pasture allowances for the
last 6 weeks of pregnancy (approximately 6 and 1 kg DM/ewe/d). Lambs
were vigour scored (1 to 10) and probed for rectal temperature and ewe
lambs were cross-fostered as soon as possible after birth in order to
obtain a 2 4 factorial design incorporating birth type (single and
twin) rearing types (single and twin), pre-natal nutrition of dam (high
and low allowance), and pre-natal nutrition of foster dam (high and low
allowance).
Lambs born from high allowance ewes had higher rectal temperatures at
birth than those born from low allowance ewes, and female lambs had
higher rectal temperatures than male lambs. Single-born lambs scored
higher on vigour than those born as multiples. Increasing vigour was
associated with increasing birth weight for all lambs, but increasing
temperature was associated with increasing birth weight only for male
lambs. There were no effects of pre-natal nutrition on lamb growth
either through the dam or foster dam. The effect of birth type on lamb
live weight was significant to 9 weeks of age whereas the effect of
rearing type was significant to 33 weeks. There were no significant
birth type x rearing type interactions at any age.
Keywords: NZSAPAB;
Ewes; pre-natal; pasture allowance; cross-fostering; neo-natal;
rectal temperature; vigour; survival; growth
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Last Updated 18-03-1997
