Nutritional needs
Reducing ewe nutrition in mid-pregnancy can reduce the size and functionality of the placenta, and restrictions during late pregnancy can reduce the growth rate and size of the foetus. - Lifetime wool production and quality are also affected by ewe nutrition during pregnancy, with linear relationships between changes in ewe condition and the amount and quality of wool produced by single and twin lambs. Production and quality losses cannot be fully compensated for by improved nutrition after birth.
- An improvement in ewe nutrition in pregnancy also increases progeny fleece weight, while poor ewe nutrition increases progeny fibre diameter.
- Improved nutrition through lactation means bigger weaners and better weaner survival. A lamb born at five kilograms that grows at 200 grams a day will be about 20kg when weaned at 14 weeks. Having good feed on offer during lactation drives lamb growth. Lamb growth rates of 200g per day for single lambs are achieved when feed on offer is above 1100kg dry matter (DM) a hectare on mixed pastures in the high-rainfall zone, and 1500kg DM/ha on annual clover-based pastures.
- The effect of weaning weight on weaner survival is also important. Live-weight at weaning explains 95 per cent of the differences in weaner mortality. It is the most important factor in weaner survival. Weaner survival is best when the lamb is more than 20 kg (for a small-frame merino) or more than 25kg (for a medium-frame merino) at weaning.
See also: Beyond the Bale article - Feeding fundamentals
Return to Beyond the Bale Issue 27 index page.