Every sheep unit has the potential to maximise the use of grazed grass, says New Zealand sheep consultant Trevor Cook, who spoke to a group of farmers in Penrith last week. Katie Jones reports.
While sheep farmers have a tight handle on feeding sheep at housing, this can change when bringing grazing into the equation.
Speaking at a farmer meeting in Penrith, New Zealand sheep consultant Trevor Cook said it was key sheep producers measured grass to be in control of how it was fed to livestock.
“Farmers have a perception measuring pasture is hard. In fact it is easy to actually do the measuring, but it is using this information which is difficult.”
He said there was a ‘multitude of fancy machines’ to measure grass, but advised using a simple sward stick and clipboard.
“This is not a precise science, but it is an essential part of the process if you want to be in control of feeding pasture to livestock.”
Once figures were in, Mr Cook said grazing time would be driven by demand and growth rate.
He said: “A ewe will consume 4 per cent of its bodyweight, although at peak lactation this would increase to 5 per cent. You can use these figures to work out how long animals should stay on the pasture.”
Mr Cook explained covers needed to be grazed down to no less than 1,200kg DM/hectare.
“How well animals are fed on pasture is down to how much is left behind. You want to leave it in a state so it can grow back.”
Mr Cook conceded it was difficult to monitor pasture grazing when lambing outdoors, but said making sure ewes were correctly fed in the run-up to lambing would alleviate difficulties afterwards.
“The state of the ewe before lambing will drive lamb vigour. The ideal scenario is to deliver two lambs which get up and suck within 20 minutes. It is all about vigour – if the lamb gets up and sucks within 20 minutes, it has a 95 per cent chance of being alive 90 days later.
“Lambs born to ewes with a body condition score of 3 or less are less likely to stand up. This is often the difference between 90 per cent and 85 per cent lamb survival.
“You need to feed these ewes really well until they lamb, then afterwards, if you do not get feed requirements right, they can use some of their body reserves.”