Early Weaning Lambs: What the Massey Trials Found
Farmers with high-quality feed available in late spring could consider weaning at least a proportion of their lamb crop early to benefit both lambs and ewes.
That was a key message to come out of a Beef + Lamb New Zealand field day on Waiouru Station earlier this month (see p23).
“Sometimes farmers will say I’m going to sow 10has of crop and the stock class is then going to have to fit that,” explained PGG Wrightson Seeds’ specialist Charlotte Westwood.
“Instead, they should be saying I have 2000 ewes to winter, therefore I have demand for X amount of dry matter per head per day over a given period.
“It’s about the need to plan: how much area you need to grow; and how to grow the best yielding crop,” she stressed.
Westwood’s other key message is, having grown a crop, accurately determine the amount of feed using quadrant samples tested for drymatter.
There’s no point “eyeballing” crops to determine yield because few, if any, people can do it accurately.
“There are book values out there for the crops, but they are unreliable, especially for kale because it’s quite variable with dry matter percentage… there can up to a 2 or 3 % dry matter difference.”
If the book value percentage is higher than actual drymatter, and farmers are unaware of this, they’ll end up underfeeding stock, she warns.
“You must send a sample away to do a dry matter assessment. And while sending it away have it nitrate tested.”
Crops are a good option in areas where pasture growing seasons are limited by climate but yields do need to be high, says Westwood.
Where cold winters limit pasture growth, beside brassicas providing a weather-proof bulk of feed to carry stock through, they also have a lower minimum temperature for growth, so will grow a little when the pasture has long since stopped.
The other benefit to factor in is growing a crop is a good start to a re-grassing programme.
