The trial began on April 1 and ran for 61 days. It involved three mobs of bought-in store lambs – a control mob on grass, a mob on fodder beet supplemented with meadow hay and a mob on fodder beet supplemented with pea hay. The lambs were weighed every two weeks.
The November-planted fodder beet crops (Ravage and Brigadier) grew an average of 27 tonnes drymatter (DM)/ha between November and June, compared to 5.5t DM/ha for the grass.
While the fodder beet crops initially struggled in the dry summer, they responded well to autumn rain which helped realise their yield potential.
Net lamb production off the fodder beet and pea hay treatment was 1200kg liveweight (LW)/ha compared to just 419kg LW/ha off the grass.
This translated into a net margin of $4416/ha off the fodder beet and pea hay, $3435/ha off the fodder beet and meadow hay and $1310/ha off the grass.
The lambs on the fodder beet treatments were not transitioned on to the crop because they took a while to learn to eat the bulbs anyway, Scott says.
This meant they did initially lose weight when compared to the control mob, but this check was only temporary.
The lambs were on the fodder beet on two or three-day breaks (although Scott found 10% of the lambs kept breaking out and eating all the tops).
A small number of lambs – 15 out of 200 – went backwards on fodder beet. These were taken off the crop.
Lamb growth rates on fodder beet on Scott Linklater ‘s Manawatu farm were not remarkable but the crop could carry 280 lambs/ha for two months.
Growth rates in the grass “control mob” were variable and while they initially surged ahead of the lambs on fodder beet, they dropped just as dramatically in response to typical autumn-related challenges such as declining pasture quality and pasture worm burdens.
Facial eczema was problematic through much of the North Island last summer, but did not affect lambs on the feed crops.
Once the lambs had grazed the fodder beet they were finished on pasture and processed over July and August.
Scott says he was rapt with the trial results and will implement the fodder beet system again next year. He plans to tweak supplement use to increase protein intake in the hope this will help improve lamb growth rates.
– Supplied by B+LNZ