The reason for the trial was that some farmers were being advised that only low dry matter cultivars are suitable for grazing young cattle, despite the fact many were successfully using medium dry matter types.
In spring 2016 a large paddock on a farm near Wairoa was sown in fodder beet, one half in the low dry matter mangel cultivar Brigadier, and the other half sown in equal areas of Kyros, Bangor and Feldherr. On the 19th of April 2017, a mob of R1 angus cattle, of the same breeding line, were weighed and randomly split into two mobs that ensured the cattle were of the same weight. One mob was placed on the Brigadier and the other on the other cultivars, and they were grazed with the same amount of pasture and supplements, until the first crop had completed grazing at the end of August.
During winter there was unusually high rainfall, resulting in more mud than normal and growth rates in the cattle lower than can be achieved during drier winters.
The cattle started at a mean liveweight of 167 kg, and at the end of August were the same weight on both treatments, 226 kg on the Kyros/Bangor/Feldherr and 228 kg on the Brigadier, with mean daily gains of 435 and 453 g/hd/day respectively. This confirmed that there were no cattle growth rate differences between the low and medium dry matter cultivars.
As the Brigadier crop had a lower yield than the medium dry matter crop, the animals finished the Brigadier crop 20 days earlier. This resulted in 21% more grazing from the Kyros/Bangor/Feldherr crop, and an estimated increase in profit of $800 per hectare.
This result is similar to a trial with Angus R2 cattle conducted previously, which also showed no cattle growth rate differences between the low and medium dry matter cultivars (click here for those results).
Both these trials show that the driver of profitability differences between cultivars of beet is their yield potential, cultivars with higher yield are more profitable.
Acknowledgements; Dave Martin, Martin Pastoral Ltd. Wayne Hurunui of the Tru-Test Group who loaned the EID and weigh equipment for the weight recording.