With winter approaching here in New Zealand, assessing feed supplies is the order of the day on many farms, including arable ones where growing one or more crops for wintering cattle or lamb finishing is common practice.
Historically, brassicas, green-feed cereals and annual ryegrasses dominated, but these days fodder beet is equally popular. Typically it produces at least 20t/ha of drymatter compared to about 12t/ha of kale or swedes. Couple that with higher energy content in beet – about 11.5MJME/kgDM compared to 10.5MJME/kgDM with kale, and it’s not hard to see why.
Beef farmers in particular have found they can keep cattle growing faster through the winter on the crop, averaging 0.5-0.6 kg of liveweight gain per day in the case of 12 producers monitored for 3-years as part of a Beef + Lamb New Zealand study*. Those growth rates don’t sound great compared to indoor systems overseas, but they are averaged commercial figures, not trials, achieved outdoors in a reasonably harsh environment (foothills of the Southern Alps) with the crop fed in situ using hot-wire breaks, eg. a very low cost system.
The cost of growing the crops on those producers’ farms averaged 14c/kgDM in the first 2 years, falling to 11c/kgDM in the final year, thanks to better yields and gradually declining growing costs. It’s worth noting these are figures from unirrigated sheep and beef farms too, ie not the best land and with nearly all field operations performed by contractors. Professional arable farmers are achieving higher yields (up to 30tDM/ha) with lower growing costs.
Often, arable farmers’ beet crops are for wintering dairy cows and therein lies a problem. They’re big animals and if it’s a wet winter, they make a mess, wrecking soil structure, delaying spring sowing, and dragging down yields for years to come. Some growers have already given up the crop rather than risk that. Others are still growing it but it’s lifted when conditions are suitable and fed to cows elsewhere. That adds cost, but it protects the paddock from pugging and can allow effluent from the cows to be collected and returned uniformly to an area of the farmer’s choice. With dairy farmers under ever increasing environmental pressure, such symbiotic systems seem set to proliferate. It’s getting more like Europe every day, environmental bureaucracy included.
*Fodder Beet Profit Partnership. See https://beeflambnz.com