The key to productive potential | Beef + Lamb New Zealand

The key to productive potential

As their tenure as B+LNZ Innovation Farmers comes to an end, the Craws believe their hill country has more productive potential than they ever thought possible.
Monday, 20 February 2017

“Particularly in light of the pressure to finish stock on hill country.”

The Craws say N is the key to unlocking this potential and the cheapest and most efficient way of getting N into a hill country system is by using legumes.

By using chemicals to control weed and poorer grass species, they are allowing existing, naturalised clovers to flourish and fix N, improving pasture quality, quantity and palatability.

This autumn they intend broadcasting clover seed into pasture, although seeding rates are still being discussed. Annabel says the clover will be inoculated to introduce fresh rhizobia with the aim of boosting N fixation.

The value of grazing

Grazing management plays a big part in maximising the potential of the hill country and this includes removing stock in that critical summer period to allow seed to set and careful grazing in autumn (preferably by cattle) to remove competing vegetation and allow the clover seedlings to come away so they are well established by late winter and spring.

In getting clover established, the couple stress the importance of breaking down thatch to expose bare ground. Annabel says subterranean clover in particular needs bare ground to spread runners and stolons and peg down seed burrs while white clover needs room to root at the nodes.

The strategic use of chemicals, combined with sound grazing management, means the Craws have clover-rich swards in spring to drive lactation, pre-weaning growth rates and ultimately grow more kilograms of lamb.

ME - what is it?

Livestock – like humans – need sufficient nutrients and energy to be supplied to the body to meet metabolic demands. These requirements are expressed as metabolizable energy or ME.

The ME requirement for maintenance is the amount of ME that must be supplied to provide energy for essential body functions. If this energy is not supplied in the diet, it must be obtained by mobilising body tissue, predominately fat. ME requirements increase during pregnancy, lactation, growth, increased activity and during bad weather.  

On hill country pastures, energy is typically the most limiting factor. Other nutrients such as protein, minerals and vitamins are usually present in adequate amounts – although protein is sometimes limited especially in poor quality, mature pastures.

This energy deficiency may be exacerbated on hard hill country due to the energy costs incurred by increased grazing activity. Maintenance requirements on this type of country are higher compared to stock grazing easier country.

The addition of legumes into hill country pastures will lift the total ME of those pastures – providing more energy for stock performance – as well as fixing nitrogen.