Sunday, July 3, 2022

Clinical about cows

They are fun to muster and don’t need crutching – but are they money-makers? On the books a beef cow gross margin stock unit return typically ranges from 30% to 70% of finishing cattle returns (beef breed finishing). In their defence cows eat poorer quality feed. The Beef Cow Focus Farm Project showed that mixed-aged cows eat feed worth eight to nine megajoules of metabolisable energy a kilogram of drymatter (MJ ME/kg DM) for most of the year. This is 1.5 to two units lower than other stock classes. Cows are pushed harder. Monitoring showed grazing residuals left by cows are lower (300 to 400kg DM less) than other stock. Calves on these cows were growing at 0.8kg liveweight each day (LW/day). Fed the same quality, it is estimated that a finishing bull would grow at only 0.1kg LW/day. Cows can be made to graze pasture containing 8 MJ ME/kg DM on average with the regrowth worth 10 MJ ME/kg DM or more. The highest gross margin from this poor feed is from breeding cows. To top it off, the Focus Farm research showed cows lifted the performance of ewes to the tune of adding $10 to the ewe gross margin (at 2008 prices).

Trick to efficient cows

“I will buy mature cows if I need them and sell them when I do not, without hesitation.” 

The trick to extracting the most value from cows is protecting calf weaning weight, without putting ewe-quality feed down beef cow throats.

Warwick and Lisa Lissaman, of Breach Oak, Marlborough, run 80 beef cows (no heifers) and see cows purely as a flexible class of stock. Warwick does not breed his own replacements and will either sell calves or take them through to weaners or to finished weights, as feed dictates. In winter around 50% of stock units are cattle but this includes finishing heifers, bulls or steers.

“I will buy mature cows if I need them and sell them when I do not, without hesitation.”

Cows clear way for clover

Cows can indirectly add the growth-stimulant nitrogen to the farm system, simply by their grazing methods.

In pastures with annual clover seed present, cows can clear the way for a great clover strike and establishment following autumn rains.

They clear dry rank grass cover late summer/early autumn without nipping out the newly germinated annual clover seedlings (as sheep would). This reduces shade and moisture competition on seedlings.

These clovers go on to fix nitrogen at a rate of about 25kg nitrogen/tonne of legume drymatter (N/t DM) grown. As an example, pasture with an extra two tonnes of legume a hectare grown over late winter/early spring (an increase from three to five tonnes legume) would produce another 50 units of N fixed/ha.

To apply this level of nitrogen via bag urea it would be around $75/ha (spreading not included).

Being pushed over late summer and autumn to eat poor quality feed is not detrimental to a cow as long as she was fed well pre- and post-calving. The Beef + Lamb NZ Fact Sheet on cow nutrition (2013) said it was actually beneficial for cows to lose around 10% of their liveweight (LW) in the post-weaning period. Cows losing that magnitude of LW have increased longevity and suffer no reduction in performance—provided their nutritional requirements are met in the pre- and post-calving periods, and lost weight is regained.


Simon and Lynda Harvey, of Glen Orkney, farm hill and high country in the Medway, Marlborough.

While running only 13% of their total 7000 stock units in beef cows, Simon said he would not be without them.

This March cows were being used to prepare a block for oversowing in annual clover. Subterranean clover had been oversown and, while conditions were still dry, cows were grazing the block to reduce thatch and grass cover. This will help seed make contact with the ground and reduce moisture and sun competition.

Simon won’t bare it to the boards, however, as a bit of shade cover can actually help seedlings if it gets hot again after the strike.

“Once it rains and the clover seed germinates we will take the cows out to let it establish.”

Beef cows are also used in other ways at Glen Orkney. They graze targeted blocks in spring to make sure quality stays high for ewes with twin lambs after tailing. The Harveys do graze low stocking rates of older cows with some ewes over lambing but avoid putting younger cattle in with them.

“Younger cattle can persecute sheep and can mismother lambs.”

After calf marking the cows graze towards the back of the property, tidying as they go. After weaning they are set-stocked for winter on country around 500m above sea level. Salt is supplied to stock every two months or so. Straight Angus cattle are used as they walk the hills really well and are saleable.

Some calves are kept on for sale as yearlings, depending on autumn growth.

“The last few years we should have been running more to groom surplus pasture but too many cows can be a liability in dry seasons.”

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