More cereals in ration could lead to acidosis _fginsight. com – news – fg insight
Facing a winter of low milk prices, producers will be looking closely at the basis of their herd’s ration and, according to Hefin Richards of Profeed Nutrition Consultancy, there may be opportunities to reduce costs provided care is exercised. Ann Hardy reports.
This winter it will probably be more important to review dairy rations than at any other time in recent history, according to independent nutritionist Hefin Richards.
reflects the fact not only is the current milk price at a historic low and the economic climate vastly different from the same time last year, but the cost of some types of feed ingredients is also significantly lower.
This means there may be scope to lose some costly ingredients from rations, and an opportunity to use more of the lower cost ones.
Cereals provide a good starting point, according to Mr Richards, who says there could be scope to safely include more in some rations. With ex-farm prices now hovering around the £105/tonne for wheat and£95/t for barley, he says they provide a cost effective source of energy – which is often a ration’s first limiting nutrient.
“Of course there are dangers associated with feeding high levels of rolled cereals as they are high in rapidly fermentable starch which can lead to acidosis,” he says.
“But there are opportunities to use caustic-treated grain, which provides a slower rate of starch break-down and is more rumen friendly.
“Grain processed with urea-based products, and moist crimped grain, will also generally be considerably less fizzy and therefore allow for higher levels to be safely fed.
“As a rule of thumb I’d say 3kg/day is a safe inclusion level for rolled wheat in a TMR, although barley and oats are progressively safer,” he says. “Keep a very close eye on cow signs and behaviour if you are feeding any more than 3kg/day.”
The opportunity to increase this safe level may exist when the cereals are fed alongside high quality, high dry matter (low acid) for-age, but also where there are high levels of cow comfort.
“Lying time is a nutritional issue – if the cow is lying comfortably and cud-ding, she is producing bicarbonate which buffers acid,” he says.
“Equally, if she is lame, she is unlikely to lie for as long as a healthy cow, which in turn means she will ruminate less and neutralise less acid.”
But where inclusion rates for cereals are edged higher, Mr Richards says a close watch must be maintained for any sign of acidosis. This includes monitoring dung consistency, cudding rate, evidence of regurgitated cud balls, and general demeanour, and also keeping an eye on milk butterfat levels which may go down if rumen health declines.
However, if cereals are caustic treated, then as a rule of thumb, twice the freshweight of caustic treated wheat can be fed than rolled.
“For example, instead of safely feeding 2.5kg of dry rolled cereals you may feed 5kg of caustic treated cereals,” he says.
This is illustrated by the 2.5kg of dry cereals at 15%moisture equating to a DMI of 2.125kg, while the 5kg of caustic-treated cereals at 30% moisture gives a DMI of 3.5kg.
“Although the caustic treated product contains a higher level of moisture, a more stable rumen pH will stimulate forage intake and utilisation,” he says.
With cereals maximised in the ration, attention can then turn to the higher cost ingredients including supplements and licks, each of which should be questioned for its role and relevance.
“I don’t subscribe to the view you should throw everything out that looks expensive, but it’s critical to evaluate each ingredient on an individual farm basis.
“Similarly, if you put something in two years ago and you left it in because it did a good job, you might actually find that you don’t need it now,” he says. “The forage base will have changed, and concentrate feeds will have been amended, so any issues oc-curring then are unlikely to recur this winter.”
This could be the case with an ingredient like mo-lasses which may have been introduced to boost intakes of low palatability silage and to make up for low sugars.
“But this year, if your silage sugars are higher – say upwards of 4.0% – and your dry matters better, you are unlikely to need it,” says Mr Richards. “Equally, in the present economic climate it may be more appropriate to make up an energy shortfall with cereals.”
Rumen buffers are an-other potential target which may have been introduced when silage quality was poor. “If you had acidic silage and cereals in the ration, 5p worth of rumen buffer may have been the key that allowed this ration to work,” says Mr Richards. “But if this year’s silage is drier and there are no signs of acidosis, it may be possible to take the buffer out.”
Similarly, he says mycotoxin binders are often used as a ‘catch-all’ and including them in a ration is always a safe option.
“That was easy a year ago with milk at 30p+/litre but is more difficult to justify today,” he says. “For many it may now be best to gradually remove the binder, and only reintroduce it if a problem is suspected.
“Alternatively, you could take a risk-based approach, excluding it if you have well-preserved silage with no visible problem and little cereal in the diet but including it if, say, you have high yielding cows on products more susceptible to mould, such as dry forage and moist grain.”
Rumen-protected fat should also be up for review according to Mr Richards, particularly for herds paid for A and B quota milk. “It’s important to see whether you are using pro-tected fats effectively and, if you are, you may get the generally projected two litre response,” he says.
However, this is less likely to be the case if protected fats are fed after 200 days in milk, when they are unlikely to be cost effective.
“If you are using them in early to mid-lactation you are probably seeing the de-sired response but you must evaluate what’s economic for your herd,” he says. “If you are on an A and B con-tract you will need to be mindful of the price you’re receiving for any extra milk, as if it’s around 14p/litre then protected fats will not be economic.”
Every decision must be made on an individual herd basis and with a full and regular analysis of the farm’s own feeds.
“There is no blueprint that can be applied across herds and it’s no good dwelling on national averages as every situation – whether for forage quality or milk contract – is subtly different for each herd,” he says.
“Analyse your forage to get a grip of its potential and repeat the analysis as time goes on to pick up any change.
“It sometimes takes this kind of economic situation to force us to revisit things that can help improve our efficiency of milk production.
“The trade may urge you to cover all risks while others may encourage you to throw everything out,” he says. “But in the real world, there are situations which merit the use of some ingredients and others which certainly do not. The devil is in the detail, so I’d suggest you objectively review your own circumstances and come up with a solution which is tailored for your farm.”