29 September 2008

6 minute read

Introduction

Manufacturers use a reseller network which supplies troughs and monitors consumption to manage the supply.

The use of these products and the animal response depends on total herbage mass on offer (kg dry matter per hectare), the amount of green herbage mass, the crude protein (6% CP or less) and the digestibility of the herbage mass, 50%–55% DOMD (Dry Organic Matter Digestibility).

What are liquid feed supplements?

Liquid feed supplements are molasses-based products designed to be fed to both feedlot and grass fed cattle, using different formulations in each case.

Liquid feed supplements come in two categories: blended liquid supplements and the newer (late 1970s technology) suspension liquid supplements.

The dry matter of these supplements is less than molasses and the increased moisture content allows them to be pumped more easily.

Understanding blended liquid supplements

Blended liquid supplements are molasses-based feeds fortified with additives such as salt, urea, protein meals and other supplemental nutrients. The major problem is that these ingredients will 'settle out' when added to molasses and this has to be overcome by agitating or recirculating the liquid supplement.

Understanding suspension liquid supplements

Suspension liquid supplements were developed in the late 1960s and then further developed in the late 1970s to overcome the 'settling out' problem of the blended liquid supplements.

The technology used to suspend the additives, added to molasses in the suspension, is based on finely dispersed clays and gums. These act to suspend the particulate matter (the additives) in the molasses. Manufacturers use mixing sequence, additive addition rates, temperature and pH of the solution to develop the colloidal suspension further.

This means that additives are uniformly available to the animal because they are homogenised, and uniformly sized, throughout the supplement.

Suspension liquid supplements need special pumps (not necessarily gear pumps) to move them. Gravity is the easiest way to 'pump' these supplements.

Custom mixes

Suspension supplements can be made to your individual specifications. Most manufacturers offer this service.

Liquid feed supplements for pasture-fed cattle

Liquid feed supplements were developed originally for use in feedlots but are now available for pasture-fed cattle as both blended and suspension supplements.

These supplements are designed to be consumed at rates between 1 and 2 kg/hd/day for adult cattle. Because of this relatively low consumption rate, they are not energy supplements in themselves but provide an 'energy' carrier for protein and mineral supplementation.

Intake rates are manipulated (‘sweet & sour’ recipes) using the taste of urea or phosphoric acid to limit intakes.

The urea is usually 'bonded' to the sugar molecules in the molasses in these supplements. This extends the ammonia release in the rumen to provide a consistent payout of ammonia to the rumen flora. It is a more efficient use of the urea supplement.

Check urea levels

The urea levels in pasture liquid feed supplements can be as high as 10.5%, so always have the urea levels explained to you.

Note. Follow the manufacturer's recommendations at all times and be aware that horses and sheep need to be excluded from paddocks when these supplements are fed.

Classes of stock

Liquid feed supplements are ideal when you wish to maintain or control liveweight loss in dry breeding cows or target less than 0.4 kg LWG (liveweight gain) in dry cattle.

Liquid feed supplements all require more than 1200 kg DM pasture/crop stubble on offer and digestibility between 50%–55% DOMD. See table 1.

Understanding the costs

These products are based on molasses, which has a dry matter of 75%. As the component ingredients, including water, are added the dry matter begins to fall, usually to 55%–60%.

The products are sold on a cost per litre delivered so they have to be converted to a cost per kilogram for accurate comparison.

For example, 1 litre of a 55% dry matter molasses based product will be approximately 1.2 times the weight of 1 litre of water. So each litre costing 65c will cost 54.2c/kg ($533 ÷ 1.2 kg) or each tonne is $542 ‘wet’.

But the moisture content must be accounted for. In this example, if the moisture content is 55%, the dry matter cost for each tonne ($542 ÷ 0.55) becomes $985/t dry matter.

For an 8% urea content liquid supplement, eaten at 1 litre/day, this means 80 grams of urea costs 65¢ to deliver into the animal each day. In addition this cost supplies approximately 0.5 litres of molasses (or 6 MJ of energy) and the mineral additives. This is not a useful amount of energy, which is why you need more than 1200 kg DM of pasture to supply the source of energy (carbohydrate).

Alternatives to liquid supplements

Roller drum mix

A molasses roller drum feeding system would deliver 50 grams of urea/head/day for about 5c/head/day based on bulk molasses prices.

Urea blocks (at least 8% urea content)

Research suggests that supplying 40–60 g of urea/head/day is sufficient for all classes of stock, providing the ‘feed’ on offer exceeds 1200 kg DM/ha, the energy value exceeds 7 MJ/kg DM (approximately 50% DOMD), and you wish to maintain liveweight or control liveweight loss.

The bottom line

The alternatives are about costs of capital and/or labour to mix or feed out (blocks). People tend to favour paying for convenience. It is up to you.

Liquid feed supplements can be used when there is adequate (more than 1200 kg DM/ha) paddock feed and during seasonal dry spells, over winter on ‘hayed off’ summer native/naturalised pastures or on crop residue when cows are at least fat score 2.

Liquid feed supplements are not drought feeds supplying energy. The manufacturers do not promote them as sole drought feeds.

Availability

Availability is not a problem.

Pasture liquid feed pasture supplement products are usually only available through a service network where the supplier delivers to the feed troughs (supplied by the service company). They do not generally deliver for bulk storage on-farm.

Convenience

The principal feature of these products is convenience, but at a price. They are well designed, well serviced and allow you to provide nutrients to cattle that cannot be done easily and conveniently through home mixes.

Roughage is essential

Liquid feed supplements increase the dry matter intake by the animal of the dry pasture and crop residue being grazed.

Once the herbage mass of crop residue or dry/ mature pasture falls to 1200 kg of dry matter/ha there is insufficient feed on offer to allow the animal to eat more. For this reason, the use of liquid feed supplements should cease at 1200 kg MD/ha.

Energy supplements are needed when herbage mass is below 1200 kg DM/ha.

August 2008