Tips for a tough season: supplementation – southern Australia

This is the fourth part in our series on planning for tough seasons.

Rain may have fallen in some parts of southern Australia, but supplementation remains an important seasonal management tool.

After assessing your production targets to determine if supplements are the economically viable choice compared to other options, such as destocking, it is important to fully understand the nutritional requirements of your livestock before developing a supplementation program.

South Australian livestock consultant Hamish Dickson said it is important to focus on the basic principles of ruminant nutrition first, before making decisions about supplementation.

“The first priority is to understand the nutritional requirements of each class of livestock, to guide decisions about how much protein or energy will need to be supplemented," he said.

This is a two-step approach:

1. Calculate the nutritional requirements of livestock. Different classes of livestock have different nutritional demands. This Making More from Sheep (MMfS) tool provides a guide to the energy and protein requirements of dry sheep, pregnant and lactating ewes (twins and singles) and rams.
2. Determine the quality of pasture available. Quality of summer feed can vary widely and a feed test is a good investment to accurately determine the nutritive value of the pasture. Remember to collect representative samples across the paddock and from the most palatable part of the plant that stock will be grazing. Check out this MMfS guide to pasture assessment techniques.

The evaluation provided by these two assessments will guide the necessary supplementation.

Supplement selection

Dry season supplementation will primarily be for energy (cereal grains, molasses, silage, good quality cereal hay) and/or protein (cotton seed meal, lupins, silage, urea, hay with legume content). 

While there is no ‘one size fits all’ approach to formulating a supplementation program, Hamish said factors to consider include:

• Class of livestock: Young sheep and cattle that are still growing require higher levels of protein in the diet compared to mature stock. Likewise, young stock have higher energy requirements. In a Merino enterprise it is important to remember that sufficient protein is required in the diet to optimise wool growth.
• Lactation: Ewes and cows in the late stage of pregnancy have higher energy requirements than dry stock or breeders in the early stage of pregnancy. Failure to provide sufficient supplementation to breeding stock could reduce lambing/calving rates, impacting on next year’s profitability.

Economics

When it comes to the economics of supplementation, Hamish says it is more cost effective to maintain condition rather than let stock go backwards and try to regain condition down the track.

Costs can be managed by assessing products based on their cost per unit of protein/energy rather than a cost/tonne. Include costs for transport, storage, handling and feeding out, and consider available/necessary infrastructure such as on-farm storage facilities and feeders/troughs.

In mixed-farming enterprises, grain and hay can be redirected to feed livestock, but Hamish said it is still prudent to use a feed test to ensure the ration is correctly formulated and money is not wasted through excess or under feeding.

Animal health

Incorrect or excessive supplementation can have a negative effect on animal wellbeing, so some issues to be aware of include:

• Grains with higher starch levels such as barley and wheat can increase risk of acidosis in sheep and cattle. Introduce stock to these products gradually so the rumen can adapt.
• Supplementation can increase the risk of pulpy kidney in sheep and cattle. Ensure stock have been recently vaccinated (3-in-1 vaccination will suffice).
• Urea toxicity is fatal. Consider feeding in a block form or ensure custom mixes contain the correct amount of urea.

“Formulating the right supplement ration is not a simple science, so draw on the advice of your consultant to ensure you are not over or under feeding stock,” he said.

When it rains

A seasonal break does not mean putting the brakes on supplementation as livestock need to transition to a new diet and pastures need time to recover.

Grazing new growth in pastures can cause livestock condition to go backwards, as early green pick is often up to 90% water. The right time to start grazing varies on the type of pasture and animal class, but Hamish said a rule of thumb is to allow at least 1,000kg of dry matter/ha.

To safely transition livestock to a new diet, Hamish suggests moving sheep or cattle to new pastures late in the day when they are already full of hay or dry matter, to aid rumen adaptation. Ensure there is roughage available to help prevent pulpy kidney or bloat in lush pastures.

Looking ahead, Hamish’s tips for summer include evaluating pasture condition and condition scores throughout the season, and forward planning supplementation of autumn lambing ewes.

Useful tools

• Stocking rate calculator
• Feed budget planner
• Feed cost calculator
• Condition scoring sheep
• Condition scoring beef cattle

More information

Hamish Dickson, AgriPartner Consulting E: hamish@agripartner.com.au

Read the other articles in this series on planning for tough seasons: 

• Water management – northern and southern
• Pasture management – northern and southern
• Animal welfare