Lucerne is a fantastic feed for growing livestock, especially from late spring onwards when winter pastures begin to mature. However, with a high level of digestibility, around 28% CP and 9.5 MJME/kg DM, there are a few variables that require attention to get the best out of grazing lucerne.
Dr Paul Meggison, local producer and Chief Nutritionist at AusFarm Nutrition Products discusses four key issues encountered when grazing lucerne and recommends solutions to assist producers in maximising production.
Issue 1: High digestibility
This can be great, as it means that they can eat and process a large amount of feed, however, the fast passage rate of the feed through the digestive tract commonly causes scouring and can lead to Red Gut.
Solution: Dr Meggison recommends feeding ad-lib roughage when grazing lucerne. “Palatable straw or cereal hay forms a rumen mat which slows the passage rate of feed. This not only reduces scouring but increases the utilisation of the feed as it makes its way through the digestive tract.”
Issue 2: Low Energy
At 9.5 MJME/kg DM, lucerne provides less energy than other lush green feeds. As energy is a key building block for production and liveweight gain, grazing lucerne alone can see energy limit potential growth rates.
Solution: Dr Meggison recommends boosting energy in the diet by feeding a high energy grain. “This is where a supplementary energy source, like barley or corn fed at 400 to 500g/hd/day, can boost dietary energy and generate growth rates that rival feedlots”
Issue 3: High Protein
Although a great protein source, lucerne is commonly too high in protein at 28% CP. Growing lambs require around 16% CP, with any excess protein in the diet excreted by the animal or converted into energy. Both these processes expend energy and therefore reduce potential growth.
Solution: Dr Meggison says that feeding grain will also solve this problem. “Put simply, energy drives growth. The key to maximising production is in balancing dietary protein and maximising energy. At approximately 12.5 MJME/kg DM and 12% CP, feeding barley dilutes the protein fraction of the lucerne while boosting energy. This can be even more pronounced when feeding corn.”
Issue 4: Low Mineralisation
Lush growing lucerne can be low in essential minerals, vitamins and trace elements that are required to assist growth in high producing animals. Common mineral deficiencies can reduce liveweight gain.
Solution: Dr Meggison suggests feeding StockMins-Lamb Finisher, free-access in troughs in the paddock, as a built-for-purpose supplement that effectively delivers essential minerals, vitamins and trace elements, while providing buffers and Bovatec® to support grain supplementation and rumen function. “Like in human nutrition, mineral supplements are built for specific purposes. StockMins-Lamb Finisher is designed to support rapidly growing lambs grazing lucerne or mature green feed where grain supplementation is required to achieve rapid liveweight gain.”
For more information about StockMins-Lamb Finisher, or assistance in growing your livestock on lucerne or mature green feed, contact AusFarm Nutrition Products today on 0412 048 055.
