ADDING corn to a dairy cow's diet has a number of benefits, including increasing total feed-intake and glucose.
Ian Sawyer from Feedworks told the Tactics for Tight Times field day at Larpent last week that corn used correctly would provide energy for milking cows in a more effective way.
"It's not more energy but better energy," he said.
But adding corn, or maize, to a diet was not suitable for all operations, Mr Sawyer cautioned.
For instance a herd averaging 5700 litres, or with only minimal grain feeding, would not benefit as much as a higher producing herd or one that feeds moderate to higher levels of grain mix or pellet.
Experiments at the Department of Primary Industries at Ellinbank suggested adding corn to a cow's diet - as a slower, fermenting starch - provided a better marginal response to feed.
With the same dry matter intake cows, with corn in their diets, performed better and continued to respond to marginal feed through to 12kg of supplement before their milk response flattened, according to Mr Sawyer.
A second stage trial also suggested cows fed corn chose to eat more overall.
Corn also decreases the signal, which is often sent to a cow 30 minutes after being slug-fed grain in the dairy which tells them that they are "not really hungry".
"It (corn) can be used in certain stages of lactation in certain herds to manage the point of inflection," Mr Sawyer said.
"Keep getting the best marginal response for milk as long as you can.
"Most Australians don't get near the point of inflection ... the reason they are not producing more milk is because the cows are not full, they are nowhere near the point of inflection."
Mr Sawyer said transition and fresh cows benefit most from corn, and the quantity in a feed ration could be up to 50 per cent.
Corn also increases glucose production, which in-turn becomes lactose which makes milk volume.
Cows that do not produce enough glucose to support milk production and a foetus take amino acids back to the liver to make glucose. These amino acids would have otherwise gone into the milk as protein.
Mr Sawyer said similar research overseas supported the Ellinbank findings.
