Dairy farmers are moving to maize over grazing, but harvesting the best quality for silage is tricky to achieve says an international expert.
When to harvest maize for a high starch content balanced with digestibility for cows was one of the key points at the Appetite for Success event in Shepparton.
Pioneer Global nutritional sciences manager Bill Mahanna spoke about how maize is grown and processed in the United States.
When looking at the yield, starch content and fibre digestibility of maize, Dr Mahanna said there were a few key contributors to look out for.
“Planting accuracy is really, really, really important,” he said.
“Fertility, growing weather or moisture and plant height as well.”
He said it may not be as simple as the variety or hybrid, so managing variability in a yield is important.
“It may not have been the genetics, it may have been the growing environment.
“Thank God our cows are quite resilient to some of this variability.
“I know we want to have as consistent a diet as we possibly could have, but the point is that there’s a lot of variability coming from our fields.”
In his presentation, he also talked about maize processing, with four main factors highlighted: chop length, roller mill wear, roller mill gap setting, and roller mill differential.
Dr Mahanna said each of these factors would impact quality and should be top of mind when harvesting.
Honing in on fibre digestibility, he said although it is out of farmers’ control, weather played a big role in increasing maize digestibility.
“The growing environment during the vegetative stage affects corn plant height, biomass yield and [fibre digestibility],” he said.
“Dry conditions lead to a shorter plant and more digestibility, wet conditions lead to taller plants and lower digestibility.
“Once the plant gets to the reproductive stage, the fibre digestibility is set. It will not change.”
The main change a plant that is passed the reproductive stage would see, was starch content, Dr Mahanna said.
“Starch yield is highly dependent on maturity of the kernel at time of silage harvest.”
Pioneer Seeds dairy specialists Greg Morris and Leighton Hart took the mic to introduce the benefits of maize silage over grazing.
The benefits included reducing milk fever, a high-quality forage, a high yield and controlling feed costs.
Following a lunch, the event concluded with a question and answer session with all of the speakers from the day.
About 100 people attended the Pioneer Seed’s Appetite for Success event in Shepparton on Thursday, May 15.
Farmers, dairy consultants, agronomists, nutritionists, resellers and contractors made up the crowd.