Professor Mike Wilkinson, who was in NZ late last year, believes in order to comply with the 3kg-per-day limit suggested by the co-op, farmers would need to look to other feed solutions, particularly when it came to getting through the predicted dry summer as well as long, cold winters.
Mike Wilkinson – quality more important than ever.
“Farmers have got to think about more strategic silage-making,” he said.
Too many were using silage as a way to get rid of surplus grass, when they needed to be planning to make a certain amount per cow.
Wilkinson, who spoke at several field days, is special professor in the School of Biosciences at the University of Nottingham. He’s previously been a livestock science consultant for the Department for Environment, Food and Rural Affairs and has lectured around the world on animal nutrition, feed use and diet formulation.
He believed most NZ dairy farmers didn’t make enough silage and needed to think more seriously about integrating it into their herd feeding plans, especially when faced with hot or cold weather that limited pasture availability. He wasn’t advocating making up to 10 tonnes/cow of silage as is the case with UK dairy farmers, which causes them storage problems.
“We feed too much and NZ consultants are telling us to focus more on grass,” he said.
But for NZ farmers, taking paddocks out of the grazing rotation and putting them into maize made sense. He was impressed with a Taranaki farm producing 1440kg milksolids (MS)/ha from its 128 cows. It used 10 out of its 40 paddocks for cropping maize, as well as growing some chicory.
“It’s working very well and they’re making more money from maize and grass than grass only,” he said.
While palm kernel had been an easy fix for many farmers, maize silage wasn’t cheap to produce and required them to pay attention to detail to do it well. They could start early on dedicating paddocks to maize growing. If it was planted in a paddock which had been in grass, 25t of drymatter (DM) could be produced with no fertiliser inputs in the first year, and minimal dressings from then on.
There were also environmental advantages with less nitrogen leaching into the soil. Wilkinson said dividing the amount of palm kernel by the size of the national herd, he calculated many cows were being fed 400kg of the feed. With a crude protein level of 18% that meant an extra 30kg of nitrogen/ha excreted by cows, on top of what came from the grass they were eating.
However, a low-protein level maize silage, when fed at 5kg/cow/day, was very complementary to the high protein levels in NZ pasture fed in spring.
While some high-input farmers were managing this system well, those who were more cost-conscious might have planted less maize this year based on the low forecast payout.
“They are caught between a rock and a hard place,” he said.
“But they’ve got to plan for a drought.”
Some might have tried to tighten spring stocking rates to put more paddocks aside for grass silage, but that might not have been possible with the slow, cold spring in many areas, which had reduced grass growth.
Wilkinson said in Ireland some dairy farmers were grazing down to 1000kg DM/ha residuals.
“The problem is that low residuals can limit the cow’s herbage intake but the benefit is that the animals eat right up to the dung patches so there’s less rejected pasture later,” he said.
Grazing to lower residuals could give farmers more paddocks of grass to make into high-quality silage. But if they left them too long to reach levels of up to 4500kg DM/ha regrowth could be slower.
If farmers weren’t looking at making silage, topping could be a useful strategy if cows weren’t grazing low enough, especially if farmers were prepared to put in the time.
“You don’t want the animal to waste time looking for grass when they should be achieving one bite every second,” he said.
Wilkinson’s visit was sponsored by the Foundation for Arable Research and Silostop silage wrap.
