Calf rearing is an important part of the farm business and feeding them enough so they develop to their full potential is essential.
Many New Zealand dairy cows don’t achieve their high-producing genetic potential because they aren’t fed enough as calves and therefore don’t grow quickly enough, vet and sharemilker Nicola Neal says.
“We have some really profound research showing that if we rear those calves as fast as we can up to weaning, that has a massive impact on the lifetime productivity of that cow,” Neal says.
A presenter at the recent South Island Dairy Event (SIDE), Neal quotes international research that shows 22% of the variation in the first lactation milk yield can be attributed to how fast calves grow before weaning.
“So when we look at how much time and effort we spend choosing a bull or selecting a cow and all that sort of thing, it is actually vastly more important how fast we grow our calves regardless of what their genetics might look like,” she says.
“If you think about a calf that’s born at 35kg and is going to get to 90% of its adult weight by calving at two years old, then it really needs to grow 600 grams a day every day of its life until it’s fully grown.”
Neal believes the importance of the role of calf rearers is often underestimated.
“I totally think the people rearing them are really important,” she says.
“It’s not the lowest job on the farm from a work point of view and having good people who are interested or dedicated or committed to it is really valuable.
“I’m a huge believer that good human welfare follows through to good calf welfare. We have to look after those people because it is a bit of a hard, frustrating job at times and people who are happy rear happy calves because they’re not frustrated by the situation.”
If calves aren’t getting as much nutrition as they need, it could just be they’re not being offered enough milk, but Neal believes there are other issues at play as well.
“Because of the way New Zealand pastoral dairy is, sometimes we’re quite time-sensitive so if it’s a job you’re not allowing enough time for. So the calf has five minutes to drink and if it doesn’t drink what it needs to drink in that time, well that’s the end of that. But the reality is that’s not how a ruminant’s stomach works,” she says.
“I’m not advocating for or against once-a-day (OAD), but it’s difficult to get enough nutrition once-a-day in calves up to about four weeks, where all of their nutrition is coming from milk.”
Neal suspects some farmers don’t feed enough milk because of outdated beliefs about the dangers of feeding too much.
“In the past there’s been a lot of literature around too much milk giving calves the scours, but that’s been pretty well debunked and we’re feeding calves to survive, not thrive, not necessarily feeding them enough to really get that 600g a day growth that we should be looking for,” she says.
That growth rate has to be maintained in the next stage of the calf’s life too, as it develops its rumen and over time transitions on to pasture.
“There are some keys to that, like having a nice tasting hard feed ready for them early so they can snuffle around and play with that and offering them a good, quality protein calf meal and fibre,” she says.
Neal says the importance of fibre in calves’ diet can’t be underestimated and actually improves digestion.
“If you feed calves the right sort of fibre, they eat more meals which seems counterintuitive that if you feed more dry, rough feed that would make them eat more high-energy feed but it is actually a thing,” she says.
And if calves have access to fresh, clean water, they’ll eat 30% more meals and grow 40% faster, Neal says, because you can’t start the rumen’s development without water.
“It’s like trying to make a loaf of bread without water. When we think about growing a rumen in a young animal, we’re actually encouraging the bugs that are going to be the powerhouse of the cow when she grows and those bugs need water,” she says.
Having the right type of fibre is important too, with international research showing that a “chaff chop”, with 2.5-5cm pieces, is much better than long, stringy hay or straw which tends to “ball-up” inside the rumen.
The dividends, if you get it right and your calves consistently grow at 600g/day, are too good to ignore.
“You’ve got to look at it as a loan; you pay the calf now and she’s going to pay you back later,” she says.
“She’s not going to do it for 18 months, until she comes into the herd, but man alive, if you can grow a calf well that then genetically is able to express what she’s born with, then you’ve got yourself a much better animal that’s going to cost you less in the long run and make you more money.”
