HERD LEAPS AHEAD ON BW/PW
Sexed semen & high heifer replacement numbers provide options
- Imagine generating enough replacements for your 380-cow herd by the end of the first round of mating (three weeks).
- Imagine a mating plan that results in up to 80% of your replacements coming from the top-half of your herd, based on breeding worth (BW) rankings.
- Imagine producing 40 excess replacements, which you have the option of either selling or sending to an alternative farm to help bolster another herd’s genetic journey.
That’s what Okaiawa farm owners Steven and Gwyneth MacDonald are doing.
And glance at their herd data over the past 10 years is impressive.
During the past decade, the herd at their home farm, Inaha, has averaged a genetic gain of nearly 19BW per year.
Taking a closer look, during the past five years alone, the Inaha herd has averaged genetic gains of 41BW per year.
Unsurprisingly, production worth is following suit: Annual production worth gains during the past five years, at 58PW, puts them at the top of the pile across the Taranaki region.
Change has clearly been happening: What are the MacDonalds doing?
“We’ve been doing the Sexed Semen thing, so in the first three weeks we’re essentially getting all our replacements,” Steven says.
“This is our fourth year… although we did it back-in-the day, using frozen semen, when it was more of a Friesian herd – back then it was merely to get the heifer numbers up to sell them for export.”
But the motive today was different, Steven said.
The fresh sexed semen of today offered near-normal conception rates, compared to the frozen alternative that typically had conception rates that were 13% below that of conventional semen.
Steven said utilising 9 fresh straws a day for the first 21 days of AB had allowed his son Danny (who sharemilks on the farm) to target the top cows each day for insemination.
“Any other good cows that are showing a heat go to Forward Pack,” Steven said.
“And we know who the bottom 20% of the herd is so they all go to beef. In the near future we could look at hitting the bottom 30-40% with beef.
“Our heifers are getting better every year, and we’re getting less passengers probably because we’re breeding from the top-half of the herd, and we’re culling hard on the heifers that don’t suit us or the system… they’re identified pretty quickly.”
The OAD factor:
Another significant change on the system 3 farm was a decision in the past decade to transition to a once-a-day herd (OAD), Steven said.
“About 10 years ago our herd was mostly-Friesian, F12-plus. Our objective was to continuously improve in terms of milksolids, efficiency, and repro. About 7-8 years ago we started putting some of the herd to OAD for parts of the season, and then we went to OAD for our first- and second-calvers, all year.
“Then for three years about 70% of the herd was OAD all season, and for the past three seasons we’ve been totally OAD.
“We’re now doing 380kgMS per cow, but the goal is to soon get to 400kgMS.
“We believe Friesians aren’t ideal for OAD, so we’ve gradually gone more crossbred and Jersey over that time.”
Steven said the decision to go OAD was a pragmatic and practical one. Beside Danny sharemilking on the farm, he also looked after the 270ha run-off down the road where replacements were reared, together with about 40 beef animals and 600-odd sheep (about 50ha on the run-off was planted in pine).
Danny was also a young father-of-three, and OAD milking made for a better work-life balance.
The mating plan:
The farm’s mating plan included colour codes for each cow, with colours representing what BW-quartile in the herd she fell in (‘green’ for high-BW cows, ‘yellow’ for mid-to-high BW, ‘red’ for lower-BW cows, and ‘grey’ for cows to avoid breeding replacements from, which go to beef).
The herd used GeneMark Genomics, so parentage was DNA verified and the robust data made for solid selection decisions at both mating and calf-selection time.
“It’s working well, we needed 85 replacements and we got 126 this year, so that meant I had 40 surplus to send to the South Island,” Steve said (Steven and Gwyneth own two herds in Southland, one is on a leased block, and the other herd is on a Wyndham farm they own).
Last season, with natural mate bulls involved at the tail-end of the 10-week mating plan, the empty rate was about 7%.
Collar technology, introduced that season, had made heat detection easier, and the wider repro results had given the farm the confidence it needed to go all-AB this year, Steve said.
“This year we’ll mate for a total of 9 weeks. The last three weeks the cows will go to SGL crossbred, bringing them forward (calving date) 10 days so we have more days in milk. So in essence we’re bringing things forward 17 days.”
