Thursday, July 7, 2022

Genes as good as gold medal

Farming in a tough climate means some creative thinking is needed to maintain income. Nelson farmers Christine and Fraser Macbeth told Anne Hardie a focus on genetics is proving a successful way to supplement the farm budget and having impressive results on the farm. In a remote Nelson valley, Christine and Fraser Macbeth are artificially inseminating yearling heifers and using embryo transplanting in the herd to achieve impressive genetic gain. They now have five bulls supplied to artificial breeding (AB) companies. The couple farm 220 cows that are 50% pedigree Jersey and 50% KiwiCross, with most of their bull success from the crossbred offspring. This is adding another income stream to their dairying business which struggles through the Nelson dry without irrigation.

Their farm lies on a narrow valley floor between steep forest-clad hills and in this case sits 360m above sea level with LakeRotoiti further up the road. The valley bakes in summer, often sitting in the low 30degC range, then dips to -10degC in winter as frosts bite and the occasional snow settles.

The Macbeths bought it eight years ago as their step into farm ownership, following management and sharemilking contracts that included Applefields in Canterbury, the Lincoln University Dairy Farm (LUDF) and a Maruia farm. Since then they have relished the ability to farm without staff, while bringing up a family of four on their own property.

Heading out every morning to milk cows and put milk in the vat was never enough though, while improving the herd's genetics is a passion. Their aim was to be in the top 1% of New Zealand herds for breeding worth (BW), but today they usually sit in the top 0.05%, with their latest figures showing a BW of 146 for the herd and a PW of 191.
"We can't target high production here, so we target genetics," Christine said.

They were offered their first contract mating in 2007 with LIC and numbers have steadily climbed since, largely due to embryo transplants (ET). So far they have five KiwiCross bulls with different companies. Cawdor Pharaoh has already sold 40,000 straws as a member of the 2011 and 2012 KiwiCross DNA team with LIC, which also has Cawdor Promotion and Cawdor Enterprise taking the traditional sire proving route. Optimist Prime went to Ambreed and Profitabull to Liberty.

A further two weaned bull calves heading to LIC this year had a tragic end when they escaped from the carrier's yards at the start of the journey and were bowled by a logging truck. That was a blow that hit Christine and Fraser hard after spending years striving for those now-wasted genetics.

Top cow

Late season embryo transplant calves.

Just as important has been using AI over the yearling heifers and the Macbeths can't understand why it's not more common as a means of accelerating genetic improvement in the herd.

"From an economic point of view I'm surprised people don't AI their heifers more," Fraser said, "but it's seen as a hassle."

They synchronise the heifers to make it easier to blanket AI them when they come on heat and have a pregnancy success rate of about 60% for that cycle, with their top yearling bulls run with the remainder.

All the heifer calves are reared, with the top half retained as herd replacements. They will generally be from cows with a minimum BW of 150, though Christine has the final say. More emphasis is placed on the dams at this stage as the bulls are still proving themselves.  At mating, semen is nominated using the best available and usually daughter proven, apart from contract matings where they use a higher proportion of genomically-selected sires.

"In the early days it was a herd of cows, but now every animal is thought of as an individual," said Fraser.

They reared about 22 bull calves this year, many from the contract mating and the result of ET, and though most will not be accepted into a scheme, the Macbeths and other bull breeders still get paid $300 by LIC. They also provide another source of income by being leased out to other dairy farmers as yearlings and then again as two year olds. Jersey bulls are readily leased out at $450 each, and though there's less demand for the crossbred bulls at this stage Fraser expects this to change as the national KiwiCross population increases.

By focusing on genetics, Christine and Fraser have added more income opportunities from a farm that will always struggle for high milk production. The idea is to make the most out of spring growth with as many days in milk as possible before Christmas. By then, the dry forces them to drop from twice-a-day (TAD) to 16-hour-milkings, though this season it was December 10. Depending on the season, they will then drop to once-a-day (OAD) some time in April, before finishing up at the end of May and sending the cows to their runoff further toward the lake.

In  all, they have 115ha effective that sits on terraces straddling the Motupiko River and to combat the summer dry without irrigation they have 10ha planted in lucerne and another 14ha in red clover mixed with prairie grass.

"The red clover and prairie grass doesn't cope with treading and hard grazing on a fast round so it's treated as a crop on a 40-day rotation," Fraser said. "At this stage the clover is lush to the base and the prairie grass, though mature and in flower, is still highly palatable with significant natural seeding taking place."

The clover root weevil (CRW) has destroyed most of the white clover in the ryegrass pasture that covers the remainder of the farm and they can't grow more red clover as it's too slow to take off at the beginning of the season. Tall fescue was tried, but it struggled in the cold at the beginning of the season too.

Extra feed

A turnip crop each year helps through summer and becomes part of the regrassing programme on the farm. But only 60-90 units of nitrogen (N) is applied, mainly in spring to the ryegrass pasture as there's just not enough rain to soak it into the soil and so little response.

All this means they carry just two cows/ha or slightly below, with palm kernel bought in for the deficit times through the season. How much feed they buy in depends upon the payout though; above $6/kg milksolids (MS) they will buy in more feed, while below $6 they choose to cut stocking rates or costs.

"As genetics improves you have to feed them more," Fraser said. "And if you don't feed them more they aren't going to be much more efficient than if you hadn't done that genetic improvement."

Most of the genetic improvement was based on the animal's ability to eat and compete.

"Everyone says we're losing our fertility (as an industry), but we're breeding these Ferraris and still farming them the same."

Along the way, the industry had lost some of the fertility and fitness traits, Fraser said, though in the last 10 years the trend had reversed as the national breeding objective, animal evaluation and the breeding companies increased the emphasis on those traits.

In their herd, despite the challenges of the climate and grass growth, the average cow weighs 415kg and the aim is to produce 100% of its liveweight. So far they are sitting around 90% and the most efficient cows are achieving 120-130%.

As Fraser pointed out, liveweight made a big difference to BW and PW and yet few farmers weighed cows.

"When we weigh animals, we'll have some that are 20-40kg different to their ancestry liveweight and that can move your BW and PW 20 points either way. They're (BW and PW) only as good as the data that goes into them, so I feel really comfortable with the data we put in. We try to keep the whole herd on a level playing field for competition because then you can compare them."

So far, LIC's purchase of their bull, Pharaoh, has been the highlight of their breeding programme and reward for the extra effort.

"It's just so satisfying getting a bull from contract mating into LIC," Fraser said. "I don't think I'd feel any better getting a gold medal as an athlete."

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