Sunday, July 3, 2022

Master of ET

For eight weeks every year, from late spring to almost Christmas, Neil Sanderson is on the road performing embryo transfers (ET) for about 50 dairy clients and a few beef breeders, mainly in the southern half of the South Island. It’s a seven-days-a-week job, involving travel most days. “The hormone drugs we use are so good these days I can phone the farmer and say I’ll be there Thursday and the cows will be ready for me,” Sanderson said. Cows are synchronised and super-ovulated by the farmers using hormone injections, which the farmer administers. Cows are then artificially inseminated (AI) – usually twice, 12 hours apart – by the farmer or an AI technician. Seven days later Sanderson arrives and flushes the cow to collect the embryos, which are identified through a microscope on farm, usually in the dairy milk room. The viable embryos are then placed into other cows, which have also been synchronised, or frozen in liquid nitrogen for future use.

The process is non-invasive and does not affect the donor cow or the recipient cow’s future fertility.  

The flushing process takes about 20 minutes for each cow, with fluid circulated through each uterine horn and fallopian tube using gravity and slight manipulation. Between five and eight embryos are usually collected. One embryo is placed in each recipient cow through the vagina and cervix, similar to AI. Embryos are frozen on farm using a computer-controlled cooling machine once “antifreeze” liquid has been added.


Neil, centre, with gauchos on the Uruguayan farm where he has a satellite herd of 100 Angus cows as a result of embryo transplants.

Sanderson achieves a 75% rate of live calves from fresh ETs and 65% using frozen. It equates to about $350/live calf in costs, although farmers who do large numbers of ET get a discounted rate. Calves produced using ET have similar genetics but are not identical, because of natural variation.

Outside the hectic spring period, Sanderson spends two to three days a fortnight during the rest of the year doing ET work, with some clients having cows flushed every six to eight weeks to produce frozen embryos. He said he had two main groups of dairy clients who use ET technology.

“There are those that are focusing on Canadian-type genetics, who are interested in showing, and in bigger cattle with high production, and then there are those farmers who are maximising breeding worths (BWs),” he said.

“They want the maximum number of heifer calves they can get from their top three or four cows.”

He said the icing on the cake for those farmers was producing bulls that were used by genetic companies.

Sanderson, a Massey-trained vet, got into ET by accident. He was doing a masters in equine radiology at the university when he was asked to assist at an ET centre because another vet was away. He now does no other vet work, with his ET businesses keeping him busy, along with his other interest – an Angus cattle stud.

Originally from Canterbury, Sanderson, the son of an English immigrant, got his farming roots from his dad, who worked as a shepherd in New Zealand. Richard and Craig Martin, of the Enterprise Cattle Company in Nelson, got him interested in Angus cattle and he still values the relationship with them, sharing genetic material and using them to bounce ideas off.

Client base

In Nelson Sanderson started the Fossil Creek Angus Stud, named after a creek that flowed through the farm where fossils could be found. A move to North Canterbury followed but for the past 10 years he has been based at Craigevar, the 80ha home farm at Ngapara, inland from Oamaru, which is closer to his ET client base.

Another 400ha, Crestlo, 25km south at Five Forks, is looked after by farm manager Brian Davidson. It’s where the 200 Angus stud cows are kept and also the 50 cows of their Roseville Charolais stud, which is also part-owned by Davidson.

At Craigevar, Sanderson and wife Rose also graze clients’ dry dairy cows and beef cattle, flushing them and freezing the embryos in a Ministry for Primary Industries (MPI)-approved embryo export centre. A pool of recipient cattle is also kept there for use by ET clients.

Fossil Creek Angus cattle regularly win awards at the annual NZ Beef Breeders Expo and the on-farm sale each June of their two-year-old Angus bulls attracts a loyal and enthusiastic following. The stud’s Angus bulls also feature in genetic company catalogues and Fossil Creek Vision, a short-gestation, easy-calving bull, will be sold through LIC.

Sanderson believes more knowledge could be shared between the beef and dairy industries and is worried about falling fertility in both national herds.
“The reproductive efficiency is now down to 82% in commercial beef herds in NZ,” he said.


He and AgResearch scientist Marcelo Martinez are still trying to gain funding for research into anoestrus cows (Dairy Exporter, February 2012, page 120).
“We have all this data but we can’t do anything with it yet until someone funds the research.

“We have to get our oestrus detection better on farms, instead of just using CIDRs. We should be doing more rectal palpations, we should be doing more scanning of ovaries to find out what is going on. By using CIDRs we may just be breeding more cows which are harder to get in-calf or which are genetically sub-fertile.”  

A director on the board of Angus NZ since 2010, he has already initiated the milestone dam programme, which identifies on a national basis Angus cows that have superior maternal traits such as fertility and longevity.

“Fertility is my hobby horse,” he said. “It’s why I got on the board of Angus NZ.  We have to do something about falling fertility rates and hopefully the Milestone initiative will identify these superior cows and they will be sought after by breeders.”

A northern hemisphere technician usually helps him in the busy spring ET season.

“All the ET technicians in NZ are too busy working for the breeding companies, so I have to bring in someone from overseas,” he said.

That, and the intermittent work through the rest of the year is making it difficult for succession planning but he does have a retirement plan for him and his family.

A vet colleague in Uruguay has two cousins who farm 8000ha at Salto near the Brazilian border. There, the Sandersons have what they call a “satellite herd” of 100 Angus cows from their Angus stud, produced from Craigevar frozen embryos, exported to the South American country and implanted in Hereford cattle there by Sanderson for the past six years. A similar herd was begun in 2011, 200km south of Buenos Aires in Argentina.

“It’s just a bit of a retirement project,” he said. “It’s not really to make money but if we can pop over every few years with the family and visit and experience the culture then it pays for itself.

“I can ask for a beer so far in Spanish.”

More articles on this topic