Michael Walker and his family run what would be a mind-boggling size of an operation in Ireland, but they don’t let their standards slip in terms of efficiency.

Owning 4,500 acres of heavy and mixed ground, with an additional 14,000 acres contract-farmed, the family operates a 750-cow suckler-to-store system, with an additional 2,500 ewes lambed down, primarily Scottish Blackface, with some homebred mules as well.

The farm essentially operates in three farmlets – with each farmlet running 200-250 cows, with its own manager. Six full-time staff work alongside the family to complete the day-to-day tasks of managing such a large operation.

Cow numbers have gradually crept up over the years – with the number of calves born in 2018 was 503, while 696 calves were born in 2025.

It’s when we look at breeding figures that things get properly interesting.

AI is heavily used in spring, often on a synchronisation programme, with stock sometimes still inside due to weather conditions. The mean calving interval on-farm sits at 366 days, with 82% of cows calving at or less than 365 days.

Breeding window

All heifers are home-bred, with 82% calved down at 24 months; 62% of cows calve within the first six weeks, with 85% calving in the first nine (with a target of 90%).

Despite a short, sharp breeding window, 97% of cows and heifers put to the bull this year or AI-ed have scanned in-calf; with 500 having received one round of AI before being put to a stock bull.

The amount of data collected for a commercial farm is extraordinary.

Average birth weight sits at 43kg, with the average weaning (200-day) weight being 245kg.

This is further split into breeds, with Charolais calves being the heaviest at weaning at 259kg, followed by Hereford at 252kg, while hardy native breed Luing cattle came in the lightest at 214kg.

Through consistent weighing of both cows and calves, Michael has shown the farm achieving an average weaning rate of 39kg calf weight per 100kg cow.

“I worked in Australia before coming back to the farm, and the first thing I did was get everything weighed. I didn’t know what I was going to do with the weights, but every time cattle passed through the yard they were weighed,” explained Michael.

Evidence on-farm has consistently shown smaller cows being more efficient in this, with below 550kg cows weaning 47% of their weight in calf weight, while 750kg+ cows are weaning 34% of their weight.

Growth and feed efficiency trials

Calves are gaining between 1kg and 1.1kg on average from birth to weaning, and matching this growth rate between weaning (200 days) and selling as stores (400 days), with average store weights last year being 427kg.

All maiden heifers selected for potential breeding pass through a specialised feed efficiency trial on-farm.

Feed conversion and RFI (residual feed intake is the difference between the expected feed intake and actual feed intake based off body weight) are measured, with heifers failing to meet the target either fattened or sold as stores.

The herd breeds its own pedigree bulls as well, after having negative experiences from buying bulls that were “bred and fed for the show ring”.

Again, any bull failing to meet the criteria is fattened, though Michael does sell some as breeding bulls, with fair warning given on their performance.

So far 943 cattle have passed through the system: “This year we had a heifer come through that ate 22kg of dry matter per kilo of growth and our best heifer was doing 3.6kg of dry matter for a kilo of growth back, so the variance is massive.

“If we convert that saving in terms of the cost of feeding and keeping an animal in the cow herd, we are effectively reducing our feed requirement, which may allow us run an extra 20 or 30 cows.

“We’ve had the same family lines (on the female side) and the exact same bull born within a 12-hour period and the variance between them can be as high as 15kg, so the dam effect is massive. I’d eventually like to get the system as fine-tuned as can be, to be able to rank store bullocks in to an A-star group, an A group and a B group [based off expected feed efficiency] and a buyer to turn up on the farm and be able give them what they want, as there is a variable cost to finishing these classes of bullock,” says Michael.

Breeding decisions

Genomic profiles for the herd have been completed in recent years to help Michael and the team to better inform themselves with breeding decisions.

Of the 690 calves born this year, 17 were caesarean sections, with 11 of these contributed to one Simmental bull.

“We had never jacked a calf from this bull in other years, but crossed over on some Hereford cows we had those sections this year. Having the genomic profile there we will see what links are there regarding myostatin, to see can we identify why that happened.

“Due to the market being so dynamic, weanlings or store cattle are both worth money, so we hope that genomically testing our breeding cattle will allow us make better decisions on what AI bulls to use on cows to meet market demands.

“In an ideal scenario we would have 200 maternal cows AI-ed to produce replacement heifers, with everything else crossed back to a white [Charolais] bull, with our Charolais-cross stores this year ahead of other breeds by £140-£150/head (€165-€177) and are off farm three weeks to a month earlier.

Use of FerAppease

The farm walk held on the day was in collaboration with the launch of FerAppease on to the Irish and UK market, with the Walkers having used and had positive experiences of the product in the previous year.

FerAppease contains a synthetic analogue of Maternal Bovine Appeasing Substance (mBAS™) – a naturally occurring pheromone produced by lactating cattle.

Pheromones are chemical signals produced by animals that can influence the behaviour or physiological responses of other animals of the same species. In the case of mBAS, the signal is associated with the presence of the mother and helps create an appeasing, reassuring effect in the calf.

Although the pheromone is naturally targeted towards the calf, the calming response to the mBAS pheromone is seen in cattle of all ages.

How does FerAppease work?

FerAppease is applied to the skin as a topical pour-on, above the muzzle and behind the poll.

The mBAS analogue is detected, which communicates with areas of the brain involved in threat perception and the subsequent stress response. FerAppease has been shown to reduce the level of cortisol present in cattle, supporting a calmer response to stressful situations.

When could FerAppease be useful?

FerAppease can be considered around multiple handling or management events Transition period post calving.

Rob Drysdale, a livestock specialist vet in southern England was attendance on the day and has been working with the US manufacturer Fera Animal Health to import in the product, noted that completion of caesarean sections and fostering of calves on the cows are also noted as applicable uses.

“It does not make animals sleepy, it just brings them down a level from their normal behaviour. If an animal is extremely hard handled it is not going to turn them in to something that you can halter break, but if you have something that is on the nervous side it can work very well.”

For the Walkers, the plan next year is to use it as part of the synchronisation programme with heifers, with the idea being lower stress levels at breeding should see improved conception rates.