CAFRE opened the doors to its dairy unit at Greenmount, Co Antrim, last week, giving farmers an opportunity to view at first hand the dairy herd and the state-of-the-art housing facilities.

With six separate information points, the event provided many take-home messages.

Heifer rearing, dry cow management and getting calves off to the best possible start in life are undoubtedly areas that the dairying team at CAFRE is getting right.

But there are some areas where progress can still be made, mostly around herd fertility and the amount of milk produced from forage, which has been falling in recent months.

Known as the Future Herd, CAFRE operates its dairy unit to demonstrate best practice, technology transfer and for student education at the college.

Cow numbers averaged 155 across the last financial year (April 2016 to March 2017) with a 305-day yield of 8,819 litres, putting it well ahead of the NI benchmarked average of 7,331 litres.

Concentrates fed per lactation averaged 2.38t per cow compared with the NI benchmarked average of 2.45t/cow.

However, concentrate use has increased to over 2.7t per cow during the current winter period.

Milk from forage was 3,361 litres last year, down from 3,600 litres in 2016 as meal levels increased. By December 2017, this figure had fallen to 2,712 litres.

Milk solids per cow are 677kg with butterfat averaging 4.16% and protein at 3.3%.

Listen to an interview with Ian McCluggage from CAFRE in our podcast below:

Calving starts in late August with two thirds of the herd calved by Christmas. The remainder of the herd calves from January through to May. The herd is gradually moving to 200 cows.

Cows go to grass once settled in-calf in spring, and grazing is an integral part of the system, despite the level of investment in housing facilities.

Housing is top-class with new purpose-built facilities for heifer rearing and dry cows, to add to the £2.5m dairy unit opened in 2016.

In practice, and given the investment made in overheads, most dairy farmers in NI would probably look to push yields well over 10,000 litres per cow in a fully contained system. However, that is not a message Greenmount wants to send to the industry, so instead cows go to grass, even though it probably means production and fertility in high-yielders takes a hit.

Calving heifers at 24 months

The target for the herd is to have replacement heifers ready to serve by 13.5 months of age at 350kg to 370kg liveweight. To meet this target, heifers must average 0.8kg/day from birth.

The age at first calving last year was just under 24 months, with heifers served to AI with a target weight at calving of 580kg to 620kg. The weight at first calving last year was 584kg.

Sexed semen has been used to increase the number of heifers as possible replacements. Bulls are selected based on the profitable lifetime index (PLI), with particular emphasis on fertility, lifespan, and fat and protein traits.

Heifers are genomically tested and, from 2010 to 2017, PLI has increased from £118 to £298.

Rearing management

Newborn calves are fed colostrum through a stomach tube in the first hour of life at a rate of 10% of calf birth weight (three to four litres), and removed to a separate rearing pen within two hours of birth.

August- to November-born calves are turned out to grass by April and graze in a leader-follower rotation with yearling heifers.

They are wormed at three, eight and 13 weeks post-turnout using Ivomec pour-on and do not receive any concentrate feed.

However, later-born calves (December onwards) are fed 2kg/day of concentrates at grass from turnout until rehousing.

Second winter

Once housed for their second winter, all heifers are fed 2kg/day of concentrate and ad-lib silage until they are scanned in-calf.

At this point, concentrates are removed from the diet and heifers remain on silage until turnout. In-calf heifers are kept as a separate group until calving.

Calving at 24 months

Just 7% of NI dairy herds calve heifers by 24 months of age, and recent analysis has shown that the average age at first calving on NI farms is around 27.5 months.

According to CAFRE senior dairy technologist Martin Mulholland, there is a lot of potential on farms to cut costs by paying more attention to heifer rearing, and calving at 24 months.

“If anything, younger heifers will be in a lower body condition score, and will have less problems calving, and less problems after calving,” he said.

Mulholland quoted from milk records of 680 Dale Farm suppliers in NI, which showed that in the top 25% of herds for lifetime performance, heifers are calved at younger ages than in the middle 50% or bottom 25% of herds.

Cows at Greenmount are dried off around eight weeks prior to the predicted calving date.

Cubicles provide lying space for 80 cows and internal dividing gates can split animals into four groups depending on feeding requirement or stage of gestation. All cows receive a teat sealer once dried off.

Staff at Greenmount have looked at the possibility of dropping the use of antibiotic tubes at drying off. A group of 44 cows, with SCC below 200,000, were dried off using teat sealers only. By three months into the next lactation, all but three of these cows still had low cell counts.

Body condition is monitored in late lactation. Cows below the target 2.75 BCS are offered an extra 2kg/day of concentrate to increase condition.

Cows are wormed and fluked, vaccinated for scour, foot-trimmed and given a mineral bolus at drying off.

Diet

Around three weeks prior to calving, cows are moved to a transition diet to prepare them for the next lactation.

They are fed 17kg of silage, 9kg of whole crop wheat, 4kg straw, 2kg of a pre-calving mix, 0.75kg soya, and 0.05kg of minerals.

Calving management

Cows are moved from the dry cow house to loose calving pens around five days before calving.

Cows are fitted with a temperature probe or a Moocall sensor, and given 50ml of iodine on the back as forage and blood samples have indicated low levels of iodine, selenium and vitamin E in the past.

First- to third-calving cows are left in loose pens until feet are showing, and then moved to individual calving pens.

Milk fever prevention

When an older cow (fourth calver or above) goes into labour, a calcium bolus is administered, and repeated again post-calving, to safeguard against milk fever.

Only two animals have had milk fever this winter, with nine having a retained placenta, although a number of these had twins.

The herd has been tested for Johne’s and is currently clear, but any cow giving an inconclusive result is tagged and retested. No colostrum is collected from any cow that gives an inconclusive result on Johne’s.

Post-calving

Cows are kept in calving pens for five days, milked twice daily and their body temperature checked each morning.

According to Greenmount farm manager Michael Graham, a significant number of cows will be found with raised temperatures before showing any outward signs of disease. “It would surprise you – it is not just cows that required assistance at calving,” he said.

Getting in early before an infection sets in means that weaker antibiotics can be used.

Around 20% to 25% of cows require some form of treatment, with a protocol in place, drawn up by a local vet. This attention to detail has practically eliminated cows having a dirty calf bed post-calving.

Cows in milk

Lactating cows are generally managed in three groups. A startup group includes freshly calved cows and heifers, with mature cows moved to the high-yielding group after 30 days.

The startup group receives 5kg/day of concentrate through the diet feeder, along with first-cut silage. A further 2kg/day is fed through the parlour, building up to 5kg by day 21.

The high-yielding group gets 7kg/day through the diet feeder and a minimum of 3kg/day in the parlour.

Cows are fed to a maintenance of 23 litres with a top-up feeding rate of 0.45kg/litre above that.

After 100 days in the high-yielding group, the minimum 3kg of parlour nut is removed from the diet and cows fed to yield.