Once-a-day Moorepark trial yields good results

There are few things in dairy farming that deliver real efficiencies. Hybrid vigour from crossbreeding and the inclusion of clover in swards have been proven to increase productivity. With labour being a major constraint on many dairy farms, finding ways to reduce labour input without compromising too much productivity will also deliver efficiencies.

Once-a-day (OAD) milking has been pioneered by a small number of farmers in Ireland and New Zealand. The reasons why farmers go once a day are varied, but usually centre on the person; such as for lifestyle or health reasons, or, on the farm: hilly, long walks, etc.

Previous Irish research has shown that milk solids production drops by around 20% when a herd goes on OAD milking. To maintain profitability at existing levels, farm working costs would need to fall by the same.

A new research project on OAD milking started in Moorepark last spring. The project is being led by researchers Emer Kennedy, Michael O’Donovan and farm manager John Paul Murphy.

There are four OAD treatments plus a control group being milked twice a day. Each treatment has 17 cows so there are 85 cows enrolled in the study in total.

The treatments are: OAD for two weeks post-calving, OAD for four weeks post-calving, OAD for six weeks post-calving and full-time OAD.

The reason for the shorter periods of OAD is that many farmers are looking at OAD milking for short periods post-calving to reduce the workload during that high-intensity period of calving.

Performance across all treatments has been excellent. The twice-a-day (TAD) milking herd has produced 425kgMS/cow to date. The cows on the shorter periods of OAD have averaged 400kgMS/cow while the full-time OAD herd has produced 360kgMS/cow. All groups have been fed 350kg meal/cow to date. Fertility performance has also been good, with those on the TAD and shorter OAD periods averaging 5% not in-calf after 12 weeks while 100% of the OAD cows are pregnant.

The great spring was a huge help

“Performance for the OAD herd has been really impressive. We didn’t set a production target for them, but based on current performance I’d expect them to produce over 400kgMS/cow this year. It all depends on how well they hold production over the coming weeks.

"The great spring was a huge help. Cows were on 36-hour grass allocations in March and grass quality has been really good all year. They got no setback which has definitely helped performance,” Michael says.

The average EBI across all treatments is €164. Age profile ranges from first lactation to sixth lactation with 23% heifers in each treatment. At the start of the season, the 85 cows were randomised across the treatments. They were randomised based on EBI, calving date and lactation. There is an equal proportion of Jersey and Holstein Friesian genetics within the various treatments. The range of Jersey blood within individual cows is from 6% to 50%.

Michael says that the preliminary results would suggest that Jersey crossbred cows are performing better on the OAD treatment, but that it’s too early yet to draw definitive conclusions.

Importantly, no cow that went on OAD had to be taken off because of low yield.

“At the moment, the average yield of the OAD cows is 11kg/day, but within that we have some cows producing 6l/day and other cows producing 22l/day.

"It’ll be interesting to see what the lower-yielding cows do over the coming weeks. Will they just get fatter and stop milking, or will they continue at current levels?”

The average farm cover across the trial ground is 905kg/ha (292kg/cow) and pre-grazing yield is around 1,800kgDM/ha of good-quality grass and clover swards. Cows are being fed 1kg of meal per day.

The OAD cows are producing 1.08kgMS/cow at an SCC of 179,000, while the TAD group are producing 1.59kgMS/cow at an SCC of 156,000. The stocking rate is 3.1 cows/ha on the trial ground, but it is not a closed system and the winter feed is not produced from that area.

Short OAD periods

The recovery in production for the cows on OAD for short periods is interesting. It seems that as soon as the OAD period was over, the yield recovered almost instantly and more or less matched the TAD cows, at least up to this time in the lactation. Based on Table 1, there is very little difference in cumulative performance between the cows on the two, four or six weeks of OAD milking with cumulative performance currently at 400kgMS/cow.

“The data in the table is raw and has not been statistically analysed. We need to compare the treatments on their whole lactation.

"When we correct for slight differences in calving date between the treatments I’d expect to see a 15kgMS/cow reduction for the four and six weeks OAD period which is about a 4% loss.

"I don’t think there’ll be any difference in the two-week OAD treatment,” Michael says.

He says that the success of OAD is based on good grassland management and a good milking routine. He says it’s not suited to farms that use a lot of supplement which displaces grass from the diet.

The plans are to continue the trial in 2020 with the same cows that were OAD this year continuing to be OAD next year

The milking routine for the OAD cows at Moorepark is to strip cows, pre-spray, dry wipe and post-spray after milking. So far, there have been two cases of mastitis from the 17 cows in the OAD treatment.

The plans are to continue the trial in 2020 with the same cows that were OAD this year continuing to be OAD next year and to be joined by new animals.

Michael says the experiment will continue to look at different periods of OAD milking but will include a new element looking at the performance of Holstein Friesian compared with Jersey crossbred cows.

Anecdotal evidence suggests that on most farms the yield in the first year of OAD is usually 350kgMS/cow, rising to 400kgMS/cow three or four years later. This depends on the farm, cow type and management.

The research is interesting as it suggests that higher performance is achievable in year one. If the TAD cows produce 500kgMS/cow and the OAD cows produce 400kgMS/cow that’s a 20% reduction in yield.

Through selective culling and running a mature herd, could it be possible to reduce the differential to 10% or even zero over time? Is this possible? It would be revolutionary if it was.

There is a merit to continuing this experiment but it must be done on a larger scale. The cows in Moorepark have the best of everything: small herd size and short walking distances.

I’d love to see a systems research experiment on OAD milking. This should be a long-term study on a research farm such as Curtin’s or Solohead where physical, financial and labour inputs can be accurately measured.

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