Securing optimal levels of carbon reduction within a robotic milking enterprise was the focus of a recent farm walk.

The event was hosted by William and Alan McConnell from Drumgaw in Co. Armagh, in association with the College of Agriculture, Food and Rural Enterprise (CAFRE).

The father and son team milk 135 cows using a robot. William is still very active on the farm, with Alan’s son James now taking on more of the herd management, although he is still at university.

The key take home messages delivered on the day related to the reduction of waste, where animal management, in tandem with fertiliser and feed use are concerned.

The McConnells have a clear focus on milk production, replacement heifer and store cattle management.

The cows are totally housed, calving between August and March. They are currently averaging 9,000L from 3.8t of concentrate feed/cow.

Current milk from forage levels have seen a dip due to weather conditions in 2023 – it is usually higher than this.

Cow longevity

Courtesy of his presentation on the day, CAFRE senior dairy advisor, Alan Hopps, discussed the latest thinking on how best to drive sustainability within a modern dairy farming enterprise.

He confirmed the role of cow longevity within a milking group in determining the number of replacement heifers needed within a dairying enterprise.

E.g., lowering the average cull rate from 35% to 25% within a 120-strong milking group reduces the total number of heifers needed on the farm at any one time – assuming a 24-month first calving date – from 105 to 60 head.

This included moving from 30-month to 24-month calving, as well as reducing the age at calving.

In turn, this reduces the amount of land that must be dedicated to heifer rearing from 24.3ha to 12.4ha.

Cows feeding on the McConnell farm

According to Hopps: “This represents a land saving of 11.9ha. It also constitutes a cost saving, as well as reducing the number of non-milking stock on the farm.”

Hopps said that there are a “number of steps that can be taken to achieve a reduction in culling rate within a milking group”, including “the use of good genetics with positives for lifespan and fertility”.

He continued: “The attainment of high growth rate in heifers accompanied by 24-month first calving date is also important, as well as early invention in disease. Remote animal monitoring can also help.

“All animals should be housed in good facilities that are not overcrowded. Good transition cow management standards, pre- and post-calving, must be achieved.

“Vaccination protocols must be put in place and adhered to, as recommended by one’s veterinary surgeon.

Further advice offered also suggested that fertility management must include high heat detection and pregnancy rates, coupled with regular scanning and intervention for problem cows.

William and Alan McConnell are currently calving their replacement heifers at an average of 25 months.

The heifers’ average weight at calving is 605kg. However, this figure rises to 650kg, at 150 days into milk.

Hopps added: “These are well-grown animals. It is also highly significant that they continue to put on weight so readily after calving.”

Soil testing

Where farm nutrient management standards are concerned, William and Alan have 53 fields tested under Northern Ireland’s Soil Nutrient Management Scheme (SNHS).

A total of 17 fields have a pH value between 5.5 and 6.0, with six fields having a pH value greater than 6.5.

ACRES soil sample

CAFRE’s Michael Verner discussed these matters at the event: “When it comes to making best use of slurries and fertiliser, all farmers should have their soils tested on a regular basis as part of a drive to reduce fertiliser wastage.

“Lime should be applied to improve efficiency of fertiliser use; target a pH of 6.5 for grass/clover swards.

“In addition, a nutrient management plan should be completed for each field targeting slurry towards low phosphate and potash index soils,” he added.

“Slurry should be applied using low emission spreading equipment. Where the application of fertiliser is concerned, protected urea products should be used, where possible.”

Cow nutrition when robotic milking

The rations fed to the milking group on the McConnell farm include a total mixed ration (TMR) comprising grass silage, whole crop rye and a purchased blend.

It is fed in the morning with additional feeding available in the robots at milking courtesy of Cosmix out-of-parlour feeders.

The cows are fed to yield after 100 days; overall ration has a crude protein content 18%.

CAFRE’s Michael Garvey discussed the impact of the three feeding strategies implemented on the McConnell farm.

He explained: “At 100 days feed-to-yield cows giving 24L gets 5.5kg of concentrates in the robot and 3.5kg in the wagon. There is a clear focus on reducing the levels of feed wastage on the farm.

“Currently, a total 1.19t of concentrate is fed across the milking group on a daily basis feeding, based on a 10kg intake per cow, per day.”

Looking ahead, William and Alan McConnell will be looking at a number of options to improve feed efficiency. Securing higher levels of milk output from forage is one of these.

They will also be looking at alternatives to wholecrop rye while reducing the overall protein content of the rations on-offer to the cows.

Meanwhile, Co. Armagh, like every other part of the country has been badly affected by the continuing rain of recent months.

“Getting slurry out has been a real issue on many farms,” Alan Hopps confirmed.