Is it possible to run a profitable, commercially focused dairy farm with net zero carbon emissions? This is the task facing the team at Shinagh dairy farm, near Bandon in Co Cork.
The 250-cow demonstration farm was established in 2011 on land owned by the west Cork co-ops. The carbon element of the project began last year with the launch of the Farm Zero C programme – a joint initiative between Carbery, Teagasc and UCD, with funding from Science Foundation Ireland.
Effectively, there are two projects – the farm project and the carbon project. Both run alongside each other, with the carbon project researchers measuring what is happening on the farm and coming up with ways of reducing the carbon footprint.
The farm project is headed by farm manager Kevin Ahern and John McNamara from Teagasc. John says practices such as reducing fertiliser use, switching to protected urea and incorporating clover are things that would have been happening anyway on the farm but are now key to the Farm Zero C project.
One change in the last 12 months is that extra land is now available to the farm. Up to now, about 250kg DM per cow of silage was being purchased from the open market each year.
An additional 17ha is now being leased into the Shinagh farm, which means that slurry is no longer being exported off the farm. This land is located up the road and will be used for three cuts of silage and a light grazing by in-calf heifers when they come back from the contract rearer.
This has the effect of lowering the overall stocking rate to just under 2.5cows/ha, while the milking platform stocking rate remains the same at just under three cows/ha. Some of this outside land was reseeded with hybrid grass and red clover last September and more is being sown in the next week or so.
Kevin says the swards reseeded last autumn were completely overtaken by chickweed and he thought that the red clover was smothered out. However, there’s a nice bit of red clover in the sward now and the plan is to oversow this with 5kg/acre of red clover seed after the silage is cut in the next week or so.
Red clover doesn’t take well to grazing as if it’s grazed too tight, the plant will die.
Not all the fields in the block will have red clover, so in wet weather or challenging conditions they can move the heifers off the red clover swards.
A total of 178kg N/ha was applied across the farm last year with similar applications planned for this year. This is much lower than other years when upwards of 250kg N/ha would have been applied. There is no difference between nitrogen rates on the milking platform and nitrogen rates on the outfarm.
Savings have been made as a result of simply applying less and making more use of slurry and soiled water.
“We’re getting braver about accounting for the nitrogen in slurry and soiled water. Fields that get soiled water now won’t get any chemical nitrogen in this round,” Kevin says.
Significantly less nitrogen is being applied on the fields with good clover contents. Ten per cent of the farm is now in multispecies and one of these got no chemical nitrogen at all this year with the other field getting a total of 74kg N/ha last year. About 4% of the farm will be sown with multispecies this year, however, the focus is very much on clover with 10% of the milking platform being oversown and another 6% being fully reseeded.
“There’s research going on at Moorepark on multispecies and we’ll probably wait and see how the results from that are looking before doing much more of it here. It’s going fine but we probably don’t know enough about it yet. There is something nice about cows eating herbs though,” Kevin says.
At this stage, there is 30% of the farm with good clover content, including the multispecies. These fields are on a reduced nitrogen plan for the rest of the summer, getting about half the rate of N compared to paddocks with little or no clover.
The contractor comes on the farm once a week to spread the fertiliser. Interestingly, a GPS-controlled fertiliser spreader began to be used midway through the season last year and an instant reduction in fertiliser use was observed.
At the moment, the farm is spread with protected urea 38:0:0 plus seven of sulphur at a rate of 17 units/acre on the low clover fields and just eight units/acre on the high clover fields.
Clover is being oversown at a rate of 2.5kg/acre using an Erth seeder. Kevin says oversowing 10% of the farm in the year is enough, as any more than that just gets too tricky to manage. They have been oversowing clover for the last four years, but John says the mistake they made is that they were doing it too late in the season, so are now doing it earlier in April and May , which can be a challenge as there are lots of other jobs on at this time of year.
The farm is concerned about bloat and one cow was lost with it last month, even though she was grazing a field with very low clover content. Bloat oil is being manually added to the water trough at every milking as part of the routine when locking in the cows after milking. This is being added at a rate of 20ml per cow per day which costs 13.5c/cow/day.
There is a big emphasis on improving the beef merit of the calves born in Shinagh. They are using high-DBI bulls and bulls with a high commercial beef value (CBV). John says they have identified easy-calving beef bulls with the ability to produce a four-star calf from a cow with minus €35 in EBI for beef.
Last year was a poor year in terms of production on the farm, with 396kg MS/cow sold to Bandon Co-op which is back from the normal production level of 430kg to 440kg MS/cow.
“The weather was very poor at the end of April last year and cows took a hit in production. They’d normally bounce back after a few days but they never did last year. Looking back at it now, we probably weren’t pro-active enough in back calculating intakes. Residuals were never too low but that could have been because the weather was poor. In hindsight, they were probably being pushed a bit too hard,” John says.
Current performance is tracking better, with the herd producing 22.8l/day at 4.41% fat and 3.54% protein or 1.87kg MS/cow per day while on 2kg of meal per day.
The EBI of the herd is €191 and while the backbone of the herd is Jersey crossbred, the team at Shinagh have tracked away a bit from Jersey in recent years.
One-hundred-and-forty straws of sexed semen is being used across the milking cows and heifers this year. The 54 heifers were synchronised and inseminated using fixed-time AI, while it is used selectively on the cows. Conception rate to sexed semen was good on the cows last year at 60%.
Breeding started on 4 May and submission rates have been good. Sexed Jersey straws are used on the heifers while cows get high-EBI Holstein Friesian and Gene Ireland straws. These are used for the first 14 days of breeding and then beef AI is used for another five weeks followed by pedigree Angus bulls to mop up.
This means that all dairy replacements are born by 22 February each year. This policy is now being reviewed as the aim is to be more selective on breeding and culling as a means of improving herd milk performance.
The key thing is to achieve this without compromising on herd fertility, which has been excellent with a six-week calving rate in excess of 90% and an empty rate of 8% on average.
“When we look at what other herds with similar genetics to ours and feeding around 500kg of meal are producing, we could be doing an extra 20kg or 30kg of milk solids per cow, which would be worth an extra €30,000 or €40,000 per year,” John says.
In terms of profitability, the farm made €870/ha last year after lease and labour costs are paid for. The initial loan of €529,000 taken out in 2011 is now fully paid back.
As for carbon emissions, the latest figures are that the farm’s carbon footprint is 0.75kgCO2e/kgFPCM. If estimated sequestration is included, that will drop to 0.65kgCO2e/kgFPCM.