Improving Carbon Efficiencies At Woodhead Farm

This article originally appeared on the Farming For A Better Climate website 

Woodhead Farm is a dairy unit near Newmilns in Ayrshire.  The farm is family owned and run in partnership by mother and son team, John and Anne Kerr.

 

Woodhead is a 180 cow dairy over 141 hectares with access to additional rented land.  At the start of the project, cropping was predominantly grass, with 16 ha of wholecrop.  There was also 12 hectares of farm woodland.

Measures to optimise fuel and energy use

Dairy units have significant energy demands for heating water and cooling milk during the twice daily milking.  Small changes on activities repeated on a frequent basis can lead to significant annual savings. Fuel for vehicles is also an on going cost, as is lighting in livestock accommodation.

The list below highlights some of the topics which were discussed during the discussion group events, and where John instigated changes during the programme.

• The use of a larger plate cooler will cool milk faster and more efficiently. John is currently installing an old bulk tank to pre-cool the water before it enters the plate cooler, with a view to investing in a larger plate  cooler in the future.
• Re-using the water from the plate cooler as drinking water for the cows. Providing pre-heated drinking water reduces the energy requirement to bring

 that water up to body temperature.  It takes 1.5MJ of energy to heat one litre of water from 0 – 37oC (body temperature). Cows in peak yield can drink over 100 litres per day, so the energy requirement is significant. By using preheated water, this energy can then be used for production as opposed to regulating the consumed water temperature.

• Shed adaptations have allowed the natural light to replace the previous reliance on fluorescent lighting which has saved approx. £103/yr.
• Following an energy and fuel audit, the use of a smaller tractor on the farm whenever possible to reduce fuel usage and in particular on the diet feeder was recommended. John does now try to use the smaller tractor for all operations when possible and has seen savings in his fuel use.  From the change of vehicle on the feed wagon, John has saved around 4,400 litres of fuel annually.  With red diesel currently at 53ppl, this equated to a saving of £2,330 and 11,792 kg CO2 per year.

Measures to optimise nutrient use efficiency

• Soil sampling at the farm identified a number of factors that were impeding and limiting grass and clover growth, such as soil pH and low levels of phosphorous and potassium. Addressing these issues with an annual liming plan and a targeted nutrient budget has improved grassland productivity.
• Grass production has increased following the improvements to soil health and as a result the need for a 3rd cut of silage was negated. This resulted in a saving of 19.2 tonnes of purchased third cut silage fertiliser (27:14:0) and 418 litres of red diesel, saving of 74,559 kg of CO2e and £5,020.
• In 2016, John and Anne decided to stop growing whole crop. This was replaced by oat, barley and pea arable silage, under sown with grass and clover. The mix includes two legumes which provide sufficient nitrogen for the crop to reach target yield and result in an equivalent saving in nitrogen fertiliser of 0.289t/ha of 34.5N, equating to £356 and 6,490 kg CO2e.
• Improvements in grazing and silage ground has allowed John to utilise his paddocks more effectively. This has increased milk from forage over the farm, meaning fewer tonnes of bought in feed were required to achieve the same output.

Measures to optimise livestock productivity

• A steady improvement in silage quality from 10.9ME to 11.1 ME (2016) and 11.9 (2017 1st cut) resulted in 65 tonnes of straw and 48.6 tonnes of wheat being saved over the 90 autumn block cows. At prices of £130/tonne wheat and £125/tonne straw it would have cost £14,500 to feed the cows to the same level of performance, saving 34,568 kg CO2e
• In addition to adaptations to existing calf accommodation, two calf igloos were purchased to provide additional calf rearing capacity. Calf performance and mortality rates improved, allowing John to sell calves for in excess of £200 at the age of 3 weeks.  The calves are reared on whole milk that would ordinarily be discarded from the food chain and have very few other costs.
• Calf jackets were introduced as a routine management practice on smaller, weaker calves, resulting in improvements in survival and growth rates.
• Developing a targeted animal health plan with assistance from SAC Consultants and his practice vets has allowed John to reduce the heifer age at calving from 27 to 24 months. Based on feed usage only, it is estimated to have cost the business £5,130 to rear these heifers for an extra 3 months, increasing emissions from feed by 21,986 kg CO2e; reducing the age of calving has meant this has now been saved.
• John diverted Astroturf destined for landfill and laid it as cow tracks through his fields. This provides a more uniform walkingsurface for the animals reducing the risk of stone damage to feet and has led to an overall improvement in lameness.  It has also allowed him better access to paddocks to help improve grazing utilisation.  It is widely accepted that lameness in dairy cows can have significant impacts on productivity and lead to an increase in the carbon footprint.
• One of the most recent changes at Woodhead has been the removal of some of the side sheeting on the cow shed. This has dramatically changed the airflow and light levels in the shed.  Following the success of this action, John intends to remove additional sheets and is going to open the ridge of the shed to further improve the air stack effect.  Increasing the light levels for the cows is estimated to result in an extra litre per cow per day (28,800 litres per year) equating to increased income of £8,300.  In terms of carbon savings, this increased yield across the herd is expected to reduce the future farm carbon footprint by 1.88%

What were the key findings from Woodhead?

• Significant financial and carbon savings can be achieved through low cost adaptations.
• Improving grass growth and utilisation can make huge differences to profitability, but soil pH and nutrient levels must be correct to achieve this.
• Animal health is key to improving livestock productivity; simple records can help identify underlying problem animals which can then be individually targeted to improve whole herd efficiency
• An energy audit can highlight areas where improvements in fuel usage can be made which can make substantial savings in the carbon audit and financially.

Download the key findings