The Logan’s milk 110 Holstein cows achieving an average yield of 9000 l/cow/annum. The herd is on an all year round calving pattern with homebred replacements entering the herd. Male calves are finished on-farm and sold live at the Caledonian Mart in Stirling. The cattle are housed through the winter and fed on a silage-based TMR supplemented with home-grown cereals and bought-in feed. Approximately 45 ha of cereals are grown each year with the rest of the land in grass for silage production and summer grazing.
With help from SRUC, SAC Consulting, industry specialists and neighbouring farmers, Ross and the farm discussion group looked at practical ways to profit from improved farm efficiency which in turn can reduce the farm carbon footprint. Ross cut the farm carbon footprint by 6% and saved over £16,000 through small tweaks to routine practices.
Fuel and energy use
During the project, Ross and his team were planning a switch from the current parlour to a robotic milking system. Ross put in place smart metering to monitor electricity use in the dairy. Variable speed milk pumps, improved insulation of hot water systems and a heat recovery system from the bulk tank chiller to preheat water going to the water heater were all identified as measures that could bring financial savings in the region of £1,500 per year. As Ross was in the process of moving over to a robotic milking system, most of these changes would be carried out during the switch.
Although fuel use at Hillend was low in comparison to similar dairy units, Ross still managed to improve diesel use. A 4.50 hectare field was direct drilled as opposed to being ploughed. By reducing field operations, fuel use fell by 140 litres, which at a price of £0.55 is a saving of £77 and 372 kg CO2. With less soil disturbance, a successful grass crop and reduced labour, Ross intends to increase the use of direct drilling going forward.
Getting calves off to a good start
With a new calf shed constructed during the project, heifer calves were no longer housed in the same air space as older cattle or young bull calves. The heifer calves were kept in individual calf pens, then moved to igloos and group pens. Gale breaks gave calves more protection from adverse weather and calf jackets were put on calves up to four week old. These actions were reflected in calf growth rates, increasing by around an extra 0.5kg per day.
Age of calving
One of the benefits from improved heifer growth rates is that heifers are reaching optimal bulling weight at a younger age, which has helped the business reduce its age of calving from 27.5 months to 26 months. As a result, approximately 30 replacement heifers have not had to be kept for an extra 1.5 months with no output. Research suggests the full cost of rearing a heifer increases by £2.87 per day for every day increase in age at first calving over 24 months, which at Hillend would equals a saving of £3,870.
Ross improved silage quality, knew its value and balanced rations with bought in feed accordingly. Based on a comparison of purchased feed used at the start of the project and at the end, there were 63 tonnes less bought-in feed fed, equating to a saving of £2,300 and 34,278 kg CO2e.
Ross changed the dry cows diet by feeding more wholecrop instead of chopping and feeding straw. This meant the feeder wagon was running for approximately 182 hours less per year, saving 1,820 litres of fuel, around £1,000 and 4,841 kg CO2. Knowing wholecrop nutritional value meant Ross could be more accurate when formulating rations.
Improving nutrient use and crop growth
With soil analysis results showing moderate to high P and K levels, Ross was better able to target slurry and fertiliser use across the farm. This resulted in a reduction of 8.8 tonnes of both P and K, saving 31.97 tonnes of CO2e and £9,143 over three years. Soil testing also highlighted low pH across parts of the farm. With this information Ross was able to identify and prioritise areas for lime, applying around 57 tonnes of lime in 2015. Although it was not possible to quantify the actual benefits from increasing pH in terms of better nutrient utilisation or tonnes of grass grown, it was expected that a targeted nutrient use and liming plan would give a significant boost to grass growth over the coming years.
Key carbon findings
- Overall, total emissions at Hillend increased by 2% during the three year project. This was due to livestock numbers increasing during the project, and partly around timing of livestock sales.
- The measure of on-farm greenhouse gas emissions in relation to saleable product, also referred to as ‘emission intensity’ fell during this time by 6% from 1.53 CO2e to 1.43 CO2e per litre of milk. This demonstrates a reduction in carbon emissions per unit of product and an improvement in efficiency.
- Ross saved around £16,000 with no loss of production as a result of straightforward, low or no cost practical efficiency measures. By the end of the project, milk yields had increased beyond what they were at the start of the project but less purchased feed was required. Ross plans to move forward with the new robotic milking facility.