When the Future Herd was established in November 2006 targets were set on the productive, reproductive and lifetime performance of the herd. These were annual milk yield of 8,000-8,500 litres/cow/year with average annual butterfat of 4.10% and protein of 3.50%, milk from forage production of 4,000 litres/cow/year and lifetime performance of 40,000 litres. Fertility targets, monitored using Fertility Benchmarking Online, are a submission rate of 80% and conception rate of 50%. All these targets are reviewed continuously and reported on at the end of each financial year.

Milk quality targets

On establishment of the Future Herd the average butterfat and milk protein contents were 4.07% and 3.22%, based on a 12-month rolling average, with a protein to butterfat ratio of 0.79:1.00. One of the aims of the Future Herd was to improve milk quality, particularly milk protein as payment incentives continue to favour milk protein as compared to butterfat, due to market returns.

In the year to the end of March 2009, the average butterfat and protein of the milk produced in the Future Herd was 4.22% and 3.38%. This is considerably higher than the current Northern Ireland average of 3.98% butterfat and 3.26% protein. The butterfat level for the herd has exceeded the target of 4.10% and increased by 0.05% from the previous year. This is a total increase of 0.15% since the herd was established. While the target of producing 3.50% protein is more challenging, the average milk protein percentage in the 12 months up to the end of March was 3.38%, an increase of 0.06% in 12 months and an increase of 0.16% since the herd was established. These improvements in milk quality can be attributed to a combination feeding, breeding and overall herd management. For a cow yielding 8,000 litres per year, the value of the milk in the Future Herd is worth an extra £65/cow/year compared to the Northern Ireland average, or £6,500/year for a herd of 100 cows.

What are we doing to achieve these targets?

As the genetic merit for milk production increases, the genetic merit for butterfat and protein percentage tends to decrease so at Greenmount there has been a long term breeding strategy to improve milk quality without compromising milk yield. The potential for increased milk quality was enhanced with the introduction of 42 replacement heifers into the herd with high PTAs for butterfat and protein, sired mainly by Shaker whose current PTA for butterfat and protein are 0.13% and 0.06%. Sires selected for use in winter 2008/09 had minimum PTAs for butterfat and protein set at +0.15% and +0.08% with Klassic Merrill Lynch, Kelstein Dynasty and Heihoeve Delta Spencer being selected. Sexed semen from Kelstein Dynasty was used on heifers. These sires also had a positive PTA for fertility and negative PTA for somatic cell count, providing an even stronger genetic base from which to move forward.

While there is a long term breeding strategy to improve milk quality in the herd, short term improvements in milk quality can be made through feeding. Cows losing a lot of body condition around peak lactation generally have the lowest levels of milk protein but this can be avoided by targeting concentrate at the cows which need it most. This is achieved through grouping of cows. In the winter-time, the herd is divided into three feeding groups with individual cows topped up to yield to meet their nutritional requirements, maximising milk production from forage. In the last winter, early lactation cows and heifers (generally less than 100 days in milk) were fed 16% protein in the total ration with the TMR comprising 3 kg of a 24% protein blend and both grass and maize silage. Mid lactation cows and heifers (generally 100-250 days in milk) were fed 18% protein in the total ration with the TMR comprising 5-6 kg of the 24% protein blend, 1-2 kg soya (to increase CP%) and both grass and maize silage. Late lactation cows got no blend in the TMR but were topped up in the parlour according to body condition score, more concentrate being targeted at thinner cows.

Lifetime performance

Lifetime performance is a relatively new term but it is influenced by a number of diverse factors such as age at first calving, milk yield, longevity, reason for culling and replacement rate. CAFRE Dairy Benchmarking has established that it costs around £1,200 to rear a replacement heifer and taken together with the sale value of a cull cow, rearing replacements costs around 2.5 pence per litre. Given this cost and results from AFBI Hillsborough (where the average dairy cow in Northern Ireland is culled after completing 3.5 lactations), a lifetime performance target of 40,000 litres per cow was established for the Future Herd. Lifetime performance from over 100 cows culled out of the Future Herd in the last four years has averaged just over 35,000 litres at an average lactation number of 4.3, considerably more than the Northern Ireland average of 28,000 litres estimated from CAFRE Dairy Benchmarking figures. This ongoing area of technology influenced by breeding, feeding and general management will continue to be investigated in the next few years with the aim of establishing a more robust and sustainable dairy cow in the future – critical for the Northern Ireland dairy industry.