about mdc Evaluations

“MDC Evaluations is dedicated to improving and promoting the genetic merit of UK cattle through the updating, calculation and dissemination of essential statistics with emphasis on genetic evaluations.”

MDC Evaluations Staff   Acknowledgements


ounded in 1991, following the publication of a report by the Wilson

Committee.This Committee, led by Professor Wilson, listened to submissions from all interested parties in the Dairy Industry, concerning ways to improve and promote genetic improvement in the UK. The report listed a number of recommendations, the first of which was to include the Bull and Cow Evaluation Unit as the core function of the ADC. From 1993 the Unit was operating as part of the ADC. Formal transfer of staff and resources from the Milk Marketing Board to ADC Ltd took place on the 1st September 1996.  In March 2002, ADC became MDC Evaluations Ltd, a company owned by the Milk Development Council and United Dairy Farmers

The policy of MDC Evaluations is set out by the Board, which includes representatives from Milk Development Council, United Dairy Farmers, Holstein UK and National Farmers Union.  The original ADC Board, which contains representatives from Milk Recording Organisations, the National Cattle Association, National Farmers Union, AI Industry and Holstein UK, remains in an advisory capacity.

FUNCTIONS OF MDC Evaluations Ltd

Predicted Transmitting Abilities (PTAs)

The most important responsibility of MDC Evaluations is to calculate PTAs for milk, fat and protein yield, fat % and protein % for the UK dairy herd. In total, this involves all milk recorded cows and their sires in eight dairy breeds. The milk, fat and protein yield PTAs are used to calculate a simple production index known as £PIN.   Linear type, together with survival information obtained from lactation data, is used to estimate Lifespan PTAs. This is combined with £PIN to produce an economic index known as Profitable Life Index or £PLI.   Other traits will be added to £PLI as evaluations are produced.

The basic milk records are obtained from Milk Recording Organisations in the UK and after adding pedigree information obtained from the Breed Societies, PTAs, £PIN and £PLI are produced four times yearly. The results are passed back to these organisations for return to farmers on registration and lactation certificates and other stationery. £PIN and more recently £PLI, are genetic indices aimed at simplifying selection for profit. £PIN in particular has been successful in focusing attention on genetic improvement and there are clear indications that the UK is bridging the gap with other countries.

The fact that the UK imports considerable amounts of semen and embryos, has led to problems because the sires and dams may not be evaluated here. This is particularly true for foreign dams which have not been milk recorded in the UK. In order to overcome this, foreign evaluations are obtained for bulls and cows, converted to UK PTA equivalents and incorporated into the system.

MDC Evaluations also calculates genetic evaluations for linear conformation traits for the Shorthorn, Ayrshire, Jersey, Guernsey, Jersey Island and Guernsey Island Breed Societies. These are supplied to the Societies for use by their members. The type information is used in the calculation of £PLI.

Genetic evaluations for Somatic Cell Counts and Lifespan are also published.

International Evaluations

MDC Evaluations is responsible for maintaining and, where appropriate, updating conversion formulae to enable foreign bull/cow evaluations to be converted to UK PTA equivalents, thus enabling foreign animals to be directly compared with those in the UK.

The Holstein Friesian, Ayrshire, Jersey and Guernsey PTAs for production and somatic cell counts are sent to the Interbull Centre in Sweden, with which the UK maintains close links. In return, International evaluations are obtained where UK bulls have been directly compared with evaluations supplied from more than 20 foreign countries. MDC Evaluations also sends Jersey conformation information to Interbull.

An important part of the work of MDC Evaluations is the transfer of genetic indices to and from evaluation units in other countries and various organisations throughout the UK.

Other functions carried out include the maintenance and update of a database containing details of abnormal calves born from bulls in AI.


After the February and August evaluation runs, Herd Genetic Reports are produced, collated and sent from MDC Evaluations to all milk recording members. Each report contains the PTAs, £PIN and £PLI for all live cows in the herd, together with a summary showing the average PTAs for each lactation group.

MDC Evaluations also supplies lists of top bulls and top cows, for each breed and produces summary statistics books containing genetic trends in the UK population; standards for bulls, cows and herds, together with lists of top bulls and cows. 

In addition, MDC Evaluations produces a Technical Bulletin and fact sheets with explanations on various topics connected with genetic evaluations. A joint publication with NMR contains detailed milk recording and genetic evaluation statistics.

Web Site

The site contains a wide variety of information on MDC Evaluations.  The main benefit is ease of access to bull and cow results.


£PIN was introduced as a simple method of ranking bulls for net margin. A recent Genus/ADC/NMR investigation on 500 farms found that an increase of 1 £PIN equates to an increase of around £5.00 in margin over feed and fertiliser (MOFF) per cow. 

In national terms, a target of 10 £PIN improvement per year, in  the average £PIN of heifers entering the herd, is a realistic objective. Assuming 2 million dairy cows, a  replacement  rate of 25% and an increase of 10 £PIN, the returns in terms of MOFF would be £25 million per year to the industry. Alternatively in a 100 cow herd the extra MOFF would be £1,250 per year. This clearly justifies the annual cost of £17 for a 100 cow herd for MDC Evaluations.

As financial pressures increase, all aspects of improving efficiency have to be closely scrutinised. Genetic improvement is permanent and cumulative and, as the figures show, highly cost effective.

At present, the cost of MDC Evaluations is approximately 17p/cow.  The overall benefit of genetic improvement to the UK dairy industry is estimated at £20-£30 million per year.  Without the information calculated and published by MDC Evaluations, this level of improvement would not be possible.