Duration 7 years commencing Spring 2000.

Team and Leader Sinclair Mayne, Rae Park, Duncan Anderson and Geoff Simm.

Organisations Involved Agricultural Research Institute of Northern Ireland, Agricultural Economics Division, Newforge Lane and Scottish Agricultural College.

Background and Summary

Current dairy cow breeding programmes have resulted in significant improvements in milk production potential of the modern dairy cow. However, this has also been accompanied by increased incidences of infertility, lameness, mastitis and other production diseases.

 With increased consumer concern over use of antibiotics and other other drugs in farming systems, coupled with the need for increased labour efficiency on dairy farms, there is an urgent need to consider options to reduce the incidence of production disease and to develop `easy-care` cows. Heterosis (hybrid vigour) is a widely used approach to improving dairy cow health, reproductive performance and profitability in the New Zealand dairy industry. It is therefore important to explore if it may provide a `fast track` solution to these problems on Northern Ireland dairy farms.

The objectives of this proposal are to:

1. Undertake detailed modelling studies, using existing international data, to investigate the potential of cross breeding to improve profitability on NI dairy farms.

2. Evaluate the potential of cross breeding to reduce the incidence of production diseases through co-ordinated on-farm research studies. Study will involve 20 dairy herds in Northern Ireland with the objective of producing 10 cross bred heifers on each farm each year for 2 years and comparing with 10 herd mates.

Timescale

Spring 2000 - Commence detailed modelling studies to investigate potential of cross breeding and identify the optimum crosses for the NI dairy industry.
February 2001 - Initiate on-farm cross breeding programme.
December 2006 - All animals completed first lactation studies
Final report due September 2007

Benefits

1. Results of the modelling studies will indicate the theoretical potential of cross breeding to improve the competitiveness and profitability of the NI dairy industry.

2. On-farm studies will evaluate effects of cross breeding on (a) production, (b) health, (c) fertility.

3. Improved consumer perception of milk and milk products through reduced use of antibiotics, drugs to maintain cow health.

Project News Update

Current dairy cow breeding programmes in the UK have resulted in significant improvements in milk production over the last years. However, recent research has shown that this is associated with declining dairy cow fertility and longevity. While new sire indices incorporating fertility and longevity will be available in the near future, heritability of these traits is low and their incorporation into the overall breeding selection programme will take considerable time to have an effect. Crossbreeding offers a more practical short-term alternative for the improvement of fertility and longevity in dairy cows as both traits benefit considerably from the effects of hybrid vigour.

Various breeds were considered for this project ranging from dairy breeds such as the Ayrshire and Jersey through to dual-purpose breeds such as the Norwegian Red and Montbeliarde. After an extensive review of the literature and evaluation of the various breeds it was clear that crossbreeding with the Jersey breed offered the greatest potential to reverse the current trends. Financial modelling has indicated that crossbred Jersey cows have a particular advantage in low to average yielding herds where more emphasis is placed on milk quality, especially if milk prices are low.

The aim of this research programme is therefore to evaluate the potential contribution of crossbreeding to improve the profitability of dairying in Northern Ireland. Fourteen herds from across Northern Ireland are currently partiipating in the study, with a range from autumn to spring calving and at various levels of concentrate input. In each herd, approximately 20 Holstein - Fresian cows are being bred with Jersey semen for two successive years, with 20 similar cows being served with the normal Holstein - Fresian bulls used on the farm. The first crossbred calves of this study have now been born (October 2002). The next part of the study aims to compare their production, reproductive performance, health and longevity with that of Holstein - Fresian herdmates of comparable age.