Duration 15 months (January 2009 – March 2010)

Team and Leader Conrad Ferris, Elaine Vance, Niamh O’Connell and Ryan Law (AFBI, Hillsborough), Duncan Anderson (Agri Food Economics Division)


Background and Summary  The Northern Ireland dairy industry continues to face increasing pressures and challenges, including increasing costs of inputs, labour shortages, unstable milk prices and low levels of fertility.   However, unlike in the Republic of Ireland, no advisory blueprint for milk production exists.  For example, while an increasing number of Northern Ireland herds are moving towards total or partial confinement systems in an attempt to increase milk production per cow, others are seeking to produce milk at minimum cost through the adoption of low input grass based systems.  

These contrasting systems differ in terms of inputs of purchased feed, fertiliser requirements, labour inputs, management expertise, nutrient management, milk output/cow and environmental impact.  However, world wide there is little research data comparing grazing systems and total confinement systems.

In addition, crossbred cows are common within these low input systems, having been advocated as having the potential to improve fertility, health, longevity, and ultimately cow profitability.  To this end, AFBI-Hillsborough is currently examining the role of crossbreeding on 12 Northern Ireland dairy farms, while in addition, Jersey crossbred dairy cows are being compared with Holstein cows at Hillsborough on spring calving grassland-based systems of milk production.  While the latter study is not yet complete, preliminary results indicate that Jersey crossbred cows have performed as well (in terms of fat + protein yield) as the Holstein cows on the higher input systems.  Thus, data from this Hillsborough study, and research findings from the USA (Heins, Hansen and Seykora, 2006; Heins et al., 2008) suggest that crossbred dairy cows may have a very real role in high input systems, both in terms of performance and functionality.

The proposed study will seek to address these two key issues, by comparing the performance of Holstein and Jersey x Holstein dairy cows when managed on two extreme management systems. In addition, this study will also provide insight and direction to the second phase of a new research proposal which will be submitted to AgriSearch in January 2009, namely ‘Managing high yielding dairy cows during the summer period’.

Proposed programme:

The proposed programme will involve a total of 80 dairy cows.  Treatments will be arranged in a classic 2 x 2 factorial design comprising two cow genotypes (Holstein Friesian and Jersey crossbreds) and two contrasting feeding regimes (Low input grazing and High input total confinement).  Cows will be managed on these two contrasting grassland-based systems of milk production over a full lactation.

Low input grazing system

20 Holstein-Friesian and 20 Jersey crossbred cows
Designed to maximise milk from grazed forage
Early turn out and extended grazing season
0.8 t concentrates/year

High input total confinement

20 Holstein-Friesian and 20 Jersey crossbred cows
Total confinement throughout the lactation
Forage component of the diet: grass silage + maize silage
Total concentrate input:  approximately 2.8 t

Key objectives-to examine the effect of cow genotype and management system on:

                Cow performance (milk output and milk composition, including detailed fatty acid profiles and N       fractions)
                Tissue changes and associated blood parameters
                Gross energetic efficiency over the lactation (total confinement system only)
                Oestrus behaviour/fertility
                Feeding behaviour
                Methane production and overall carbon footprint
                Hoof health and welfare
                Theoretical N and P use efficiency
                Costs and bottom line profit
                                                
Milestones with proposed dates:


Timescale

January 2009: Commence study

March 2010: Completion of study  

September 2010: Final report

October 2010: Publication of farmer booklet.  It is proposed that a joint booklet be prepared highlighting the findings of this study and the findings of the Holstein vs Jersey crossbred component of the spring systems study (D-29-06).

Benefits to industry

1)   Provision of comparative data for a wide range of parameters from two extreme milk production systems.  This is an area where information is lacking internationally, and yet is particularly relevant for our own industry in view of diverging practices on-farm.

2)  This study will provide strategic direction and act as a solid basis on which to build future research projects, especially in relation to managing high yielding cows during the summer.

3) Provision of information on the potential of crossbred dairy cows in high input systems, and provision of underpinning scientific data to explain differences.

4)  Proposed associated measurements in relation to methane production, and N and P utilisation efficiency have the potential to be extremely useful with regards future dealings with the EU Commission, particularly in relation to determining the environmental footprint of contrasting milk production systems.

5)  Provision of highly practical information concerning the impact of system on hoof health and oestrus behaviour .

Findings from this work will be presented in the local press, to visiting groups at the Institute, at farmers meetings and at Scientific Conferences.

Attachments:
FileDescriptionFile size
Download this file (Final report for AgriSearch (D-45-08) Breed comparison.pdf)Cow genotypes comparrisonComparison of the performance of two cow genotypes within a low input grazing system and a high input total confinement system893 kB