Project code: D-30-06
Duration 3 years
Team and Leader Lynne Dawson and Ian McCluggage
Organisations involved ARINI & CAFRE
Background and Summary
Rearing heifer replacements represents one of the main costs in any dairy enterprise. Recent Greenmount benchmarking data (CAFRE, 2005) indicated that the average total cost (excluding labour) of rearing heifers was £745 per heifer and that a 37% improvement in net farm profit could be achieved through a 10% reduction in heifer rearing costs.
Within heifer rearing, calf mortality represents a major economic and welfare cost. Recent on-farm data reported alarming levels of calf mortality, with levels of up to 13% for calves from first-calving replacements (Ferris et al., 2004). Further losses occur in the pre-weaning period and the first month of life in particular has been shown to be a critical period for survival, with mortality of on average 9.4% reported in North American studies (Jenny et al., 1981), although, information on calf mortality during the latter period in Northern Ireland is limited. Benchmarking data also indicated that the average age at first calving for dairy herd replacements on recorded farms is 30-months of age, significantly greater than the economic optimum age of 24-months (Pirlo et al., 2000).
Research undertaken at ARINI (AgriSearch project ‘Developing Improved Heifer Rearing Systems’) has clearly demonstrated that Holstein Friesian heifers should be reared to calve at 540–560 kg at a body condition score of 2.75 to 3.0 at 24 months of age. While heifers reared to calve at heavier weights produced 11% more milk in the first lactation, they lost large amounts of live weight and body condition in early lactation compared with heifers calving at lighter weights and subsequently had longer calving intervals. However, despite this research, benchmarking data suggests that dairy producers are continuing to rear heifers to calve at heavier weights and at greater age than current recommendations.
In view of this background, work is urgently required to ensure the effective adoption of improved heifer rearing systems at farm level. The first step is to evaluate current systems of heifer rearing in detail to clearly identify levels of performance throughout the rearing period on-farms and to determine the factors influencing the current systems adopted. This will deal with issues such as labour and land availability, calving patterns and methods for recording and assessing heifer performance. The second component of the study will evaluate farmers’ responses to research findings and factors affecting the implementation of results of research programmes. The findings of these two studies will be then be used as a basis for targeted technology transfer programmes on heifer rearing by CAFRE. The third component of the programme, being undertaken along with John Thompsons and Sons Ltd., will provide additional data from farms across Northern Ireland on the economic and animal welfare benefits of adopting improved heifer rearing regimes. Overall, this project comprises an integrated research, development and technology transfer programme and represents a major and ground breaking initiative in taking heifer rearing systems forward for the Northern Ireland dairy industry.
In summary, the aim of this study is to facilitate the widespread adoption of improved heifer rearing systems through an integrated research, development and technology transfer programme, leading to economic and welfare benefits for the Northern Ireland dairy industry.
Timescale Final report due to be submitted to AgriSearch in December 2008