As with all aspects of dairy farming attention to detail regarding replacement rearing pays dividends. Michael Verner from CAFRE stated that the average cost of rearing replacement dairy heifers is 3.3pence per litre or approximately £1200 per animal on N Ireland farms, making them both a valuable asset and a cost to the farm business.

Michael was speaking at the series of meetings on summer management of dairy heifers organised by CAFRE, John Thompson and Sons and Pfizer animal Health. He highlighted the following points regarding heifer management

• Serve heifers early (14/15 months of age)
• Have good grazing systems
• Maximise grazing days for heifers
• Make quality silage
• Have more heifers born in the autumn than in the spring.

James Black from John Thompson & Sons followed on from this theme and highlighted research work his company had carried out in association with AFBI and CAFRE looking at a heifer rearing blueprint which was piloted on eight Northern Ireland dairy farms. The aim was to have heifers calving at 24 months of age which were well grown at about 580kg bodyweight but not over fat. These heifers were fed according to a standard blueprint from weaning through to calving down depending on the time of year at which they were born.

Another crucial element of this management system was regular weight recording of a representative sample of these groups of heifers using a specially calibrated weigh band. Based on performance and forage quality feeding levels at various time points were altered slightly on individual farms. A key learning from their work was the need to weigh heifers regularly to ensure they were approximately 370kg at around 14/15 months with an overall aim of having a DLWG of 0.8kg per day from weaning to calving down.

They noted variation in performance on specific farms highlighting the following points on which farmers should focus

• Silage quality- good silage quality is crucial even for heifers!
• Grassland managment-  graze swards tight in the early part of the season while ensuring heifers are regularly changed to fresh pasture
• Health issues can have a major impact on heifer performance.

William Sherrard from Pfizer Animal Health concluded each meeting by focusing on three health issues affecting heifers at grass with an emphasis on prevention rather than treatment of disease.

• Worm control strategy. There are two key elements-

–  Disease prevention- Treat early e.g. Dectomax™ Pour On at or within 3 weeks of turnout and again eight weeks later. An alternative is a pulse release bolus such as Autoworm® First Grazer at turnout if handling animals during the grazing season is difficult.

–      Development of immunity- It is crucial that heifers entering dairy herd build up immunity to lungworm and intestinal worms. It is essential that naive animals are exposed to small controlled amounts of worms on the pasture throughout the grazing season to aid the development of immunity.

•  Fly control

–  Avoid grazing heifers in sheltered fields with high hedges and nearby water courses.

–  Apply topical insecticides such as Coopers® Spot On regularly commencing well before the main fly season in mid summer.

•  Clostridial disease

–  Usually fatal and one death equates to cost of approximately 500 primary vaccination courses.

–  There are various different clostridial diseases which can affect cattle so farmers should choose a multivalent vaccine such as Covexin® 8 with animals ideally a primary course of two injections in advance of turnout.