New Final Report Released on Heifer Management as AgriSearch PhD Student Alastair Boyle Graduates
A new final report on dairy heifer management is now available to download from the AgriSearch website.
“Strategies for maximising health, welfare and performance in first lactation heifers” was undertaken as a PhD study by Dr Alastair Boyle who recently graduated from Queens.
Dr Niamh O’Connell and Dr Conrad Ferris also formed part of the research team.
It takes 2 years and approximately £1,220 to rear a dairy heifer to the point of replacement.
Heifer replacement rate impacts on overall herd profitability and greenhouse gas emissions.
The calving period is highly stressful for dairy heifers:
- · Calving stress
- · Removal of the calf
- · New experience of the milking parlour
- · Metabolic stress
- · Mixing with mature cows
Improved welfare may result in improved longevity.
Alastair’s PhD was comprised of four experiments
1. Introducing the heifers after AM or PM milking
2. Mixing heifers with older cows prior to calving
3. Keeping heifers in a separate group for 2 weeks after calving
4. Retaining heifer on straw for either 12-24 hours versus 36-48 hours.
While there was no difference in lying behaviour those animals who were introduced after the PM milking received significantly less aggression from their herd mates.
Heifers who were mixed with older cows prior to calving were also much less likely to receive aggression from their herd mates (0.03 butts / minute com-
pared to 0.15 butts / minute for the unmixed heifers). During the post-feeding period the pre-mixed heifers spent more social time in the loafing areas.
There also were significant behavioural differences between heifers who were directly introduced to the herd after calving and those who were kept in a separate group after calving as well as keeping heifers on straw for 36-48 hours.
Alastair’s optimal blueprint for management of dairy heifers:
- · Mix heifers with older animals prior to calving
- · After calving keep on straw for 36-48 hours
- · Retain in separate heifer group for 2 weeks
- · Introduce to main dairy herd after the evening milking
For further details on the project and a link to download the Final Report click on the link below.
Managing first lactation heifers to maximise welfare and productivity - QUB-D-40-08