The future of Dairy Cow Housing (PhD)

Summary

A new term “a living space” was described to define the additional space availability for dairy cows above a minimum baseline requirement and accounts for all areas of excess space in cubicle sheds using a set definition and method of calculation, based on discussions from an industry led stakeholder group meeting.

Current guidelines and definitions for space measurements in dairy cow housing are ambiguous and lack scientific clarity. Guidelines for total space per cow range from 6.5m² (Red Tractor Farm Assurance) to 10.5m² (AHDB housing guidelines) per cow. This has caused large variation within dairy cow accommodation across GB dairy farms (range: 5.4-12.7m² per cow; Thompson et. al, 2020).

This combination of current variation in housing management, alongside ambiguous definitions, recommendations and a lack of scientific literature meant that research was urgently required to understand how current housed conditions in the UK impact on dairy cow production, reproduction, behaviour and economics. 

Key Findings

• There is large variation in current housing conditions across GB dairy farms, highlighted by a range on total space allowances of 5.4-12.7m2 per cow and living space allowances of 0.5-6.4m2 per cow. 
• A year-long randomised controlled trial has shown that increased living space allowances: 
  • Increase milk volume production by as much as 600L per 305-day lactation in heifers. 
  • Change cow behaviour, with cows lying down for over 1 hour longer per day without any changes to the cubicles themselves. 
  • Increase days to conception because of a reduced conception rate. 
• Importantly, the costs associated with providing increased living space allowances appear to be offset by the increased productive performance of the cows. 

Aims and Ojectives

The main aims of the research were: 

• To quantify and define key housing areas utilised on commercial GB dairy farms. 
• To evaluate farmer perceptions of space allowance recommendations and the importance of loafing space. 
• Undertake a long-term randomised controlled trial to investigate the impact of living space on: 
  • The production of housed dairy cows
  • The reproductive performance and physiology of housed dairy cows
  • The behaviour of housed dairy cows 

• Evaluate the farm economics associated with providing additional living space for housed dairy cows 

Key results

Compared to cows in the commercial average space group, cows with increased space produced more milk per 305 day lactation (primiparous cows; 12235L vs 11592L (P<0.01), multiparous cows 14746L vs 14644L (P<0.01) but took longer to conceive, 135DIM vs 101DIM (P<0.05).

In terms of underlying physiology, cows with increased living space ruminated for 15 minutes/d longer than those with less space. No differences were observed between trial groups for all other reproductive and production parameters measured.

Cows with less living space spent less time in lying (65 minutes/d) and feeding (9 minutes/d) areas, and more in passageways (64 mins/d).

When these results were imputed into a simulation model, it suggested that the reduced reproductive performance was negated by increased milk volume production for cows in the high space group. The results suggest that providing more living space will be economically viable as well as offering potential for enhancement of cow welfare.