The impact of living space on dairy cow production, reproduction and welfare

Thompson, Jake S (2021) The impact of living space on dairy cow production, reproduction and welfare. PhD thesis, University of Nottingham.

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Abstract

The majority of dairy cows worldwide are housed for several months of the year, yet there is limited literature available on how the housed environment impacts on their productivity, health and wellbeing. The extent to which specific housing conditions affect individuals or herds of cows or how to improve housing to optimise productivity, health and welfare is unclear. Furthermore, the terminology used for housing requirements is often poorly defined or lacks a standard definition.

It is likely that the housed environment will affect dairy cows. Research on housing for humans has shown that space allowance is the single most important characteristic of the housed environment. Sustainable intensification has suggested that animal welfare and production are inter-linked meaning higher welfare standards should be factored into assessments around the suitability of a cow’s environment, alongside health and production which have been used historically. The conditions within dairy cow housing are therefore fundamental to the sustainability of dairy farming and the wellbeing of farmed cattle.

The context of this research was underpinned by a UK stakeholder group convened by funders of the research, the Agricultural and Horticultural Development Board (AHDB) to identify areas related to cow housing which were deemed to have an inadequate scientific basis or limiting the industry. The stakeholder group comprised retailers, milk processors, dairy consultants, academics and farmers, and the group undertook a one-day workshop with detailed discussions on all aspects of dairy cow housing. There was unanimous agreement that “loafing space” was an essential component of housing for adult cows for which the scientific basis was poor. This insight provided the basis for this research; to provide important and relevant information to the industry to enhance the understanding of space provision for dairy cows.

The aims of this thesis were to investigate:

1. The quantity, types and variability of space allowances currently provided for dairy cattle in British dairy herds.

2. The extent to which an increase in living space influenced productivity, fertility, behaviour and economic returns of dairy cows.

Initially a field survey of 53 randomly selected dairy farms across Great Britain was undertaken to obtain representative data on current commercial housing systems, to measure space provision for cows and gained farmers opinions on the housed infrastructure. Living space, a novel metric to describe the additional space above that deemed to be a baseline requirement for housed dairy cows was defined. Statistical analysis showed that there was large variation among GB dairy farms in terms of total space allowance (range from 5.4m2 to 12.7m2, mean= 8.3m2, median= 8.2m2, IQR= 1.9m2) and living space allowance (range from 0.5m2 to 6.4m2, mean= 2.5m2, median= 2.4m2, IQR=1.6-3.2m2). Questionnaire responses regarding loafing space importance revealed that the majority of farmers felt it was essential for cow health, welfare and production.

To evaluate the extent to which an increase in living space could influence productivity, fertility, behaviour and economic returns of adult dairy cows a 1-year randomised controlled trial (RCT) was carried out. The RCT was a longitudinal, matched, parallel-group, cross-over trial to quantify the superiority/inferiority of specified living space allowances for housed dairy cows. Two groups of matched commercial Holstein cows were provided with 9m2 (3m2 living space; Control space group) and 14m2 (6.5m2 living space; High space group) respectively. Three main outcomes were investigated: milk production, reproductive performance and behaviour.

In terms of milk production, it was found that a primiparous cow given a greater living space produced 643L more milk over a 305-day lactation than a primiparous cow in the control space group (12,235 vs. 11,592L). Less of a difference was observed in the multiparous subpopulation, with cows in the high space group producing 14,746L compared to the control space cow of 14,644L per 305-day lactation. Physiologically, the high space cows ruminated for a greater duration per day and produced more milk solids per lactation.

Analysis of reproductive performance showed a negative association between increased space allowance and time to conception. Primiparous cows in the high space group had median time to conception of 155 days compared to primiparous cows in the control space group of 83 days. Median time to conception for multiparous cows was 133 days when in the high space group compared to 109 days in the control space group. However, no physiological reproductive parameters were different between groups, thus evidence of an underlying mechanism for the difference in reproductive outcome was not identified.

Analysis of daily time budgets identified that lying times increased by 63 minutes (High space: 12.43 hours/day, 95% CI = 11.70-13.29; Control space: 11.35 hours/day, CI = 10.73-12.12) and time spent in passageways decreased by 87 minutes (High space: 7.10 hours/day, 95% CI: 6.48-7.53; Control space: 8.17 hours/day, 95% CI: 7.48-8.88) when an increase in living space was provided. Therefore, fundamental changes in behaviour were associated with changes in the living environment.

Using a theoretical simulation model, it was shown that an increase in living space is likely to lead to increased financial returns. Dairy herds with average culling rates for the UK were estimated to have an increased financial return of £33.75-53.34 per cow per year for a living space allowance of 6.5m2 compared to 3m2. This is likely to be economically viable in terms of payback for the fixed costs associated with providing 3.5m2 more living space allowance, mainly due to the increased financial returns from additional milk yield of the cows given greater living space.

In conclusion, this research provides evidence that the quantity of living space offered to adult dairy cows affects milk production, reproductive performance and behaviour. Additional research is urgently needed to allow further exploration of this complex issue to optimise the housed environment for adult dairy cows and therefore enhance the sustainability of dairy farming.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Green, Martin J
Hudson, Christopher D
Kaler, Jasmeet
Coffey, Tracey J
Robinson, Robert S
Woad, Kathryn J
Keywords: Dairy cows, Living space, Production, Reproduction, Animal welfare, Behaviour, Economics
Subjects: S Agriculture > SF Animal culture
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Veterinary Medicine and Science
Item ID: 66763
Depositing User: Thompson, Jake
Date Deposited: 08 Dec 2021 04:40
Last Modified: 08 Dec 2021 04:40
URI: http://eprints.nottingham.ac.uk/id/eprint/66763

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