The Animal WelfareScience Centre

The effect of milking shed noise on dairy cow behaviour using a Y mazeAdele Arnold (NZL)

University of MelbourneAnimal Welfare Science CentrePrimary Industries Research Victoria, Australia

Introduction Introduction

The milking parlour is a novel and possibly stressful environment for dairy cattle.

– Human contact

– Conspecifics

– Physical environment:

illumination, noise, confinement, flooring surfaces, etc.

Noise in the milking parlour Noise in the milking parlour

The background sound level in a normal commercial milking facility ranges from 75-85 dB

Acknowledgment of both physiological and psychological effects of environmental noise on human health.

What effect does this noise have on the behaviour and physiology of the dairy cow?

Y maze choice test Y maze choice test

Aimed to evaluate the effect of milking parlour noise on choice behaviour of heifers using a Y maze

Also measured heart rate (HR), time to choose and ease of moving animals

Y maze apparatus Y maze apparatus The Y maze contains two alternative directions of travel

(short maze arms)

Subjects were trained to form associations between each direction and either presence or absence of noise

Procedure Procedure

Day 0: habituation 3 trials

Day 1: training + test 5 trials

Day 2: training + test 5 trials

Day 3: one-off test 1 trial

For each animal, the noise stimulus was presented in the first arm entered on day 1.

16 heifers

Maze side choice Maze side choice

0

20

40

60

80

100

1 2 3 4

Choice No.

% q

uie

t s

ide

ab, p<0.01

a

b b

b

Additional measurements Additional measurements

1. Training trials:

Heart rate in maze arm

Restlessness in maze arm

Number of stops

Handler interventions

2. Choice trials: Maze junction transit time (reflects choice time)

Heart rate in arm

Heart rate in maze arm Heart rate in maze arm

50

60

70

80

90

100

110

120

1 2Day of training

BP

M

NoiseQuiet

ab, p<0.01

b

a

Restlessness in maze arm Restlessness in maze arm

0

0.1

0.2

0.3

0.4

0.5

1 2

Day of training

pro

po

rtio

n o

f ti

me

Noise

Quiet

ab, p<0.01

bb

a

a

Number of stops Number of stops

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1 2Day of training

sto

ps

NoiseQuiet

ab, p<0.01

bb

a

a

Maze junction transit time - choices Maze junction transit time - choices

0

5

10

15

20

25

1 2 3 4

Choice No.

Se

cs

Noise

Quiet

Heart rate in maze arm - choices Heart rate in maze arm - choices

50

60

70

80

90

100

110

120

1 2 3 4

Choice No.

BP

M

NoiseQuiet

Discussion - noise Discussion - noise

These results suggest that dairy heifers prefer to avoid exposure to milking parlour noise if given the opportunity

Noise may affect:

— time to enter the milking facility — ease of moving animals for handlers — restlessness of animals in the parlour

Discussion - method Discussion - method

Heifers showed an increasing tendency to choose the quiet arm

This was slow to develop in some heifers.

— Learning time, or— original bias for choosing the noise arm (first side

chosen)

An original maze arm bias may also explain the increased choice times and reduced HR in those animals that continued to choose the noise arm.

Acknowledgements Acknowledgements

This research was funded by Dairy Australia

PhD Supervisors: Paul Hemsworth, Ellen Jongman and Kim Ng

Number of handler interventions Number of handler interventions

0.0

0.2

0.4

0.6

0.8

1.0

1 2Day of training

tap

s

NoiseQuiet

b

ab, p<0.01

b

a

a