Canadian Poultry Magazine

Human Impact

By by L.E. Edwards1 P.H. Hemsworth1 and G.J. Coleman   

Features New Technology Production

Increasing interaction with hens improves productivity

Increasing interaction with hens improves productivity

This study found that increased stockperson interactions were associated with lower fear of humans in laying hens and increased productivity.

Extensive studies in the livestock industries have shown marked between-farm variation in the fear responses of farm animals, including poultry, to humans.1 Furthermore, studies have found a negative inter-farm correlation between fear of humans and the productivity of laying hens; this relationship was considered to be mediated by a stress response.2 Such negative correlations indicate that high levels of fear of humans may be an important factor limiting the productivity of laying hens.
Studies in the dairy and pig industries have shown significant relationships between the stockperson attitudes and behaviour towards animals and the fear responses and productivity of animals. Similar work in the broiler industry found no relationship between stockperson attitudes and behaviour, but did find evidence for the existence of relationships between stockperson behaviour, bird behaviour and bird productivity.3 The existence of relationships between human and animal variables in the livestock industries indicates that the opportunity exists to modify stockperson attitudes and behaviour in order to improve livestock welfare and productivity, and such opportunities may also exist in the poultry industries.


Since earlier studies, new strains of laying hens have been introduced to the Australian industry, and the use of fully enclosed environmentally controlled sheds has increased. In addition, Barnett’s work did not measure the attitudes of the stockpeople, nor observe stockpeople interacting with the hens, although an estimate of time spent working in the sheds was provided by the stockpeople themselves. Due to the observed behavioural differences in hen strains and the more intensely controlled environment of the fully enclosed laying sheds, which reduces the amount of stockperson labour required, the present impact of human-bird relationships is unknown.4 The aim of the present study was to explore the relationships between stockperson attitudes and behaviour and bird fear in today’s egg industry.

Material and methods
Data were collected at 29 laying sheds on 21 commercial egg farms located in Victoria and New South Wales, Australia, and Ohio, U.S., over a two-year period. Each shed was visited for three days, and during this time data were collected on the attitudes and behaviour of stockpeople working in that shed, and the fear of an unfamiliar human displayed by the hens. The human observation data from five farms is still being collated and thus the results from 24 laying sheds are presented in this paper.

Individual stockperson behaviours were recorded for the main stockperson managing each shed over a two-day period. The total amount of time that the stockperson spent in different areas of the shed and the total number of stockperson interactions with birds (tactile, close visual and auditory contact) were recorded during bird inspections, as bird inspection was a common task performed in every shed. From these observations the following stockperson behaviour variables, adjusted for aisle length, were calculated: time spent in the aisle, time spent stationary in the aisle, close approach to birds, contacting the cage, feeder or egg belt, hand in cages, incidence of noise and total number of husbandry activities that occurred in the aisles without cage approach. Frequency of the above behaviours was recorded using a 5-s bout criteria interval. Speed of movement was calculated using the duration of time spent walking and the length of the aisle, producing the average speed of movement along the aisle. The individual stockperson data were used for analysis of the attitude-behaviour data, while the total behaviour data for all stockpeople in each shed were used for the analysis of the stockperson and bird behaviour data, using shed averages.

The attitudes of individual stockpeople were assessed using an attitude questionnaire, which was composed of three sections: beliefs about working with laying hens, beliefs about the characteristics of laying hens and beliefs about interacting with laying hens. Due to the large number of questionnaire items, separate Principal Components Analyses were used to reduce the number of items in each section to a manageable number by identifying a small number of components, or groups of variables, that were statistically interrelated. The seven resulting variables accounted for between 39 and 48 per cent of the variance in responses, and all item groups obtained a Cronbach alpha score greater than 0.62. The questionnaire data were converted to scores and arbitrarily labelled to represent the group of questionnaire items that formed each component.

The level of fear of humans in laying hens was assessed by measuring the withdrawal response of birds to an unfamiliar human using the Approaching Human Test (AHT)5. During the AHT, the experimenter moved directly in front of the focal cage for 5 seconds and then stepped away for another five seconds. This procedure was repeated twice over a 20-second period. During each five-second period, the experimenter counted the number of birds with heads extended through the front of the cage and the maximum number of birds that moved their head into the front 5 cm of the cage, and made a point count of the number of heads still at the cage front at the end of each five-second period. This test resulted in a large number of variables, and a Principal Component Analysis was used to reduce the number of variables studied from 12 to two. These two resulting variables accounted for 81 per cent of the variance in the avoidance response. These data were converted to scores and labelled as the variables “FORWARD SCORE” and “HEADS OUT SCORE.” A high score for either was considered to indicate less avoidance or low fear of humans. Shed averages of these scores were used in analysis.

The study found that U.S producers spend less time withy the bird and the hens are more anxious.

Birds in sheds in the U.S. displayed significantly greater (P < 0.01) avoidance responses than those in the Australian sheds, and stockpeople in the U.S. spent significantly less (P < 0.04) time in the sheds and interacted less with their birds. Thus, country was controlled for in partial correlations  conducted to examine the correlations between stockperson attitudes, stockperson behaviour and bird behaviour.

Four of the seven attitude scores correlated with the individual stockperson behaviours observed during routine bird inspections and the main correlations between two of the scores and stockperson behaviours are reported in Table 1 as an indication of these attitude-behaviour correlations. Agreement by stockpeople with the statements in the attitude score labelled – DILIGENCE – which consisted of statements reflecting the importance of keeping a regular work routine, a thorough routine, and ensuring that the birds’ requirements are met, was positively correlated with the stockperson behaviour variables “TIME IN AISLE,” “TIME STATIONARY,” “CAGE APPROACH” and “CAGE ENTRY” during inspection of the birds by the stockperson. Agreement by stockpeople with the statements in the attitude score “NEGATIVE ASPECTS OF THE JOB,” which consisted of statements reflecting dissatisfaction with the job, was positively correlated with the stockperson behaviour variables “SOM” and more “NOISE” by the stockperson during inspections.

 Several stockperson behaviours were correlated significantly with bird behaviour. The variable “NOISE” was negatively correlated with both the “FORWARD SCORE” (r = -0.57, P = 0.01) and the “HEADS OUT SCORE” (r = -0.46, P = 0.03), indicating that birds showed greater avoidance of the experimenter in sheds where there was a higher incidence of noise.

The “HEADS OUT SCORE” was positively correlated with the variables “VISUAL CONTACT” (r = 0.55, P = 0.01), “CAGE APPROACH” (r = 0.43, P = 0.04) and “CAGE CONTACT” (r = 0.43, P = 0.04), indicating that birds showed lower avoidance of the experimenter in sheds where there was an increased frequency of human activity.


The results of the present study provide evidence of relationships between stockperson attitudes, stockperson behaviour and bird fear. Stockpeople who scored highly on the attitude score “DILIGENCE” (that is, agreed with the statements on the importance of diligence) tended to spend more time working in the aisles during inspections, whilst stockpeople who scored highly on the attitude score “NEGATIVE ASPECTS OF THE JOB” tended to move more quickly and make more noise during inspections. On farms where there was a lower incidence of noise and a higher incidence of human activity in the aisles the birds displayed low fear of humans. These results suggest that selection or training of stockpeople on poultry farms should target diligence and job motivation. This may lead to improved stockperson behaviour and reduced bird fear. These results also are consistent with similar work conducted in the pork and dairy industries, in which stockperson attitudes were correlated with stockperson behaviours, which in turn were correlated with animal fear.6,7

Fear is an undesirable emotional state of suffering that may reduce the welfare of intensively farmed poultry, and thus these relationships between stockperson attitudes, stockperson behaviour and bird behaviour have implications for bird welfare.8 As shown in other livestock industries, training and selection programs targeting these key stockperson attitudes and behaviour may provide opportunities to improve bird welfare in those situations in which human-animal relationships are less than optimal.9 The implications of bird fear on bird productivity require rigorous examination.

1Animal Welfare Science Centre, University of Melbourne, Parkville, Victoria, Australia, 3052.
2Department of Psychology, Monash University, Clayton, Victoria, Australia, 3800.

The financial and technical support of the Australian Poultry Cooperative Research Centre, the University of Melbourne, Cooper Farms, Ohio State University and the Department of Primary Industries for this research is gratefully acknowledged.


  1. Hemsworth, P.H. and Coleman, G.J. (1998) Human-livestock interactions. The stockperson and the productivity and welfare of intensively farmed animals, Oxon, CAB.
  2. Barnett, J. L., Hemsworth, P.H. and Newman, E.A. (1992). British Poultry Science, 33, 699-710.
  3. Cransberg, P.H., Hemsworth, P.H. and Coleman, G.J. (2000). British Poultry Science, 41, 272-279.
  4. Craig, J.V., Craig, T.P. and Dayton, A.D. (1983). Applied Animal Ethology, 10, 263-273.
  5. Hemsworth, P.H., Barnett, J.L., and Jones, R.B. (1993). Applied Animal Behaviour Science, 36, 197-210.
  6. Breuer, K., Hemsworth, P.H., Barnett, J.L., Matthews, L.R. and Coleman, G.J. (2000). Applied Animal Behaviour Science, 66, 273-288.
  7. Hemsworth, P.H., Barnett, J.L., Tilbrook, A.J., and Hansen, C. (1989). Applied Animal Behaviour Science, 22, 313-326.
  8. Jones, R.B. and Waddington, D. (1992). Animal Behaviour, 43, 1021-1033.
  9. Hemsworth, P.H. (2003). Applied Animal Behaviour Science, 81, 185-198.

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