Naomi Adele Arnold

The relationships between characteristics of milking sheds and the attitudes to dairy cows, working conditions, and quality of life of dairy farmers

This study consisted of a survey of dairy farmers and their milking sheds at 198 Victorian dairy farms to examine the relationships between physical features in the milking shed and a number of job-related characteristics of the farmer, such as attitudes to handling cows and job satisfaction. Furthermore, farmers’ opinions of the effects of specific design features of the milking shed on cow behaviour were sought. A further objective of this survey was to use the relationships between shed characteristics and job-related characteristics of the farmer to identify, for future research, possible features of the milking shed that may affect cow behaviour. There was substantial variation in both the behavioural beliefs of farmers about cow behaviour in the milking shed and reports by farmers on comfort and working conditions in the dairy, indicating that considerable opportunities exist to improve these key job-related characteristics. A principal component analysis (PCA) of the responses to the questions on job-related characteristics of the farmer identified 6 factors: 2 of the factors identified were related to behavioural beliefs by farmers about cow behaviour (labelled ‘Cow Movement’ and ‘Cow Behaviour’); one of the factors related to comfort of the farmer in the shed (labelled ‘Operator Comfort’); and 3 of the factors related to aspects of the quality of life of the farmer (labelled ‘Workload’, ‘Farmer Mood’, and ‘Job Characteristics’). Positive beliefs about both cow movement (factor called Cow Movement) and cow behaviour (factor called Cow Behaviour) were correlated with farmers being more positive about working in the dairy (factor called Operator Comfort; P < 0.05 and P < 0.01, respectively) and the characteristics of the job (factor called Job Characteristics; P < 0.01). These relationships suggest that improvements in cow behaviour may lead to improvements in both job satisfaction and the quality of life of the farmer. Furthermore, regression analysis revealed that a number of the shed features, such as height of the breast rail, presence of stall gates, length and width of the platform and solid side on first milking bail, were significant predictors of one or more of these 6 PCA factors. Although these results may not reflect causal relationships, these relationships between shed characteristics and a number of job-related characteristics of the farmer highlight the potential importance of shed design to both the cow and the farmer and provide a valuable guide in identifying features of milking sheds that require future examination as to their effects on cow behaviour.

Behavioural responses of lambs to plastic clips as an alternative procedure to mulesing

OBJECTIVE Compare the effects on the behaviour of lambs of applying occlusive plastic clips, as an alternative procedure to surgical mulesing, with tail docking, surgical mulesing and a control treatment. PROCEDURE We allocated 48 6-7-week-old Merino lambs to four treatment groups: plastic clips (Clip); surgical mulesing (Mules); tail docking with a rubber ring (Tail ring); no treatment (Control). For each posture and behaviour observed on each of the 4 days post-treatment, a Dunnetts multiple comparison test was used to simultaneously compare the Clip treatment with each of the comparator treatments (Control, Tail ring and Mules treatments). RESULTS Most of the significant differences (P < 0.05) detected between the comparator treatments occurred on day 1. For four of these measurements, the Clip treatment differed (P < 0.01) from the Mules treatment, but from not the Control and Tail ring treatments: the Clip lambs spent less time standing immobile not interacting with ground, hay or feeder, less time standing immobile head down not interacting with ground, hay or feeder, more time walking and more time interacting with ground, hay or feeder. CONCLUSION These behavioural results, together with previous behavioural and physiological research, indicate that the effect on lamb welfare of applying occlusive clips is less than that of surgical mulesing.

The choice behaviour of pigs in a Y maze: effects of deprivation of feed, social contact and bedding.

We examined effects of deprivation of feed, social contact and bedding on the choice behaviour in Y maze tests. Eighty pigs were used to study two main effects: feed (estimated voluntary feed intake (VFI) vs. 70% VFI) and bedding (presence vs. absence), experiment 1; social contact (full vs. restricted) and bedding (presence vs. absence), experiment 2; and feed (as in experiment 1) and social contact (as in experiment 2), experiment 3. Overall pigs consistently chose feed and social contact over bedding. While social contact was more preferred than feed in experiment 3, there was substantial variation between pigs in their choice behaviour. The overall choice behaviour in experiment 3 contradicts previous research, but differences such as the preference methodology as well as the level of deprivation, level of reward and cost involved in accessing reward, may be responsible. Average daily weight gain (ADG) was affected in experiment 3: both feed and social restriction reduced ADG. While the feed effect is expected, one interpretation of the social effect is that social deprivation, through stress, may have reduced ADG. These results provide limited support for the notion that deprivation of a highly preferred resource may disrupt biological function.

Examining the usefulness of a Y-maze choice method to measure the preferences of laying hens

Measurement of animal preferences can be used as an indirect, but persuasive, method for assessing animal welfare on the basis that preferences may identify resources and behaviours that might be important to animals. The present experiment examined the usefulness of a Y-maze methodology, incorporating alteration of motivational state through prior restriction of resources of potentially differing value in assessing and understanding animal preferences. The choice behaviour of laying hens for feed, a dustbath substrate (sawdust; ‘dust’) and social contact was measured under three pairwise comparisons in a Y-maze apparatus. In each of the three experiments, 48 birds (HyLine Brown Strain; n = 24 per experiment) were offered a choice of two resources in a Y-maze test, with one of the three possible resource pairings. In each experiment, after Y-maze training, an equal number of birds was deprived in a factorial design of Resource 1, Resource 2, both, or neither resource. Analysis of choices over 24 trials per bird in each experiment revealed that birds preferred feed over social contact or dust, irrespective of restriction of any of these resources, and further, were quicker (P < 0.01) to make feed choices than dust or social-contact choices. In the social contact and dust comparison, restriction of dust significantly (P < 0.05) increased choice for dust in the 24 trials (38 vs 53% dust choice), suggesting that dust restriction increased the birds’ motivation to access dust. This result potentially highlights the impact of the resource of comparison in pairwise tests on overall choice response to restriction. The inclusion of measurements of speed of movement through the Y maze proved a useful aspect of the methodology, providing results consistent with choice behaviour in all three experiments. Although overall choices for dust and social contact were not significantly (P = 0.328) different from random, birds were quicker (P < 0.05) to make dust choices than social-contact choices, suggesting that speed of choice may be a particularly sensitive correlate of current motivation levels. The consistency of results across these experiments, together with results reported in the literature on laying-hen preferences, suggests that the methodology is a promising option for assessing the relative preference for resources for laying hens. Additional evidence, particularly on the occurrence of abnormal behaviour, stress physiology and health, when restricted of the resource of interest is necessary to provide a more comprehensive assessment of the impact of the restriction on animal welfare.

Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: evidence of fear of heights in cows (Bos taurus).

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows.