From the August 2001 Pork News & Views Pork News and Views is prepared by the Swine Advisory Team of the Ontario Ministry of Agri- culture, Food and Rural Affairs Editor: John Bancroft Clinton OMAFRA, 519-482-3133,

Stockpeople and pigs are in regular and, often times, close contact during the course of a normal day. Pigs are sometimes restrained and subjected to some form of management or health procedure. Our behaviour during these interactions in the barn influences the pig’s response. These interactions also have an effect on the stockperson, influencing such work-related characteristics as job satisfaction. Hemsworth points to handling studies that have shown that pigs are very sensitive to brief tactile interactions from humans. Negative tactile interactions imposed briefly but regularly will produce high levels of fear of humans.

Observations in the Australian pig industry have revealed significant relationships between the attitudes of stockpeople towards interactions with pigs, the behaviour of the stockpeople, the behavioural response of breeding pigs towards humans and the reproductive performance of pigs. Experiments involving daily, short aversive handling treatments (brief shocks or slaps) resulted in pigs being less willing to approach humans.

This fear of humans has been shown to markedly reduce the growth and reproductive performance of pigs. Hemsworth has looked at pig response to humans on 19 farms in Australia and found that each farm had a different average rate of response time – it took from 80 – 160 seconds for the pigs on the various farms to approach the stockperson. These same farms also displayed a 20% variation in productivity. The differences in productivity are a result of the adverse affects of fear. Fear leads to the development of a physiological chronic stress response in the pigs as well as the potential for injuries while trying to avoid human contact. Stress hormones may adversely affect growth and reproductive performance by disrupting protein metabolism and key reproductive endocrine events.

Hemsworth has looked at ways to increase the welfare and productivity of pigs through improved handling techniques. However, simply showing stockpeople the best way to handle pigs is not the answer. Hemsworth advocates changing the attitudes of stockpeople towards their pigs. The change in attitude ultimately leads to a change in the behaviour at the farm level. This approach is known as "cognitive-behavioural therapy". Based on this theory, Hemsworth has developed and delivered a commercial multi-media training program (ProHand) which has successfully improved stockperson attitudes and behaviour, as well as pig behaviour (i.e., fear of humans) and productivity in Australia. Such a training program has the added effect of reducing staff turnover and increasing job satisfaction.

Pigs that are handled by stockpeople with a positive attitude perform better. Producers need to understand the relationship between attitudes and behaviour and to begin training staff and selecting new staff with positive attitudes. The best stockpeople:

• Like their pigs
• Are determined to meet the pig’s needs
• Have a good understanding of the requirements of their pigs, and
• Can translate this understanding through their handling practices into a high level of care which results in a high level of pig health, welfare and performance.

Seabrook et al. (1990) evaluated 12 different experienced pig stockpeople and concluded that successful stockpeople are conscientious, caring, eager to learn, humble and have good observational skills of pig behaviour.

• Dr. Hemsworth has conducted several studies investigating the effects of positive and negative handling on both behavioural and physiological responses in pigs. In 1981 he demonstrated that a handling regime consisting of regular aversive treatments (a brief shock using an electric prod) resulted in increased avoidance of pigs to the handler and reduced growth rate in juvenile pigs.

• A later study with male and female pigs indicated the effect of aversive handling; minimal handling and positive handling on the pigs would alter the behavioural, physiological and reproductive response. Gilts and boars were handled three times per week in either a positive (stroking of the pig), neutral, or aversive manner (use of an electric prod) from 11 to 22 weeks of age. Positive treatments and aversive treatments were measured against corticosteriod concentrations and reproductive performance was measured in gilts and boars after 22 weeks of age.

• Gilts in the positive handling treatment demonstrated a lower avoidance response to the handler and had lower concentrations of glucocorticoids than the unpleasantly handled pigs. The most impressive finding was the reproductive performance of the boars and gilts. The boars in the pleasant group were able to breed sooner than boars in the unpleasant group and the gilts in the pleasant handling group maintained an 87% pregnancy rate compared to the 33% pregnancy rate of gilts in the unpleasantly handled treatment.

A Model of Human-Animal Relationshipsin the Australian Pig Industry

Hemsworth et al., 1989

Penny Lawlis, (519) 873-4090 [email protected]