The frequency and distance of movements of pigs and semen between commercial and non-commercial piggeries in New Zealand

Abstract

AIMS: The study was conducted to identify movement patterns of disease conveyors in the New Zealand pig industry. The principal objective of the study was to identify data relating to the frequency and distance of movements of pigs and semen amongst pig holdings. A secondary objective of the study was to generate criteria suitable for categorisation of different pig breeding or raising operations.

METHODS: Prospective data were collected by a census of all known pig holdings in New Zealand using a mailed-out questionnaire.

RESULTS: The survey yielded 1,477 responses (114 commercial and 1,363 non-commercial pig holdings) for descriptive analysis. Seven farm-types were created to describe typical pig holdings and were based on pig herd inventory, herd type, and participation in the movement of pigs or semen: Commercial genetic supplier, commercial feeder, commercial weaner producer, para-commercial genetic supplier, para-commercial feeder, para-commercial weaner producer, and non-commercial herd. The farm-type with the highest frequency of movements off the piggery was the para-commercial genetic suppliers with a median of 5.3 movements off per month. Commercial feeders had the second highest off farm movement with a median of 4.6 movements per month; these primarily represented movements to an abattoir. The highest frequencies of movements on to a piggery were experienced by commercial genetic suppliers (3.5 per month) and were due to the delivery of semen or replacement gilt/boars. Para-commercial and non-commercial farm-types reported less frequent movement activities both onto and off the piggery compared to their commercial counterparts. Most movements of pigs and semen occurred over distances of less than 100 km.

CONCLUSIONS: The study showed that New Zealand has a relatively small but widely dispersed commercial pig industry with a large number of non-commercial pig holdings and there was a substantial geographic overlap between these industry sectors. Knowledge of the frequency of movements of pigs and semen among different pig farm-types and the distance over which these movements occur helps to assess the likely connectivity between piggeries, abattoirs, and sale yards. However, the study also highlighted the knowledge deficiencies that result in the absence of mandatory livestock identification and tracking schemes.

CLINICAL RELEVANCE: In an industry with substantially more non-commercial pig holdings than commercial pig-holdings, key issues such as biosecurity education, ensuring sufficient veterinary involvement in non-commercial sectors, and building robust systems to ensure border security will remain critical in the effort to keep the pig industry at its current level of high health.

KEY WORDS:

• Pig
• epidemiology
• infectious disease transmission
• biosecurity
• semen

Acknowledgements

Funding for this study was provided by MAF. Assistance with database development and data input was provided by Angus Davidson, Grant Jeffrey, and Rhona MacKenzie from Prime Consulting International Ltd and staff at AsureQuality. The assistance of NZ Pork and its members in pilot testing the questionnaire is gratefully acknowledged.

Notes

¹ http://dx.doi.org/10.1080/00480169.2012.715377

² FL Clement, NZ Pork, Wellington, New Zealand.

³ Personal communication. Robert Sanson, AsureQuality, Palmerston North, New Zealand.

* Non-peer-reviewed