A cross-sectional survey of biosecurity practices on Thoroughbred stud farms in New Zealand

AIM: To examine the on-farm biosecurity practices of a group of commercial Thoroughbred stud farms in the North Island of New Zealand, in the absence of an exotic disease outbreak.

METHODS: A cross-sectional survey of biosecurity practices was conducted during the 2006/2007 Thoroughbred breeding season, and consisted of data from commercial Thoroughbred farms in the North Island of New Zealand standing a stallion. Data were collected on-farm by a single interviewer, using 17 open, closed and multiple-choice questions examining general farm/operation size and features, general animal health and biosecurity practices, biosecurity practices in relation to breeding stock, and opinions about the application of on-farm quarantine measures. Data were examined for differences in biosecurity practice between farms with and without shuttle stallions, and differing in size.

RESULTS: Data were collected from 28/34 selected farms during the 2006/2007 breeding season. Thirteen farms were classified as small, 10 medium, and five large; shuttle stallions were present on 12 farms. Commercial transporters were responsible for the delivery of 79% (3,116/3,945) of the mares. On arrival non-resident mares were rarely isolated though they were screened for cough (25/28; 89%) or nasal discharge (28/28; 100%); constraints on implementing arrival quarantine protocols for such mares were time (5/28; 18%), space (11/28; 39%), and staff workload (4/28; 14%).

In the absence of disease, few farms (3/28; 11%) implemented protocols between cohorts of horses. However, focal points of high interaction between horses, such as foaling paddocks, isolation yards and crushes, were regularly cleaned and/or disinfected. In the presence of disease, the vast majority of farms (92–100%) implemented control measures such as changing clothes and washing hands between cohorts.

Stallions were rarely quarantined on arrival. If the stallion was imported many considered pre-importation quarantine to be sufficient. Farms with shuttle stallions were more likely to have an arrival protocol in place than those that did not (92% vs 50%; p<0.05).

CONCLUSIONS AND CLINICAL RELEVANCE: Most stud managers were aware of the need for on-farm biosecurity; management constraints meant that protocols might not always be followed. The absence of an exotic disease outbreak and the overwhelming confidence of stud managers in the Ministry of Agriculture and Forestry (MAF) in preventing an exotic disease incursion were reasons for a lack of implementation of on-farm biosecurity protocols.

KEY WORDS: Horse, biosecurity, Thoroughbred, breeding, equine influenza