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

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.

Vitamin E, selenium and polyunsaturated fatty acids in clinically normal grower (9-16 weeks old) pigs and their feed: their relationship to the vitamin E/selenium deficiency ("VESD") syndrome.

Vitamin E, selenium and polyunsaturated fatty acids (PUFAs) were determined in feed used at three piggeries over.a four week period and compared with corresponding concentrations in clinically normal grower pigs at slaughter. Mean values were vitamin E: 59 IU/kg (feed), 6 micromol/kg (liver), 1.7 micromol/l (serum); and selenium: 310 microg/kg (feed), 5200 nmol/kg (liver), 1700 nmol/l (blood). Alpha-tocopherol accounted for 80% of the mean vitamin E activity in the feed and over 95% that in the liver and serum. The mean ratio of PUFA to total fatty acid (FA) in the feed (38%) was similar to that in the serum (36%) and liver (39%), but the ratio of peroxidisable PUFA (PPUFA) to FA increased from 1.7% in the feed to 4.2% in the serum and 10.8% in the liver. The ratio of alpha-tocopherol (mmol) to PPUFA (mol) in the liver varied from 0.16 to 0.48. The relationship of these data to the VESD syndrome is discussed in the light of other published data.