Animal health and production results in swine stocks originated from Dalland SPF farms

Animal health and production results of swine stocks have been reported that originated from the French SPF nucleus farm of Nieuw-Dalland Hybrid Pig Breeding Centre (Venray, the Netherlands). The farm operated with 400 sows was established in 1990 and yearly 9000 SPF piglets are born on the farm. The stock is free of 14 diseases, as well as pathogens (Table 1). The free status has systematically been checked by laboratory (serological, bacteriological,virological and parasitological) investigations. After having treated the main purposes of establishing SPF swine stocks, production results of SPF and conventional Dalland breeding stocks have been compared in Table 2. Fattening results of high health state and conventional Dalland fatteners have been compared in Table 3. Results of Hungarian high health state Dalland breeding stocks are also excellent: of the 2120 gilts imported in 1994 2059 (98.1) became pregnant and 1975 (93.2) farrowed (Table 4). Only artificial insemination (A. I.) has been used. By the Dalland A. I. method 90.6 of gilts became pregnant after a single insemination. Losses up to weaning were 6.3, on an average and 2.4 from weaning up to marketing (Table 5). Production and test results of end product have been summarized in Tables 6 to 7. After a brief summary of biological reasons for the better production of results of SPF pigs, as well as arguments and counter-arguments against breeding pigs under SPF conditions, adaptation methods of SPF pigs to conventional rearing conditions have been reported. During the use of the specific adaptation method under the umbrella of vaccinations, there is a possibility for the eradication of certain infectious diseases (first of all Aujeszky's disease, atrophic rhinitis and Antinobacillus pleuropneumoniae) and improvement of the health state of the former stock. The so-called 'dirty' adaptation method ensures the protection of introduced SPF pigs without improving significantly the former health state of the stock