The position of the Dutch Farmers' Union on lessons learned and future prevention and control of foot and mouth disease.

Foot and mouth disease (FMD) has devastated animal husbandry in The Netherlands frequently in the past and still constitutes a threat. The use of vaccination reduced the number of outbreaks in The Netherlands in the 20th Century. However, the desire of some member states of the European Community not to use vaccination led to a new strategy based on stamping-out of infected and contagious farms and to strict transportation regulations. In 2001, this proved very disruptive to the wider rural economy, such as the recreational and tourism sectors. The policy also caused severe animal welfare problems and psychological problems among farmers and their families. This raised questions about the wider, and not only veterinary or agricultural, implications of control strategies of foot and mouth disease virus (FMDV). The technology seems to be in place for a return to the use of protective vaccination against FMDV during an outbreak, provided the Office International des Epizooties (OIE: World organisation for animal health) and European Commission (EC) receive data that substantiate the reliability of differentiating tests such as the 3ABC enzyme-linked immunosorbent assay (ELISA) for use in individual animals. Research is in progress but may not be able to produce these data until 2003 or 2004. High potency vaccines should be used to elicit sufficient immunity within three to four days. During an FMD crisis, farmers should be assisted to find markets for products from areas affected by FMDV. The human dimension of any FMD outbreak must be dealt with sufficiently in any contingency plan.

Karyotypes of 3- or 4-day-old pig embryos after short in-vitro culture.

Pig embryos (3-4 days old) were grown for approximately 21 h in microdroplets under mineral oil with vinblastin sulphate as the mitotic inhibitor. From 10 gilts, 115 eggs were cultured: 8 proved to be unfertilized oocytes, 9 did not contain mitotic figures, 16 contained fewer than 3 good mitotic figures and 80 were judged to be of normal karyotype. A few polyploid cells were encountered, possibly of trophoblast origin. One embryo was a haploid and another one a 2N/6N mixoploid. In one gilt, in which there was no evidence of fertilization, a tetraploid embryo was discovered, and was assumed to be parthenogenetic.