Determination and analysis of the economic optimum culling strategy in swine breeding herds in Western Europe and the USA.

Abstract

Optimal sow culling strategies were compared for the Netherlands, Belgium, UK, Denmark, German Federal Republic and the USA. The annual sow replacement rate for the 6 countries averaged 47, 57, 39, 49, 50 and 59% resp. The net present value of the total extra profits (termed retention pay-off; RPO) to be expected from keeping a sow until an optimal parity (estimated using the PorkCHOP economic replacement model) instead of replacing her immediately is tabulated for parities 1, 2, 3, 5, 7 and 9 for each country. In the Netherlands, Belgium, the UK and USA, sows of av. merit had a small positive RPO index after 9 parities, indicating an economic optimal lifespan of 10 parities. In Denmark and the German Federal Republic, the optimal lifespan was 6 and 7 parities resp. The loss in income due to delayed conception (since fewer pigs can be sold) was highest in Denmark and the USA (both Dfl 4.80 per extra day open), and lowest in Belgium and the UK (Dfl 3.35 and Dfl 3.33 resp.). For all countries, the more favourable the ratio of slaughter price of culled sows:cost of replacements, then the shorter was the optimal herd life. (Abstract retrieved from CAB Abstracts by CABI’s permission)