What the textbooks don’t tell you about… Seasonal infertility: the sting in the tail

The textbooks cover the technicalities of seasonal infertility well, if a little heavy-handedly – especially that of its core problem of autumn infertility, which I discussed last month. In the months of September and October especially, this shows up mainly in lowered farrowing rate (-8 to 10%), reduced litter size (averaging in all sows, affected or not, 0.6 fewer pigs litter) and weaning to conception intervals well over seven days in many sows.   Not every year, however. Puzzlingly