although your record will not show it, there is a big probability na nagkaroon ng problem ang inahin during sa 2nd trimester it is either hindi lang masyado nagmanifest externally, or like heat stress lang siya.
Kung titingnan kais natin ang timeline ito magiging itsura...
Breeding 1st trimest(0-38 days) 2nd trimester (39-76) 3rd trimester (77-114)
ok 6 eggs fertilezed 5 died to stress etc development of piglet 1 piglet farrowed
kung less than 5 kasi ang fertilized pag dating ng 2nd trimester reheat na ito. Kaya ang pinapatingnan for reheat is day 21 and 42. yun day 42 pasok sa second trimester.
sa case sa boar ok din na tingnan nyo kasi kung overused nga siya at 1st trimester konti nga lang mafefertilize dahil konti lang semilya niya.