Journal of Archaeological Science 1983, 10, 483-488 Pigs, Piglets and Determining the Season of Slaughtering Roel C. G. M. Lauwerier" The procedure for determining the season of slaughtering of pigs on the basis of age at the time of death is discussed. The starting points of this procedure, the frequency and time of birth, are contested on the basis of biological and historical data. The factors that determine the frequency and time of birth of pigs, that must be known for the correct use of this procedure are described. Keywords: PIG, BREEDING, SEASON OF SLAUGHTERING, HISTORICAL INFORMATION. Introduction In a 4th century cemetery in Roman Nijmegen (The Netherlands) dishes in some graves contained the bones of sucking pigs and piglets. I wanted to determine which season the people were buried on the basis of these pig bones. In a number of publications the season of slaughtering of pigs has been estimated on the basis of the age of the animal at the time of death (Clason, 1967; M0hl, 1978; Prummel, 1980; van Wijngaarden, 1980; IJzereef, 1981). This procedure is based on the assumption that piglets are born once a year, in March, April or May. On the other hand Boessneck & von den Driesch (1979) and Hatting (1981) take into account the possibility of having two farrowings a year, in February-March and August-September. In this paper I discuss biological and historical evidence that frequency and time of farrowing can vary depending on several factors such as food supply, climate, economic factors and the farmers' know-how. For the graves from Roman Nijmegen this has the consequence that the season of slaughtering of the pigs found and, in consequence of this, the season in which the people were buried can not be determined. The Nijmegen bones are only used as an example in this paper and are not repre- sentative of the whole cemetery. From only eight of 56 graves containing dishes could the very fragile contents of the dishes be partly saved during the excavation. Three of these contained pig bones for which the age of the animal at death could be determined. Modern Pig and Wild Boar The modern sow is on heat every three to four weeks, this not being bound to any particular season (Reinders, 1879; Dommerhold, 1951; Pond, 1983). Therefore the pig could actually be served throughout the year. However in professional breeding as well as "Archaeozoological Department, Biologisch-Archaeologisch Instituut, Groningen, The Netherlands. 483 0305-4403/83/050483+06 $03.00/0 © 1983 Academic Press Inc. (London) Limited Journal of Arch. Science 1983_10. pdf