Sus scrofa domestica
Order: Artiodactyla Family: Suidae
1) General Zoological Data
Suidae had their origin in Eurasia and distributed widely while speciating into significantly different phenotypes and behavioral repertoires. The Suiformes are presumed to be the most primitive of the artiodactyls. The Artiodactyla are considered to have formed three major groups: the Suiformes, Tylopoda and Pecora (Groves, 1981). Warthogs are believed to be perhaps the most recent derivatives of suidae. Bosma (1978) reviewed the reasons for placing Phacochoerusaway from the other suidae because of their differential dental structures. Nevertheless, the similarity of chromosomes (v.i.) argues against this notion. She suggested a recent origin of this species. On the other hand, in his searching discussion of suid development, Thenius (1970) found justification of separating this most recent suid species; he placed the first ancestor into the middle of the Oligocene (+/- 28 MYA).
There are a very large number of special strains of domestic pigs. Some of the better-known varieties being the pot-bellied pig, miniature pig, etc. Males are generally larger. The longevity of various Sus species in captivity was given by Jones (1993). Maximal life span for a European wild pig was 21 years. Domestic pigs were not included in that survey. It is known, however, that external influences (leg weakness Jorgensen, 2000), age of first conception (Koketsu et al., 1999) and other factors affect longevity and productivity of swine and these may have important commercial ramifications (D'Allaire et al., 1992).
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