Factors affecting growth and body dimensions of pigs reared in alternative production

The objective of the present study was to investigate the effect of farrowing month (FM) and sex on growth performance (GP), measured in terms of body weight (BW) and dimensions such as the girth, length and the leg heights, of purebred Berkshire pigs reared in a hoop structure. Body weights were recorded at birth and every four weeks until 20th week for all traits. Backfat thickness (BF) was measured at the shoulder, in the middle and at the back with an ultrasound prior to slaughter. Least square means of GP traits were estimated with Proc Mixed in SAS 9.3 for fixed effects such as sex, parity, FM and FM by day of age interaction. Sex did not have a significant effect on GP. Farrowing month made a difference in GP, however. Pigs farrowed in June were born the heaviest and the largest and finished the heaviest and the largest at 20th week, closely followed by pigs farrowed in October. The smallest pigs were found in those farrowed in September. Prominent trend in correlation between BW and body measurement ratios could not be found. However, pigs with taller legs and shorter length at 8th week have smaller BF, indicating leaner meat.