EFFECT OF CARCASS WEIGHT AND FAT THICKNESS OF LAMB CARCASSES ON SURFACE BACTERIA COUNTS

Microbial studies were conducted to determine the rate of build‐up of surface bacteria during chilling and holding on carcasses of 141 lambs. Samples were obtained using the swab technique. Initial bacterial load was determined on hot carcasses. Chilled carcasses were sampled at 24 hr and after 4 and 7 days post slaughter. Bacterial counts indicated substantial reduction in numbers during chilling, at ‐2.2 °C for 24 hr from 6.4 × 103 to 5.1 × 102/cm2 for the total aerobic count on light lamb carcasses. Reduction in numbers of total aerobes during 24‐hr chilling was not as great for heavy lamb carcasses, from 5.1 × 103 to 1.7 × 103/cm2 Numbers of phychrotrophic organisms after 4 and 7 days appear to be related to the thickness of fat cover. Carcasses having 0.36 cm or less of fat cover had significantly (P < 0.05) higher psychrophilic counts. No Salmonella were isolated and numbers of Clostridium perfringens in both groups of lamb carcasses were low. Copyright © 1979, Wiley Blackwell. All rights reserved