The present study was undertaken to investigate the effects of increasing pig market weight on the incidence of the 'caky-fatty' belly, carcass grade and carcass quality traits. To this end, 500 (Yorkshire × Landrace) × Duroc market pigs consisting of equal numbers of barrows and gilts were slaughtered at body weights ranging from 85 to 150 kg and their carcasses were analyzed. Backfat thickness (BFT; mm) of the barrows and gilts regressed on live weight (kg) linearly as follows: BFT (y) = 0.1827x + 3.4825 (r 2 = 0.4671) and y = 0.2015x-0.6972 (r 2 = 0.4736), respectively. The caky-fatty belly, which, by definition of the present study, had = 55% fat by weight in the dorsal-side half of a 5 cm-wide belly strip between the 11 th and 12 th ribs, was found in 10 carcasses from barrows. However, no belly was condemned as 'caky-fatty' by the retailers. Total number of carcasses which were down-graded on account of overweight was as many as 101 (20.2%). The 1 + A-grade carcasses exhibited a superior intramuscular fat score to all other grades, but except for this and the defective quality traits, no visible differences were found in carcass quality among different carcass grades. In conclusion, the current carcass grading system, which is sparingly reflective of the carcass quality and also under-evaluates the larger but otherwise normal carcasses, may as well be revised. Moreover, the incidence of the caky-fatty belly appears not to be a critical factor to be considered when increasing the pig market weight.

The present study was undertaken to investigate the effects of the decreased carcass grade due to overweight on meat quality traits of the loin and belly. Out of 500 carcasses from 85-to 150-kg market pigs, seven average-size 1 + A carcasses, seven 1Aand twelve 1B carcasses almost weighing the upper limits allowed for the A (95 kg) and B (99 kg) grades, respectively, and 12 1B carcasses weighing 100 kg or greater were selected for the present study. Marbling score was greater in the 1 + A grade than in any other grade, whereas color and textural properties of the muscle and fat of the carcass did not differ among the four carcass grades. Physicochemical characteristics of the loin including the color, pH, chemical composition, and others pertaining to the textural properties changed minimally with decreasing carcass grade. Off-odor of the fresh loin and belly was not influenced by the carcass grade whereas dripping was lowest in the 1 + A grade; color and marbling were not influenced or minimally influenced by the carcass grade. Overall acceptability of the fresh primals, however, did not differ among the carcass grades. In cooked loin and belly, a trend of decreased taste and acceptability with decreasing carcass grade was evident, albeitat a low slope, with a significant difference detected between 1 + A and 2C grades. In conclusion, the decreased pig carcass grade due to overweight is accompanied by a slightly decreased meat quality, suggesting that the yield grade of pig carcass is also somewhat reflective of meat quality.