Studies on the muscles of meat animals. II. Differences in the ultimate pH and pigmentation of longissimus dorsi muscles from two breeds of pigs

1. Longissimus dorsi muscles from twenty Landrace and twenty Large White pigs of accurately known history, which had been reared under identical conditions at a Progeny Testing Station, and killed at similar weights, were sampled for ultimate pH and colour at the levels of the 5th, 7th, 9th, 11th, 13th and 15th thoracic, and of the 1st, 3rd, 5th and 6th lumbar, vertebrae. 2. The mean ultimate pH at all ten locations in Landrace muscles was invariably lower than at corresponding locations in Large White muscles, the difference being minimal at the level of the 15th thoracic vertebra, but being highly significant overall. 3. The scatter of ultimate pH values was markedly different between the breeds at the levels of the 5th and 9th thoracic, and of the 1st and 6th lumbar, vertebrae. 4. The mean colour at all locations, except 1st and 5th lumbar vertebrae, was higher in Large White muscles than at corresponding locations in Landrace muscles: the difference was especially marked at the level of the 5th thoracic vertebra. 5. Only in longissimus dorsi muscles from Landrace pigs were there significant correlations between ultimate pH and colour.