A comparison between the effects of two cropping methods on the meat quality of impala (Aepyceros melampus)

Abstract

Impala (Aepyceros melampus) constitute one of the most commercially important species in game farming in South Africa. The purpose of this study was to compare the effects of day and night cropping on the meat quality characteristics of impala. Emphasis was placed on the influence of the cropping method on muscle pH45 (45 minutes post mortem), pHu (ultimate pH), pH decline, and the related influence on drip loss, cooking loss, toughness and colour of the meat in the M. longissimus lumborum. Measurements taken from 16 animals cropped at night were compared to those taken from 24 animals cropped in daytime. A mean pH45 of 6.67 + 0.11 was recorded for the night cropped animals compared to a mean pH45 of 6.55 + 0.23 for the day cropped animals. A mean pHu of 5.39 + 0.08 for animals cropped at night was recorded compared to a mean pHu of 5.45 + 0.11 for the animals cropped in the day. Regression analysis showed the rate of pH decline to be slower in the night cropped animals compared to those cropped in the day. This persisted when the pH values were adjusted to correct for ambient temperature. The cooling rate of the M. longissimus lumborum was twice as fast in the night cropped group. Shear force values and drip losses respectively, for the night-cropped animals were 19.11 + 5.68 g/mm2 and 2.93 + 1.59%, whereas for the day cropped animals the values were 23.42 + 8.13 g/mm2 and 4.15 + 2.34%. The results of this study indicate that night-time cropping does have a beneficial effect on certain meat quality parameters.


Keywords: Meat quality, Impala, Cropping methods


South African Journal of Animal Science Vol.33(4) 2003: 233-241