TISSUESPECIFIC PENTOSEPHOSPHATE OXIDATIVE ACTIVITY IN ANGUS AND WAGYU STEERS AFTER EXTENDED FEEDING1
Additional Document Info
Angus (n = 10) and American Wagyu crossbred (n = 10) steers were fed for 552 days to gain 0.9 kg/day. Samples of liver, longissimus muscle, sternomandibularis muscle, mesenteric, kidney, and subcutaneous (s.c.), intermuscular, and intramuscular (i.m.) adipose tissues were obtained immediately post exsanguination to determine glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) activities. Subcutaneous adipose tissue had the highest (P < 0.05) activities for both G-6-PDH and 6-PGDH. Fat depots exhibited higher activity rates than muscle samples for both G-6-PDH and 6-PGDH. No differences (P > 0.05) were found between cattle types for these enzymatic activities. However, there was a trend for Wagyu to have higher lipogenic activity for fat depots than Angus steers. Narrow sense heritability estimates were -0.02 and 0.13 for G-6-PDH and 6-PGDH, respectively. This indicates that there was no additive genetic variation, and that most of the phenotypic variation in these enzymes is due to environmental variation.