Effect of Genetic Line on Lipid Characteristics of Rabbit Muscle

The effect of genetic line on intramuscular fat content, perirenal fat content and the activity of some enzymes related to lipid metabolism was studied. Longissimus (LD) and Semimembranosus proprius (SP) muscles were used in this experiment. A total of 60 animals from three lines (A, V and R) selected for different criteria were slaughtered at 9 and 13 weeks of age. Differences between lines were found for intramuscular fat (IMF) and perirenal fat content (PF), having line A higher values than V and R. IMF and PF content were positively correlated in line A and V, but no relationship was found in line R. PF increased with age in three lines, whereas IMF increased only in line A and V. SP muscle showed higher lipogenic activities (glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS)) than LD. A line effect was observed for lipogenic activities. Line A had higher lipogenic activity and line R showed lower activity. An increase of G6PDH and malic enzyme activities with age was observed. Glycolytic activity was higher in LD, whereas SP showed higher oxidative activity. An influence of genetic line was found for oxidative enzymes in SP, HAD and CS activity was higher in line R compared with A and V. The LDH activity increased with age in both muscles, while the HAD activity decreased in LD. Results from this study indicate that genetic line has an effect on intramuscular fat deposition and related characteristics that could lead to differences in meat quality.