Changes in the pyridinoline concentration of the gastrocnemius and soleus muscle in goats from 2 weeks prenatal to 24 weeks of age

The objective of this study was to monitor changes in the pyridinoline concentration of collagen of the fast-twitch gastrocnemius and slow-twitch soleus muscles of Japanese Saanen male goat kids during the period from 2 weeks before birth to 24 weeks of age. The moisture concentrations of both muscles decreased and the crude protein concentration increased steadily throughout the experimental period. The percentage of total collagen in the muscular protein showed a marked decrease (80.6-41.8% in the gastrocnemius and 77.9-40.5% in the soleus muscle) during the 2 week prenatal period. Similarly, there was a decrease in soluble collagen concentration (27.8-11.6% in the gastrocnemius and 32.6-18.1% in the soleus muscle) during the prenatal period, but the decrease in total and soluble collagen concentration was slight thereafter. There was no clear tendency for change in collagen heat solubility of both muscles, and no strong relationship was identified between collagen heat solubility and pyridinoline concentration. Pyridinoline concentration in total collagen increased during the prepubertal period in both muscles, but the soleus muscle increased faster and had a higher concentration of pyridinoline (0.22 mol/mol collagen at 20 weeks of age) than the gastrocnemius muscle (0.11 mol/mol collagen at 20 weeks of age). It was found that the increase in pyridinoline concentration began during the prenatal period, and the development of a cross-linking with age was faster in the soleus than in the gastrocnemius muscle, without collagen concentration between the muscles. It is suggests that meat toughness would be improved when the proportion of fast-twitch muscular fibrils could be increased.