Comparative Study on Slaughter Performance and Meat Quality of Laiwu Black Goats Slaughtered at Different Ages

The slaughter performance and the nutritional quality and processing quality of the meat of Laiwu black goats were analyzed by measuring dressing percentage, meat pH, meat color, cooking loss, crude protein, crude fat contents and the number of fast and slow muscle fibers. Sensory evaluation was also performed on meat samples. The results showed that there were significant differences in all tested parameters among goat carcasses slaughtered at different ages. However, there was no significant difference in dressing percentage between carcasses at 12 (48.21%) and 24 months (48.75%) of age, which was significantly higher than that (43.55%) at 8 months, and the meat to bone ratio at 12 months was 4.04, lower than that at 8 and 24 months. The meat color at 8 months of age was redder and brighter than that at other ages. The crude protein contents of goat meat at 8, 12 and 24 months were 19.29%, 21.34% and 22.00% respectively, and the crude fat contents were 1.83%, 2.08% and 2.10% respectively. The shear force of meat at 8 months was 4985.98 g, which was significantly lower than that at other ages. The best meat tenderness appeared at the slaughter age of 8 months. At this age, the number of fast muscle fibers was the highest and the ratio of fast to slow muscle fibers was 6.36, significantly higher than that at other ages; the sensory evaluation score was the highest. Based on the above experimental results, 8-month-old Laiwu black goats can be produced as high-grade lamb, and the slaughter benefit of 12-month-old lamb carcasses is higher.