Abstract: To study the effects of total mixed ration with different concentrate∶roughage ratios on meat quality, serum indices and organ development of goats, thirty six two-month old healthy Nubian goats with similar body weights were chosen and divided into three groups with 12 goats per group. The groups of goats were then fed total mixed rations with low (L, 40∶60), medium (M, 50∶50 M) and high (H, 60∶40) concentrate∶roughage ratios. The experimental period was 70 days, with a diet adaptation period of 14 days and a formal experiment period of 56 days. The results were as follows: 1) The diets with different concentrate∶roughage ratios had no significant effect on body measurement traits of the goats over the whole experimental period (P>0.05). 2) The activities of aspartate aminotransferase, alanine aminotransferase and creatine kinase were significantly lower in serum of diet H goats than in diet L goats on day 14 of the formal experiment (P<0.05). The ratio of aspartate aminotransferase to alanine aminotransferase was significantly higher in group H goats than in group L goats on day 56 of formal experiment (P<0.05), but the activity of alkaline phosphatase showed the opposite pattern. 3) Rate of water loss was significant lower in diet H goats than the other two groups (P<0.05), but pH value showed the opposite result. The redness of meat was significantly lower in diet M goats than the other two groups (P<0.05). There were no significant differences between dietary groups in other indices (P>0.05). Rumen weight, liver weight and liver index were significantly higher in diet L goats than in diet H goats (P<0.05), but the opposite pattern was observed for lung index. Reticulum and omasum weights, reticulum and omasum indices, and abomasum index were significantly higher in diet M goats than in diet L goats (P<0.05), but the opposite pattern was observed for spleen weight and spleen index. Villus height and villus height∶crypt depth of duodenum, and villus height∶crypt depth of jejuna were significantly higher in diet L goats than in diet H goats, but crypt depth of jejuna showed the opposite result. Villus height and villus height∶crypt depth of the ileum were significantly higher in diet M goats than in diet H goats. In conclusion, total mixed rations with low concentrate∶roughage ratio promoted gastrointestinal development of Nubian goats, and high concentrate∶roughage ratio improved meat quality. For conditions in this experiment, feeding Nubian goats a total mixed ration diet with low concentrate∶roughage ratio is recommended.

Key words: goat, meat quality, blood biochemical indexes, organ development