Effect of Caragana korshinskii Kom. on Meat Quality of Adipose Tissue, Volatile Fatty Acids and the Microbiota in Gastrointestinal Tract for Tan Sheep

To explore the effect of Caragana korshinskii Kom. (CK) on meat quality and the main fatty acids of adipose tissue, which were supposed to be modulated by the level of volatile fatty acids from the microbiota of rumen and colon in sheep, twelve Tan ewe lambs (4-month-old) were randomly divided into two groups, NC was fed with 30% concentrate and 70% alfalfa, while CK with 10% CK instead of equivalent alfalfa. After 10 days of pre-trial and 60 days of feeding trial, the lambs were slaughtered and sampled with M. longissimus dorsi, quadriceps femoris, subcutaneous fat, and the contents of rumen and colon collection. Then the analyzing was carried out aimed to determine the characters of meat physical and chemical properties as usual method, the microbiota of gastrointestinal tract by 16S rRNA sequencing, and fatty acid contents either from subcutaneous adipose tissue or from rumen and colon by gas chromatography-mass spectrometry. The results showed that feeding CK to Tan sheep could tend to increase mill loss, decrease water holding capacity and cooked meat percentage of quadriceps femoris. It also had the tendency effect to decrease saturated fatty acid and increase unsaturated fatty acid content in the meat. Furthermore, feeding CK could decrease the content of palmitic acid in subcutaneous adipose tissue significantly (P<0.05). Besides, the concentrations of butyric acid in rumen and acetic acid in colon decreased significantly (P<0.05), while the levels of branched chain fatty acids such as iso-butyric acid and iso-valeric acid in colon increased significantly (P<0.01). Through correlation analysis by Spearman method, both 5-7N15 and YRC22 in rumen genera tended to positively correlated with butyric acid concentration, while Treponema in colon genera tended to positively correlated with acetic acid content, but negatively correlated with the level of iso-butyric acid (0.05<P<0.1). In colon, iso-butyric acid was high inversely and positively correlated with the cooked meat percentage, water holding capacity and mill loss of quadriceps femoris, and acetic acid was negatively correlated with the pH value of M. longissimus dorsi. In conclusion, feeding CK to Tan sheep with partly instead of alfalfa could improve unsaturated fatty acid contents of adipose tissue, and then it could be developed as ruminant forage for utilization.