Effects of fermented Caragana korshinskii on the intramuscular fat content and expression of FABP3, UBE3C, ADRB3, LIPE, and SCD in different muscles of Tan sheep

The aim of this study was to investigate the effects of fermented Caragana korshinskii on the intramuscular fat content and varied expression of the intramuscular fat deposition-related genes FABP3, UBE3C, ADRB3, LIPE, and SCD among four muscle tissues (m. psoas, gluteus, quadriceps, and supraspinatus) of Tan sheep. Twenty-eight male animals of similar age (270 ± 10 days) and weight (24.6 ± 1.06 kg) were randomly divided into a control group (fed the basal diet) and an experimental group (fed the same diet except 10% of corn stalks were replaced with fermented C. korshinskii). Soxhlet petroleum-ether extraction and quantitative real-time PCR were applied to evaluate the fat content and gene expression in tissues, respectively. We observed a significant improvement (P < 0.05) in the intramuscular fat contents in the m. gluteus and supraspinatus of treated sheep compared to those of non treated sheep. The FABP3 mRNA level was markedly higher (P < 0.05) in the m. quadriceps and supraspinatus of treated sheep than in the control sheep. UBE3C mRNA levels were significantly decreased in the m. gluteus, quadriceps, and supraspinatus (P < 0.05) of treated sheep compared with those of the control sheep. ADRB3 mRNA levels were significantly lower (P < 0.05) in the m. psoas, gluteus, and supraspinatus of sheep fed fermented C. korshinskii than in the control group, whereas LIPE mRNA levels were significantly increased (P < 0.05) in the m. gluteus and quadriceps of sheep fed fermented C. korshinskii. The SCD mRNA levels in m. psoas, quadriceps, and supraspinatus of sheep fed fermented C. korshinskii were significantly higher than those of the control group (P < 0.05). Our results indicated that fermented C. korshinskii could partially replace the roughage used in Tan sheep feed, and its substitution affected the intramuscular fat content and altered the expression of intramuscular fat deposition-related genes. The present study lays a solid foundation for further exploring the utilization of C. korshinskii in ruminant husbandry.