Study on Effects of Leucine and α-KIC-Ca on Protein Synthesis in Sheep
|School||Inner Mongolia Agricultural University|
|Course||Animal Nutrition and Feed Science|
|Keywords||Sheep Rumen-protected leucine Rumen-protectedα-KIC-Ca Protein synthesis mTOR signaling pathway Muscle quality|
The effect of the different rumen-protected leucine andα-KIC-Ca on protein synthesis in sheep were studied and the results of that were as follows.The paper divided into five parts:Part 1 Estimate of the stability of rumen-protected leucineLeucine was treated by using the coating material that is sensitive to the pH value,and stability and release rate of RPAA was tested through artificial saliva digestion test, nylon bag method, duodenal fluid digestion simulation test simulating the physical characteristics of the digestive tract of ruminants. The experimental results showed that the rumen-protected leucine was more stable in the artificial saliva and rumen fluid and had well digestibility in the duodenum.Part 2 Effects of the different dietary level of rumen-protected leucine andα-KIC-Ca on nitrogen metabolism in sheepTwenty-one growing wethers sheep with good body condition, BW of 25±2.86kg, were randomly divided into7 groups, namely, the control group(Group1), the rumen-protected leu-0.5(Group2), the rumen-protected leu-1.0 (Group3), the rumen-protected leucine leu-1.5(Group4), the rumen-protectedα-KIC-Ca-0.5(Group5), the rumen-protectedα-KIC-Ca-1.0(Group6)and the rumen-protectedα-KIC-Ca-1.5(Group 7). The effects of different supplemental levels of the rumen-protected leucine andα-KIC-Ca on rumen nitrogen metabolism through total collection of feces and urine in the same protein conditions of the basic diets.The results showed that the retained nitrogen of Group 3 and Group 7 were significantly higher than that of Group 1(P<0.05), the other group all had no significantly difference(P>0.05).the concentration of UUN of Group 1 was significantly higher than Group 1、Group 6 and Group7(P<0.05),and the other group all had no significantly difference(P>0.05). Free amino acids concentration in plasma of the groups were all significantly difference(P<0.05), it was Group7> Group1 > Group 5 > Group 6, and Group 3 > Group 1 > Group 2 > Group 4 respectively. TAA concentration in plasma of the groups were all significantly difference(P<0.05), it was Group7> Group6 > Group 5 > Group 1, and Group 3 > Group 4 > Group 2 > Group 1 respectively.The above results showed that diets with supplemental the rumen-protected leucine andα-KIC-Ca increased nitrogen intake (P<0.05) and decreased the urine urea nitrogen excretion (P<0.05) and had a tendency to increase plasma concentration of free amino acids (P<0.05).Part 3 Effects of the different dietary level of rumen-protected leucine andα-KIC-Ca on protein synthesis in sheepThe treatment of experiment was samed as Part 2. Experimental animals will be slaughtered in the end of the feeding examination,The test study the effect of organization protein synthesis through the diets with supplemental the rumen-protected leucine andα-KIC-Ca in sheep by using d5-phe of one-time infusion with high-dose based on the Part 2.The results showed that biceps femoris protein FSR of Group 3 was significantly higher than that of Group 1、Group 2 and Group 4(P<0.05);Group 7 was significantly higher than that of Group 1 and Group 5(P<0.05).The longissimus dorsi muscle FSR of groups except Group 5 were all significantly higher than that of Group 1 (P<0.05).The liver FSR was no significantly difference of the control group. The skeletal muscle protein FSR was Group 3 > Group 4 > Group 2, and Group 7 > Group 6> Group 5 respectively. The effects of fractional synthesis of protein were all significantly on the biceps femoris , longissimus dorsi muscle and liver protein synthesis of rumen-protected leucine andα-KIC-Ca (P<0.05).the treatent groups all were significantly higher than the control group, and it was Group 3> Group 2> Group 4, and Group 7> Group 6> Group 5 respectively.Part 4 Effects of the different dietary level of rumen-protected leucine andα-KIC-Ca on skeletal muscle mTOR signaling pathway in sheepThe treatment of experiment was samed as Part 2. Experimental animals will be slaughtered in the end of the feeding examination, the 4E-BP1、p70S6K of longissimus dorsi muscle were mensurated by using the Western bloting method after slaughtering based on the part 2.The results showed that: Groups of the leu andα-KIC-Ca were all significantly higher than that of the control group(P<0.05). the experimental group compared with the control group, 4E-BP1 and p70S6K phosphorylation in varying degrees of increased .group 3> group 4> group 2> the control group; group 7 Group> Group 6> 5 group> control group. 3 group (Leu-1.0 group) and 7 groups (α-KIC-Ca-1.5 group) 4E-BP1, p70S6K phosphorylation degree were the most significant.Part 5 Effects of the different dietary level of rumen-protected leucine andα-KIC-Ca on the muscle quality of sheepThe treatment of experiment was samed as part 2.Experimental animals will be slaughtered in the end of the feeding examination, the longissimus dorsi muscle and biceps femoris muscle were determinated after slaughtering. The results showed that meat pH, water loss rate, the rate of cooked, meat color and tenderness were no significantly difference among the groups. Under the same levels of rumen-protected leucine andα-KIC-Ca , except pH value ,other indicators of the different sheep meat had the significantly differences.