| This experiment mainly studied the effect of adding AKG into low-protein diet on growth performance,nitrogen metabolism,blood biochemical indexes,blood and skeletal muscle amino acid levels of finishing pigs.36 DLY finishing pigs with a weight of(54.21 ± 2.95 kg)were selected and randomly divided into 4 experimental groups with 3 replicates in each group,and 3 pigs in each replicate.The crude protein content in the daily ration of each group was 10.99%,with the first group as the control group without the addition of AKG.AKG addition amounts in the other three test groups were 0.5%,1.0% and 1.5%,respectively.In accordance with the standard requirements for digestible amino acids in the ileum,the addition of synthetic amino acids was adjusted to the essential amino acid balance.The trial period was 42 days.The results show that:1.Compared with the control group,the 1%AKG supplementation group significantly improved the growth performance of finishing pigs(P<0.05),and significantly reduced the emission of fecal and urine nitrogen(P<0.05).Among them,growth performance improvement and fecal nitrogen emission reduction were significant in the 1%AKG supplementation group and 1.5% AKG supplementation group(P<0.05),but urine nitrogen emission reduction was not significant(P>0.05).The growth of growth performance and the reduction of fecal and urine nitrogen emissions were significantly different between the control group and the 0.5%AKG addition group(P<0.05).This indicated that both 1.0% and 1.5% AKG could improve the growth performance of finishing pigs and reduce the nitrogen emission.2.When fed daily rations with low protein level,both 0.5% and 1.0%AKG supplementation groups had better effects on improving the total protein and glucose in the serum of finishing pigs,and could effectively reduce the content of urea nitrogen in the serum,so as to promote the growth of finishing pigs on the premise of maintaining the balance of amino acids in the body.3.Both 1.0% and 1.5% AKG supplementation groups significantly increased the total free amino acid levels in the portal vein after 3h and 4.5h of the diet(P<0.05),and in terms of some essential amino acids,such as Thr,Lys,Phe and other essential amino acids for pigs increased significantly(P<0.05).For example,the 1% added group also had higher levels of skeletal muscle amino acid composition than the other three groups.At the amino acid level of tissue metabolism degradation,the concentration of amino acid in the blood of anterior vena cava tends to decrease with the increase of AKG content.To sum up,Both 1.0% and 1.5% AKG can improve growth performance of finishing pigs,and significantly reduce fecal and urine nitrogen emissions.At the same time,they can better reduce the content of urea nitrogen in the blood,with the role of nitrogen reduction.1.0% and 1.5% AKG can steadily increase the free amino acid level in the portal vein and better deposit in skeletal muscle,simultaneously,they can effectively reduce the amino acid level in the anterior vena cava.In addition,1.0% and 1.5% AKG play a very good role in reducing the decomposition and metabolism of proteins in the body and betternitrogen fixation and emission reduction. |
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