Reduced dietary protein level influences the free amino acid and gene expression profiles of selected amino acid transceptors in skeletal muscle of growing pigs.
This study was conducted to evaluate the effect of reduced dietary protein level on growth performance, muscle mass weight, free amino acids (FAA) and gene expression profile of selected amino acid transceptors in different fibre type of skeletal muscle tissues (longissimus dorsi, psoas major, biceps femoris) of growing pigs. A total of 18 cross-bred growing pigs (Large White × Landrace × Duroc) with initial body weight (9.57 ± 0.67 kg) were assigned into three dietary treatments: 20% crude protein (CP) diet (normal recommended, NP), 17% CP diet (low protein, LP) and 14% CP diet (very low protein, VLP). The results indicated improved feed-to-gain ratio was obtained for pigs fed LP and NP diets (p < 0.01), while the pigs fed VLP diet showed the worst growth performance (p < 0.01). There was no significant difference in the weights of longissimus dorsi and psoas major muscle between LP and NP groups (p > 0.05). Majority of the determined FAA concentration of LP group were greater than or equal to those of NP group in both longissimus dorsi and psoas major muscle (p < 0.01). Further, the mRNA expression levels of sodium-coupled neutral amino acid transceptor 2, L-type amino acid transceptor 1 and proton-assisted amino acid transceptors 2 were higher in skeletal muscle tissue in LP group compared to those of the pigs fed NP or VLP diet. These results suggested that reduced dietary protein level (3 points of percentage less than recommended level) would upregulate the mRNA expression of amino acid transceptors to enhance the absorption of FAA in skeletal muscle of growing pigs. There seems to be a relationship between response of AA transceptors to the dietary protein level in skeletal muscle tissue of different fibre type. To illustrate the underlying mechanisms will be beneficial to animal nutrition.
['Li|Y H|YH|', 'Li|F N|FN|', 'Wu|L|L|', 'Liu|Y Y|YY|', 'Wei|H K|HK|', 'Li|T J|TJ|', 'Tan|B E|BE|', 'Kong|X F|XF|', 'Wu|F|F|', 'Duan|Y H|YH|', 'Oladele|O A|OA|', 'Yin|Y L|YL|']
D000596:Amino Acids D000821:Animal Feed D000824:Animal Nutritional Physiological Phenomena D000818:Animals D004032:Diet D004044:Dietary Proteins D018507:Gene Expression Regulation, Developmental D012333:RNA, Messenger D017459:Receptors, Amino Acid D013552:Swine D059467:Transcriptome
dietary protein level free amino acid amino acid transceptor skeletal muscle growing pig