Effects of dietary lysine levels on apparent nutrient digestibility and cationic amino acid transporter mRNA abundance in the small intestine of finishing pigs, Sus scrofa

Abstract

One hundred and twenty pigs were used to evaluate the effects of different dietary lysine levels on the growth performance, apparent nutrient digestibility, and abundance of cationic amino acid transporter messenger RNA (mRNA) in the small intestine of finishing pigs. Pigs received a low lysine diet (LL, 0.60% lysine), moderate lysine diet (ML, 0.80% lysine) or a high lysine diet (HL, 1.00% lysine) for 28 days. A digestion test was carried out during the third week. Although the apparent nutrient digestibility in pigs fed experimental diets were different (P < 0.05) and the highest when pigs were fed ML diet, diets did not change the growth performance. In the duodenum, mRNA abundance of PepT-1, as detected by real-time RT-PCR, was reduced in the LL diet (P < 0.05). A greater abundance of b(0,+) AT and PepT-1 mRNA was associated with the ML diet (P < 0.05) in the jejunum and ileum, respectively. In the ileum, the HL diet had a lower abundance of CAT-1 mRNA compared with other diets. These results showed that the finishing pigs would gain better nutrient digestibility when the dietary lysine content was 0.80%, and dietary lysine levels influenced the expression of cationic amino acid transporter mRNA in the small intestine of finishing pigs.

Effects of Dietary Lysine Levels on Apparent Nutrient Digestibility and Serum Amino Acid Absorption Mode in Growing Pigs

“…These results suggested that the dietary lysine levels could influence the apparent nutrient digestibility in pigs. We also found that different dietary lysine levels can affect the apparent nutrient digestibility in a previous study with finishing pigs (Wang et al, 2012). According to the report by Wu (2010), functional amino acids (e.g.…”

“…At low values of amino acid intake, aminoacyl tRNA synthetases have a higher affinity for their respective amino acid than the enzyme catabolizing that amino acid (Harper, 1986). Wang et al (2012) have also found that the mRNA abundances of cationic amino acid transporters in the small intestine of finishing pigs were affected by the dietary lysine levels.…”

Effects of dietary lysine levels on jejunal expression of amino acids transporters and hindgut microflora in weaned pigs

“…In the present study, the mRNA levels of B0AT1, EAAC1 and PEPT1 in jejunum were not influenced by dietary SID Lys levels. However, different dietary SID Lys levels affected the mRNA level of CAT1 in jejunum, which is in line with the recent reports stating that diets with different Lys levels have different effects on the expression of cationic AAs transporters in the small intestine of weaned pigs (García-Villalobos et al, 2012;Wang et al, 2012). Moreover, the quantities of CAT1 mRNA in the 1.35% SID Lys group were greater in jejunum, and the mRNA levels of CAT1 linearly increased as dietary SID Lys increased significantly.…”

Evaluation of standardized ileal digestible lysine requirement for 8–20 kg pigs fed low crude protein diets

“…It was indicated that diet with 13.5 g/kg SID Lys has a higher utilization of N. Notably, this is further confirmed the results of Experiment 1 that the optimal SID Lys requirement of 8–20 kg pigs fed 18.5% CP diet was estimated at 13.1 g/kg. Moreover, previous studies have shown that diet with a higher Lys content enhanced the apparent CP digestibility in growing and finishing pigs (Wang et al., ; Zeng et al., ) .…”