摘要：
Simple Summary The present study indicated that excessive energy enhanced fat deposition by upregulating expression of lipogenic genes in the longissimus thoracis of a Chinese fat-type pig. In addition, impairment in meat quality resulted in reduced meat tenderness and increased cross-sectional area of muscle fiber aroused by promoting glycolytic muscle fibers differentiation in muscles. These results provided a new perspective on the energy needs of Ningxiang pigs. This study investigated the effects of excessive or restrictive energy on growth performance, meat quality, intramuscular fat (IMF) deposition, and related gene expression in finishing Ningxiang pigs. A total of 36 Ningxiang pigs (43.26 +/- 3.21 kg) were randomly assigned to three treatments (6 pens of 2 piglets per treatment) and fed by one of three dietary treatments until the pigs of each treatment weighed approximately 75 kg equally. The three treatments were control diet (digestible energy, DE:13.02 MJ/kg, CON), excessive energy diet (DE 15.22 MJ/kg, EE), and restrictive energy diet (DE 10.84 MJ/kg, RE). Results showed that EE improved average daily gain (ADG) and feed conversion ratio (FCR) (p < 0.01), while nothing significantly changed by RE except FCR increasing (p < 0.01). EE increased the content of IMF and triglycerides (TG) (p < 0.05), L*(24h) and b*(45min) (p < 0.01), while decreasing cooking loss and meat tenderness in longissimus thoracis (LT) (p < 0.05). b*(24h) was significantly increased with the increase of energy level (p < 0.01). Meanwhile, EE increased the cross-sectional area (CSA) of muscle fiber and the mRNA expression of myosin heavy chain (MyHC) IIb, acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), and adipocyte fatty-acid binding protein (FABP4) (p < 0.05). In addition, throughout: A diet supplemented with excessive energy promoted IMF deposition by positively changing lipogenic potential while decreasing tenderness by increasing glycolytic muscle fibers, which together affected meat quality. In terms of growth performance and meat quality, the present study suggests that the low-energy diet is suitable for finishing Ningxiang pigs.
关键词：
Antioxidant system;Laying hens;Selenium;Trace elements
摘要：
The purpose of this study was to investigate the interactions between different selenium (Se) compounds including sodium selenite (SS), selenium-enriched yeast (SY), and nano-selenium (NS) and various essential trace elements involved in the antioxidant systems, and to evaluate the effects on laying performance and egg quality. A total of 288 21-week-old Hyline Sophie hens were allotted to four dietary treatments: (1) basal diet without Se supplementation; (2) basal diet supplemented with 0.3 mg/kg Se of SS; (3) basal diet supplemented with 0.3 mg/kg Se of SY; (4) basal diet supplemented with 0.3 mg/kg Se of NS. Each treatment had eight replicates with nine hens per replicate. The trial lasted for 35 days. Results demonstrated that NS supplementation decreased the egg production (EP) and increased the feed conversion rate (FCR) and eggshell thickness and that SY changed the egg shape index (p < 0.05). Supplementation with three Se compounds significantly increased serum Se concentration and glutathione peroxidase (GSH-Px) activity in all treatment groups, as well as total superoxide dismutase (T-SOD) activity in the SY and NS groups. Yolk iron (Fe) and copper (Cu) concentrations in the NS group were also increased with Se supplementation. While the serum zinc (Zn) concentration decreased in the NS and SY groups, as well as the yolk manganese (Mn) concentration in the SY group. And the total antioxidant capability (T-AOC) of yolk with 3 days of storage in the SY and NS groups, malondialdehyde (MDA) value in the NS group, and the T-SOD activity and MDA value of yolk with 10 days of storage in the SY group also decreased. Thus, the source of Se compounds may influence the balance between Se and other trace elements including Zn, Mn, Fe, and Cu, which is important for proper antioxidant defense in blood and egg yolk of laying hens.
摘要：
This study was conducted to investigate the effects of diet 7.5 g/kg alpha-ketoglutarate (AKG) on the growth performance, antioxidant defense system, digestive enzymes, and immune response of grass carp (Ctenopharyngodon idellus). A total of 400 grass carp with an average body weight 10.81 +/- 0.68 g was randomly allocated into 2 groups with 4 replicates of 50 fish respectively. The experiment was conducted in net cages (1.5 mx1.5 mx1.5 m) suspended in an indoor cement pool. Fish were fed a basic diet containing either 0 (control) or 7.5 g/kg AKG (supplemented diet). The experiment lasted for 8 weeks (56 days). Results indicated that compared with the control group, the final weight (FW), weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) in the AKG group were increased significantly (P <0.05). However, the feed conversion ratio (FCR) was decreased significantly (P <0.05). The 7.5 g/kg AKG supplementation significantly increased the activities of glutamine synthetase (GS), glutathione peroxidase (GSH-Px), catalase (CAT), total superoxide dismutase (T-SOD), and hexokinase (HK), as well as the concentrations of glutathione (GSH), total antioxidant capacity (T-AOC), and complement 3 (C3) in blood (P<0.05), while significantly decreased the concentrations of malondialdehyde (MDA) and hemoglobin (Hb) (P<0.05). The GS activity and GSH concentration in hepatopancreas were increased significantly (P<0.05), whereas the glycogen concentration in hepatopancreas, and the glycogen concentration and GS activity in the muscle were significantly decreased (P <0.05). In addition, 7.5 g/kg AKG supplementation significantly increased the concentration of GSH and the activities of amylase, protease, and lipase in fore-gut, alkaline phosphates (ALP) in the mid-gut, and Na-ATP and Ca-ATP in the gill (P <0.05), as well as gamma-glutamyl transpeptidase (gamma-GT) both in fore-gut and mid-gut (P <0.05), whereas the activity of acid phosphatase (ACP) in the mid-gut was decreased significantly (P <0.05). In conclusion, diet 7.5 g/kg AKG supplementation in grass carp may improve the growth performance and immune response and play crucial roles in regulating the activities of GS, antioxidant defense system, and digestive enzymes.
摘要：
<jats:p>The intestinal microbiome plays a crucial role in promoting intestinal health, and perturbations to its constitution may result in chronic intestinal inflammation and lead to colorectal cancer (CRC).<jats:italic>α</jats:italic>-Ketoglutarate is an important intermediary in the NF-<jats:italic>κ</jats:italic>B-mediated inflammatory pathway that maintains intestinal homeostasis and prevents initiation of intestinal inflammation, a known precursor to carcinoma development. The objective of this study was to assess the potential protective effects of<jats:italic>α</jats:italic>-ketoglutarate intervention against CRC development, which may arise due to its known anti-inflammatory and antitumour effects. CRC was induced in C57BL/6 mice using azoxymethane (AOM) and dextran sulfate sodium (DSS). Tumour frequency, histological rating, and colonic microbiota were assessed in colonic samples. The findings demonstrated that<jats:italic>α</jats:italic>-ketoglutarate offered significant protection against CRC development in mice. Furthermore,<jats:italic>α</jats:italic>-ketoglutarate also exhibited immunomodulatory effects mediated via downregulation of interleukin (IL)-6, IL-22, tumour necrosis factor (TNF)-<jats:italic>α</jats:italic>, and IL-1<jats:italic>β</jats:italic>cytokines. Finally, intervention with<jats:italic>α</jats:italic>-ketoglutarate tended to minimise the frequency of opportunistic pathogens (<jats:italic>Escherichia</jats:italic>and<jats:italic>Enterococcus</jats:italic>) while increasing the populations of<jats:italic>Akkermansia, Butyricicoccus</jats:italic>,<jats:italic>Clostridium,</jats:italic>and<jats:italic>Ruminococcus</jats:italic>. Taken together, our findings show that dietary<jats:italic>α</jats:italic>-ketoglutarate intervention may protect against inflammation-related CRC.</jats:p>
关键词：
Intramuscular fat;Lipid;Meat quality;Methionine;Myofiber type
摘要：
The effects of methionine restriction on lipid metabolism in the liver and adipose tissue have been well determined, while its effects on the skeletal muscle have not been fully studied. The present study was conducted to explore whether methionine restriction in weanling piglets would affect skeletal muscle lipid content and fiber type and whether such changes would further affect the meat quality of growing-finishing pigs. A total of 28 crossbred healthy barrows weaned at the age of 21 days were randomly allotted to two treatments and fed either a methionine-restricted diet (0.25% methionine) or a control diet (0.48% methionine) for 4 weeks. After this period, the pigs were fed the same basal diet throughout the growing-finishing period. The results showed that methionine restriction during the post-weanling period of piglets enhanced lipid accumulation and promoted the formation of slow-twitch muscle fibers in the skeletal muscle, while it had no effects on growth performance. We hypothesized that such effects might be mediated by AMPK-PGC-1alpha signaling pathway. Furthermore, the effects of methionine restriction on the skeletal muscle of pigs at the post-weanling period had a subsequent effect on growing-finishing pigs, which showed a higher intramuscular fat content. Our results suggest that dietary methionine restriction in piglets at an early stage might be an alternative method for improving meat quality.
摘要：
本试验以猪小肠上皮细胞( IPEC-1)为模型,探讨牛膝多糖( ABPS)对IPEC-1增殖、紧密连接相关蛋白mRNA表达和沙门氏菌侵染的影响.在IPEC-1细胞培养基中分别加入相应剂量的ABPS,使培养基中ABPS终浓度分别为0(对照) 、50、100、200、400 μg /mL.分别采用噻唑蓝( MTT)法、实时荧光定量PCR法和平板细菌计数法检测ABPS对IPEC-1的影响.结果表明: 1)与对照组相比,ABPS对IEPC-1增殖无显著影响( P>0.05) .2) ABPS处理能显著抑制沙门氏菌的侵染,随着ABPS浓度的增加,其抑制效果先增加后减少,浓度为50 μg /mL时抑制效果达到峰值,其细胞被侵染的沙门氏菌数量极显著低于对照组和200、400 μg /mL ABPS组( P< 0.01) .3)与对照组相比,50、200 μg /mL ABPS均极显著上调IEPC-1紧密连接相关蛋白[Ras相关的C3肉毒素底物1( RAC1) 、细胞质密闭小带-1( ZO-1) 、闭锁蛋白( occludin) 、闭合蛋白-1( claudin-1) ]mRNA的相对表达量( P<0.01) .由此可知,适量的ABPS能够通过上调IEPC-1紧密连接相关蛋白mRNA表达,从而增强小肠黏膜的屏障功能,抑制沙门氏菌的侵染. <&wdkj&>This experiment was conducted to evaluate the effects of Achyranthes bidentata polysaccharides (ABPS) on proliferation,mRNA expression of tight junction related proteins and infection of Salmonella in intestinal porcine epithelial cells-1 ( IPEC-1) . Adding ABPS in IPEC-1 culture medium,the final concentration of ABPS were 0 ( control) ,50,100,200,400 μg /mL. The effects of ABPS on IPEC-1 were detected using MTT assay,quantitative real-time PCR and plate colony counting method. The results showed as follows: 1) compared with the control group,ABPS had no significant effect on IPEC-1 proliferation (P>0.05) . 2) The ABPS significantly inhibited Salmonella infection in IPEC-1,with the increase of ABPS concentration,the number of infected Salmonella decreased first and then increased. The number of infected salmonella in IPEC- 1 treated with 50 μg /mL ABPS was the lowest among all groups,and was significantly lower than that in control group and 200 and 400 μg /mL of ABPS groups (P<0.01) . 3) Compared with the control group,50 and 200 μg /mL of ABPS significantly up-regulated the mRNA relative expression level of tight junction related proteins ( ras-related C3 botulinum toxin substrate 1,zonula occluden-1,occludin,claudin-1) in IEPC-1 (P< 0.01) . Above results indicate that suitable ABPS concentration can promote IEPC-1 proliferation,strengthen the barrier function of intestinal mucosa and inhibit Salmonella infection with up-regulation the mRNA expression of tight junction related proteins.
摘要：
<b><i>Background/Aims:</i></b> Our previous reports suggested that dietary supplementation with lysine influenced intestinal absorption and metabolism of amino acids. In this study, we further investigated the effect of lysine restriction (30%) on feed intake and we also tested the hypothesis that gut microbiome contributed to the potential mechanism of lysine restriction-mediated feeding behavior. Here, we profiled gut microbial communities by sequencing 16S ribosomal ribonucleic acid (rRNA) genes from gut samples as well as growth performance, serum hormones, and intestinal lysine transport in a piglet model. <b><i>Results:</i></b> Piglets preferred to the lysine restricted diet when giving three diets and the feed intake was markedly higher in the lysine-restricted group than that in the control group. Altered hormones (leptin, CCK, and ghrelin) might contribute to the feeding behavior caused by lysine restriction. Meanwhile, lysine transporting ability (SLC7A1 and SLC7A2 expression, intestinal electrophysiological changes, and amino acid pool in mesenteric vein) was decreased in response to lysine restriction. Through deep sequencing of bacterial rRNA markers, we observed that bacterial diversity was enhanced in the lysine-restricted group (Shannon H, PD, and Chao1). At the phylum level, lysine restriction enhanced gut <i>Actinobacteria,</i> <i>Saccharibacteria</i>, and <i>Synergistetes</i> abundances. At the family level, <i>Moraxellaceae,</i> <i>Halomonadaceae,</i> <i>Shewanellaceae, Corynebacteriaceae, Bacillaceae, Comamonadaceae, Microbacteriaceae, Caulobacteraceae</i>, and <i>Synergistaceae</i> abundances were increased in response to lysine restriction. Predictive functional profiling of microbial communities by PICRUSt also confirmed that dietary lysine restriction affected gut microbiome, which might further mediate amino acid metabolism, membrane transport, and endocrine system. <b><i>Conclusion:</i></b> Our results indicated that lysine restriction inhibited intestinal lysine transport and promoted feed intake, which might be associated with gut microbiome.
