Effects of L‐methionine on performance,gut morphology and antioxidant status in gut and liver of piglets in relation to DL‐methionine

This study investigated the hypothesis that dietary supplementation of L‐methionine (L‐Met) in weaned piglets in relation to DL‐methionine (DL‐Met) results in a higher antioxidant status and lower need for antioxidant enzyme activation in intestinal epithelium and body tissues, and improves gut morphology and gut barrier function as well as performance. A total of 99 early‐weaned 21‐day old piglets were allotted to six groups and fed a semi‐synthetic wheat–barley‐based basal diet supplemented with 0.067%, 0.107% and 0.147% of either DL‐Met (MetAmino; Evonik, Hanau, Germany) or L‐Met (L‐Met100; CJ Europe, Schwalbach am Taunus, Germany) to reach dietary Met concentrations of 0.16%, 0.20% and 0.24%, of which the latter met the requirements for maintenance and growth based on a pre‐experiment. Feed intake and body weights were recorded weekly, and samples of plasma, liver and duodenum and jejunum mucosa were collected after 3 weeks at slaughter. Plasma concentrations of L‐Met were similar, and those of D‐Met and total Met were higher in piglets fed DL‐Met in relation to those fed L‐Met. Feed intake, daily gains and feed:gain ratio, and the relative bio‐efficacy based on gains and feed:gain ratio were similar for both groups. Likewise, villi length, crypt depth, the villi length:crypt depth ratio in duodenum and jejunum and gene expression of tight junction proteins in the jejunum did not differ. Concentrations of antioxidants like glutathione and tocopherol, the total antioxidant capacity, the mRNA abundance or activity of antioxidant enzymes like superoxide dismutase and glutathione peroxidase, concentrations of thiobarbituric acid reactive substances, markers for oxidative damage of lipids and the expression of inflammatory genes were similar in liver and jejunum mucosa. These data indicate that the effects of L‐Met and DL‐Met supplementation are comparable considering both piglet performance and parameters of gut health and function like gut morphology and the intestinal antioxidant status.     

Effects of dietary methionine supplementation on growth performance,intestinal morphology,antioxidant capacity and immune function in intra‐uterine growth‐retarded suckling piglets

This study investigated the effects of dietary supplementation with _L‐methionine (_L‐Met), _DL‐methionine (_DL‐Met) and calcium salt of the methionine hydroxyl analog (MHA‐Ca) on growth performance, intestinal morphology, antioxidant capacity and immune function in intra‐uterine growth‐retarded (IUGR) suckling piglets. Six normal birthweight (NBW) female piglets and 24 same‐sex IUGR piglets were selected at birth. Piglets were fed nutrient adequate basal diet supplemented with 0.08% _L‐alanine (NBW‐CON), 0.08% _L‐alanine (IUGR‐CON), 0.12% _L‐Met (IUGR‐LM), 0.12% _DL‐Met (IUGR‐DLM) and 0.16% MHA‐Ca (IUGR‐MHA‐Ca) from 7 to 21 days of age respectively (n = 6). The results indicated that IUGR decreased average daily milk (dry matter) intake and average daily gain and increased feed conversion ratio of suckling piglets (p < 0.05). Compared with the NBW‐CON piglets, IUGR also impaired villus morphology and reduced antioxidant capacity and immune homeostasis in the intestine of IUGR‐CON piglets (p < 0.05). Supplementation with _L‐Met enhanced jejunal villus height (VH) and villus area and ileal VH of IUGR piglets compared with IUGR‐CON piglets (p < 0.05). Similarly, _DL‐Met supplementation increased VH and the ratio of VH to crypt depth in the jejunum compared with IUGR‐CON pigs (p < 0.05). Supplementation with _L‐Met and _DL‐Met (0.12%) tended to increase reduced glutathione content and reduced glutathione: oxidized glutathione ratio and decrease protein carbonyl concentration in the jejunum of piglets when compared with the IUGR‐CON group (p < 0.10). However, supplementation with MHA‐Ca had no effect on the intestinal redox status of IUGR piglets (p > 0.10). In conclusion, supplementation with either _L‐Met or _DL‐Met has a beneficial effect on the intestinal morphology and antioxidant capacity of IUGR suckling piglets.     

Tissue and plasma antioxidant status in response to dietary methionine concentration and source in broilers

This study hypothesized that plasma and tissue antioxidant status of broilers is positively influenced when dietary Met concentrations exceed, and negatively when they go below NRC recommendations. In addition, different Met sources are hypothesized to affect the antioxidant defence system differently. Day‐old male Cobb‐500 broilers (n  = 336) were allotted to seven groups and phase‐fed three wheat–soya bean meal‐based basal diets during days 1‐10, 11‐21 and 22‐35. The basal diets (Met? group, Met + Cys concentration 15% below NRC recommendations) were supplemented with 0.10%, 0.25% or 0.40% Met either as DL ‐Met (DLM ) or DL ‐2‐hydroxy‐4‐(methylthio) butanoic acid (DL ‐HMTBA ) (equimolar comparison). Growth performance and carcass weights were lower in the Met? group compared to the groups whose diets met or exceeded Met requirements. The antioxidant defence system was not influenced by the Met source. However, in the liver, concentrations of glutathione increased with increasing dietary Met concentrations. Tocopherol concentrations in the liver at days 10 and 21 were lower in the Met? group than in the groups supplemented with Met. However, liver concentrations of thiobarbituric acid reactive substances (TBA ‐RS ) and protein carbonyls (PC ) were largely not influenced by dietary Met concentration. Plasma tocopherol concentrations at day 35 were lower, and those of TBA ‐RS and PC at day 35 were higher in Met? group than in the groups fed the Met‐supplemented diets. In jejunum, but not in liver, relative mRNA abundances and activities of superoxide dismutase, catalase and glutathione peroxidase were higher in the Met? group than in the groups fed Met‐supplemented diets. These data indicate that suboptimum supply of Met results in decreased antioxidant concentrations in plasma and body tissues, and increases oxidative stress in the jejunum mucosa. However, supplementation of Met in excess of the requirements (based on NRC ) compared to diets adequate in Met + Cys did not influence the antioxidant defence system.     

Effects of Inulin Supplementation in Low‐ or High‐Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low‐ or high‐fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low‐fat diet (L), low‐fat diet containing 1.5% inulin (LI), high‐fat diet (H) and high‐fat diet containing 1.5% inulin (HI). Inulin‐rich diets lowered the within‐litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0–1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat‐rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning‐to‐oestrous interval (WEI, p < 0.01) compared with sows fed low‐fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T‐SOD) and glutathione peroxidase (GSH‐Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T‐SOD and GSH‐Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat‐rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin‐rich diets fed to sow during gestation had beneficial effects on within‐litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.     

Supplemental methionine sources have a neutral impact on oxidative status in broiler chickens

To determine the effect of different dietary Met sources on oxidative status, male Cobb 500 broiler chickens were fed from day of hatch to 26 days of age (d26) a diet deficient in sulfur amino acids (control) or a diet containing 0.22% DL‐Met, 0.22% L‐Met or 0.31% Met precursor, DL‐2‐hydroxy‐4‐(methylthio) butanoic acid (DL‐HMTBA) to meet the Met + Cys requirements. Liver, breast muscle, duodenum, jejunum, and ileum were collected at day 10 (d10) and d26 to assay markers of oxidative stress, including total glutathione (TGSH), oxidized glutathione (GSSG), reduced glutathione (rGSH), protein carbonyls, thiobarbituric acid reactive substances (TBARS) and ferric reducing/antioxidant power (FRAP). In breast muscle, TGSH and rGSH were greater in L‐Met and DL‐HMTBA groups than in the control group (p < 0.05). An interaction of treatment and age was observed for TGSH in ileum (p = 0.01) and jejunum (p = 0.01), for GSSG in jejunum (p < 0.001), and for rGSH in ileum (p = 0.02). The ratios of rGSH to GSSG and GSSG to TGSH, which define oxidative status, were not affected by Met source. Protein carbonyls varied among groups in jejunum (p = 0.05) and breast muscle (p < 0.001), but were in the normal physiological range. No difference among treatment groups was observed for TBARS and FRAP in different tissues. Age effects were observed in all tissues for multiple oxidative stress markers. In conclusion, consuming different sources of supplementary Met did not alter the oxidative status in several tissues of broilers. Met + Cys deficiency did not compromise antioxidant capacity of chickens although growth was retarded.     

Dose–responses of zinc–methionine supplements on growth,blood metabolites and gastrointestinal development in sheep

The effects of zinc–methionine (Zn‐Met) supplementation on growth, blood metabolites and gastrointestinal development were investigated in two experiments with sheep. The objective of Experiment 1 was to determine the effects of Zn‐Met supplementation on hormones and metabolites involved in growth and energy balance regulation, while Experiment 2 aimed to determine the effects of Zn‐Met on feed intake, body weight, gastrointestinal development and liver glycogen concentration in lamb. The animals were assigned to groups with different concentrations of dietary Zn‐Met (0, 0.4, 0.8 and 1.2 g/day) in both experiments. In Experiment 1, feeding different doses of Zn‐Met increased plasma insulin‐like growth factor 1 (IGF‐1) concentration, but it linearly decreased plasma growth hormone (GH). No differences were observed in blood cortisol, insulin and glucose concentrations among the treatments. In Experiment 2, addition of Zn‐Met to the diets did not lead to changes in the body weights of the lambs. Both average daily gain and dry matter intake (DMI) increased linearly with increasing concentrations of dietary Zn‐Met. Lambs receiving Zn‐Met showed higher liver glycogen concentrations than the control. While significant increases were observed in the villus height and crypt depth in the duodenum and jejunum as a result of Zn‐Met supplementation, no change was detected in blood glucose concentrations (p > 0.05). Our findings suggest that dietary Zn‐Met may improve growth, energy balance and gastrointestinal development in sheep.     

Effects of lycopene supplementation in both maternal and offspring diets on growth performance,antioxidant capacity and biochemical parameters in chicks

This study investigated the effects of different supplementation ways of lycopene during pre‐hatch (from the diet of hens) and post‐hatch (from the diet of progeny) on production performance, antioxidant capacity and biochemical parameters in chicks. In total, 360 hens were fed diets supplemented with 0 (control group) or 40 mg lycopene/kg diet. From 28 to 34 days after the start of supplementation (30 weeks old), 650 qualified eggs were collected to artificial incubation. In this trial, 2 × 2 factorial designs were used. Male chicks hatched from hens fed with 0 or 40 mg lycopene/kg diet were fed a diet containing either 0 or 40 mg lycopene/kg diet. The results showed that, relative to control, in ovo‐deposited lycopene significantly increased chick birth body weight, improved liver total antioxidant capacity (T‐AOC), glutathione peroxidase (GSH‐Px) and glutathione to oxidized glutathione ratio (GSH: GSSG), and significantly declined liver malondialdehyde (MDA) level and increased liver lycopene content during 0–14 days after hatching. On days 14 after hatching, dietary lycopene in diet began to take over gradually. Both supplementation ways of lycopene increased immune organ index, serum high‐density lipoprotein (HDL) cholesterol, villus length and villus/crypt in duodenum, jejunum and ileum. Data in this study suggested lycopene supplementation could improve antioxidant capacity and immune function, and regulate lipid metabolism in chicks.     

Effect of fermented blood cells on growth performance and intestinal characteristics of weaned piglets

The increase in feed costs has led feeder to replace protein source. Blood meal can be used in piglet diets instead of fish meal (FM). The objective of this study was to investigate the effect of fermented blood cells (FBCs) on the growth performance and intestinal health of weaned piglets. One hundred eighty 28‐day‐old piglets were assigned and were divided into 4 groups (9 L per groups and 5 pigs per litters) randomly. The piglets were fed one of four experimental diets, fish meal, blood cells (BCs), liquid‐state fermented blood cells (LFBCs) or solid‐state fermented blood cells (SFBCs) respectively. The dietary with LFBCs and SFBCs increased the average daily gain and feed intake (ADFI) and average daily gain (ADG) (p < .05). In duodenum, LFBC group increased the villous height (p < .05). The SFBC and LFBC group significantly increased the villous height (p < .05) in the jejunum. Fermented blood cells exhibit a positive regulatory function on the intestinal tract and modulate intestinal microflora. Compared with the fish meal group, the CAT, GSH‐PX and SOD activity, and MDA level was no significant differences in jejunum and plasma of weaned piglets (p > .05). LFBCs and SFBCs significantly increased the bifidobacteria and lactobacillus number in the caecum (p < .05). Dietary LFBCs increased the expression of ZO‐1 mRNA in the jejunal of weaned piglets (p < .05). In conclusion, dietary with fermented blood cells in weaned piglets had improved growth performance and intestinal health of weaned piglets.     

Dietary levels of protein and free amino acids affect pancreatic proteases activities,amino acids transporters expression and serum amino acid concentrations in starter pigs

The dietary contents of crude protein and free amino acids (AA) may affect the protein digestion and AA absorption in pigs. Trypsin and chymotrypsin activities, AA serum concentrations and expression of AA transporters in the small intestine of pigs fed a low protein, AA‐supplemented (19.2%, LPAA) or a high protein (28.1%, HP), wheat‐soybean meal diet were measured in two 14‐d trials. The LPAA diet contained free L‐Lys, L‐Thr, DL‐Met, L‐Leu, L‐Ile, L‐Val, L‐His, L‐Trp and L‐Phe. All pigs were fed the same amount of feed (890 and 800 g/d for trial 1 and 2 respectively). In trial 1, samples of mucosa (duodenum, jejunum and ileum) and digesta (duodenum and jejunum) were collected from 14 pigs (17.2 ± 0.4 kg); in trial 2, blood samples were collected from 12 pigs (12.7 ± 0.3 kg). The trypsin and chymotrypsin activities in both intestinal segments were higher in pigs fed the HP diet (p < 0.01). Trypsin activity was higher in jejunum than in duodenum regardless the dietary treatment (p < 0.05). Pigs fed the LPAA diet expressed more b^0,+AT in duodenum, B⁰AT1 in ileum (p < 0.05), and tended to express more y⁺LAT1 in duodenum (p = 0.10). In pigs fed the LPAA diet, the expression of b^0,+AT was higher in duodenum than in jejunum and ileum (p < 0.01), but no difference was observed in pigs fed the HP diet. Ileum had the lowest b^0,+AT expression regardless the diet. The serum concentrations of Lys, Thr and Met were higher in LPAA pigs while serum Arg was higher in HP pigs (p < 0.05). Serum concentrations of AA appear to reflect the AA absorption. In conclusion, these data indicate that the dietary protein contents affect the extent of protein digestion and that supplemental free AA may influence the intestinal site of AA release and absorption, which may impact their availability for growth of young pigs.     

Water extract of Artemisia ordosica enhances antioxidant capability and immune response without affecting growth performance in weanling piglets

The present experiment was conducted to investigate the effects of water extract of Artemisia ordosica (WEAO) on growth performance, antioxidant capability and immune response in weanling piglets. Seventy‐two 28‐day‐old weanling piglets were randomly allocated into four treatments with six replicate pens per treatment and three piglets per pen (n = 18). These four treatment diets were formulated by adding 0, 250, 500 and 750 mg/kg WEAO to the basal diet. The experiment lasted for 28 days. Body weight and feed intake were measured. Blood samples were collected to determine immune and antioxidative parameters. The experimental results showed that WEAO supplementation improved the apparent nutrient digestibility of piglets in a linear or quadratic dose‐dependent manner. In addition, dietary WEAO quadratically increased serum concentrations of cytokines interleukin (IL)‐1, IL‐4, tumour necrosis factor (TNF)‐α, soluble surface antigen CD8 (sCD8), immunoglobulins (Ig)‐A and linearly increased serum concentrations of IL‐2, IL‐6, IgG, IgM. Furthermore, dietary WEAO linearly or quadratically decreased serum concentrations of malondialdehyde but quadratically increased activities of antioxidant enzymes and total antioxidative capacity. These results suggested that WEAO may prove useful as a natural phytogenic feed additive with antioxidative potential and could be incorporated into diets of piglets.     

Dietary apple polyphenols supplementation enhances antioxidant capacity and improves lipid metabolism in weaned piglets

Apple polyphenols (APPs) are biologically active flavonoids that have antioxidant, anti‐inflammatory, improving insulin sensitivity, hypocholesterolaemic effect and antiviral properties. This study was conducted to explore effects of dietary APPs supplementation on antioxidant activities and lipid metabolism in weaned piglets. Fifty‐four weaned piglets (half male and female) were randomly divided into three groups with six replicates in each group and three piglets in each repetition. Piglets were fed control diet (basal diet) or a control diet supplemented with 400 mg/kg or 800 mg/kg APPs for 6 weeks. Blood and liver samples were collected to determine biochemical, antioxidant and lipid metabolism parameters. Here we showed that dietary APPs supplementation increased HDL‐C and decreased T‐CHO, TG and LDL‐C concentrations. Dietary APPs supplementation increased antioxidative capacity in serum and CAT activity in liver, and significantly increased the mRNA expressions of CAT, GST and SOD1 in liver. ACC mRNA level and LPL activity were tended to decrease by APPs. HMG‐CoAR, CTP7A1, CD36 and FATP1 mRNA levels were decreased by APPs, while LDL‐R, PGC‐1α, Sirt1 and CPT1b mRNA levels were increased by 400 mg/kg APPs. No alterations in growth performance were found in all treatments. This study firstly provided the evidence that dietary APPs supplementation could enhance systemic antioxidant capacity and improve lipid metabolism in weaned piglets. The mechanism by which APPs improve lipid metabolism might be through regulating hepatic cholesterol metabolism and increasing fatty acid oxidation, and decreasing fatty acid uptake and de novo synthesis.     

菊粉对断奶仔猪生长性能、养分表观消化率及抗氧化能力的影响

本试验旨在研究饲粮添加不同水平菊粉对断奶仔猪生长性能、养分表观消化率及抗氧化能力的影响。选取32头平均体重为(7.10±0.20)kg的杜长大(DLY)断奶仔猪,随机分为4组,每组8个重复,每个重复1头猪。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加2.5、5.0和10.0 g/kg的菊粉(等量替代基础饲粮中的玉米)。试验期21 d。结果表明,与对照组相比:1)饲粮添加2.5、5.0和10.0 g/kg菊粉对断奶仔猪平均日采食量和平均日增重无显著影响(P>0.05),饲粮添加2.5、5.0和10.0 g/kg菊粉可显著提高断奶仔猪粗灰分表观消化率(P<0.05),饲粮添加2.5和5.0 g/kg菊粉可显著提高断奶仔猪粗蛋白质表观消化率(P<0.05)。2)饲粮添加2.5 g/kg菊粉可显著提高血清中总超氧化物歧化酶(T-SOD)活性(P<0.05);饲粮添加2.5、5.0和10.0 g/kg菊粉可显著降低肝脏中丙二醛(MDA)含量(P<0.05);饲粮添加2.5和5.0 g/kg菊粉可显著提高空肠中过氧化氢酶(CAT)活性(P<0.05),饲粮添加2.5和5.0 g/kg菊粉可显著降低回肠中MDA含量(P<0.05),饲粮添加2.5 g/kg菊粉可显著提高十二指肠中CAT活性(P<0.05)。3)饲粮添加2.5、5.0和10.0 g/kg菊粉可显著提高肝脏中核因子E2相关因子2(Nrf2)的mRNA相对表达量(P<0.05),饲粮添加5.0和10.0 g/kg菊粉可显著提高肝脏中血红素氧合酶-1(HO-1)的mRNA相对表达量(P<0.05)。4)饲粮添加2.5、5.0和10.0 g/kg菊粉可显著提高十二指肠中HO-1的mRNA相对表达量和空肠中Nrf2的mRNA相对表达量(P<0.05),饲粮添加2.5和5.0 g/kg菊粉可显著提高回肠中HO-1和Nrf2的mRNA相对表达量(P<0.05),饲粮添加2.5 g/kg菊粉可显著提高空肠中Kelch样环氧氯丙烷相关蛋白1(Keap1)的mRNA相对表达量(P<0.05),饲粮添加10.0 g/kg菊粉可显著提高空肠中HO-1和Keap1的mRNA相对表达量(P<0.05)。综上所述,饲粮添加菊粉对断奶仔猪生长性能无显著影响,但可改善养分表观消化率,提高抗氧化能力。本试验条件下,断奶仔猪饲粮中菊粉适宜添加水平为2.5 g/kg。     

Effect of gestation dietary methionine-to-lysine ratio on methionine metabolism and antioxidant ability of high-prolific sows

The uptake and metabolism of methionine (Met) are critical for epigenetic regulation, redox homeostasis, and embryo development. Our previous study showed that appropriate supplementation of dietary Met promoted the birth weight and placental angiogenesis of high-prolific sows. To further explore the metabolic effect of Met on pregnant sows, we have evaluated the influence of dietary Met level on Met metabolism, and the relationship between metabolites of Met and reproductive performance, antioxidant ability, and placental angiogenesis throughout the gestation of high-prolific sows. Sixty sows (the 3rd parity, Large White) were randomly divided into 5 groups that were fed diets with standardized ileal digestible (SID) methionine-to-lysine (Met:Lys) ratios of 0.27 (control), 0.32, 0.37, 0.42, and 0.47 from the mating day (gestational d 0, G0d) until the farrowing day. HPLC-MS/MS analysis was used to simultaneously evaluate the metabolites related to Met, e.g. S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), homocysteine (Hcy), cysteine (Cys), and glutathione (GSH). The concentration of SAM and SAH in plasma had significant fluctuations, especially in late pregnancy. Increasing dietary Met supplementation significantly improved the plasma SAM and methylation potential (SAM-to-SAH ratio) at d 114 of pregnancy (G114d). Moreover, a positive association of the plasma SAM concentration at G114d was observed with the litter weight of born alive (P < 0.05; R² = 0.58). Furthermore, Hcy concentration in plasma was at the lowest level for 0.37 ratio group at G114d. However, it significantly increased during late pregnancy. Moreover, there were negative correlations between plasma Hcy concentration at G114d (P < 0.05) and the placental vascular density in the fold and stroma (P < 0.05). Compared with the control group, the expression of vascular endothelial growth factor-A (VEGF-A) in the placenta tissue of 0.37 ratio group increased significantly (P < 0.05). Collectively, these findings indicate that dietary Met:Lys ratio (0.37 to 0.57) in the pregnant diet dose not influence the antioxidant ability of the high-prolific sows; however, the improvement of fetal development and placental angiogenesis of high-prolific sows by supplementation of Met are closely associated to the key Met-related metabolite of SAM and Hcy, respectively.     

Effects of sodium butyrate on growth performance,haematological and immunological characteristics of weanling piglets

The experiment was conducted to study the effects of sodium butyrate (SB) on growth, haematological and immunological characteristics in weanling pigs. A total of 100 male piglets (Duroc×Landrace×Yorkshire) with a body weight of 8.0 ± 0.2 kg weaned at the age of 28 days were randomly assigned to two treatments with five replicates and 10 pigs per replicate. Piglets received a basal diet (control group) or diets supplemented with 1000 mg/kg SB. The feeding trial lasted for 21 days. The results showed that dietary SB significantly decreased (p < 0.05) diarrhoea incidence of weaned piglets, but did not affect (p > 0.05) the average daily feed intake (ADFI), average daily gain (ADG) and feed to gain (F/G). Furthermore, piglets fed dietary SB had higher (p < 0.05) serum concentrations of glucose and triglycerides and lower (p < 0.05) serum concentrations of urea nitrogen, cortisol, D‐lactic acid and diamine oxidase when compared with the control group. However, dietary SB did not affect concentrations of serum albumin, total protein, insulin and glucagon (p > 0.05). There were no significant (p > 0.05) treatment effects on serum IgA and IgM, whereas serum IgG concentration and IgA+ cell count in jejunum from pigs fed SB were significantly higher (p < 0.05) than in those given the basal diet. In conclusion, the present study indicated that dietary SB significantly decreased diarrhoea incidence of weaned piglets and increased the efficiency of nitrogen utilization. Also, dietary SB could regulate and enhance the immune function of piglets by increasing the serum IgG concentration and IgA+ cell count in jejunum. Our results suggest that SB may reduce some of the adverse effects of weaning stress and play an important role in maintaining the integrity of intestinal mucosa.     

Digestibility,ruminal fermentation,blood metabolites and antioxidant status in ewes supplemented with DL‐methionine or hydroxy‐4 (methylthio) butanoic acid isopropyl ester

The effects of supplementing ewe diets with either DL‐methionine (DL‐Met) or 2‐hydroxy‐4 (methylthio) butanoic acid isopropyl ester (HMBi) were investigated on ruminal in situ degradability of grain and forage diets, in vivo digestibility, rumen fermentation, blood metabolites and antioxidant status. Six ruminally cannulated ewes were used in a replicated 3 × 3 Latin square design with 28‐day periods. The dietary treatments were as follows: (i) no supplemental Met (control; CON), (ii) DL‐Met at 1.2 g/kg DM intake and (iii) HMBi at 1.8 g/kg dry matter (DM) intake. Corn grain, barley grain and alfalfa hay were evaluated for their ruminal degradability by both in situ incubation and effective degradability measurements of DM, neutral detergent fibre (NDF) and acid detergent fibre (ADF). Compared to other treatments, HMBi supplementation increased (p < 0.05) the digestibility of organic matter, crude protein and NDF and also tended (p = 0.08) to increase the digestibility of DM and ADF. Moreover, HMBi supplementation increased (p < 0.01) total VFA concentrations, the molar proportions of valerate and iso‐butyrate in the rumen. Compared to the CON treatment, DL‐Met and HMBi treatments tended (p = 0.08) to increase the molar proportion of acetate but decreased (p < 0.05) ruminal ammonia‐N concentration. Ewes supplemented with HMBi and DL‐Met recorded greater (p < 0.05) serum concentrations of glutathione peroxidase, total antioxidant capacity and superoxide dismutase than the CON treatment. Serum concentrations of glucose, total protein, albumin, high‐density lipoprotein and very low‐density lipoprotein were greater (p < 0.01) and serum urea nitrogen (p < 0.05), malonyl dialdehyde and triglyceride were lower (p < 0.02) in the HMBi and DL‐Met animals than in the CON ewes. The results concluded that HMBi is a very effective form of dietary Met supplementation for ewes with a positive effect on digestion, rumen fermentation and serum antioxidant function.     

Effects of Piper sarmentosum extract on the growth performance,antioxidant capability and immune response in weaned piglets

The biological properties of Piper sarmentosum render it a potential substitute for antibiotics in livestock feed. This study evaluated the effects of P. sarmentosum extract (PSE) on the growth performance, antioxidant capability and immune response of weaned piglets. Eighty 21‐d‐old weaned piglets were selected and randomly allocated to one of four dietary treatments with five replicates of four pigs each. The dietary treatments consisted of a basal diet supplemented with 0 (T0), 50 (T50), 100 (T100) or 200 (T200) mg/kg PSE. The feeding trial lasted 4 weeks. The results revealed that the T50 group had the highest average daily gain (ADG) and average daily feed intake (ADFI) throughout the feeding trial (p < 0.05). Additionally, the T50 group had higher (p < 0.05) serum glutathione peroxidase activity (GSH‐Px) and lower (p < 0.05) serum malondialdehyde (MDA) levels than the T0 group at 4 weeks post‐weaning (p < 0.05). Serum levels of interleukin‐1β (IL‐1β) and tumour necrosis factor‐α (TNF‐α) decreased, while serum levels of interleukin‐4 (IL‐4), interleukin‐10 (IL‐10) and transforming growth factor‐β (TGF‐β) increased by PSE supplementation at 4 weeks post‐weaning (p < 0.05). PSE supplementation upregulated the mRNA expression of IL‐4, IL‐10 and TGF‐β and downregulated the mRNA expression of TNF‐α, IL‐1β and interleukin‐6 (IL‐6) in the ileal mucosal layer of piglets (p < 0.05). In summary, our study findings revealed that PSE supplementation improved the antioxidant capability, and reduced inflammation, which may be beneficial to weaned piglet health.     

Effect of dietary supplementation of organic zinc on laying performance,egg quality and some biochemical parameters of laying hens

This study was conducted to evaluate the effects of zinc methionine (Zn‐Met) supplementation on the performance, egg quality, antioxidant status and some biochemical parameters of blood serum in laying hens from 22 to 34 weeks of age. A total of 120 Hisex Brown laying hens of 22‐week‐old were randomly allocated into five treatments with six cage replicates for each (four hens/replicate). Dietary treatments consisted of the basal diet with no Zn‐Met supplementation (control group) and basal diet supplemented with 25, 50, 75 or 100 mg Zn‐Met/kg diet. No significant differences were observed on body weight, body weight gain or feed conversion ratio due to dietary Zn‐Met supplementation. However, highly significant impact was observed on daily feed intake. Egg number, egg weight and egg mass were increased in the group fed diet supplemented with the highest level of Zn‐Met (100 mg/kg of diet) as compared to other groups. All egg quality traits were statistically (p > .05 or .01) affected as a response to dietary Zn‐Met supplementation except egg shape index, shell percentage and yolk index. In comparison with the control group, dietary supplementation of 25, 50, 75 or 100 mg Zn‐Met/kg decreased serum triglyceride and LDL‐cholesterol levels. Serum cholesterol level was increased with all dietary levels of Zn‐Met in comparison with the control group. Dietary Zn‐Met supplementation increased the serum content of zinc, where the highest values were recorded with 50 and 100 mg Zn‐Met/kg diet. Dietary Zn‐Met levels did not affect the antioxidant indices in blood serum except for the activity of copper–zinc superoxide dismutase (Cu‐Zn‐SOD). The activity of Cu‐Zn‐SOD was increased with Zn‐Met supplementations with no differences among supplemental zinc levels. It is concluded that dietary Zn‐Met supplementation reduced serum triglyceride, LDL‐cholesterol and increased Zn status and resulted in promoting antioxidant ability of laying hens, and the addition of 100 mg Zn‐Met/kg to layer diet was appropriate for improving the above parameters in addition to egg production indices and Haugh unit score.     

Effects of dietary leucine on antioxidant activity and expression of antioxidant and mitochondrial‐related genes in longissimus dorsi muscle and liver of piglets

The study was conducted to investigate the effects of dietary leucine on antioxidant activity and expression of antioxidant‐ and mitochondrial‐related genes in longissimus dorsi muscle and liver of piglets. Three diets were formulated with different levels of supplemented leucine (0%, 0.25%, 0.5%). Results showed that supplementation of 0.25% leucine significantly increased antisuperoxide anion (ASA) and antihydroxyl radical (AHR) levels and activities of total superoxide dismutade (T‐SOD), glutathione peroxidase (GPx), glutathione S‐transferase (GST), and total antioxidant capacity (T‐AOC) in serum, longissimus dorsi muscle and liver of piglets as compared with the control group. The SOD2, catalase (CAT), GPx, GST, glutathione reductase (GR), and nuclear factor erythroid 2‐related factor 2 (Nrf2) mRNA levels in longissimus dorsi muscle and liver were significantly increased by 0.25% leucine supplementation. However, the malondialdehyde (MDA) content and the mRNA level of Kelch‐like ECH‐associated protein 1 (Keap1) exhibited an opposite tendency. Additionally, supplementation of 0.25% leucine significantly increased the mRNA levels of mitochondrial‐related genes in longissimus dorsi muscle and liver of piglets. Results suggested that supplementation of 0.25% leucine improved antioxidant activity and mitochondrial biogenesis and function of piglets, which was related to the increase in antioxidant enzymes activities and upregulation of expression of antioxidant‐ and mitochondrial‐related genes.     

苜蓿皂苷对断奶仔猪生长性能、肠道菌群、组织抗氧化能力及相关酶mRNA表达的影响

本试验旨在研究苜蓿皂苷对断奶仔猪生长性能、肠道菌群、组织抗氧化能力及相关酶mRNA表达的影响。选取24头平均体重为8 kg的大×长杂交断奶仔猪,随机分为2组,每组3个重复,每个重复4头猪。对照组饲喂基础饲粮,苜蓿皂苷组饲喂在基础饲粮中添加0.25%苜蓿皂苷的饲粮。预试期10 d,正试期30 d。结果表明:1)与对照组相比,饲粮中添加苜蓿皂苷可显著提高断奶仔猪平均日增重(P0.05),并显著降低料重比(P0.05)。2)与对照组相比,饲粮中添加苜蓿皂苷可显著降低仔猪十二指肠和盲肠的pH(P0.05),显著提高十二指肠、空肠和回肠中乳酸菌数量(P0.05)。3)与对照组相比,饲粮中添加苜蓿皂苷可显著提高仔猪肝脏和肾脏中谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)活性(P0.05),并显著提高仔猪肝脏和空肠中GSH-Px mRNA表达量及十二指肠和回肠中CAT mRNA表达量(P0.05)。综上,苜蓿皂苷可以提高断奶仔猪生长性能,增强其组织抗氧化能力并有效改善其肠道菌群。     

Imbalanced dietary methionine-to-sulfur amino acid ratio can affect amino acid profiles,antioxidant capacity,and intestinal morphology of piglets

Animal protein sources such as fishmeal and plasma powder are excellent and indispensable sources of energy, amino acids, and minerals in animal production. Amino acid imbalance, especially methionine-to-sulfur amino acid (Met:SAA) ratio, caused by an imbalance of animal protein meal leads to growth restriction. This study was conducted to evaluate the effects of imbalanced Met:SAA ratio supplementation of different animal protein source diets on growth performance, plasma amino acid profiles, antioxidant capacity and intestinal morphology in a piglet model. Twenty-four weaned piglets (castrated males; BW = 10.46 ± 0.34 kg), assigned randomly into 3 groups (8 piglets/group), were fed for 28 d. Three experimental diets of equal energy and crude protein levels were as follows: 1) a corn-soybean basal diet with a Met:SAA ratio at 0.51 (BD); 2) a plasma powder diet with a low Met:SAA ratio at 0.41 (L-MR); 3) a fishmeal diet with a high Met:SAA ratio at 0.61 (H-MR). Results revealed that compared to BD, L-MR significantly decreased (P < 0.05) the activities of plasma total antioxidant capacity and glutathione peroxidase, plasma amino acid profiles, and significantly reduced (P < 0.05) villus height and crypt depth in the duodenum and jejunum. Additionally, L-MR significantly reduced (P < 0.05) the mRNA expression level of solute carrier family 7 member 9 (SlC7A9) in the ileum, and significantly increased (P < 0.05) mRNA expression levels of zonula occludens-1 (ZO-1) in the duodenum, and Claudin-1, ZO-1, sodium-coupled neutral amino acid transporters 2 (SNAT2) and SlC7A7 in the jejunum. H-MR significantly increased (P < 0.05) plasma SAA levels, and significantly reduced (P < 0.05) average daily feed intake, villus height, and villus height-to-crypt depth (VH:CD) ratio in the ileum compared to BD. In conclusion, L-MR may result in oxidative stress and villous atrophy but proves beneficial in improving intestinal barrier function and the activity of amino acid transporters for compensatory growth. H-MR may impair intestinal growth and development for weaned piglets. The research provides a guidance on the adequate Met:SAA ratio (0.51) supplementation in diet structure for weaned piglets.