Growth,digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp Ctenopharyngodonidella fed graded levels of dietary threonine

Background:This study was carried out to investigate effects of threonine levels on growth,digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp(Ctenopharyngodonidella).Results:Weight gain,specific growth rate,feed intake and feed efficiency were significantly improved by dietary threonine(P0.05).Intestinal activities of trypsin,chymotrypsin,alpha-amylase,lipase,alkaline phosphatase,y-glutamyl transpeptidase and creatine kinase took the similar trends.Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation(P0.05).Anti-superoxide anion capacity,anti-hydroxyl radical capacity,glutathione content and activities of superoxide dismutase,catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine(P 0.05).Conclusions:Dietary threonine could improve growth,enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp.The dietary threonine requirement of sub-adult grass carp(441.9-1,013.4 g) based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis.     

The relationship between dietary methionine and growth,digestion,absorption,and antioxidant status in intestinal and hepatopancreatic tissues of sub-adult grass carp(Ctenopharyngodon idella)

Background: Methionine is an essential amino acid for fish. The present study was conducted to investigate the effects of dietary methionine on growth performance, digestive and absorptive ability, as well as antioxidant capacity in the intestine and hepatopancreas of sub-adult grass carp(Ctenopharyngodon idella).Results: Dietary methionine deficiency significantly decreased percentage weight gain(PWG), feed intake, feed efficiency and protein efficiency ratio, as well as activities of hepatopancreatic glutamate-oxaloacetate transaminase and muscle glutamate-pyruvate transaminase in sub-adult grass carp(P 0.05). Furthermore, methionine deficiency significantly reduced activities of trypsin, lipase and amylase in the intestine, Na~+/K~+-ATPase, alkaline phosphatase and γ-glutamyl transpeptidase in three intestinal segments, and creatine kinase(CK) in the proximal intestine(P 0.05). However, an unexplained and significant increase in CK activity in the mid intestine was associated with dietary methionine deficiency. Malondialdehyde and protein carbonyl contents in the intestine and hepatopancreas were significantly increased by methionine deficiency(P 0.05), whereas anti-hydroxyl radical capacity in the hepatopancreas and intestine, and anti-superoxide anion capacity in the intestine, were significantly decreased by methionine deficiency(P 0.05). Moreover, methionine deficiency significantly decreased superoxide dismutase and glutathione reductase activities, glutathione contents in the hepatopancreas and intestine, as well as glutathione peroxidase activity in the intestine(P 0.05), whereas it significantly increased activities of catalase in the hepatopancreas and glutathione-S-transferase in the hepatopancreas and intestine(P 0.05).(Continued on next page)(Continued from previous page)Conclusions: The present results demonstrated that dietary methionine deficiency induced poor growth, and decreased digestive and absorptive function and antioxidant capacity in the hepatopancreas and intestine of sub-adult grass carp. Methionine requirements for sub-adult grass carp(450-1, 170 g) based on PWG, intestinal trypsin, and hepatopancreatic anti-hydroxyl radical activities were estimated to be 6.12 g/kg diet(21.80 g/kg protein),6.99 g/kg diet(24.90 g/kg protein) and 5.42 g/kg diet(19.31 g/kg protein), respectively, in the presence of 1.50 g cysteine/kg(5.35 g/kg protein).     

Effects of dietary L-threonine levels on antioxidant capacity,digestive enzyme activities,and antibody production of Xinyang green-shell laying hens

Xinyang green-shell laying hens (n = 720), 32 wk of age were allocated to 5 dietary treatments groups, each of which included 6 replicates of 24 hens. The control group was given a basal corn-peanut-soybean meal diet containing 0.47% L-threonine (L-Thr). L-Thr levels of the experimental groups were 0.57, 0.67, 0.77, and 0.87%, respectively. The trial lasted 10 wk. Serum concentrations of total superoxide dismutases (T-SOD) and superoxide dismutases (SOD) were maximized at 0.67% L-Thr group. The 0.57% L-Thr group had the highest serum total antioxidative capacity (T-AOC), while the 0.67% L-Thr group had the lowest serum malondialdehyde (MDA) concentration. Hens fed 0.67% L-Thr of the diet resulted in the highest SOD and T-AOC levels in the liver. The activity of amylase and lipase in the jejunum was maximized at 0.77% L-Thr level. Hens fed 0.77% L-Thr in the diet resulted in the highest IgM and IgG levels in the jejunum. In conclusion, we suggest that a L-Thr level above 0.67% may have had an antioxidant capacity and positive effect on digestive enzyme activities and antibody production in the jejunum of Xinyang green-shell laying hens.     

黑水虻幼虫替代饲料直接投喂对锦鲤生长消化、肝胰脏抗氧化酶和血清非特异性免疫指标的影响

以锦鲤为试验对象,将黑水虻幼虫活虫和黑水虻幼虫干虫分别替代饲料对锦鲤进行投喂,投喂30 d后测定血清和组织中抗氧化酶活性和非特异性免疫指标。结果表明,干虫组的特定生长率、增重率显著低于对照组和活虫组(P<0.05),而体均重与肥满度各组间差异不显著(P>0.05)。血清中ALT活力活虫组显著高于干虫组(P<0.05),AKP活力对照组显著低于活虫组和干虫组(P<0.05),AST活力、ACP活力和溶菌酶活力各组间差异不显著(P>0.05)。肝胰脏T-SOD活力和T-AOC对照组显著低于活虫组和干虫组(P<0.05),CAT活力和GSH-Px活力各组间差异不显著(P>0.05)。前肠淀粉酶、脂肪酶、胰蛋白酶活力各组间差异不显著(P>0.05)。可见,将黑水虻作为一种环保、价格低廉的饲料投喂锦鲤,对其生长、抗氧化能力和非特异性免疫有促进作用,作为新型饲料具有可行性。     

Effects of different dietary sources and levels of selenium supplements on growth performance,antioxidant status and immune parameters in Ross 308 broiler chickens

1. Although different impacts of various sources of selenium (Se) on chicken performance have been largely studied, there is a lack of comparative experiments studying the effects of these sources on the immune system and antioxidant indices of broiler tissues. The aim of this study was to examine the effects of various sources and levels of dietary Se supplements on performance, antioxidant status and immune parameters in Ross 308 broiler chickens.

2. A total of 1200 1-d-old male broilers (Ross × Ross 308) were divided into 8 treatments with 6 replicate pens and 25 birds per pen. This experiment was conducted as a completely randomised design with a 4 × 2 factorial arrangement. Main factors included Se sources as sodium selenite (SS), Se-enriched yeast (SY), DL-selenomethionine (SM) and nano-selenium (NS) and levels at 0.1 or 0.4 mg/kg Se.

3. Dietary supplementation of organic Se sources significantly improved average daily gain (ADG), gain: feed ratio and European production efficiency factor (P < 0.05) compared to birds fed on diets supplemented with inorganic source. In addition, ADG was increased in response to increased level of supplemental Se. Based on contrast comparison, there were significant differences in these parameters between organic versus inorganic sources of Se. However, there was no difference between contrast comparisons of NS versus SM and SY.

4. Total anti-sheep red blood cell (SRBC) and Immunoglobulin G (IgG) titres and hypersensitivity were enhanced by increasing supplemental concentration of Se and using organic sources of Se rather than SS (P < 0.05).

5. Oxidation resistance assessment of tissues demonstrated that supplementation of organic sources of Se and increase in supplemental concentration of Se ameliorated glutathione peroxidase activity, total antioxidant capacity and malondialdehyde formation (P < 0.05). Mostly, there were significant differences between organic versus inorganic sources of Se in oxidation resistance.

6. Overall, dietary supplementation of 0.4 mg/kg Se from an organic source resulted in better production performance and immune system response. Moreover, minimum formation of malondialdehyde in broiler tissue was observed in birds fed on diets supplemented with SM at 0.4 mg/kg.

7. It can be concluded that SM is more effective than other sources of Se in reducing lipid oxidation.     

Betaine improves growth performance,liver health,antioxidant status,breast meat yield,and quality in broilers fed a mold-contaminated corn-based diet

Betaine has been demonstrated to improve growth performance and antioxidant status of animals under various stress conditions. However, there is no literature on the effects of betaine in animals exposed to mycotoxins, which are among the most prevalent contaminants in feed. Therefore, this study was conducted to evaluate the influence of dietary betaine on broilers fed a diet based on mold-contaminated corn (MCC). A total of 192 Ross 308 male broiler chicks at 1 d of age were randomly divided into 4 groups with 6 replicates and fed an MCC-based diet supplemented with 0, 250, 500, and 1,000 mg/kg betaine, respectively. Betaine increased average daily gain (linear, P = 0.030) and decreased feed conversion ratio (linear, P = 0.027) of broilers during d 1 – 21, and decreased feed conversion ratio during d 22 – 42 (linear, P = 0.012; quadratic, P < 0.001) and d 1 – 42 (linear, P = 0.003; quadratic, P = 0.004), whereas feed intake was not affected. Total cholesterol (linear, P = 0.024), alanine aminotransferase (quadratic, P < 0.001) and alkaline phosphatase (linear, P = 0.007; quadratic, P = 0.025) activities in serum were decreased by betaine. Betaine linearly increased breast muscle yield (P = 0.003) and pH_24 h (P = 0.008), and decreased drip loss (P = 0.022). Betaine increased (linear, P = 0.025; quadratic, P = 0.016) total superoxide dismutase activity in breast muscle and reduced malondialdehyde content in serum (linear, P = 0.006), liver (quadratic, P = 0.006) and breast muscle (linear, P = 0.003). Moreover, the zearalenone concentrations in breast muscle were linearly decreased by betaine (P = 0.006). It was concluded that betaine could improve growth performance, liver health, antioxidant status, and breast meat yield and quality, and reduce zearalenone residue in broilers fed the MCC-based diet, especially at 500 or 1,000 mg/kg.     

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.     

Growth, haematology, blood constituents and immunological status of lambs fed graded levels of animal feed grade damaged wheat as substitute of maize

The aim of this study was to explore possibilities of utilization of animal feed grade damaged wheat (ADW) in lamb feeding, and assess the effect of ADW and its aflatoxin on intake, growth, haematology, blood biochemical constituents and immunological status. The ADW is a slightly mouldy feed resource, which is not suitable for human consumption. The experimental ADW contained dry matter (DM) 964, organic matter 974, crude protein 153, cellulose 205 and lignin 24, and starch 732 g/kg DM. ADW also contained aflatoxin B1 50 microg/kg due to mould infestation. Thirty-five weaner lambs (90 +/- 15 days of age and 16.1 +/- 0.82 kg body weight) in a randomized design were fed for 91 days on one of four composite feed mixtures (roughage to concentrate ratio of 25:75) containing 0, 118, 235, 353 or 470 g/kg ADW, which replaced equal amounts of maize and at these inclusion levels ADW replaced 0%, 25%, 50%, 75% and 100% maize in lamb diets respectively. Dry matter intake (DMI) was similar in different level of ADW fed lambs but ADW inclusion linearly (p = 0.016) reduced DMI. Average daily gain (g/day) was higher (p = 0.038) in lambs fed 353 g ADW diet. Haematological attributes viz. WBC, haemoglobin (Hb) and mean corpuscular volume did not affect by ADW feeding whereas it increased haematocrit, mean cell Hb and decreased neutrophil, RBC counts and mean cell Hb concentration. Blood glucose and urea-N increased whereas albumin and protein level reduced by ADW feeding. ADW feeding of lambs did not affect serum IgG level. The activities of serum aspartate aminotransferase, alkaline phosphates and acid phosphates were not affected, whereas alanine aminotransferase increased linearly (p = 0.001) with increasing levels of ADW. It is concluded that ADW containing aflatoxin B1 50 microg/kg DM can safely be incorporated in growing lamb feeding up to 353 g/kg diet without affecting growth and cellular immunity, however ADW may induce a transient alteration of hepatic enzymatic activities. Further aflatoxin content of the diet should be kept within permissible limits of respective country.     

不同蛋白水平对金边鲤生长、血清生化、消化酶及抗氧化能力的影响

为了探讨不同蛋白水平对金边鲤(暂定名)生长、血清生化、消化酶及抗氧化能力的影响,以进口鱼粉和大豆粕为蛋白源制备了蛋白水平分别为30%、32%、34%、36%和38%的饲料,投喂金边鲤[初始体重(18.16±0.57) g]56 d。结果表明:①蛋白水平对金边鲤的增重率和特定生长率有显著影响(P0.05),蛋白水平为34%的试验组增重率和特定生长率显著高于30%试验组(P0.05)。根据各生长指标,采用折线和二次曲线模型分析,金边鲤适宜蛋白水平为34.05%～35.12%。②蛋白水平对金边鲤血清中的甘油三酯和白蛋白含量影响显著(P0.05),蛋白水平为32%和36%试验组的甘油三酯含量显著高于30%试验组(P0.05),蛋白水平为30%的试验组血清白蛋白含量显著低于34%、36%和38%试验组(P0.05)。③蛋白水平对金边鲤肠道消化酶没有显著影响(P0.05),肠蛋白酶含量在32%组达到最大值,肠脂肪酶的含量在36%组达到最大值。④蛋白水平对金边鲤肝脏中的丙二醛、超氧化物歧化酶和过氧化氢酶均无显著影响(P0.05),超氧化歧化酶和过氧化氢酶呈现先上升后下降的趋势,在34%取得最大值。综合生长性能、血清生化、消化酶及抗氧化能力等指标,在本试验条件下,适宜金边鲤生长的饲料蛋白水平为34.05%～35.12%。     

Effects of dietary Selenomethionine supplementation on growth performance,antioxidant status,plasma selenium concentration,and immune function in weaning pigs

Background

This study was designed to evaluate the efficacy of DL-selenomethionine (DL-SeMet) supplementation on growth performance, antioxidant status, plasma selenium (Se) concentration, and immune function of weaning pigs. 216 weaning pigs were randomly allocated to 6 treatments with 6 replicates each according to a complete randomized block design. Each replicate had six pigs. Diet of group one was corn-soybean basal diet without any additional Se supplement. Group 2 was supplemented with 0.3 mg/kg of Se from sodium selenite. Groups 3-6 were supplemented with 0.1, 0.3, 0.5, and 0.7 mg/kg of Se from DL-SeMet, respectively. The trial lasted for 42 days.

Results

Pigs supplemented with 0.3 and 0.7 mg/kg DL-SeMet obtained better feed gain ratio (P < 0.05). The best antioxidant ability (serum, liver, and muscle) was shown in 0.1-0.3 mg/kg DL-SeMet groups (P < 0.05). The plasma Se concentration increased as the dietary DL-SeMet level elevated. The immunity among groups was not affected.

Conclusions

DL-SeMet supplementation in the diet significantly improved the growth performance, antioxidant ability and plasma Se content of weaning pigs. DL-SeMet can replace sodium selenite in the diet of weaning pigs.     

饲料中添加发酵桑叶对草鱼生长性能、血清生化指标的影响

文章旨在研究不同发酵桑叶添加量对草鱼幼鱼生长性能、机体营养成分、血清生化指标的影响,试验分别采用添加发酵桑叶0%(对照组)、2.5%、5.0%、7.5%、10.0%的5组等氮等能试验饲料(粗蛋白质32.14%,粗脂肪4.95%),投喂初始重量(15.01±0.12)g的草鱼幼鱼50 d。试验结果显示,与对照组相比,添加发酵桑叶提高了草鱼幼鱼的增重率、特定生长率,饲料效率。其中,发酵桑叶添加量为7.5%时草鱼幼鱼的特定生长率和增重率最大,饲料效率最高,并显著高于对照组(P <0.05);添加不同计量发酵桑叶对试验鱼的全鱼水分、粗蛋白质以及肌肉粗脂肪含量无显著影响(P> 0.05),添加量为10%时,全鱼粗灰分含量最大,全鱼和肝脏的粗脂肪含量最小(P <0.05);添加发酵桑叶对血清葡萄糖无显著影响(P> 0.05),但显著降低了血清总胆固醇、甘油三酯、谷草转氨酶、谷丙转氨酶、低密度脂蛋白含量(P <0.05)。结合本试验结果,饲料添加不超过7.5%发酵桑叶不会影响草鱼的生长和饲料利用效率,添加发酵桑叶后有助于草鱼脂类代谢和肝脏健康。     

Growth performance,carcass traits and digestive function of broiler chickens fed diets with graded levels of corn resistant starch

ABSTRACT

1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.

2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.

3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.

4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens.     

不同水平的蚯蚓和蚯蚓粪对草鱼肌肉品质的影响

实验在基础饲料中添加不同浓度的蚯蚓(5%、7.5%、10%)和蚯蚓粪(2%、4%、6%),饲养平均体重(54.03±0.15)g的草鱼100 d,研究蚯蚓和蚯蚓粪对草鱼肌肉品质的影响。结果表明:添加蚯蚓和蚯蚓粪可显著提高肌肉中粗蛋白的含量(P<0.05),以添加7.5%～10%蚯蚓和6%蚯蚓粪效果最好,对水分、粗脂肪和粗灰分均无显著影响(P>0.05);在肌肉氨基酸总量方面,除去2%蚯蚓粪组与对照组相比差异不显著外,其余实验组均显著高于对照组,并以添加7.5%蚯蚓实验组氨基酸总量最高;在肌肉必需氨基酸含量方面,7.5%蚯蚓组显著高于对照组,其余各实验组有高于对照组的趋势;在肌肉鲜味氨基酸含量方面,各实验组间差异不显著;氨基酸营养价值评价结果表明,添加适量的蚯蚓和蚯蚓粪均可提高EAAI值,以添加7.5%蚯蚓时EAAI值最高。综上所述,添加一定浓度的蚯蚓和蚯蚓粪有改善草鱼肌肉品质的趋势,以添加7.5%蚯蚓时效果最好。     

Growth performance, metabolic and endocrine traits, and absorptive capacity in neonatal calves fed either colostrum or milk replacer at two levels

Colostrum (CO) contains high amounts, whereas whole milk and milk replacer (MR) contain small amounts, of bioactive and growth-promoting substances, such as IGF-I. An experiment was designed to study the effects of feeding CO or MR on the first 3 d to neonatal calves, followed by whole milk up to d 7, at low and high density. Intestinal absorptive capacity, plasma metabolite and hormone concentrations, and growth performance were measured during the 1st wk of life. Body weight increased (P < .05) similarly in calves fed low or high amounts of CO but did not rise in MR-fed calves. Loose feces were more frequent (P < .05) and absorption of xylose on d 5 was lower (P < .01) in MR- than in CO-fed calves, but there were no effects of feeding density within CO-fed or within MR-fed groups. However, high feeding density within CO-fed groups enhanced (P < .05) total protein, globulin, triglyceride, cholesterol, and insulin concentrations, whereas in the initially high and low MR-fed groups only plasma glucose and insulin after the first meal and plasma NEFA on d 2 were modified (P < .05) by different feeding density. Thus, feeding different amounts of CO partly influenced protein and fat metabolism in calves during the 1st wk of life, but it did not measurably affect intestinal function. However, feeding different amounts of MR, in the absence of CO, barely affected metabolic and endocrine traits and absorptive capacity. Thus, high density CO feeding, and therefore a high supply of nutrients, together with greater amounts of bioactive and growth-promoting substances influenced neonatal metabolism and growth more than a high density of MR feeding containing only small amounts of bioactive and growth-promoting substances. Factors in addition to nutrient density seem to be important for the development of neonatal calves.     

The influence of graded levels of available phosphorus on growth performance,muscle antioxidant and flesh quality of young grass carp(Ctenopharyngodon idella)

Growth, muscle composition, meat quality characteristics and antioxidant capacity in muscle of young grass carp(Ctenopharyngodon idella)(initial weight 282.9 ± 3.3 g) fed graded levels of phosphorus(1.0,2.5, 3.8, 5.6, 7.8 and 9.5 g/kg diet) for 8 wk were investigated. Results indicated that percentage weight gain, feed intake, feed efficiency, serum phosphorus and alkaline phosphatase were improved with optimal phosphorus supplementations(P 0.05). Muscle protein content and water holding capacity were significantly elevated, while moisture, lipid and ash contents were significantly decreased with dietary phosphorus to a certain level(P 0.05). The meat shear force value and hydroxyproline content were not influenced by different levels of phosphorus. Muscle anti-hydroxyl radical, superoxide dismutase, catalase, glutathione S-transferase activities and glutathione content were significantly improved(P 0.05). Conversely, anti-superoxide anion, glutathione reducase and glutathione peroxidase activities were decreased(P 0.05) with dietary phosphorus to a certain level. These results indicated that suitable dietary phosphorus improved growth performance, meat quality and muscle antioxidant capacity. Dietary available phosphorus requirement of young grass carp for percentage weight gain was4.0 g/kg diet.     

Effects of dietary supplementation with Allium mongolicum Regel extracts on growth performance,serum metabolites,immune responses,antioxidant status,and meat quality of lambs

The present study was to evaluate the effects of dried Allium mongolicum Regel (AMR) powder and its water- and fat-soluble extracts (AWE and AFE) on the growth performance, serum metabolites, immune responses, antioxidant status, and meat quality of lambs. A total of 32 male small-tailed Han lambs (5 months old; initial body weight = 34.8 ± 0.40 kg) were used in a 60-d feeding experiment after a 15-d adaptation period. The lambs were randomly divided into 4 groups (n = 8) and fed a basal diet (control, CON group), the basal diet supplemented with dried AMR powder at 10 g/d per lamb (AMR group), the basal diet supplemented with AWE at 3.4 g/d per lamb (AWE group), or the basal diet supplemented with AFE at 2.8 g/d per lamb (AFE group). Blood samples were collected on d 0, 30, and 60 in the feeding experiment (n = 8). At the end of the experiment, the lambs were sacrificed and the longissimus dorsi muscles collected. Growth performance was not significantly affected by dietary supplementation of AMR, AWE and AFE (P > 0.05). However, significantly lower albumin (P = 0.006), total protein (P = 0.006), globin (P = 0.025), and blood urea nitrogen (P = 0.024) concentrations were observed in AFE group relative to CON and AMR groups. Similarly, a significantly lower lactate dehydrogenase activity (P = 0.018) was observed in AFE group relative to AWE group, but not in other groups (P > 0.05). In addition, significantly increasing trends in glutathione peroxidase (P = 0.06) in AMR, AWE, and AFE groups were observed relative to the control group. Furthermore, significantly lower drip loss (P = 0.011) across the treatment groups and cooking loss (P = 0.048) were observed in the AMR group relative to the control group. Taken together, these results indicate that AMR and its extracts had no significant effect on lamb growth performance, antioxidant status, and immune responses, but could significantly improve meat quality without the occurrence of pathological kidney and liver lesions.     

Carcass traits,meat quality,antioxidant status and antioxidant gene expression in muscle and liver of Hu lambs fed perilla seed

The effects of perilla (Perilla frutescens L.) seed on carcass traits, meat quality, antioxidant status and antioxidant gene expression in the liver and muscle of Hu lambs were investigated in this study. Sixty Hu lambs (23.02 ± 1.36 kg) were randomly divided into four experimental groups receiving diets containing 0%, 5%, 10% or 15% perilla seed (CD, 5%PFSD, 10%PFSD and 15%PFSD, respectively). The addition of perilla seed had no significant impacts on carcass traits (p > .05). There were no differences in pH, meat colour, drip loss, cooking loss or shear force among the four treatments (p > .05). Addition of perilla seed increased (p < .05) deposition of intramuscular lipids but had no effect on other chemical components in the longissimus dorsi (LD) (p > .05). The 15%PFSD diet decreased the total antioxidant capacity (T‐AOC) and malondialdehyde (MDA) content in the liver (p < .05 for both) but increased the activity of these antioxidant enzymes in LD (p < .05 for both). Compared to CD, addition of perilla seed increased superoxide dismutase (SOD) and glutathione peroxidase (GPX) expression in the liver and LD (p < .05 for all). These results indicate that perilla seed supplementation in lambs’ diets can increase deposition of intramuscular lipids and improve muscular oxidative status and meat quality.