Effect of dietary resveratrol in ameliorating aflatoxin B1‐induced changes in broiler birds

Consumption of aflatoxin B1 (AFB1) contaminated feed by poultry affects the health of broiler birds causing severe economic losses. The use of phytochemicals is a safe, effective, alternative and practical approach to combat the toxic effect of AF in broilers. Resveratrol, a polyphenol derived from red grapes, berries and peanuts, exerts anti‐inflammatory, antioxidant and immunomodulatory effects. Our study was aimed at evaluating the possible protective effects of resveratrol against the adverse effects of AFB1 in broiler birds. A feeding trial of 42 days of duration was undertaken in a completely randomized design with five dietary treatments: G1‐AFB1(1.0 ppm); G2‐CTR (basal diet alone); G3‐AFB1(1.0 ppm)+Resv 0.5%; G4‐AFB1(1.0 ppm)+Resv 1%; and G5‐Resv 1%. Gain in body weight (BWG) and feed intake (FI) was observed to be highest (p < 0.05) in the AFB1 birds followed by the control group. Feed conversion ratio was lowest in G2‐CTR birds and failed to record any significant variation (p > 0.05) between groups as well as within groups. Birds fed resveratrol at both 0.5% and 1.0% levels in combination with AFB1 as well as alone along with basal diet had lower BWG and FI between the fourth and fifth week and also at the fifth week (p < 0.05). No variation (p > 0.05) was obtained in the FCR of AFB1 and resveratrol group of broiler birds. AFB1 feeding significantly increased the activities of aspartate‐(AST) and alanine‐(ALT) amino transferase, superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.05) but lowered glucose, cholesterol and triglyceride levels in serum. Supplementation of resveratrol helped in increasing the activities of the oxidative enzymes and in improving the plasma total antioxidant capacity (TAOC) and total protein (TP) significantly (p < 0.05) and protein values. The livers of AFB1 group showed degeneration of hepatocytes, bile duct hyperplasia and microgranuloma formation. In resveratrol supplemented birds, the severity and degree of the liver lesions was far less. Apoptotic proteins failed to show any variation in expression between AFB1, control and resveratrol group of birds. The inclusion of resveratrol in broiler diets enhanced antioxidant status of birds indicating the protective effect of resveratrol against AFB1‐induced toxicity. So, we advice use of resveratrol as a feed additive to control aflatoxicosis in poultry farms.     

Increased fatty acid β‐oxidation as a possible mechanism for fat‐reducing effect of betaine in broilers

Two hundred and forty 1‐day‐old male Arbor Acres broiler chickens were randomly assigned to five dietary treatments with six replicates of eight chickens per replicate cage for a 42‐day feeding trial. Broiler chickens were fed a basal diet supplemented with 0 (control), 250, 500, 750 or 1000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine decreased the absolute and relative weight of abdominal fat (linear P < 0.05, quadratic P < 0.01), low‐density lipoprotein cholesterol (LDL‐C), triglyceride (TG) and total cholesterol (TC) (linear P < 0.05), and increased concentration of nonesterified fatty acid (NEFA) (linear P = 0.038, quadratic P = 0.003) in serum of broilers. Moreover, incremental levels of betaine increased linearly (P < 0.05) the proliferator‐activated receptor alpha (PPARα), the carnitine palmitoyl transferase‐I (CPT‐I) and 3‐hydroxyacyl‐coenzyme A dehydrogenase (HADH) messenger RNA (mRNA) expression, but decreased linearly (P < 0.05) the fatty acid synthase (FAS) and 3‐hydroxyl‐3‐methylglutaryl‐CoA (HMGR) mRNA expression in liver of broilers. In conclusion, this study indicated that betaine supplementation did not affect growth performance of broilers, but was effective in reducing abdominal fat deposition in a dose‐dependent manner, which was probably caused by combinations of a decrease in fatty acid synthesis and an increase in β‐oxidation.     

Effects of chestnut tannins on intestinal morphology,barrier function,pro‐inflammatory cytokine expression,microflora and antioxidant capacity in heat‐stressed broilers

A study was conducted to evaluate the effects of chestnut tannins (CT) on intestinal morphology, barrier function, pro‐inflammatory cytokine expression, microflora and antioxidant capacity in heat‐stressed broilers. Four hundred 28‐day‐old male Ross 308 broilers were randomly assigned into four groups, with 10 replicates per group and 10 broilers per replicate. The broilers in the normal (NOR) group were kept at 22 ± 1°C and fed the basal diet, and each of the other three groups were treated with cyclic heat (33 ± 1°C from 0800 to 1800 and 22 ± 1°C from 1800 to 0800) and fed the basal diet with 0 (HT), 1 (CT1) or 2 (CT2) g of CT/kg of diet. The experiment lasted for 14 days. Compared with the HT group, broilers in the NOR and CT2 groups had higher (p < .05) average daily gain and villus height in the jejunum and lower serum d ‐lactate (p < .001) and diamine oxidase (p < .01) levels. The addition of 2 g CT/kg of diet increased the total antioxidant capacity (p < .001) and superoxide dismutase activities (p < .05) and zonula occludens‐1 mRNA expression level (p < .05) and decreased the malondialdehyde concentration (p < .01) and mRNA expression levels of interleukin‐6 (p < .001) and nuclear factor kappa B (p < .001) in the jejunal mucosa of heat‐stressed broilers. The populations of Escherichia coli and Clostridium in the jejunum (p < .01) and caecum (p < .05) of broilers in the HT group were higher than those in the NOR and CT2 groups. In conclusion, the addition of 2 g CT/kg of diet seemed to be a feasible means of alleviating the negative effects of heat stress on the growth performance and intestinal function of broilers.     

蒙脱石对采食霉变花生粕型饲粮肉仔鸡生长性能和免疫机能的影响

本试验旨在研究蒙脱石对采食天然黄曲霉素毒素B1(AFB1)污染花生粕型饲粮的肉仔鸡生长性能和免疫机能的影响,确定蒙脱石作为霉菌吸附剂的饲用效果。选用288只1日龄爱拔益加(AA)健康公雏,随机分为4组,每组6个重复,每个重复12只鸡。正对照组饲喂玉米-豆粕型基础饲粮,负对照组饲粮用自然霉变花生粕(含AFB11 284.21μg/kg;前期、后期饲粮分别添加8.8%和12.0%)替代部分豆粕,试验组分别在负对照组饲粮中添加2.0 g/kg的天然或改性蒙脱石。试验期42 d。结果表明:1)与正对照组相比,霉变花生粕显著降低了肉仔鸡平均日增重(ADG)、平均日采食量(ADFI)、42日龄胸肌率和腿肌率以及血浆蛋白含量(P0.05),显著提高了料重比和免疫器官指数(P0.05)。2)与负对照组相比,天然或改性蒙脱石均显著提高了肉仔鸡ADG、ADFI及血浆蛋白含量(P0.05),显著降低了免疫器官指数(P0.05)。3)与天然蒙脱石组相比,改性蒙脱石显著提高了肉仔鸡ADG及血浆总蛋白和白蛋白含量(P0.05),显著降低了胸腺指数(P0.05)。综上,AFB1污染的霉变花生粕能降低肉仔鸡的生长性能和免疫功能,蒙脱石能缓解AFB1引起的不良影响,改性蒙脱石作用效果更佳。     

Capability of different non‐nutritive feed additives on improving productive and physiological traits of broiler chicks fed diets with or without aflatoxin during the first 3 weeks of life

An experiment was conducted to determine whether some non‐nutritive feed additives (NNFA) could block the adverse effects of aflatoxin (AF) on growth performance and physiological parameters of Cobb broilers throughout the period from 1 to 21 day of age. There were eight treatments consisting of two levels of AF at 0 and 200 ppb and four NNFA within each AF level. These additives included mannan oligosaccharides (MOS) at 2 g/kg diet, hydrated sodium calcium aluminosilicate (HSCAS) at 2 g/kg diet and Lactobacillus acidophilus (Lac) at 2 g/kg diet. At 21 day of age, five chickens of each treatment were slaughtered to study dressing percentage and relative weight of inner organs and glands. AF had a significant negative effect on body weight gain (BWG), and feed intake, while impairing feed conversion ratio (FCR). Aflatoxin significantly increased percentage liver, lymphocyte (%), monocyte (%), serum triglyceride level, and the aspartate aminotransferase (AST), and alanine aminotransferase (ALT), concentrations while decreasing dressing percentage, intestinal percentage, white blood cells (WBCs), red blood cells (RBCs), haemoglobin (Hgb), packed cell volume (PCV), heterophil (%), heterophil/lymphocyte ratio, total serum protein and serum albumin. Aflatoxin adversely affected the morphology of the liver, bursa and the thymus. There was a significant interaction between AF and NNFA on the relative weights of liver, heart and intestine. Lac completely blocked the negative effects of AF on the percentage liver and the heart and partially on the intestine. In conclusion, Lac was most effective in reversing the adverse effects of AF on growth and FCR and on the percentage, functions and morphology of the liver. Hydrated sodium calcium aluminosilicate also improved the economic traits of broilers but was less effective than Lac and more effective than MOS.     

Free availability of high‐energy foods led to energy over‐ingestion and protein under‐ingestion in choice‐fed broilers

The objective of this study was to compare energy and protein content of the diet selected by choice‐fed broilers with that of broilers fed a balanced diet. One hundred and eighty 1‐day‐old male broilers were randomly assigned in groups of 10 to one of three experimental treatments (n = 6). Control broilers were fed a standard balanced diet, whereas choice‐fed broilers were fed three foods which were more concentrated (Choice C+ treatment) or less concentrated (Choice C– treatment) in protein, carbohydrate or fat. We evaluated food intake behavior, nutrient intake, and performance parameters of broilers from 2 to 7 weeks of age. Choice C+ broilers showed enhanced preference for the high‐fat food, which led to higher energy intake and lower protein intake than those of control broilers at 2 to 4 weeks of age. Body weight, weight gain and feed conversion efficiency were negatively affected by diet selection of Choice C+ broilers. Choice C– broilers selected a balanced diet, and showed performance parameters similar to those of control broilers. Our results supported the hypothesis that free availability of high‐energy foods bias ingestive behavior of choice‐fed broilers toward selecting a diet with higher energy and lower protein than needed for normal growth.     

Effects of fermented garlic powder supplementation on growth performance, blood profiles and breast meat quality in broilers

The aim of this study was to investigate the effects of dietary supplementation with fermented garlic powder (FGP) on growth performance, blood profiles and breast meat quality in broilers. A total of 500 broilers were randomly allotted to 4 treatments with 5 replications per treatment and 25 chicks per pen. The experiment lasted for 5 weeks and dietary treatments were as follows: 1) CON (basal diet); 2) FGP1 (basal diet + 1 g/kg fermented garlic powder); 3) FGP2 (basal diet + 2 g/kg fermented garlic powder); 4) FGP4 (basal diet + 4 g/kg fermented garlic powder). No effects were observed (P > 0.05) in body weight gain (BWG), feed intake (FI) or feed conversion ratio (FCR) throughout the whole experiment. The white blood cell (WBC) counts, lymphocyte and immunoglobulin G (IgG) was increased (P < 0.05) in response to FGP treatments. Broilers had lower (P < 0.05) total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol and cortisol concentrations in blood when they were provided with FGP2 and FGP4 diets. Compared with CON, FGP2 and FGP4 treatments decreased (P < 0.05) TBARS and pH in breast meat. In conclusion, FGP administration had no effect on growth performance but improved immunity and meat quality as well as decreased cholesterol and cortisol in blood.     

镰刀菌毒素对断奶仔猪的抗营养效应及葡配甘露聚糖吸附剂的保护作用

选择125头始重(8.04±0.64)kg去势约×荣仔猪,采用2×2+1因子设计,研究被镰刀菌毒素自然污染的玉米以25%和50%的比例等量替换基础饲粮中的正常玉米并在此基础上加或不加葡配甘露聚糖(EGM)霉菌毒素吸附剂霉可吸TM对断奶仔猪生产性能、养分利用率的影响。结果表明:饲喂被镰刀菌毒素污染的饲粮降低了仔猪的生产性能,随霉变玉米替代比例增加,采食量和日增重降低程度增加(P<0.05或P<0.01);显著或极显著降低仔猪饲粮中有机物质、蛋白质、钙、磷的表观消化率(P<0.05或P<0.01)和蛋白质生物学价值(P<0.05),25%污染玉米饲粮对钙的表观消化率无影响(P>0.05);在被镰刀菌毒素污染饲粮中添加0.2%EGM吸附剂可使上述不良效应得到改善,尤以在25%污染玉米饲粮中添加0.2%EGM吸附剂可获得显著的保护效应。     

Influence of dietary fat source and supplementary α‐tocopheryl acetate on pulmonary hypertension and lipid peroxidation in broilers

An experiment was conducted to examine pulmonary hypertension and lipid peroxidation of broilers as affected by dietary fat source and α‐tocopheryl acetate. Two hundred and forty day‐old male chicks were used in a completely randomized design with five treatments consisted of four replicates and 12 chicks per replicate. Treatments included a control group that received no supplemental fat (treatment 1) or groups that received diets supplemented with beef tallow, soybean oil, a 50:50 blend of beef tallow and soybean oil, or soybean oil plus α‐tocopheryl acetate added at 220 mg/kg (treatments 2 to 5). All diets were kept isoenergetic and isonitrogenous and diet treatments 2 to 5 had 50 g/kg of fat supplement. Results showed that weight gain and feed consumption were significantly (p ≤ 0.05) increased by adding fat to the diet during the starter stage. However, birds that received fat‐supplemented diets gained less (p ≤ 0.05) during the grower period. Serum malone dialdehyde concentration and glutathione peroxidase activity were not affected by dietary treatments with the exception that inclusion of α‐tocopheryl acetate to the diet supplemented with soybean oil significantly (p < 0.05) reduced the activity of the enzyme when measured at 21 days of age. The relative weights of heart and liver and the right ventricle weight to total ventricle weight ratio were greater in broilers fed fat‐supplemented diets (p < 0.05).     

黄曲霉毒素B1、复方中药和硒对肉鸡肝组织匀浆中自由基代谢的影响

为观察黄曲霉毒素B1(AFB1)对肉鸡肝组织匀浆自由基代谢的变化,并研究复方中药与硒对AFB1的拮抗效应,将10日龄120只试验肉鸡随机分成4组,每组30只,分别为Ⅰ组(对照组)、Ⅱ组(AFB1组:AFB10.2mg/kgBW)、Ⅲ组(AFB10.2mg/kgBW+亚硒酸钠2mgSe/kgDM)和Ⅳ组(AFB10.2mg/kgBW+复方中药20g/kgDM)。分别处理后于17、24、31、38日龄宰杀5只肉鸡,提取肝组织,检测肝组织中的总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)活性和过氧化氢酶(CAT)及丙二醛(MDA)含量的变化。结果显示,口服AFB1(0.2mg/kgBW)后T-SOD、T-AOC和CAT活性降低(P<0.05),MDA含量明显升高(P<0.05),而复方中药与硒治疗组T-SOD、T-AOC和CAT活性升高(P>0.05或P<0.05),MDA含量明显下降(P>0.05或P<0.05)。证实,由自由基增多而引起的脂质过氧化损伤在肉鸡AFB1慢性中毒发病机理中起着重要的作用,复方中药与硒均可有效降低脂质过氧化造成的损伤。     

The effect of Epigallocatechin‐3‐gallate on small intestinal morphology,antioxidant capacity and anti‐inflammatory effect in heat‐stressed broilers

This study was to investigate the effects of Epigallocatechin‐3‐gallate (EGCG) on intestinal morphology, antioxidant capacity and anti‐inflammatory response in heat‐stressed broiler. A total of 192 2‐week‐old Arbour Acres broilers chickens were divided into four groups with six replicates per group and eight chickens per replicate: one thermoneutral control group (28°C, group TN), which was fed the basal diet; and three cyclic high‐temperature groups (35°C from 7:00 to 19:00 hr; 28°C from 19:00 hr to 7:00 hr, heat stress group), which were fed the basal diet supplementation with EGCG 0 mg/kg (group HS0), 300 mg/kg (group HS300) and 600 mg/kg (group HS600). The gut morphology and intestinal mucosal oxidative stress indicators, as well as intestinal barrier‐related gene expression, were analysed. The results showed that compared with group TN, heat stress reduced the villus height (VH), activities of glutathione peroxidase (GSH‐Px), superoxide dismutase (SOD)and catalase (CAT), increased the crypt depth (CD) and malondialdehyde (MDA)content at 21, 28 and 35 days (p < 0.05). After the heat‐stressed broilers were supplemented with EGCG, VH, VH/CD (V/C), and the activities of GSH‐Px, SOD and CAT were increased, and CD and MDA content were reduced compared with those in group HS0 without EGCG supplementation at 21, 28 and 35 days (p < 0.05). The EGCG supplementation promoted the gene expression of nuclear factor‐erythroid 2‐related factor 2 (Nrf2), Claudin‐1, Mucin 2 (Muc2) and alleviated the nuclear factor‐kappa B (NF‐κB) and lipopolysaccharide‐induced tumour necrosis factor (LITAF) gene expression compared with group HS0 (p < 0.05). Moreover, intestinal morphology was strongly correlated with antioxidant ability and inflammatory response. In conclusion, EGCG alleviated the gut oxidative injury of heat‐stressed broilers by enhancing antioxidant capacity and inhibiting inflammatory response.     

Effects of berberine on the growth performance,antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response‐related genes in lipopolysaccharide (LPS)‐challenged broilers. We assigned 120 one‐day‐old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T‐SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS‐induced decreases in the mRNA expression of nuclear factor‐kappa B (NF‐κB), TNF‐α, IL‐1β, inducible nitrite synthase and cyclooxygenase‐2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF‐κB signalling and the expression of inflammatory mediators.     

Selenium‐enriched Saccharomyces cerevisiae improves growth,antioxidant status and selenoprotein gene expression in Arbor Acres broilers

One hundred and fifty 7‐day‐old Arbor Acres broilers were randomly assigned into five groups: group 1 served as a control that was fed a basal diet without selenium (Se) supplementation; groups 2, 3 and 4 were fed the basal diet supplemented with 0.15, 0.5 and 1.5 mg Se as Se‐enriched Saccharomyces cerevisiae (SSC) per kg of diet; and group 5 was fed the basal diet supplemented with 0.15 mg per kg of Se as sodium selenite (SS). Growth performance, glutathione peroxidase (GP_X) and superoxide dismutase (SOD) activities, total antioxidant capacity (T‐AOC), and malondialdehyde (MDA) content in plasma and liver, and cellular glutathione peroxidase (GP_X‐1) and phospholipid hydroperoxide glutathione peroxidase (GP_X‐4) mRNA levels in liver were determined. Compared with group 1, groups 2–4 exhibited higher body weights (p < 0.05), lower feed/gain ratios, and higher GP_X activities in plasma (p < 0.05) and GP_X and SOD activities and GP_X‐1 and GP_X‐4 mRNA levels in liver (p < 0.05). Compared with group 5, group 2 exhibited higher GP_X activity in plasma on day 21 (p < 0.05). Compared with group 2 and 5, group 3 exhibited lower MDA content in plasma on day 7 (p < 0.05), higher GP_X activity in plasma, SOD activity and GP_X‐1 mRNA levels in liver on day 14 and 21 (p < 0.05), and higher GP_X‐4 mRNA levels on day 14 (p < 0.05). Compared with group 4, group 3 exhibited lower MDA contents in plasma on day 14 (p < 0.05) and in liver on day 21 (p < 0.05), higher T‐AOC in plasma and higher GP_X‐1 mRNA levels on day 14 and 21 (p < 0.05), and higher SOD activity in plasma and higher SOD and GP_X activities in liver on day 21 (p < 0.05). Thus, SSC improves growth and antioxidant status of broilers; the short‐term bioavailability of SS was faster than that of SSC, but the long‐term bioavailability of SSC was greater than SS.     

Effects of pre‐weaning dietary substitutions on plasma insulin and glucose profiles in primiparous sows

The objective of this study was to investigate the effects of substituting 1 kg of a standard lactation diet with 1 kg of a sugar‐rich (15.75 DE MJ/kg) or fat‐rich (23.85 DE MJ/kg) diet during late lactation on blood glucose and insulin changes in primiparous sows. During a 4‐week lactation period, 21 primiparous sows were fed to appetite with a standard lactation diet (14.10 DE MJ/kg). At 9 days before weaning, sows were assigned to a control (C, n = 7), fat (F, n = 6) or sugar (S, n = 8) treatment. During the treatment period (from 8 days before weaning until weaning), 1 kg of the lactation diet was substituted with 1 kg of a sugar‐rich or fat‐rich diet for S and F sows. At 3 days before weaning, serial blood samples were collected for a total of 228 min around feeding to establish pre‐ and postprandial plasma glucose and insulin concentrations. Preprandial plasma glucose and insulin concentrations did not differ between treatments (p > 0.05); however, mean plasma glucose and insulin concentrations were higher for S compared to F (p < 0.05) and intermediate for the C sows. Postprandial plasma concentrations of glucose and insulin were higher for the S sows than for C and F sows (p < 0.05). Sow body weight loss during late lactation did not differ between treatments (p > 0.05). The results from our study suggest that a sugar‐enriched diet during the last week of lactation elevates circulating glucose and insulin concentrations and may potentially improve post‐weaning fertility in primiparous sows.     

Sequential feeding of whole wheat to growing broiler chickens

1. Four broiler feeding trials were performed to examine the suitability of a whole wheat sequential feeding regimen for commercial broiler production. The sequential feeding programme gave a continuous cycle of ad libitum access to only whole wheat followed by the same time of access to only a pelleted diet. The pelleted diet provided a concentration of nutrients to balance that provided by the whole wheat. This was called a balancer diet.

2. The first trial used 144 cage‐reared broilers from 28 to 49 d of age. Four different times of access (4, 8, 12 and 24 h) to the two alternate foods were compared. A whole wheat choice‐feeding treatment and a complete single diet treatment were also compared. Whole wheat accounted for over 40% of the broilers’ total food intakes when they were given the sequential feeding treatments of 8 h or greater. The whole wheat intakes of the birds given the 4 h sequential feeding and the choice‐feeding were only 20 and 5% respectively. There was a non linear relationship between the weight gains of the broilers and the length of the sequential feeding period (P< 0.01). The growth rates of the broilers given sequential feeding were lowest (P< 0.05) in the 4‐h feeding periods but highest (P< 0.05) in the 8‐h periods. Weight gains decreased (P< 0.01) linearly as the sequential feeding periods were increased above 8 h.

3. A second trial, using 144 cage‐reared broilers, examined the effect of different balancer compositions or different wheat varieties in 8‐h sequential feeding. The broilers selected more whole wheat in their diet when they were given balancers with increased cereal contents. However, these broilers did not eat enough whole wheat to compensate for the reduced cereal content of the balancers and their overall diets had lower energy: protein ratios. The two different wheat samples did not result in any differences (P> 0.05) in the proportion of whole wheat selected by the broilers.

4. A third trial compared the diet selections, weight gains, food intakes and water excretions of 72 cage‐reared broilers given whole wheat feeding regimens. The growth rates of the broilers given a loose mix of whole wheat and a pelleted balancer diet were similar (P> 0.05) to broilers given a complete single diet. The growth rates of these two groups were 7% greater (P< 0.05) than broilers given choice‐feeding or 8‐h sequential feeding. There were no differences (P> 0.05) in the total amounts of water excreted among the 4 treatments.

5. The fourth trial used 828 broilers distributed in 6 floor pens. They were given either a complete diet or an 8‐h whole wheat sequential feeding regimen from 25 to 46 d of age. The food intakes and the growth rates of the broilers were reduced (P<0–05) in die sequential feeding treatment by 9% and 5% respectively. There was no difference (P> 005) in litter moisture between the 2 treatments.     

Effect on hepatonephric organs, serum metabolites and oxidative stress in post-weaning piglets fed purified zearalenone-contaminated diets with or without Calibrin-Z

The objectives of this study were to investigate the toxicity of zearalenone (ZEA) on hepatonephric organs, serum metabolites and oxidative stress of piglets and to evaluate the efficacy of Calibrin‐Z (CAZ) in preventing ZEA‐induced adverse effects. The experiment was conducted for 22 days using 36 piglets weaned at 21 days of age (Landrace × Yorkshire × Duroc, 18 females and 18 males; 8.84 ± 0.21 kg average body weight). Piglets of each gender were randomly allocated to the following six dietary treatments: (i) Control (basal diet only); (ii) Control + 1 g/kg CAZ; (iii) Control + 1 mg/kg ZEA; (iv) Control + 1 mg/kg ZEA + 1 g/kg CAZ; (v) Control + 1 mg/kg ZEA + 2 g/kg CAZ; (vi) Control + 1 mg/kg ZEA + 4 g/kg CAZ. Piglets were housed and fed individually for the entire experimental period. Blood samples were taken, and piglets were killed at the end of the experiment to obtain organs for physiological assessment. Results showed that piglets fed the ZEA‐contaminated diet had increased (p < 0.05) activities of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma‐glutamyltransferase (GGT), creatine kinase and cholinesterase, concentrations of urea, and creatinine in serum, and malondialdehyde (MDA) in serum and liver. Pigs fed the ZEA‐only diet also showed reductions in serum (p < 0.05) globulin, triglycerides and high‐density lipoproteins (HDL), and reductions in total superoxide dismutase (TSOD) and glutathione peroxidase (GSHPx) activity in both serum and liver. Supplementation of CAZ at the dosages of 1–4 g/kg to the diet containing 1.05 mg/kg ZEA linearly increased (p < 0.05) concentrations of triglycerides and HDL in serum, activity of TSOD and GSHPx in serum and liver, but linearly reduced (p < 0.05) all tested serum enzymes and lowered (p < 0.05) the elevated concentrations of urea, and creatinine in serum, and MDA in serum and liver caused by dietary ZEA. Piglets fed the ZEA‐contaminated diet showed increased (p < 0.05) relative weight of liver and kidney compared with the control, whereas only numerical improvement on relative weight of liver and kidney was observed with simultaneous addition of CAZ at 4 g/kg diet and ZEA. However, feeding the diet with CAZ alone at 1 g/kg had no impact on any of the measured parameters when compared to the control. It is suggested that feeding ZEA at 1.05 mg/kg exerted a deleterious effect on piglets, which was totally or partly ameliorated by dietary supplementation of CAZ at concentrations between 1 and 4 g/kg diet.     

The role of bentonite binders in single or concomitant mycotoxin contamination of chicken diets

1. Concomitant presence of mycotoxins is more likely to appear than a single mycotoxicosis since many mycotoxigenic fungi grow and produce their toxic metabolites under similar conditions.

2. The present study was designed to evaluate the efficacy of 4 mycotoxin binders to protect meat-type chickens against single and concomitant administration in the feed of two mycotoxins, namely aflatoxin B1 (AFB1) and ochratoxin A (OTA) both at concentration of 0.1 mg/kg.

3. A total of 440 as hatched, d-old, Ross 308 broilers were reared for 42 d. There were 11 dietary treatments. Chickens were fed on either an uncontaminated basal diet, basal diet and AFB1, basal with concomitant presence of AFB1 and OTA, basal diet and three binders A, B and C (1%) with or without AFB1 or basal diet and binder D (0.5%) with or without concomitant presence of AFB1 and OTA. Performance, carcass yield and several biochemical parameters were examined.

4. Mycotoxin concentration in liver and breast muscle samples was determined. Broiler performance under concomitant mycotoxin contamination was poorer than that under single mycotoxicosis. Mycotoxin presence increased relative heart weight compared to that of broilers fed on uncontaminated diets. Only OTA and not AFB1 was detected and only in the liver. OTA concentration was four-fold lower in broilers fed on a diet with binder compared to those fed on contaminated diets without binder.

5. In conclusion, the study revealed that binder composition and presence or not of multiple toxins may be important factors for optimum broiler performance under mycotoxicosis.

     

Effects of Saccharomyces cerevisiae extract on haematological parameters, immune function and the antioxidant defence system in breeder hens fed aflatoxin contaminated diets

1. The study was conducted to investigate the efficacy of Saccharomyces cerevisiae extract (SC) on haematological parameters, immune function, and the antioxidant defence system in breeder hens fed a diet contaminated with low level aflatoxin (AF).

2. Forty-eight Ross 308 breeder hens were fed on diets containing AF (0 or 100?µg/kg) and SC (0 or 1?g/kg) in a 2?×?2 factorial arrangement. Red blood cell (RBC), white blood cell (WBC), and platelet counts, differential leucocyte counts, blood CD3⁺, CD4⁺, CD8⁺ and CD5⁺ T cell ratios, phagocytic activity and oxidative burst of heterophils, plasma and liver catalase activity, and malondialdehyde (MDA) and ascorbic acid concentrations were measured.

3. Plasma and liver MDA concentrations increased (P?P?P?=?0·082) in hens fed the contaminated diet. WBC count, monocyte percentage, phagocytic activity and oxidative burst of heterophils increased (P?P?=?0.088) in SC extract supplemented hens. There was a significant interaction between AF and SC on heterophil, lymphocyte, CD5⁺ cell percentages, and plasma catalase activity. Blood heterophil percentage decreased but lymphocyte percentage increased in hens fed on the AF contaminated diet without SC supplementation. SC supplementation counteracted the negative effect of AF on heterophils and lymphocytes. The CD5⁺ cell percentage decreased in unsupplemented hens fed the AF contaminated diet and this negative effect was minimised in SC supplemented hens. Plasma catalase activity increased in SC supplemented hens fed the uncontaminated diet whereas the effect of SC decreased in hens fed the AF contaminated diet.

4. The SC reduced some of the some adverse effects of AF, and improved functions of the non-specific immune system. Therefore, the SC extract which has been used for improving productive performance in birds and mammals may also be useful for modulating some of the effects of a low level, chronic dosage of AF.     

饲养密度和硫辛酸对肉鸡血清指标、行为及骨骼发育的影响

本试验旨在研究高饲养密度条件下饲粮中添加硫辛酸(LA)对肉鸡血清指标、行为及骨骼发育的影响.试验选取健康状况良好、体重相近的1530只21日龄爱拔益加(AA)肉鸡,随机分成3组,即常规饲养密度组(ND组,15只/m2,饲喂基础饲粮)、高饲养密度组(HD组,18只/m2,饲喂基础饲粮)和高饲养密度+LA组(HD+LA组,...     

Zinc‐bearing zeolite clinoptilolite improves tissue zinc accumulation in laying hens by enhancing zinc transporter gene mRNA abundance

A study was conducted to investigate effects of zinc‐bearing zeolite clinoptilolite (ZnCP), as an alternative for zinc sulfate (ZnSO₄), on laying performance, tissue Zn accumulation and Zn transporter genes expression in laying hens. Hy‐Line Brown laying hens were allocated to three treatments, each of which had six replicates with 15 hens per replicate, receiving basal diet supplemented with ZnSO₄ (control, 80 mg Zn/kg diet), 0.23% ZnCP (40.25 mg Zn/kg diet) and 0.46% ZnCP (80.50 mg Zn/kg diet) for 8 weeks, respectively. Compared with control, hens fed diet containing 0.23% ZnCP had similar Zn content in measured tissues (P > 0.05). A higher ZnCP inclusion (0.46%) enhanced Zn accumulation in liver (P < 0.05) and pancreas (P < 0.05). In addition, ZnCP inclusion increased blood iron (Fe) content (P < 0.05). ZnCP supplementation enhanced jejunal metallothionein‐4 (MT‐4) messenger RNA (mRNA) abundance (P < 0.05). ZnCP inclusion at a higher level (0.46%) increased mRNA expression of MT‐4 in pancreas (P < 0.05) and zinc transporter‐1 (ZnT‐1) in jejunum (P < 0.05). The highest ZnT‐2 mRNA abundance in jejunum was found in hens fed 0.23% ZnCP inclusion diet (P < 0.05). The results indicated that ZnCP reached a higher bioavailability as compared with ZnSO₄ as evidenced by enhanced tissue Zn accumulation and Zn transporter genes expression.