早期限饲对肉鸡心肌易颤性和血清心肌酶活性、电解质水平的影响

艾维因商品肉鸡于 4～ 12日龄时进行 10 %限饲 ,分别于 2 5、32日龄进行心肌易颤性的评价和血清心肌酶活性、血清电解质水平的检测。结果如下 :(1)早期限饲可以提高肉鸡的输钾诱颤阈 ,表明可降低肉鸡的心肌易颤性 ;(2 )早期限饲可以降低血清心肌酶 (AST、L DH、CK)的活性 ,表明可增强肉鸡的心肌机能 ;(3)早期限饲对血清电解质水平无明显影响。本试验验为进一步阐明早期限饲降低肉鸡猝死综合征发生的机制提供了理论依据     

肉鸡和蛋鸡心肌易颤性的比较研究

以常规饲养的肉鸡和蛋鸡作为试验动物,通过电刺激诱颤阈和输钾诱颤阈的测定以及进行冷加压试验,对同体重肉鸡和蛋鸡的心肌易颤性进行了比较研究。结果表明:(1)同体重肉鸡和蛋鸡相比,电刺激诱颤阈和输钾诱颤阈肉鸡均极显著低于蛋鸡(P<0.01);(2)在电刺激诱发室颤的过程中,开胸时室颤的发生率肉鸡(14%)显著高于蛋鸡(0%)(P<0.05);(3)冷加压试验:冷加压5min内,心率和PT波宽出现了显著的变化,而且变化幅度肉鸡均明显大于蛋鸡。上述试验结果从不同方面均表明肉鸡心肌易颤性高于蛋鸡。     

复合微生态制剂与饲用抗生素对肉鸡血清生化指标和肠道酶活性的影响

研究添加复合微生态制剂和饲用抗生素对肉鸡血清生化指标和肠道酶活性的影响。试验选取500只1日龄雌性健康AA肉鸡随机分为5组,每组4个重复,每个重复25只。试验预试期7d,Ⅰ组为对照组,饲喂不含抗生素的基础饲粮,Ⅴ组为饲用抗生素组,Ⅱ、Ⅲ、Ⅳ组为微生态制剂组,添加量分别为1.0‰、2.0‰、4.0‰。正试期为35d。结果表明,除42日龄外,其余各试验阶段Ⅲ组肉鸡血清总蛋白含量均显著高于对照组和抗生素组（P〈0.05）;除14日龄外,Ⅲ组肉鸡血清尿素氮含量均显著低于对照组和抗生素组（P〈0.05）;在每个试验阶段,Ⅲ组回肠内容物蛋白酶活性均显著高于对照组和抗生素组（P〈0.05）,且除14日龄外,Ⅲ组肉鸡空肠内容物蛋白酶活性最高,显著高于对照组和抗生素组（P〈0.05）;除14日龄外,Ⅲ组空肠和回肠内容物淀粉酶活性均最高,显著高于对照组和抗生素组（P〈0.05）。由此可知,2.0‰复合微生态制剂能够显著提高肉鸡血清总蛋白水平,增强空肠和回肠内容物蛋白酶和淀粉酶活性,同时在一定程度上降低了肉鸡血清尿素氮含量。     

不同磷源及无机磷水平对肉鸡血清无机磷、碱性磷酸酶及增重的影响

选用西德TATELA公司公雏216只,3×4复因子设计。试验磷源为国产商品饲料级磷酸氢钙,苏联产磷酸氢钙、苏联产磷酸三钙。设0.1％、0.2％、0.3％、0.4％四个无机磷添加水平。以玉米,大豆粕、玉米油配制成全植物性基础饲粮,分别添加上述三种磷源,共组成12种饲粮,每个饲粮组重复三次,每个重复3—3只鸡。出壳、21日龄、42日龄分别测定血清无机磷、血清碱性磷酸酶活性及增重。结果表明:不同磷源及无机磷水平对血清无机磷、血清碱性磷酸酶活性无显著影响(P>0.05),二因子间交互作用不显著(P>0.05)。出壳、21日龄、42日龄三次测得的血清碱性磷酸酶活性呈二次曲线变化,出壳时为12091U/L,21日龄最高(6631IU/L),42日龄又恢复到较低水平(1337IU/L)。三个日龄测得的血清无机磷呈对数曲线变化。不同磷源及无机磷水平对肉鸡增重有显著影响。苏联磷酸氢钙最佳,生物效价为国产磷酸氢钙的106％(100—115);苏联磷酸三钙较差,为国产磷酸氢钙的93％(80—101％)。添加0.3％0.4％无机磷对生长效果较好(P<0.05)。血清无机磷、血清碱性磷酸酶活性与各组体增重无相关。     

营养水平和发酵果渣对断奶仔猪生长性能、血清生化指标和消化酶活性的影响

试验旨在研究不同营养水平和发酵果渣对断奶仔猪生长性能、血液生化指标和消化酶活性的影响,以及二者的互作效应.选择144头21日龄断奶的杜×长×大杂交公猪,采用2×2双因子设计,随机分为4个组,分别为低营养水平组、低营养水平+2％发酵果渣(等量代替麦麸)组、高营养水平组和高营养水平+2％发酵果渣(等量代替麦麸)组,每个组设...     

饲料中添加不同水平山楂对土杂肉鸡生长性能和血清生化指标的影响

选用 1日龄健康土杂肉鸡 40 0只 ,随机分成 4组 ,每组 1 0 0只。分别饲喂添加 0、1 %、 2 %和 3%山楂粉的日粮 ,研究不同添加量的山楂对 0～ 60日龄土杂肉鸡采食量、日增重、料重比及成活率的影响 ,以评定山楂作为中药饲料添加剂的价值及最佳添加量。结果添加 2 %山楂组的日增重最高 (P <0 0 5) ,料重比最低。而在 0～ 30日龄 ,添加山楂各组与不添加山楂组比 ,采食量、日增重、料重比均无显著差异 (P >0 0 5)。血清中胆固醇含量以添加 2 %山楂组最低 ,而血清总蛋白含量最高。综合各项指标以添加 2 %山楂对提高土杂肉鸡生长性能最好。     

日粮赖氨酸、蛋氨酸水平对不同性别肉鸡生长性能的影响

本试验研究日粮赖氨酸或蛋氨酸水平对不同性别肉鸡生长性能的影响以及与血清总蛋白和尿酸含量之间的关系。试验１日粮采用３个赖氨酸水平（１．２％，１．３％和１．３５％）。试验２日粮采用３个蛋氨酸水平（０．２５％，０．４５％和０．５５％）。结果表明，公鸡比母鸡生长速度快（１４％～１６％），饲料报酬高。公鸡随着日龄的增长，对日粮赖氨酸的需求降低，从１．３５％降至１．２％。采食较低水平的赖氨酸（１．２％），母鸡就可达到较快的生长速度。母鸡比公鸡较早地可以降低其日粮中的蛋氨酸水平。本试验的结论是，公母肉鸡对日粮赖氨酸或蛋氨酸的需求与利用具有不同的特点。母鸡对日粮中赖氨酸或蛋氨酸的需求比公鸡低，利用效率比公鸡高。母鸡的生长速度与其血清中尿酸水平呈显著的负相关。母鸡的生长速度越快，其血清中的尿酸水平越低。     

Effect of organic acids or probiotics alone or in combination on growth performance,nutrient digestibility,enzyme activities,intestinal morphology and gut microflora in broiler chickens

A feeding trial was conducted to determine the effect of organic acids or probiotics alone or in combination on growth performance, nutrient digestibility, enzyme activity, intestinal morphology and gut microflora in broiler chickens (Ross308). A completely randomized design was used, with 1,440 broiler chicks across four treatments and five replications of 72 chicks each. The chicks in the control treatment were fed on a control diet (CD), whereas for the other treatment groups, the CD was supplemented with 0.2 g/kg organic acids (CDOA), probiotics (CDP) or a combination of organic acids and probiotics (CDOAP). All the chicks were fed ad libitum during the feeding trial throughout 35 days. A total of 20 chicks were randomly allotted to individual metabolic cages to measure the nutrient digestibility (35–42 days) and the digestive enzyme activities (42 days). The intestinal morphology and gut microflora of 80 chicks were examined at the end of experiment. There were no significant (p > .05) differences in the feed intake, body weight gain or feed conversion ratio of the chicks across the four dietary treatments. The crude fibre digestibility was significantly increased in chicks fed on CDOA or CDOAP relative to CD (p < .05). Nutrient utilization, in terms of digestive enzyme activities and excreta thermal property, was unchanged by any supplementation. The chicks fed on the CDOAP had significantly higher duodenal villi height and crypt depth than the chicks fed on CDOA (p < .05). This dietary treatment dramatically improved gut microflora by decreasing the population of Escherichia coli and increasing the Lactobacillus spp.:E. coli ratio. Based on our investigations, supplementation of organic acids and probiotics in chick diets can increase the ability to digest crude fibre and villus height and decrease intestinal E. coli without impairing growth performance.     

Effects of dietary inclusion levels of palm oil on growth performance,antioxidative status and serum cytokines of broiler chickens

This study was conducted to investigate the effects of dietary palm oil inclusion levels on growth performance, serum antioxidative status and cytokines in Sanhuang broiler chickens. A total of 208 one‐day‐old female Sanhuang chickens were randomly allocated to four treatment groups with four replicates per group and of 13 birds each for a 42‐day feeding trial. Dietary treatments were basal diet without palm oil (control) and diets containing 2%, 4% or 6% palm oil. During days 22 to 42 and the overall experimental period, chickens fed diets supplemented with 4% and 6% palm oil had a lower average daily feed intake (ADFI) (p = 0.019) and feed to gain ratio (F/G) (p = 0.031). Average daily gain (ADG) tended to be higher (p = 0.089) for palm oil inclusion treatments compared with the control treatment from days 1 to 42. Dietary 2% and 4% palm oil treatments significantly lowed serum malondialdehyde concentration on day 21 when compared to the control and 6% palm oil treatments (p = 0.027). Dietary 6% palm oil treatment significantly reduced the catalase (CAT) activity (p = 0.018) and total antioxidant capacity (T‐AOC) (p = 0.027) in serum in comparison with the control treatment on day 21. No significant differences were observed in superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activities in serum among dietary treatments on day 21. There were no significant differences in T‐AOC, CAT, SOD and GSH‐Px activities among dietary treatments on day 42. Dietary inclusion of 4% and 6% palm oil significantly increased (p = 0.01) serum interleukin‐1β (IL‐1β) content, but improved transforming growth factor‐β (TGF‐β) content in serum on both days 21 and 42 (p = 0.032 and 0.022 respectively) as well as IL‐10 content on day 42 (p = 0.022) when compared with the control treatment. Furthermore, dietary inclusion of 6% palm oil significantly reduced tumour necrosis factor‐α (TNF‐α) content on days 21 and 42 (p = 0.021 and 0.001 respectively) compared with the control treatment. These results suggest that dietary inclusion of 4% and 6% palm oil could improve the growth performance, modulate the balance between pro‐ and anti‐inflammatory cytokines, and show limited effect on antioxidative status in Sanhuang broiler chickens.     

Effects of epigallocatechin gallate on lipid metabolism and its underlying molecular mechanism in broiler chickens

The objective of this study was to investigate the effects of epigallocatechin gallate (EGCG) on fat metabolism and to establish the molecular mechanism of these effects in broilers. Seventy‐two 28‐day‐old male Ross 308 broiler chickens were divided into three groups with different levels of EGCG supplementation for 4 weeks: normal control (NC) group, L‐EGCG (a low‐level supplement of EGCG, 40 mg/kg body weight daily) and H‐EGCG (a high‐level supplement of EGCG, 80 mg/kg body weight daily). After 4 weeks of oral administration, EGCG significantly reduced the level of abdominal fat deposition in broilers. The serum triglycerides and low‐density lipoprotein cholesterol of chickens in H‐EGCG group were also significantly decreased compared with the NC group, and the high‐density lipoprotein cholesterol was notably increased at the same time. Moreover, the vital role of the liver and abdominal adipose tissue in lipid metabolism of poultry animals was examined through gene expression and enzyme activities related to fat anabolism and catabolism in these organs. Our data show that EGCG supplementation for 2 weeks significantly downregulated the expression of fatty acid synthesis and fat deposition‐related genes, and upregulated the expression of genes involved in fatty acid β‐oxidation and lipolysis genes. Simultaneously, the activities of hepatic fatty acid synthesis enzymes (fatty acid synthase and acetyl CoA carboxylase) were significantly decreased, and the activity of carnitine palmitoyl transferase‐1 was notably elevated. The results suggest that EGCG could alleviate fat deposition in broilers through inhibiting fat anabolism and stimulating lipid catabolism in broilers.     

Effects of different sulphur amino acids and dietary electrolyte balance levels on performance,jejunal morphology,and immunocompetence of broiler chicks

As alterations of dietary electrolyte balance (DEB) can influence amino acid metabolism via changes the ions incur in their configurations, performance and immunological responses of broiler chicks might be affected. So, the current study was carried out to investigate the effects of different levels of sulphur amino acids (SAA) and DEB on performance, jejunal morphology and immunocompetence of broiler chicks. A total of 360 1‐day‐old male Ross 308 broiler chicks were randomly assigned to nine experimental treatments with four replicates of 10 birds each. Experimental treatments consisted of three levels of SAA (100, 110, and 120% of NRC recommendation, provided by methionine supplementation in diets with the same cysteine level) and three levels of DEB (150, 250, and 350 mEq/kg) that were fed during the entire of trial in a 3 × 3 factorial arrangement. Results showed that the relative weights of intestine and abdominal fat were decreased markedly (p < 0.001) with increasing levels of SAA and DEB respectively. Antibody titre against sheep red blood cell was neither individually nor in combination influenced by supplementation of SAA or DEB. Nevertheless, a decrease in DEB level led to a suppression in heterophile (p < 0.05) and an increase in lymphocyte counts (p = 0.06); consequently, heterophile to lymphocyte ratio was significantly decreased (p < 0.05) by decremental levels of DEB. Albumin to globulin ratio was increased after inclusion of at least 10% SAA (p < 0.001) and 150 mEq DEB/kg in the diet (p = 0.11). Although feeding high‐DEB level led to a remarkable decrease in villus height (p < 0.01) and goblet cell numbers (p < 0.001), supplementing the highest level of SAA improved the height of jejunal villus. During the entire trial period, average daily feed intake (ADFI) was increased by incremental SAA levels (p < 0.05). However, inclusion of 150 mEq/kg led to not only a remarkable increase (p < 0.0001) in both ADFI and average daily weight gain (ADWG) but also to improved (p < 0.001) feed conversion ratio (FCR) both during the growing and over the entire trial periods. The present findings indicated that inclusion of low DEB decreased the heterophile to lymphocyte ratio and improved both the albumin to globulin ratio and intestinal health indices. The best growth performance was obtained with 150 mEq DEB/kg in the diet for each level of SAA.     

Evaluation of dietary stevioside supplementation on anti-human serum albumin immunoglobulin G, Alpha-1-glycoprotein, body weight and thyroid hormones in broiler chickens

Sixty male broiler chickens fed a diet supplemented with 130 mg/kg stevioside (S group) or an unsupplemented diet (C group) from day 1 of age onwards. On day 21 of age, ten birds from either the S (SH) or C (CH) group were injected subcutaneously with 100 μg human serum albumin (HSA) and ten others from either S (SP) or C (CP) group injected with 100 μl phosphate-buffered saline (PBS) in the same way. There were no significant effect of supplementation nor interaction with age on average body weights, T(3) and T(4) concentrations of non-injected chickens. After the primary immunization, α(1) -glycoprotein concentrations increased in all treatment groups except the CP group, and were significantly higher in the CH group in relation to the other groups. Fourteen and 18 days after the primary immunization, HSA injected chickens of both dietary treatments had significantly higher anti-HSA immunoglobulin G (IgG) levels than their PBS injected controls. No effect of stevioside supplementation was observed for IgG level. In conclusion, dietary stevioside inclusion can attenuate the pro-inflammatory response after stimulation of the innate immune response in broiler chickens.     

谷氨酸锌对肉仔鸡生长性能、血清含锌酶活性及免疫器官指数的影响

本试验旨在研究谷氨酸螯合锌(zinc glutamine,Glu-Zn)对肉仔鸡生长性能、血清含锌酶活性、免疫器官指数的影响。选用240只7日龄商品代AA肉用仔鸡,随机分成6个处理。1组为对照组饲喂含80mgZnSO4·H2O形式的Zn的基础日粮,其余5组分别在基础日粮中添加20、40、60、80mg/kg和100mg/kg谷氨酸螯合锌形式的Zn。饲养期为35d。结果表明:试验各周及全期,随着日粮中谷氨酸螯合锌水平的增加,肉仔鸡日增重和饲料转化效率均得到改善,同时,40mg/kg谷氨酸螯合锌组显著提高了试验全期的平均日增重(P0.05);血清碱性磷酸酶活性随着日粮锌水平的增加先上升,而后又下降,在锌添加水平为60mg/kg时取得最大值;谷氨酸螯合锌组在胸腺指数、脾脏指数上,明显优于对照组,且存在显著差异(P0.05),而法氏囊指数并不敏感。从本试验各项指标和经济效益综合分析,建议肉仔鸡饲料中添加60mg/kg的谷氨酸螯合锌。     

Effects of enzymatic treatment and shell content of palm kernel expeller meal on performance,nutrient digestibility,and ileal bacterial population in broiler chickens

The objective of this study was to examine the effects of enzymatic treatment and shell content of palm kernel expeller meal (PKE) on the performance, nutrient digestibility, and ileal bacteria population in broiler chickens. Part of the PKE sample was sieved (3 mm) to remove the shell (lower shell PKE) and part was used as is. The primary mannan-oligosaccharides in the experimental diets were determined using HPLC analysis. During the finisher phase, one hundred male broiler chickens (Cobb-500) were fed a control diet or the diets containing 200 g/kg of normal PKE (70 g/kg shell), low shell PKE (30 g/kg shell), enzymatically (cellulase and mannanase) treated PKE, or low shell, enzymatically treated PKE. The DM, CP, and ether extract digestibility coefficients were measured using acid insoluble ash as an insoluble marker. The quantitative rea-time PCR was used to determine the ileal bacteria populations. The enzymatic treatment significantly increased the mannose and also mannan-oligosaccharides content of PKE. Feed intake was not affected by dietary inclusion of PKE. In the birds fed the low shell PKE diet the average daily weight gain was lower and the feed conversion ratio was higher than those in the control and other PKE fed groups. The digestibility coefficients of dry matter and ash were lower in PKE containing diets than the control diet. However, there were no differences in the crude protein and ether extracts digestibility coefficients between the diets containing the enzymatic treated PKE (normal or low shell) and the control diet. The lowest ileal Lactobacilli population was found in the chickens fed the low shell PKE diet. Dietary normal PKE or low shell-enzymatic treated PKE decreased the Escherichia coli population compared to the control diet. The results suggested that PKE could be included up to 200 g/kg in the finisher diet without any apparent adverse effect on performance in broilers; however, any screening practice to reduce the shell content of PKE without enzymatic degradation of β-mannan, decreased its nutritive value.