乳酸恩诺沙星可溶性粉在鸡体内的药动学研究

24只苏禽黄羽肉鸡随机分成2组,分别按10 mg/kg体重剂量静注和内服乳酸恩诺沙星。测定乳酸恩诺沙星在鸡体内的药动学参数和生物利用度。恩诺沙星血药浓度数据用3p87计算机软件处理。静注乳酸恩诺沙星后的血药浓度-时间数据符合二室开放模型,主要动力学参数:t1/2α(0.45±0.16)h,t1/2β(7.02±1.42)h,CL(s)(0.38±0.10)L/kg/h,AUC(23.69±5.56)(mg/L)×h。内服乳酸恩诺沙星的血药浓度时间数据,符合有吸收因素二室模型,主要动力学参数:t1/2ka(0.60±0.01)h,t1/2ke(8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/L,AUC(20.74±3.80)(mg/L)×h,F 87.54%。结果表明,乳酸恩诺沙星可溶性粉在鸡体内具有吸收快、分布广、消除较慢以及内服生物利用度高的药动学特征。     

恩诺沙星在肉鸡组织中残留消除规律研究

选择250只1日龄"AA"肉鸡,喂养至35日龄开始在饮水中添加75 mg/L恩诺沙星,自由饮水,连续用药5日后休药.休药0时,肉鸡胸肌、肝脏、脂肪和肾脏中恩诺沙星含量分别为1 381.62、2 247.20、219.45、1 616.81μg/kg.休药48 h后,肉鸡组织中未检出恩诺沙星.结果表明农业部规定恩诺沙星在肉鸡中的休药期为8日是科学合理的.     

Influence of amount and type of dietary fat on deposition, adipocyte count and iodine number of abdominal fat in broiler chickens

This study described the relation between the type and amount of dietary fat on the deposition of abdominal fat by broiler chickens. It was hypothesized that at higher fat intakes, the well-known lowering effect of polyunsaturated fatty acids on the deposition of abdominal fat would be diminished. Experimental diets were formulated to contain three levels of added fat (3%, 6% and 9%). Each level had different proportions of the saturated fatty acids (SFA) and unsaturated fatty acids (UFA) by installing the ratios of 1:1, 1:2, 1:3, 1:4 and 1:5 with the use of tallow and soybean oil. Arbor Acres chicks, aged 7 days, were fed one of the 15 experimental diets until they were aged 42 days. Feed and water were provided ad libitum. There was no systematic effect of the dietary fat type and the amount on the weight gain and the feed intake. The lowest SFA:UFA ratio of 1:5 produced the lowest feed conversion rates, irrespective of the amount of the fat in the diet. The abdominal fat deposition was similar in the birds fed on diets containing either 3% or 6% added fat, but deposition was lower than in those fed 9% fat. A decrease in the SFA:UFA ratio of the diet was associated with a dose-dependent decrease in abdominal fat, irrespective of the amount of fat in the diet. This observation leads to the rejection of the hypothesis stated above. A decrease in the dietary SFA:UFA from 1:1 to 1:4 caused a decrease in the number of the fat cells per surface unit of breast meat. It is concluded that an increased intake of soybean oil at the expense of tallow reduced the abdominal fat deposition and the number of fat cells in the breast meat of broiler chickens.     

Pharmacokinetics and relative bioavailability of tiamulin in broiler chicken as influenced by different routes of administration

The bioavailability and pharmacokinetic disposition of tiamulin in broiler chicken were investigated after administration through the crop, drinking water, and feed at 40 mg/kg body weight. Residues of tiamulin in tissues of broiler chicken were also assessed. Plasma and tissue concentrations of tiamulin were analyzed by reverse‐phase high‐performance liquid chromatography (HPLC) method. Plasma concentration–time data were described by the non‐compartmental model for all three routes, and pharmacokinetic parameters were calculated. There were no significant differences (p > 0.05) in pharmacokinetic parameters and mean plasma concentrations of tiamulin between three routes tested (crop, water, and feed), indicating equal efficacy. Tiamulin residues in edible tissues (muscles, skin, and fat) were lower than the advocated maximum residue limit (MRL of 0.1 µg/g and that of liver was 1 µg/g) on the 3rd day. No traces were found on the 5th day after drug administration. This indicated that the withdrawal period (less than 5 days) is very short, which makes it safer. This study shows that tiamulin can be used with equal efficacy through all routes of administration in broiler chicken (crop, water, and feed).     

单诺沙星在蛋雏鸡体内的药物动力学及生物利用度的研究

选用 4～ 5周龄健康蛋雏鸡 12 5只 ,按 5 mg/kg的剂量进行静脉注射和内服单诺沙星的药动学研究及生物利用研究。高效液相色谱内标法测定血浆中药物浓度 ,MCPKP药动学程序处理药时数据。静脉注射和内服给药后血药浓度—时间数据分别符合无吸收因素二室开放式模型和一级吸收一室开放式模型。静脉注射给药的主要药动学参数为 :t1 /2α=0 .3313h、t1 /2β= 5 .994 0 h、Vd=7.5 2 4 6 L/kg、AU C=5 .6 916 μg/m l· h、CLB=0 .8935 L/kg· h。内服给药后主要药动学参数为 :t1 /2 Ka=0 .30 2 9h、t1 /2 K=6 .5 12 8h、tmax=1.2 10 0 h、Cmax=0 .5 15 9μg/m l、AU C=5 .132 9μg/ml· h。生物利用度为 90 .18%。     

Efficacy of chlorine dioxide gas in reducing Escherichia coli and Salmonella from broiler house environments

Escherichia coli and Salmonella spp. are considered to be the major pathogens associated with human transmissible infectious diseases in the air of poultry houses. Chlorine dioxide (ClO₂) is an effective biocide against a wide range of microorganisms. Accordingly, this study investigated the efficiency of gaseous ClO₂ application for disinfecting broiler houses by collecting air samples before and after fumigation using a passive method. Fumigation was performed with 125 mL or 250 mL of ClO₂ liquid (containing 2,000 ppm of ClO₂) and 3 trials were conducted for each dose. A total of 27 petri dishes were used for each trial (for each type of bacteria: E. coli or Salmonella) and placed in 3 different locations (front, middle and back) and 3 different positions (top, middle and floor) of the broiler shed. Air samples were collected at 10 min, 1 h, 3 h, 6 h, and 12 h before and after fumigation to evaluate the air quality in terms of the concentration of E. coli and Salmonella. Both levels of ClO₂ were capable of reducing the concentration of E. coli from broiler house air during all measuring periods except 10 min, with highest disinfection rate being observed at 6 h. With the exception of 1 h, the concentration of Salmonella was also reduced after fumigation with ClO₂ in all measuring period; with the highest disinfection rate occurring at 6 h. Fumigation with ClO₂ had no negative effect on birds’ health condition. Taken together, these results suggest that the application of gaseous ClO₂ at the investigated levels can be an effective option for reducing bacterial load from broiler house environments.     

福美双诱发肉鸡胫骨软骨发育不良的组织病理学变化

120羽1日龄健康AA肉鸡预饲1周后随机分为2组,对照组饲以基础日粮,试验组饲以基础日粮添加100mg/kg福美双,进行了肉鸡胫骨长度、生长板厚度、肉鸡胫骨软骨发育不良(TD)指数及TD发病率等指标的检测,并进行了形态学和组织病理学观察。结果显示,患病鸡胫骨长度、生长板厚度和TD指数均有显著变化(P<0.01),TD发病率显著上升(P<0.05);病鸡胫骨近端的纵切面有玉白色楔状软骨团块深入干骺端甚至骨髓腔,呈现典型的胫骨软骨发育不良病理学变化。结果提示,100 mg/kg福美双可显著提高AA肉鸡TD发病率,并引起相应的组织病理学变化,为TD分子机理的研究提供了一个理想的实验动物模型。     

肉鸡低血糖-尖峰死亡综合征调查研究

本研究对发生在华北地区的新型高致死性肉鸡疾病进行调查研究。发病主要集中在 8～ 18日龄 ,11～ 16日龄出现死亡尖峰。病鸡的血糖 (89.8± 7.9mg/dl)极显著低于正常鸡 (2 2 0 .3± 18.7mg/dl) (P<0 .0 1)。日死亡率高达 4 %～ 8%。典型症状表现为发病突然、头部震颤、运动失调、瘫痪、昏迷死亡。剖检可见肝脏弥漫性坏死 ,胰腺萎缩 ,十二指肠出血 ,胸腺、法氏囊、脾脏和盲肠扁桃体等免疫器官萎缩。泄殖腔聚集大量白色米汤样稀便。显微观察可见肝细胞坏死、淋巴滤泡排空、淋巴细胞坏死。依据国际诊断肉鸡低血糖 -尖峰死亡综合征 (HSMS)的标准 ,在国内首次确定我国有 HSMS发生 ,且在华北地区分布广泛 ,死亡率远高于国外报道的大于 0 .5 % ,而是高达 4 %～ 8%。已经成为危害肉仔鸡的重要疾病。采用控制光照和饮水中添加葡萄糖及多维等措施对 HSMS具有一定缓解作用     

Pharmacokinetics and oral bioavailability of pentoxyfylline in broiler chickens

The pharmacokinetic properties of pentoxyfylline and its metabolites were determined in healthy chickens after single intravenous and oral dosage of 100 mg/kg pentoxyfylline. Plasma concentrations of pentoxyfylline and its metabolites were determined by a validated high-performance liquid chromatographic method. After intravenous (i.v.) and oral (p.o.) administration, the plasma concentration-time curves were best described by a one-compartment open model. The mean elimination half-life (t(1/2el)) of pentoxyfylline was 1.05 h, total body clearance 1.90 L/h x kg, volume of distribution 2.40 L/kg and the mean residence time was 2.73 h, after i.v. administration. After oral dosing, mean maximal plasma concentration of pentoxyfylline was 4.01 microg/mL and the interval from p.o. administration until maximum concentration was 1.15 h. The mean oral bioavailability was found to be 28.2%. Metabolites I, IV and V were present in chicken plasma after both i.v. and p.o. administration, with metabolite V being the most dominant.     

The effects of benzoic acid supplementation on the performance of broiler chickens

To determine the efficiency of benzoic acid, a feeding experiment was carried out with 240 one‐day old ROSS 308 cockerels. Birds were divided into three dietary treatments: I (C) – no additives, II (B1) – 0.1% inclusion of benzoic acid, III (B2) – the inclusion of 0.2% benzoic acid. The performance results were similar in birds fed the control diet and the diet with 0.1% of benzoic acid. The dietary inclusion of benzoic acid at 0.2% depressed the growth of broiler chickens (p < 0.05). The dry matter of the digesta increased in the crop and caeca after benzoic acid supplementation. The pH of the caecal contents decreased following benzoic acid supplementation and was the lowest in the B2 group. No differences were found in the pH of the crop, ileal, gizzard digesta and rectum content. Lactic acid bacteria populations were the lowest in the caeca of the B1 group (p < 0.05). Coliform bacteria decreased in the caeca contents following increased benzoic acid supplementation.     

Supplemental magnolol improves the antioxidant capacity and intestinal health of broiler chickens

Magnolol is a multifunctional polyphenol rich in Magnolia officinalis. The objective of this study was to investigate the effects of magnolol on growth performance, carcass traits, antioxidant capacity, and gut health of broiler chickens. A total of 240 1-day-old broilers were randomly allocated into five dietary treatments: control (Ctrl); control diet supplemented with 100, 200, or 300 mg/kg of magnolol (M100, M200, and M300); and control diet supplemented with 200 mg/kg of bacitracin zinc (PC). The results showed that magnolol linearly decreased the feed conversion ratio between d 0 and d 14, linearly decreased the amount of malondialdehyde and increased the activity of total superoxide dismutase (T-SOD) in both serum and ileal mucosa on d 42 with increasing magnolol levels (p < 0.05). Moreover, the ileal villus height, the ileal villus height to crypt depth ratio, and the jejunal gene expressions of SOD1, glutathione peroxidase, and Claudin1 were linearly up-regulated with increasing magnolol levels (p < 0.05). The supplementation of magnolol had no effect on carcass traits or cecal short chain fatty acids (p > 0.05). The results indicated that magnolol could be applied in the diet of broiler chickens to benefit their antioxidant capacity and intestinal health.     

Effect of dietary astaxanthin rich yeast,Phaffia rhodozyma,on meat quality of broiler chickens

We evaluated effects of dietary supplementation with astaxanthin (Ax)‐rich yeast, Phaffia rhodozyma (Xanthophyllomyces dendrorhous), on broiler chicken meat quality. Fourteen‐day‐old female Ross broilers were divided into three groups: control group, Ax‐free diet; Ax 10 group, 10 mg/kg Ax diet; and Ax 20 group, 20 mg/kg Ax diet for 28 days. At 42 days old, chickens were slaughtered, and then growth performance, meat quality and sensory attributes were analyzed. Compared with the control, a* values increased significantly after slaughter and 48 h postmortem for Ax 20 samples (P < 0.05) and for b* values in Ax 20 and Ax 10 groups (P < 0.05). Cooking loss decreased in the Ax 20 group (P < 0.05). After 120 h aging, contents of several free amino acids and total free amino acid content of Ax 20 group were significantly higher than the control (P < 0.05). In sensory evaluation, meat texture attributes improved significantly in the Ax 20 group (P < 0.01). No significant changes occurred in flavor attribute scores of meat soup from the Ax 20 group compared with the control even though most assessors preferred meat soup from the Ax 20 group. Overall, Ax‐rich yeast in the diet improves broiler chicken meat quality.     

木聚糖酶对肉仔鸡后肠道微生物的影响

主要研究了小麦基础口粮添加木聚糖酶对肉仔鸡后肠道微生物的影响.将120只7日龄肉仔鸡分成2组,日粮分别添加0,0.1%木聚糖酶,饲喂至21日龄,研究木聚糖酶对肉仔鸡后肠道菌群数量变化的影响.结果表明,加酶未使同肠和盲肠乳酸杆菌、双歧杆菌和大肠杆菌数量发生显著变化.利用变性梯度凝胶电泳技术研究了木聚糖酶对肉仔鸡后肠细菌群体的影响.结果表明,加酶组回肠和盲肠的图谱比对照组条带相对较多,但差异不显著;组内个体间的图谱相似性比组问的相似性相对较大.木聚糖酶影响肉仔鸡后肠微生物数量和种群的作用效果不明显.     

Toxicokinetics and absolute oral bioavailability of melamine in broiler chickens

The objective of this study was to investigate the toxicokinetic characteristics of melamine in broilers due to the limited information available for livestock. Melamine was then administered to broiler chickens at an intravenous (i.v.) or oral (p.o.) dosage of 5.5 mg/kg of body weight, and plasma samples were collected up to 48 h. The concentration of melamine in each plasma sample was analyzed using liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Melamine was measurable up to 24 h after i.v. and p.o. administration. A one‐compartment model was developed to describe the toxicokinetics of melamine in broilers. Following i.v. administration, the values for the elimination half‐life (t_1/2β), the volume of distribution (V_d), and the clearance (CL) were 4.42 ± 1.02 h, 00.52 ± 0.18 L/kg, and 0.08 ± 0.01 L/h/kg, respectively. The absolute oral bioavailability (F) was 95.63 ± 3.54%. The results suggest that most of the administered melamine is favorably absorbed from the alimentary tract and rapidly cleared by the kidneys in broiler chickens.     

马齿苋粉对肉鸡生长性能和抗氧化能力的影响

文章旨在研究饲粮中添加马齿苋粉对肉鸡生长性能和抗氧化能力的影响。试验选取平均体重接近的1日龄AA肉鸡160只,称重后随机分为4组,试验1、2、3组在对照组饲粮的基础上分别添加0.30%、0.60%、0.90%的马齿苋粉,共处理42 d。结果发现,与对照组相比,肉鸡21日龄时,试验1、2、3组ADG分别增加5.5%、10.0%、6.8%(P <0.05),试验1、2组F/C分别降低8.2%、6.4%(P <0.05);42日龄时,试验1、2、3组ADG分别增加8.9%、9.6%、8.7%(P <0.05),F/C分别降低8.6%、9.6%、10.1%(P <0.05)。此外,21日龄时,试验1、2、3组肉鸡血清中T-AOC比对照组分别增加12.0%、14.4%、10.1%(P <0.05),T-SOD活性分别增加6.6%、10.5%、9.1%(P <0.05),MDA浓度分别降低6.3%、8.0%、5.6%(P <0.05);42日龄时,试验1、2、3组肉鸡血清中T-AOC比对照组分别提高13.9%、20.3%、13.6%(P <0.05),T-SOD活性分别提高10.5%、14.8%、9.5%(P <0.05),MDA浓度分别降低11.1%、14.9%、9.7%(P <0.05),试验1、2组血清中GSH-Px活性较对照组分别提高10.2%、11.8%(P <0.05)。结果表明,饲粮中添加马齿苋粉显著促进肉鸡生长及增强抗氧化能力。     

功能性饲料添加剂复方制剂对肉鸡生产性能和脂肪代谢的影响

本试验观察了一种功能性饲料添加剂复方制剂对肉鸡生产性能和脂肪代谢的影响。试验结果表明,在基础日粮中添加该复方制剂500mg·Kg-1可使49日龄肉鸡体重提高5.83%,料重比降低8.48%,成活率提高7.03个百分点;并同时降低肉鸡血清总胆固醇含量、血清甘油三酯含量、腹脂率和肝脏粗脂肪含量,而对胸肌粗脂肪含量无明显影响。