叶酸对肉仔鸡营养物质利用的影响

选用艾维茵商品代白羽肉鸡120只,随机分成4组,按叶酸添加水平不同分为4个不同处理组,分别为0、0.75、1.5、3.0mg/kg,于35～42日龄用全收粪法进行消化代谢试验,研究叶酸对肉仔鸡营养物质利用率的影响。研究结果表明,添加叶酸可以不同程度地提高饲料养分表观利用率,1.5mg/kg组的干物质、粗蛋白、粗脂肪、粗纤维、有机物和无氮浸出物的表观代谢率最高,分别比对照组提高10.33%、19.83%、14.32%、13.89%、6.07%和16.09%,差异显著,而其余各养分的代谢率各组间均差异不显著。     

Effects of ethylenediaminetetraacetic acid on phytate phosphorus utilization and efficiency of microbial phytase in broiler chicks

Previous studies have suggested that organic acids may improve P utilization in animals. To evaluate the ability of ethylenediaminetetraacetic acid (EDTA) to improve phytate P utilization and the possible synergistic effect between EDTA and microbial phytase (MP) an experiment was conducted using 360 Ross 308 broiler chicks. The experiment was carried out using a completely randomized design with a 3*2 factorial arrangement (0, 0.1 and 0.2% EDTA and 0 and 500 IU MP). Four replicate of 15 chicks per each were fed dietary treatments including (i) P-deficient basal diet [0.2% available phosphorus (aP)] (NC); (ii) NC + 500 IU MP per kilogram of diet; (iii) NC + 0.1% EDTA per kilogram of diet; (iv) NC + 0.1% EDTA and 500 IU MP per kilogram of diet; (v) NC + 0.2% EDTA per kilogram; and (vi) NC + 0.2% EDTA + 500 IU MP per kilogram of diet. Weight gain (WG), feed efficiency and serum Ca, P and alkaline phosphatase (ALP) were assessed. Addition of 0.2% EDTA to low aP diets resulted in significantly lower feed consumption (FC) and WG, but 0.1% EDTA did not depress WG compared to NC. Phytase supplementation of P-deficient diets significantly improved WG and feed efficiency, but it had no effect on FC. Microbial phytase supplementation significantly decreased ALP concentration. Results obtained in our study suggest no synergistic effect between phytase and EDTA in broiler chicks.     

Histologic lesions in broiler chicks given cyclopiazonic acid orally

Cyclopiazonic acid dissolved in corn oil was administered by gavage to broiler chicks (n = 80) daily, from the day of hatching for 23 days. Chicks were assigned to 3 groups (1, 2, or 4 mg of cyclopiazonic acid/kg of body weight); a control group was given corn oil. Each group was composed of 10 male and 10 female chicks. Surviving chicks were euthanatized and necropsied on day 24. Histologic examination revealed that the most common lesions consisted of necrosis and hemorrhage or hyperplasia of the mucosa of the proventriculus and hepatocellular vacuolation. Skeletal muscle degeneration, characterized by myofiber swelling or fragmentation accompanied by an infiltrate of macrophages and heterophils, was detected in the group given 4 mg/kg. This degeneration was associated with an increase of plasma creatine kinase activity. Focal hepatocellular and splenic necrosis also developed in the groups given 4 mg/kg.     

Effects of growth hormone on tissue metabolism in broiler chicks.

1. The effect of bovine growth hormone (GH) on cartilage, liver, muscle, pancreas and spleen has been investigated. 2. Tissue RNA was elevated in the liver, muscle and spleen of the GH-treated chicks while uptake of radioactive phosphate into RNA was stimulated for both liver and spleen. 3. The GH-treated chicks had an increased cartilage protein content together with a higher rate of incorporation of 14C-methionine pancreatic protein.     

Dietary conjugated linoleic acid improves antioxidant capacity in broiler chicks

1. The influence of dietary conjugated linoleic acid (CLA) on the antioxidant status in the absence or presence of endotoxin exposure was studied with male broiler chicks. 2. In experiment 1, a total of 240 1-d-old broilers were allotted into 4 dietary groups (0, 2.5, 5.0 or 10.0 g pure CLA/kg) to study the influence of CLA on growth performance and antioxidant defence systems. The results showed that growth performance was not altered by 42 d of CLA consumption. Increased total superoxide dismutase (TSOD) activities in liver, serum and muscle were observed in chicks given 10.0 g CLA/kg diet. Dietary CLA at 10.0 g/kg also markedly elevated liver catalase (CAT) activity. Malondialdehyde (MDA), a marker of lipid peroxidation, decreased in liver, serum and muscle in chicks given 5.0 and 10.0 g CLA/kg diet. 3. In experiment 2, a total of 120 1-d-old broilers were fed on a control diet (without CLA) or 10.0 g CLA/kg diet. Half of the birds fed on each diet were injected intraperitoneally with 0.25 mg/kg body weight of Salmonella enteritidis lipopolysaccharide (LPS) at 16, 18 and 20 d of age. Decreased glutathione peroxidase (GSH-Px), TSOD activity and increased ceruloplasmin and MDA concentrations were seen in the challenged chicks. Dietary CLA prevented the loss of body weight gain and feed conversion ratio of chicks followed repeated endotoxin exposure. CLA partially inhibited the increase of serum ceruloplasmin and MDA at 17 and 21 d of age and notably suppressed the decrease of serum TSOD activity at 21 d of age. 4. These results suggested that dietary CLA enhances the activity of antioxidant enzymes including TSOD and CAT. Supplementation of CLA has been shown to ameliorate the antioxidant balance and performance of chicks during oxidative stress.     

盐酸克林霉素对实验性猪链球菌病的药效试验

克林霉素是林可霉素的半合成衍生物 ,抗菌活性较林可霉素强 4～ 8倍。在医学临床上克林霉素应用较多 ,但克林霉素在兽医临床的药效学研究国内尚未见报道。为此 ,进行了本研究。1　材料与方法1 .1　药品与试剂　盐酸环丙沙星原料药 ,由浙江新昌制药股份有限公司提供 ;盐酸克林霉素 ,由重庆环松医药科技开发公司生产 ;盐酸林可霉素 ,由华北华滦制药厂生产。1 .2　动物　由长春市光明养殖场提供军牧 1号35日龄仔猪 85头 ,公母兼有 ,随机分为 6组。试验前观察 1周 ,不注射任何疫苗。饲料自配 ,不含抗菌药物。1 .3　猪链球菌病的人工诱发　将冻干…     

不同添加剂预混料配方对肉仔鸡生产性能的影响

添加剂预混料是配合饲料生产的核心和关键,其质量好坏直接影响配合饲料产品质量、动物生产性能以及动物产品的质量。笔者曾通过试验筛选出了添加剂的理想组合,本试验旨在通过对肉仔鸡生产性能的观察,探讨添加剂预混料的最佳配方,为实际生产中的广泛应用提供理论依据。1 试验材料与方法1.1 试验动物与分组 选用1日龄商品代艾维茵混合健雏360只,采用完全随机单因子设计分成4组进行试验。每组设3个重复,每重复30只（开始体重组间差异不显著,p>0.05）。试验期49d。     

蛋氨酸羟基类似物及甜菜碱对肉鸡血清生化指标的影响

试验选用AA肉仔鸡72只,采用3×2二因素随机分组试验设计,共计6个处理组,每处理4个重复,每重复3只鸡。在笼养条件下,对试鸡进行急性热应激试验,试验共进行1周,测定和评价甜菜碱、DL-蛋氨酸和液态蛋氨酸羟基类似物在急性热应激下对肉鸡血清生化指标的影响。结果表明,在急性热应激下,添加甜菜碱可不同程度地降低血糖、甘油三酯、尿酸和尿氮的水平。蛋氨酸羟基类似物(MHA)有利于防止热应激下血糖的升高,降低血清甘油三酯的含量,MHA比蛋氨酸更利于降低血清甘油三酯的含量;与蛋氨酸相比,添加MHA可降低血清甘油三酯、尿酸和尿氮的水平。甜菜碱可降低血中二氧化碳(CO2)的排出。     

日粮中添加(-)-羟基柠檬酸对肉鸡脂肪代谢的影响

为探讨(-)-羟基柠檬酸[(-)-HCA]对肉鸡脂肪代谢的影响,120羽21日龄罗氏308肉鸡随机分成4组,每组3个重复,每个重复10羽。分别于基础日粮中添加0、150、300和600 mg/kg的(-)-HCA,饲喂至50日龄,各组分别从每个重复中随机抽取4只肉鸡宰杀,采集血液、肝脏、腹脂、肌肉等样品。试验结果表明,与对照组相比,3个剂量组的(-)-HCA对腹脂率、日采食量、料重比影响虽无统计学上的差异,但3个剂量(-)-HCA的处理均有降低使腹脂率、日采食量,并提高饲料转化率的趋势。与对照组相比,600 mg/kg的(-)-HCA处理能显著降低肉鸡血清中甘油三酯(TG)和总胆固醇(TC)的含量(P0.05),但3个剂量组的(-)-HCA均可显著降低血清中游离脂肪酸(NEFA)的含量显著(P0.05)。与对照组相比,300和600 mg/kg的(-)-HCA处理可显著升高血清中高密度脂蛋白-胆固醇(HDL-C)的含量(P0.05),3个剂量的(-)-HCA处理均可显著降低血清中低密度脂蛋白-胆固醇(LDL-C)的含量(P0.05)。与对照组相比,300 mg/kg的(-)-HCA处理可显著提高肉鸡肝糖元的含量(P0.05),但3个剂量组的(-)-HCA对肌糖元的含量均无显著影响(P0.05)。3个剂量的(-)-HCA处理对肝脂酶活性均无统计学上的差异(P0.05),但不同剂量的(-)-HCA处理均有提高肝脂酶活性的趋势。提示(-)-HCA可通过抑制脂肪酸的合成、加快脂肪的分解,从而减少脂肪在肉鸡体内的沉积。     

Evaluation of transgenic event CBH 351 (StarLink) corn in broiler chicks

The influence of transgenic event CBH 351 (StarLink; SL)-derived hybrid corn on the growth performance, health condition and physiological function in broiler chicks, as well as the possible transfer of the cry9C gene and Cry9C protein to blood, liver and muscle were examined in comparison with chicks fed on a diet with non-transgenic corn (SL-F). Bodyweight gain and feed conversion ratio in the chicks fed on a diet with SL were significantly greater than in chicks fed on a diet with SL-F during the starter phase (0–3 weeks of age), but this significant difference disappeared during the finisher phase (4–7 weeks of age). No abnormalities in health condition in either SL or SL-F groups were observed, and livability did not differ significantly between SL and SL-F groups. Moreover, no significant differences in serum biochemical and hematological values, histopathological observation and necropsy findings were observed between SL and SL-F groups at the end of the experiment. The cry9C gene and Cry9C protein were not detected in blood, liver and muscle of chicks at 3, 5 or 7 weeks of age. The results indicate that feeding SL does not influence growth performance, health condition or physiological function in broiler chicks, and the cry9C gene and Cry9C protein are not transferred to the blood, liver and muscles of broilers.     

核黄素对肉仔鸡免疫功能和生产性能的影响

100只1日龄肉仔鸡随机分成4组，每组25只，I－Ⅲ组为试验组，第Ⅳ组为对照组。对照组喂以基础日粮，其他3组分别喂以含核黄素3．6、7．2、14．4mg/kg的日粮，饲喂6周后观察它们对肉仔鸡外周血细胞、免疫器官及生产性能的影响，结果表明：各试验组鸡血浆中白细胞及异嗜细胞数目均高于对照组，其中Ⅱ、Ⅲ组异嗜细胞数与对照组差异显著（P＜0．05）；脾体比试验Ⅱ、Ⅲ组与对照组有显著差异，I组与对照组无差异；各试验组生产性能也均高于对照组。试验结果表明，核黄素可提高机体的抗感染能力及和免疫力，并可提高肉仔鸡生产性能。     

Matrix metalloproteinase expression and localization in turkey (Meleagris gallopavo) during the endochondral ossification process

Vertebrate long bones are formed by endochondral ossification, a process accompanied by changes in extracellular matrix synthesis and remodeling, performed mainly by the matrix metalloproteinases (MMP). The temporal/spatial expression patterns of 5 members of the MMP family known to be important for endochondral ossification were studied, for the first time, in the turkey growth plate during embryonic and juvenile stages. The expression of MMP-2 was detected in the proliferative zone, MMP-3, MMP-9, and MMP-13 in cells lining the blood vessels; MMP-13 was also detected in hypertrophic chondrocytes. The MMP-16 expression was detected in the reserve zone of the growth plate. These results present a detailed survey of turkey MMP, serving as a data source (atlas) for further studies in this subject.     

β-葡萄糖苷酶对肉鸡骨骼生长及抗氧化功能的影响

选用240羽1日龄艾维茵肉用仔公鸡,随机分为4个组,每组设4个重复,每个重复15羽.在玉米-豆粕基础日粮中添加不同水平的β-葡萄糖苷酶制剂(0、2、4、6 g/kg).试验期为42 d.结果显示,饲粮中添加β-葡萄糖苷酶的水平为0.2%时,肉鸡生长最佳,但对肉鸡的股骨、胫骨生长无显著影响,血清中钙、磷及碱性磷酸酶(ALP)指标均无显著变化;可显著提高血清中SOD和肝脏中GSH-PX、GR活力(P<0.05),同时使血清中MDA含量明显降低(P<0.05);极显著地提高了胸肌的a*(红度)值(P<0.001),而L*(亮度)值显著低于对照组(P<0.001).     

Effects of probiotics and maternal vaccination on Salmonella enteritidis infection in broiler chicks

The effects of probiotics and maternal vaccination with an inactivated Salmonella Enteritidis (SE) vaccine on day-old chicks challenged with SE were evaluated. A 2 X 3 factorial arrangement was used (with or without probiotics; breeders nonvaccinated, vaccinated intramuscularly, or vaccinated intraperitoneally). Three trials were conducted in isolation cabinets and SE challenge was different between trials. The number of SE organisms per chick and the time interval between housing and introduction of seeder birds (hereafter called challenge) were 1.6 X 10(8) and 1 hr (Trial I), 1.8 X 10(6) and 12 hr (Trial II), and 1.2 X 10(4) and 24 hr (Trial III). SE recovery was assessed in ceca and liver at 3, 5, and 7 days postchallenge, and the number of colony-forming units (CFU) in ceca was evaluated at 5 and 7 days postchallenge. The number of SE (log CFU) in the ceca reduced 0.56 log (from 7.59 to 7.03) and 1.45 log (7.62 to 6.17) because of the treatment with probiotics in Trials II and III, respectively. The greater reduction in Trial III indicates the importance of the early use of probiotics on the prevention of SE infection. Treatment with probiotics resulted in a smaller number of SE-positive livers after 5 days postchallenge on Trial III. Although there was no significant effect of maternal vaccination on the number of SE CFU in the ceca, a significant effect of maternal vaccination on the SE CFU was observed in the liver, but not in the ceca at 5 days after challenge.     

Dietary conjugated linoleic acid enhances spleen PPAR-gamma mRNA expression in broiler chicks

1. The anti-inflammatory effects of dietary conjugated linoleic acid (CLA) on broilers repeatedly challenged with lipopolysaccharide (LPS) were investigated. 2. Day-old broiler chicks were allotted into three treatment groups and fed on a control diet or diets containing 5.0 or 10.0 g CLA/kg diet. Six chicks from each treatment were injected with LPS (0.25 mg/kg body weight) at 16, 18 and 20 d of age. Splenic cyclooxygenase (COX) and inducible nitric oxide synthase (iNOS) activities, and prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production as well as peroxisome proliferator-activated receptor-gamma (PPAR-gamma) mRNA expression were measured at 21 d of age. 3. Chicks fed 10.0 g CLA/kg diet had lower COX activities and PGE(2) production that the controls. Dietary CLA (10.0 g/kg) did not significantly diminish LPS-induced enhancement of COS-2 activity, inhibited the subsequent increase in PGE(2) production. 4. Regulation of COX-1 activity contributed to the difference in PGE(2) production. 5. CLA did not markedly attenuate the increase of iNOS activity and NO production caused by LPS challenge. Chicks fed CLA had lower iNOS activity and NO production than the controls. 6. Dietary CLA activated splenic PPAR-gamma mRNA expression and increased PPAR-gamma mRNA expression after LPS injection. 7. These results suggest that dietary CLA has immunomodulatory effects in the spleen by restricting basal PGE(2) and NO to lower levels and enhancing PPAR-gamma mRNA expression. During the inflammatory response, dietary CLA did not alleviate the increase in COX-2 and iNOS activities but enhanced PPAT-gamma mRNA expression.     

Fumonisin toxicity in broiler chicks.

The effects of dietary fumonisin B1 were evaluated in young broiler chicks. The experimental design consisted of 5 treatments each with 9 randomly allotted male broiler chicks. Day-old chicks were fed diets containing 0 (feed control), 100, 200, 300, or 400 mg fumonisin B1/kg feed for 21 days. Response variables measured were chick performance, organ weights, serum biochemistry, and histologic parameters. Body weights and average daily gain dramatically decreased with increasing dietary fumonisin B1, and liver, proventriculus, and gizzard weights increased. Diarrhea, thymic cortical atrophy, multifocal hepatic necrosis, biliary hyperplasia, and rickets were present in chicks fed diets containing fumonisin B1. Serum calcium, cholesterol, and aspartate aminotransferase levels all increased at higher fumonisin dietary levels. Results indicate that fumonisin, from Fusarium moniliforme culture material, is toxic in young chicks.     

Gizzerosine-induced histopathological lesions in broiler chicks

1. The aim of this study was to investigate pathomorphological changes in broiler chicks fed with different doses of gizzerosine, a substance produced during the heat treatments of fish meal. 2. The experiment was carried out in Ross broiler chicks which were divided into three groups: group A received 100% of non-medicated commercial mash for broiler chicks. During an experimental 5-d period, 50% of commercial mash was replaced with unheated fish meal (0.65 ppm gizzerosine) in group B and in group C with heated fish meal (1.15 ppm gizzerosine). Fourteen chicks from each group were killed every day. Samples of gastrointestinal and lymphoid organs, lung, pancreas, liver, brain and kidney tissue were sampled for histopathological analysis. Organs were embedded in paraffin and stained with hematoxylin-eosin stain and using periodic acid-Schiff reagent (PAS) and Sudan III (frozen sections). 3. Necropsy did not reveal notable differences between treated groups. There were no significant histopathological changes in immunocompetent organs nor in the lungs, the pancreas, the kidney or the brain. Sharply demarcated multiple vacuoles were observed in the myocardium in group C toward the end of the experiment. In group C, the prevalent changes in the gizzard and the proventriculus were slight to severe cuticle erosions and oedema of the lamina propria with or without multiple vacuoles, respectively, towards the end of the experiment. The most prominent changes toward the end of the experiment were dispersed cell vacuolisation in duodenal, jejunual, ileal and caecal lamina propria in group C. 4. In conclusion, it should be emphasised that extra-gizzard gizzerosine-induced lesions are probably not mediated by H2-receptor stimulation, but could be a consequence of cellular hypoxia.     

Effect of dietary palmitic acid on broiler chicks fed on various concentrations of calcium.

1. The effect of dietary palmitic acid on body weight and bone-ash of chicks fed three concentrations of calcium was studied in a 2 X 3 factorial design (0 and 10% palmitic acid, 0.4, 0.7 and 1.0% calcium). 2. Body weight of chick not influenced by the calcium concentration when palmitic acid was not included in the diet. 3. When 10% palmitic acid was included the body weight of chicks fed 0.4 and 0.7% calcium was lower (P less than 0.01) than for the other groups. 4. Bone-ash was lower (P less than 0.01) for chicks fed 0.4% calcium than for the other two calcium concentrations when palmitic acid was not added and palmitic acid at 10% of the diet reduced bone-ash of the chicks fed 0.4 and 0.7% calcium (P less than 0.01).