黄曲霉毒素降解酶对饲喂含AFB_1日粮肉仔鸡生长性能及肝生化指标的影响

试验通过测定AA肉仔鸡生长性能及肝脏相关酶活指标,评价黄曲霉毒素降解酶(ADTZ)对黄曲霉毒素B1(AFB1)的解毒效果。试验选取624只1日龄AA肉仔鸡,公、母各半,随机分为3个处理,每处理8个重复,分别饲喂基础日粮、基础日粮+0.1 mg/kg AFB1、基础日粮+0.1 mg/kg AFB1+0.3%ADTZ。试验全程42 d。结果表明:肉仔鸡长期摄入含0.1 mg/kg AFB1的日粮生长性能显著降低(P<0.05)。AFB1可导致肉仔鸡肝脏相关代谢酶活异常,且严重影响肝脏抗氧化指标。在含有0.1 mg/kg AFB1日粮中添加0.3%ADTZ后上述指标均基本恢复到正常水平,表明ADTZ可改善AFB1对肉仔鸡生长性能及肝脏酶活的影响,基本消除AFB1的毒性。     

霉菌毒素分解酶对育肥猪生产性能及肝功能的影响

在含有黄曲霉毒素B1(AFB1)的育肥猪日粮中添加100 mg/kg的霉菌毒素分解酶,以研究其对育肥猪生产性能和肝脏功能的影响,以及AFB1在肝脏中检出量的影响。试验表明,在育肥猪日粮中添加黄曲霉毒素B1会造成育肥猪生产性能下降,肝功能减弱,在含有黄曲霉毒素B1的日粮中添加100 mg/kg的霉菌毒素分解酶,显著提高了育肥猪的生长性能,料重比也显著降低,尤其显著降低了黄曲霉毒B1在肝脏中的检出量。     

日粮添加黄曲霉毒素解毒酶制剂对黄羽肉鸡生产性能、血清生化指标和毒素残留的影响

选用1日龄健康岭南黄肉仔鸡420只,随机分为7个处理组,分别为基础日粮组、基础日粮+20μg/kg AFB1组、基础日粮+50μg/kg AFB1组、基础日粮+20 μg/kg AFB1+0.1%解毒酶组、基础日粮+20 μg/kg AFB1+0.3%解毒酶组、基础日粮+50 μg/kg AFB1+0.1%解毒酶组、基础日粮+50 μg/kg AFB1+0.3%解毒酶组,试验为期42 d.试验结果表明:①基础日粮中加入20 μg/kg和50 μg/kg AFB1,肉鸡的平均出栏重、日采食量显著下降,料重比升高;血清中总蛋白、白蛋白含量显著下降,谷草转氨酶、谷丙转氨酶活性显著升高.②在20 μg/kg和50 μg/kg AFB1日粮中加入饲用黄曲霉毒素解毒酶制剂,明显改善肉鸡的生长性能,血液和肝脏中AFB1残留量降低,以上相关指标基本恢复到正常水平.③饲料中黄曲霉毒素污染量为20～50 μg/kg时,饲用黄曲霉毒素解毒酶制剂在饲料中适宜添加量为0.3%.由此可知,饲用黄曲霉毒素解毒酶制剂减轻或基本消除了AFB1对肉鸡生长性能、组织器官的不良影响.     

黄曲霉毒素对猪生长性能及内脏器官的影响

选用60头体质量28 kg左右的杜长大三元杂交猪,随机分为2组,每组3个重复,每个重复10头猪(公母各半),分别饲喂基础日粮(C组)、基础日粮添加0.1 mg/kg黄曲霉毒素(AF组),试验期90 d,研究黄曲霉毒素(AF)对猪生长性能及内脏器官的影响。结果表明:AF显著影响试验猪的生长性能和内脏器官相对重量,与C组相比,AF组试验猪日增重降低了12.90%(P<0.01),料重比提高了7.54%(P<0.01);AF组试验猪肝脏、肾脏、脾脏、胰脏的相对重量分别提高了8.24%(P<0.05)、27.27%(P<0.01)、41.18%(P<0.01)、42.86%(P<0.01);AF组试验猪肝细胞和肾细胞发生了严重的脂肪变性和空泡变性。提示:长期饲喂0.1 mg/kg黄曲霉毒素污染的日粮可诱发猪黄曲霉毒素的慢性中毒。     

黄曲霉毒素解毒酶制剂对饲喂黄曲霉毒素B1饲粮的断奶仔猪生长性能及肝脏生化指标的影响

本试验旨在通过研究黄曲霉毒素解毒酶制剂(aflatoxin-detoxifizyme,ADTZ)对饲喂黄曲霉毒素B1(AFB1)饲粮的断奶仔猪生长性能及肝脏生化指标的影响,探讨其应用效果。选用日龄相差不超过3 d、品种相同的断奶仔猪108头,按照遗传背景相同、体重相近、性别比例一致的原则随机分为3个组,分别为对照组(基础饲粮)、AFB1组(基础饲粮+0.1 mg/kg AFB1)、ADTZ组(基础饲粮+0.1 mg/kg AFB1+0.2%ADTZ),每组6个重复,每个重复6头仔猪。试验期30d。结果表明:1)与对照组相比,AFB1组仔猪平均日增重、平均日采食量有下降趋势(P>0.05),料重比有上升趋势(P>0.05);肝脏中谷胱甘肽还原酶、过氧化氢酶、琥珀酸脱氢酶活性显著下降(P<0.05),超氧化物歧化酶、谷胱甘肽过氧化物酶与胆碱酯酶活性下降,但差异不显著(P>0.05),碱性磷酸酶活性和丙二醛含量有上升趋势(P>0.05);2)与对照组相比,当添加0.2%的ADTZ后,仔猪平均日增重、平均日采食量均有所改善,同时有降低料重比的趋势(P>0.05);以上相关生化指标均恢复到正常水平。因此,在基础饲粮中添加AFB1可导致断奶仔猪生长性能下降,肝脏生理功能受损;添加ADTZ可有效消除AFB1对断奶仔猪的危害,改善其生长性能,保护肝脏生理功能。     

沸石粉和酵母细胞壁对仔鸡黄曲霉毒素感染的防治作用

文章旨在评估两种吸附剂沸石粉与沸石粉+酵母细胞壁预防肉鸡黄曲霉毒素的效果。试验将550只1d肉仔鸡随机分为11组,每组5个重复,每个重复10只鸡。11个处理中包括3个没有添加吸附剂的日粮(含0、1和2mg/kg黄曲霉毒素B1),8个处理组日粮含1或2mg/kg黄曲霉毒素B1,添加沸石粉或沸石粉+酵母细胞壁。试验共持续21d。结果发现,随着日粮黄曲霉毒素B1水平的升高,肉鸡采食量、增重较对照组显著降低(P<0.05),肝脏重量较对照组显著提高(P<0.05)。在饲喂2mg/kg黄曲霉毒素B1日粮的仔鸡中观察到严重的肝脏损伤,病变与黄曲霉毒素病一致。日粮黄曲霉毒素B1污染显著降低了肉鸡血清葡萄糖、白蛋白、总蛋白、钙、磷含量和碱性磷酸酶活力(P<0.05)。1mg/kg黄曲霉毒素B1污染日粮中添加沸石粉或沸石粉+酵母细胞壁均可缓解毒素对肉鸡生长和肝脏病变的影响(P<0.05)。但2mg/kg黄曲霉毒素B1污染日粮中添加沸石粉+酵母细胞壁对毒素的影响无显著缓解效果,其中2mg/kg黄曲霉毒素B1污染日粮添加沸石粉的预防效果显著高于沸石粉+酵母细胞壁(P<0.05)。结果表明:日粮黄曲霉B1毒素污染显著降低了肉鸡的采食量、体增重,并导致高死亡率,同时导致肉鸡肝脏增大,肝功能受损。在本实验条件下,沸石粉和沸石粉+酵母细胞壁均能在较低黄曲霉毒素B1污染水平(1mg/kg)下有效缓解其负面影响,但沸石粉对2mg/kg黄曲霉毒素B1的缓解作用强于酵母细胞壁。     

黄曲霉毒素B1分解酶对肉牛生长性能、胴体品质及毒素组织残留的影响

选取30头体质量344kg左右健康西门塔尔杂交牛,随机分为3组:对照组,饲喂基础饲粮;试验Ⅰ组和Ⅱ组分别在基础饲粮基础上添加0.05%和0.10%的黄曲霉毒素B1分解酶,试验期90d。结果表明:各组之间生长性能、胴体指标、血液和肝脏生化指标差异不显著(P0.05);添加黄曲霉毒素B1分解酶显著降低了毒素在肝脏(P0.01)和肾脏(P0.05)中的残留。试验Ⅰ、Ⅱ组肝脏黄曲霉毒素的B1残留量分别比对照组下降了44.87%(P0.01)和49.15%(P0.01);试验Ⅰ、Ⅱ组肾脏中黄曲霉毒素的B1残留量分别比对照组下降了32.20%(P0.05)和33.90%(P0.05)。由此可知,肉牛饲料中添加黄曲霉毒素B1分解酶可降低毒素在组织中的残留。     

黄曲霉毒素解毒酶对岭南黄肉仔鸡日粮中黄曲霉毒素B1解毒效果的研究

本文通过测定岭南黄肉仔鸡生长性能和血清指标及对肝脏组织切片的观察,旨在探讨黄曲霉毒素解毒酶对黄曲霉毒素B1(AFB1)的解毒作用.选用1日龄健康岭南黄肉仔鸡420羽,随机分为7个处理,每个处理4个重复,每个重复15羽,雄鸡10羽,雌鸡5羽.7个处理分别为基础日粮组、基础日粮+100 μg/kg AFBi组、基础日粮+100μg/kg AFB1+0.1%解毒酶组、基础日粮+100 μg/kg AFB1+0.2%解毒酶组、基础日粮+100μg/kg AFB1+0.3%解毒酶组、基础日粮+100μg/kg AFB1+0.4%解毒酶组、基础日粮+100μg/kg AFB1+0.5%解毒酶组,试验期42 d.结果表明:1)基础日粮中加入100μg/kg AFBi,肉仔鸡的平均日采食量、平均日增重和平均末重有所下降(P>0.05);血清中总蛋白(P<0.05),白蛋白(P>0.05)和球蛋白(P<0.05)含量下降,谷草转氨酶、谷丙转氨酶活性升高(P<0.05);肝脏组织病理切片观察到肝细胞广泛性坏死,胆管异常增生;2)在100μg/kg AFB1日粮中加入黄曲霉毒素解毒酶,能一定程度的改善肉仔鸡的平均日采食量、平均日增重和平均末重(P>0.05),0.2%、0.4%和0.5%的水平能显著降低毒素在肝脏和血液中的残留(P<0.05),减弱毒素对肝脏的损伤,一定程度地改善血清学指标.由此可知,黄曲霉毒素解毒酶能有效保护肉仔鸡肝脏,减轻或基本消除AFB1对肉仔鸡组织器官的不良影响,一定程度的提高肉仔鸡的平均日采食量和日增重.     

霉菌毒素分解酶枯草杆菌制剂对日粮含AFB1的艾维茵肉鸡的解毒效果研究

为研究在含有微量黄曲霉毒素B1 (AFB1)日粮中添加霉菌毒素分解酶枯草杆菌制剂对肉鸡生长性能、免疫器官指数和抗氧化能力的影响,本研究将120羽7日龄艾维茵肉鸡随机分成4组,每组3个重复。A组饲喂基础日粮,B、C、D组在基础日粮中分别添加50μg/kg AFB1、50μg/kg AFB1+0.1%枯草芽孢杆菌Pab02制剂和50μg/kg AFB1+0.1%霉菌毒素分解酶枯草杆菌制剂,饲喂28 d后测定肉鸡的生长性能、免疫器官指数、抗氧化能力及AFB1在肝脏和肌肉的残留量。结果显示:试验期间,除B组鸡出现精神沉郁和6.67%死亡率外,其余3组鸡均未出现病理症状和死亡现象;净增重D>A>C>B组(p>0.05),料重比B>C>D>A组(p>0.05);脾脏指数A>D>C>B组,并且A、D、C组极显著高于B组(p<0.01);B组血清和肝脏中的超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC)显著或极显著低于A、D组(p<0.05或p<0.01),丙二醛(MDA)含量极显著高于A、C、D组(p<0.01);各组肉鸡肝脏和肌肉中黄曲霉毒素的残留量A相似文献   

黄曲霉毒素对猪生长性能及免疫和抗氧化指标的影响

选用60头体质量28 kg左右的“杜长大”三元杂交猪,随机分为2组,每组3个重复,每个重复10头猪（公母各半）,分别饲喂基础日粮（C组）、基础日粮添加0.1 mg/kg黄曲霉毒素（AF组）,试验期90 d。饲养试验结束时,对猪的生长性能、免疫指标和抗氧化指标进行分析。结果表明：黄曲霉素显著影响试验猪的生长性能,日增重降低12.90%（P〈0.01）,料重比提高7.54%（P〈0.01）,同时显著降低试验猪的免疫功能和抗氧化能力。提示：长期饲喂0.1 mg/kg黄曲霉素可诱发猪黄曲霉毒素慢性中毒。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in