伊维菌素和乙基多杀菌素对埃及伊蚊作用研究

利用伊维菌素与乙基多杀菌素对埃及伊蚊幼虫进行生物测定,通过使用诱饵结合药物处理伊蚊成虫,观察其生存情况,了解上述两种药物对蚊虫的作用效果,从而为蚊媒防控提供一定的参考。伊维菌素与乙基多杀菌素处理幼虫后得到半致死浓度LC_(50)分别为1.427 mg/L、0.031 mg/L。饲以1.82mg/kg(A1组)与9.1mg/kg(A2组)伊维菌素血餐成蚊的半数生存期分别为7.681 d和5.400 d,平均产卵量为31.58和13.79,孵化率也降低为23%与0%,二次吸血后的产卵量受影响较小,但孵化率为0;以0.1、1、5、10、20 mg/L(B1-B5组)伊维菌素糖水饲养成蚊,B4组与B5组的蚊虫半数生存期分别为3.110 d与2.980 d,B1组与B2组的平均产卵量为91.80和94.95,与对照无明显差异,但孵化率仅为10%和0.3%。试验表明,乙基多杀菌素可用于伊蚊幼虫的生物防治,伊维菌素的不同诱饵处理后对埃及伊蚊成蚊从产卵至二次吸血以及卵的孵化率均有较明显的影响。     

硼对根瘤菌在紫花苜蓿体内运移和定殖及对幼苗生长的影响

通过向青色荧光蛋白(CFP)标记的两种根瘤菌菌液Ensifer meliloti LZgn5f (gn5f) 和Ensifer meliloti 12531f (12531f)内添加不同浓度硼并接种于苜蓿幼苗根部,研究硼对荧光标记根瘤菌在甘农5号紫花苜蓿幼苗体内运移和定殖的动态变化及接种对苜蓿幼苗生长的影响。结果表明,添加1 mg/L硼较利于12531f生长, 100 mg/L硼较利于gn5f生长。添加适宜浓度硼对苜蓿幼苗体内荧光标记根瘤菌运移和定殖具有促进作用,两种荧光标记根瘤菌在根部定殖数量较多,其中添加100 mg/L硼15 d时根部12531f数量最高,达2184.99 cfu/g,添加0.5 mg/L硼60 d时gn5f数量最高,达58307.11 cfu/g;同时可向地上运移,主要运移并定殖于下部茎叶内,1 mg/L硼利于12531f在下部茎叶内定殖,100 mg/L硼利于gn5f在下部茎内定殖。对照各部位未检测到两种荧光标记根瘤菌。添加硼处理的单株结瘤数、单株根瘤重、单株叶片数、株高、根长、地上鲜重、地上干重、根鲜重和根干重均高出对照和单独接菌处理,1 mg/L硼+12531f处理高出对照和单独接菌处理,范围在21.31%~909.28%之间;100 mg/L硼+gn5f处理高出对照和单独接菌处理,范围在15.07%~1424.24%之间;虽然单独接种12531f抑制了叶绿素的形成,但添加1 mg/L硼后其含量则升高,分别显著高出对照和单独接菌处理18.31%和36.86%(P<0.05),而接种gn5f则促进了叶绿素的合成,添加100 mg/L硼后含量分别显著高出对照和单独接种处理24.41%和12.92%(P<0.05)。因此,1 mg/L硼与12531f混合接种,100 mg/L硼与gn5f混合接种对根瘤菌在苜蓿幼苗体内运移和定殖及对幼苗的生长具有促进作用,为苜蓿种植提供了依据。     

杀螨剂“克螨特”亚致死剂量对朱砂叶螨实验种群生命参数的影响

为了科学合理地使用桑园杀虫剂,采用Jackkn ife统计推断技术,在16 L、(30±1)℃、RH 75%±10%,8D、(20±1)℃、RH 65%±15%的条件下,对寄主为桑树的朱砂叶螨种群水平上的亚致死效应进行了研究。朱砂叶螨成螨经杀螨剂“克螨特”亚致死剂量(60.83 mg/L)处理后,成螨寿命降低,雌螨总产卵量显著低于对照组;处理组内禀增长率(0.272 0±0.007 5)也显著低于对照组(0.338 6±0.005 5)。     

三种杀虫剂对多异瓢虫的毒力及亚致死效应

为协调化学防治和生物防治,指导田间合理用药,采用接触处理（滤纸）和毒蚜饲喂两种方式,测定了3种杀虫剂吡虫啉（I）、阿维菌素（Ab）和高效氯氰菊酯（Al）对多异瓢虫（Hippodamia variegate）的毒力,及亚致死剂量对多异瓢虫发育历期和繁殖力的影响。结果表明：多异瓢虫接触3种杀虫剂的亚致死剂量后的日平均产卵量均显著低于对照（P<0.05）,而且当代累积平均产卵量显著低于对照（P<0.05）;毒蚜饲喂组的瓢虫日平均产卵量与对照无显著差异,当代累计平均产卵量与对照无显著差异。多异瓢虫各处理当代第1 d产卵孵化率均显著低于对照（P<0.05）。接触处理瓢虫组各处理的F₁代总发育历期显著长于对照,而毒蚜饲喂处理与对照差异不显著。各处理的F₁代产卵量与对照无显著差异,Al接触处理瓢虫组的F₁代第1 d产卵孵化率显著低于对照。本试验LC₂₀亚致死剂量的杀虫剂不仅对当代而且对下一代的生长均有抑制作用,药剂接触处理对多异瓢虫发育和繁殖的影响大于取食毒蚜处理。     

牛至草粉对肉鸭生长性能、抗氧化、肉品质及经济效益的影响

文章旨在评估日粮添加牛至草粉对1～42?d肉鸭生长性能、抗氧化和肉品质的影响。试验选择1日龄、平均体重为（48.63±0.06）g的商品肉鸭560只,随机分为4组,每组5个重复,每个重复26只。对照组肉鸭饲喂基础日粮,处理1组肉鸭饲喂基础日粮+50?mg/kg抗菌肽,处理2组和处理3组分别饲喂基础日粮+20和40?mg/kg牛至草粉。结果：与对照组相比,20?mg/kg牛至草粉组42?d肉鸭的体重显著提高7.23%（P＜0.05）,同时该组1～42?d肉鸭的饲料报酬显著提高14.81%（P＜0.05）。与对照组相比,20和40?mg/kg牛至草粉组肉鸭肌肉谷胱甘肽过氧化物酶活性分别显著提高23.08%和23.93%（P＜0.05）。抗菌肽组和20?mg/kg牛至草粉组肌肉丙二醛含量较对照组分别显著降低47.49%和52.36%（P＜0.05）。对照组血清丙二醛含量最高,20?mg/kg牛至草粉组丙二醛含量最低,对照组血清丙二醛含量较处理组分别显著提高87.53%、156.96%和78.07%（P＜0.05）。与对照组相比,处理组肌肉蒸煮损失分别显著降低35.86%、41.73%和39.95%（P＜0.05）,20和40?mg/kg牛至草粉组肌肉硫代巴比妥酸值分别显著降低11.76%和14.71%（P＜0.05）。结论：在本试验条件下,日粮添加牛至草粉对肉鸭的影响可以达到与抗菌肽一致的效果,其中粮添加20?mg/kg牛至草粉可以显著改善1～42?d肉鸭的饲料报酬,提高肌肉和血清的抗氧化性能,降低肌肉蒸煮损失。 [关键词]牛至草|肉鸭|生长性能|抗氧化|肉品质     

外源复合酶对断奶仔猪生长性能、养分消化及肠道健康的影响

本研究旨在评估外源复合酶对断奶仔猪生长性能、养分消化和肠道健康的影响。试验将24日龄断奶、平均初始体重为(7.52±0.98)kg的540头断奶仔猪随机分为3组,每组6个重复,每个重复30头。对照组饲喂基础日粮,处理组在基础日粮中添加100和200 mg/kg复合酶日粮。试验分为1～7 d和8～28 d两个阶段,试验结束时后收集肠道食糜样品,用于测定挥发性脂肪酸含量、pH、黏度和微生物含量。结果 :第1～7天200 mg/kg复合酶组日增重较对照组显著提高16.49%(P 0.05),而8～28 d和1～28 d 100和200 mg/kg复合酶组日增重较对照组显著提高12.02%、15.14%和11.70%、15.60%(P 0.05)。日粮添加复合酶对1～7 d、8～28 d和1～28 d猪的日均采食量无显著影响(P 0.05)。两个复合酶组(100和200 mg/kg)猪在8～28 d和试验全期(1～28 d)饲料报酬较对照组显著提高10.53%、15.79%和8.33%、11.67%(P 0.05)。干物质、能量和粗蛋白质表观消化率随着酶添加水平的升高呈显著线性升高(P 0.05)。与对照组相比,补充复合酶显著提高了盲肠和结肠中乙酸、丙酸和丁酸的浓度(P 0.05)。日粮添加复合酶对盲肠大肠杆菌、结肠乳酸杆菌含量无显著影响(P 0.05),但200 mg/kg复合酶组盲肠乳酸杆菌较对照组显著提高了6.23%(P 0.05),结肠大肠杆菌数量显著降低9.94%(P 0.05)。200 mg/kg复合酶组胃食糜黏度较对照组显著提高45.65%(P 0.05)。综上所述,日粮添加含有淀粉酶、蛋白酶和木聚糖酶的复合酶可以提高断奶仔猪养分消化和肠道挥发性脂肪酸浓度,降低肠道致病菌数量,进而改善生长性能。     

腰果叶提取物对肉鸡生长性能、血液生化及肉品质的影响

文章旨在评估腰果叶提取物对肉鸡生长性能、血液生化指标及肉品质的影响。试验将504只1日龄肉仔鸡随机分为3组,每组6个重复,每个重复28只。在试验过程中,对照组、处理1和2组肉鸡分别饲喂阶段基础日粮+0、100和200 mg/kg的腰果叶提取物。结果：与对照组相比,100 mg/kg腰果叶提取物组肉鸡的末重（42 d）、22～42 d平均日增重分别显著提高2.20%和3.40%（P＜0.05）,生长后期（22～42 d）和全期（1～42 d）料重比分别显著降低3.78%和2.71%（P＜0.05）。200 mg/kg腰果叶提取物组与对照组和100 mg/kg腰果叶提取物组对肉鸡生长指标的影响无显著差异（P＞0.05）。与对照组相比,100和200 mg/kg腰果叶提取物组肉鸡白细胞数量分别显著降低66.60%和68.03%（P＜0.05）,而红细胞数量分别显著提高23.00%和26.20%（P＜0.05）,血红蛋白浓度分别显著提高73.93%和77.03%（P＜0.05）。100和200 mg/kg腰果叶提取物组肉鸡的腹脂相对重量、胸肌TBARS值和滴水损失显著低于对照组（P＜0.05）。结论：在本研究条件下,综合考虑血液指标、肉品质和饲料转化率,日粮中腰果叶提取物的适宜添加水平为100 mg/kg。 [关键词]腰果叶提取物|肉鸡|生长性能|血液生化|肉品质     

猴卡氏肺孢子虫肺炎的实验研究

通过检测实验猴对卡氏肺孢子虫的易感性和致病性,使用1～4号实验猴经气管接种2.8×1O5卡氏肺孢子虫包囊,接种后,按25mg/kg体重肌注醋酸可的松;5～8号实验猴接种7.0×105包囊;9号猴为对照.结果表明:接种后27～33 d,1～4号实验猴出现体温上升,厌食,消瘦,虚弱,咳嗽和呼吸急促,其中1～2号实验猴显得极度衰弱和呼吸困难,于第29 d,31 d死亡.5～8号实验猴呈亚临床症状,接种后30 d亦即连续肌注醋酸可的松的第22 d,出现类似于1～4号实验猴的临床症状,其中5号实验猴于23 d死亡.对照猴无任何临床变化.结论用醋酸可的松处理的1～4号实验猴,接种卡氏肺孢子虫包囊后,出现典型的卡氏肺孢子虫肺炎,有显著的致病性.虽然5～8号实验猴接种大剂量卡氏肺孢子虫包囊,只呈现亚临床症状,接受醋酸可的松处理后,出现类似于1～4号实验猴的症状,说明隐性感染卡氏肺孢子虫的实验猴经免疫抑制剂处理后可激活病原体,导致严重发病.     

羔羊运输应激干预对其生长性能和血清生化指标的影响

本试验旨在研究羔羊运输前后不同时间和处理对湖羊羔羊生长性能、血清应激指标、免疫球蛋白及炎症因子含量的影响。选用平均体重（20.71±0.70） kg的健康4月龄湖羊公羔50只,随机分为5组,每组10只,均进行8 h的长途运输,运输当天记为0 d。1组为对照组,运输前后饲喂基础饲粮;2组为电解多维组,运输前2 d至运输后7 d在基础饲粮中添加电解多维粉0.375 g/（d·只）;3、4和5组分别为乳酸菌组、γ-氨基丁酸组和新霉素组,运输当天至运输后7 d分别在基础饲粮中添加乳酸菌液4 mL/（d·只）、γ-氨基丁酸粉200 mg/（d·只）和新霉素粉200 mg/（d·只）,并在运输后0、7和14 d对比不同处理缓解运输应激的效果。试验羊在运输前1 d和运输后14 d称重,运输后0、7、14 d采血。结果表明：1）道路运输后羔羊体重的增长率由大到小为电解多维组（20.82%）>新霉素组（17.81%）>乳酸菌组（16.98%）>对照组（15.40%）。2）与对照相比,处理极显著影响了羔羊血清促肾上腺皮质激素（ACTH）含量、乳酸脱氢酶（LDH）活性（P <0.01...     

复方中草药和植物精油替代抗生素对肉仔兔生长性能、腹泻、死亡率及养分表观消化率的影响

为研究复方中草药和植物精油替代抗生素对肉仔兔生长性能、腹泻、死亡率及养分表观消化率的影响，选择体重相近、健康、32日龄左右、体重（693.98±119.57）g肉仔兔48只，公母各半，随机分为4个处理，分别记为抗生素组（基础日粮添加30 mg/kg金霉素+200 mg/kg土霉素，阳性对照组）、精油1组（600 mg/kg复合植物精油1）、精油2组（600 mg/kg复合植物精油2）、中草药组（5000 mg/kg复方中草药），每处理6个重复，每重复2只兔。试验期28 d。结果表明：（1）试验全期（1～28 d）各组平均日采食量（ADFI）、平均日增重（ADG）、料重比（F/G）无显著差异（P>0.05）。（2）试验全期（1～28 d）各组腹泻指数、腹泻频率无显著差异（P> 0.05）。（3）试验前期（1～14 d）各组死亡率无显著差异（P> 0.05），其中精油2组与抗生素的死亡率相同，均为8.33%；试验后期（15～28 d）抗生素组死亡率为16.67%，而精油1组和中草药组死亡率为0.00%；试验全期（1～28 d）各组死亡率无显著差异（P> 0.05），...     

肉鸡饮服“必补-18”的抗应激效果研究(Ⅱ)

本文研究了“必补＿１８”对应激条件下肉鸡的影响。结果表明：“必补＿１８”显著改善了０～３周龄肉鸡的增重、饲料转化率，显著提高了血清γ＿球蛋白水平和成活率，采食量未见有显著改变。５～８周龄肉鸡经历高温３２℃一周，其增重、饲料转化率和采食量均显著下降（Ｐ＜０．０１），饮服“必补＿１８”显著提高了增重和饲料转化率（Ｐ＜０．０１），采食量未见有差异，高温一周过程中，３２℃１６小时血浆皮质酮，Ｔ３先显著下降（Ｐ＜０．０１）、Ｔ４显著升高（Ｐ＜０．０１），３２℃１２０小时时，血浆皮质酮、Ｔ３回升且显著高于常温组（Ｐ＜０．０５），Ｔ４较１６小时显著下降（Ｐ＜０．０１）但仍高于常温组（Ｐ＜０．０５）。在高温条件下饮服“必补＿１８”血浆皮质酮、Ｔ３和Ｔ４呈现与高温对照组同样规律的变化，但这种变化得到显著缓解（Ｐ＜０．０５）     

断奶日龄对仔猪断奶期腹泻和死亡影响的研究

选择杜洛克×豫农白猪Ⅰ系杂交仔猪８窝共７２头，均分为两组，每组４窝３６头。试Ⅰ组采用２８日龄断奶，试Ⅱ组采用３５日龄断奶。试验期从断奶前１周至６０日龄，分析比较不同断奶日龄对仔猪断奶期腹泻和死亡的影响。结果：①试Ⅰ组和试Ⅱ组仔猪，断奶后至６０日龄间发生腹泻１５９头次和８５头次，全群日平均腹泻发生率为１４．７６％和９．０８％；②试Ⅰ组和试Ⅱ组仔猪，断奶后至６０日龄间死亡数为４头和０头；③试Ⅰ组和试Ⅱ组仔猪，断奶后至６０日龄发生腹泻的高峰期在断奶后５～２２天和断奶后３～８天，持续期为１８天和６天，日腹泻发生率最高达４２．４２％和３３．３３％；④试Ⅰ组４窝仔猪在断奶至６０日龄期间，有３窝出现多个腹泻高峰，只有１窝为１个高峰；而试Ⅱ组４窝仔猪中，只有１窝出现多个腹泻高峰，其它３窝为１个高峰。     

喉支康对实验性鸡败血霉形体和大肠杆菌混合感染的疗效

以人工诱发鸡败血霉形体和大肠杆菌混合感染模型，评价复方制剂－喉支康水溶性粉的疗效。按每升水加入20，40，80mg喉支康的用量给病鸡饮水给药，连续5d，对混合感染鸡的治愈率分别是70．0％，93．3％，96．7％，而感染对照组的死亡率为63．3％；上述用药组的增重效果极显著高于感染对照组（P＜0．01）。     

饲粮锌水平对肉鸡血锌、组织锌及含锌酶含量的影响

为研究饲粮中不同锌水平对某些含锌酶活性及血、胰和胫骨锌含量的影响,试验选择1日龄健康AA肉鸡公雏300只,随机分为5个处理组,各处理组锌的含量分别为30、60、90、120、150 mg/kg。结果表明:(1)21日龄时,120、150 mg/kg锌组血锌含量显著增加(P<0.05),与对照组相比,分别提高了56.75%和91.45%;150 mg/kg锌组胰锌含量显著增加(P<0.05),与对照组相比,提高了130.77%;90、120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高14.16%、19.50%和26.61%。42日龄时,150 mg/kg锌组血锌含量显著增加(P<0.05),比对照组提高77.25%;60、90、120 mg/kg锌组胰锌含量显著增加(P<0.05),分别比对照组提高194%、198%和212%;120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高37.80%和43.29%。(2)21日龄时,120、150 mg/kg锌组心肌金属硫蛋白(MT)含量显著增加,分别比对照组提高9.79%和32.17%;90、120、150 mg/kg锌组骨骼肌MT含量显著增加,分别比对照组提高54.55%、57.02%和90.91%。42日龄时,心肌和骨骼肌中的MT含量没有表现出显著的差异。(3)21日龄时,150 mg/kg锌组肝脏铜锌超氧化物歧化酶(CuZn-SOD)活性显著提高,42日龄时,150 mg/kg锌处理组肝脏CuZn-SOD活性显著低于其他处理组。在本试验条件下,饲粮中添加硫酸锌可以显著提高肉鸡血清、胰脏、胫骨组织中的锌沉积,并对肝脏CuZn-SOD活性有一定的影响。     

Efficacy of oseltamivir phosphate to horses inoculated with equine influenza A virus

We investigated the efficacy of the oral administration of oseltamivir phosphate (OP) in horses experimentally infected with equine influenza A virus (H3N8). Nine horses were divided into three horses each of control, treatment and prophylaxis groups. An administration protocol for the treatment group (2 mg/kg of body weight, twice a day for five days) was started immediately after the onset of pyrexia (above 38.9 degrees C). An administration protocol for the prophylaxis group (2 mg/kg of body weight, once a day for five days) was started on a day before viral inoculation. In the treatment group, periods of virus excretion (mean days +/- standard deviation, 2.3 +/- 0.6) and pyrexia (2.0 +/- 0.0) were apparently shorter than those of the control group (6.0 +/- 0.0 and 8.0 +/- 1.0, respectively). In the prophylaxis group, although virus excretion and pyrexia were not prevented, the periods of virus excretion (5.0 +/- 0.0) and pyrexia (4.7 +/- 1.5) were shorter than those of the control group. Moreover, in the treatment and prophylaxis groups, bacterial counts of Streptococcus equi subsp. zooepidemicus known as the common pathogen of secondary bacterial pneumonia in bronchoalveolar lavage fluids collected seven days after inoculation were significantly fewer than that of the control group. The results indicated that the oral administration of OP to horses affected with equine influenza would contribute to reduce the magnitude of virus excretion, pyrexia and consequent secondary bacterial pneumonia.     

The efficacy of an oral treatment with paromomycin against an experimental infection with Giardia in calves

A controlled and blinded study was conducted to evaluate the efficacy and safety of a treatment with paromomycin sulphate against an experimental Giardia infection in calves. Animals were infected with 10(5)Giardia cysts of cattle origin and were either treated 11 days later with 25, 50 or 75 mg paromomycin/(kg body weight per day) during 5 consecutive days or not treated (control group). Efficacy was evaluated based on reduction in cyst excretion. Furthermore weight gain and diarrhea scores were monitored. In the group treated with 75 mg/kg per day there was a 100% reduction in cyst excretion until 9 days after the start of the treatment (D9) and a very high reduction (> or =98%) until D13. There was a high reduction (> or =93%) until D9 and D13 in the groups treated with 25 and 50 mg/kg, respectively. The cumulative cyst excretion on D13 was significantly (P<0.05) lower in the groups treated with 75 and 50 mg/kg compared to the control group. Although there was a trend towards higher weight gain and less diarrhea in the treated groups, differences between groups were not significant. No adverse reactions to the paromomycin treatment were recorded. Furthermore, the need for reliable parameters for evaluation of treatments against protozoal infections is emphasised.     

Efficacy of a milbemycin oxime-praziquantel combination product against adult and immature stages of Toxocara cati in cats and kittens after induced infection

Two studies were performed to examine the efficacy of milbemycin oxime against fourth-stage larvae or adults of Toxocara cati. In the study to determine efficacy against fourth-stage larvae, 20 domestic shorthair cats were inoculated with 500 embryonated eggs. Four weeks after inoculation, the animals were allocated to two groups, and cats in one group were treated with medicated tablets containing 4 mg milbemycin oxime and 10mg praziquantel (MILBEMAX) and cats in the other group with placebo tablets. Seven days after treatment the animals were euthanatized and necropsied for worm counting. The number of worms found was significantly (p=0.0002) lower in cats treated with medicated tablets than in cats treated with placebo tablets. The reduction in the number of worms was 96.53%. In the study to determine efficacy against mature adult worms, 13 kittens were inoculated with T. cati embryonated eggs. On day 45 after inoculation and after the infection had been confirmed through faecal examinations for 11 out of the 13 animals, the 11 infected animals were allocated to two groups and treated as in the first study. Seven days after treatment, all animals were euthanatized and necropsied for worm counting. The number of worms found was significantly (p=0.0043) lower in kittens treated with medicated tablets than in kittens treated with placebo tablets. The reduction in the number of worms was 95.90%. No adverse effects were recorded during either study. It is concluded that the milbemycin oxime-praziquantel tablets that were used are efficacious for the control of T. cati infections in cats.     

Evaluation of fenbendazole as an extended anthelmintic treatment regimen for swine

Fenbendazole was given in the feed to swine at a cumulative dosage of 9 mg/kg of body weight over a period of 3, 6, and 12 days to compare efficacy. Four treatment groups of ten 2- to 3-month-old pigs each, with a mean of 15 kg of body weight per group, received 3 mg of fenbendazole/kg/day for 3 days, 1.5 mg/kg/day for 6 days, 0.75 mg/kg/day for 12 days, and no medication. Medicated feed was scheduled so that all treated pigs reached the last day of treatment on the same day, thus making the time between the last treatment and necropsy equal for all groups. Ascaris suum and Trichuris suis were the target species, their presence before treatment being determined by fecal egg counts and at necropsy by worm counts. At necropsy, 9 control pigs were infected with A suum (mean of 18.0 worms/pig), and all control pigs had T suis infection (mean of 36.5 worms/pig). All 3 treatment schedules were 100% effective in removal of A suum; and for T suis, the 3-day regimen was 100% effective, the 6-day regimen, 99.2%, and the 12-day regimen, 91.0%.     

Efficacy of albendazole for prevention of fascioliasis in sheep

Daily doses of albendazole administered as a premix in the feed for 35 days were effective in preventing Fasciola hepatica infections in 17 sheep in three groups: 5 mg/kg/day (6 sheep) was 100% effective; 3 mg/kg/day (5 sheep) was 98% effective; and 1 mg/kg/day (6 sheep) was 42% effective. Infective cysts were given daily for 5 days during the first week of treatment, treatment was continued an additional 28 days, and sheep were necropsied 14 weeks after final cyst inoculation. There were no visible lesions in any livers of sheep given albendazole at the rate of 5 mg/kg/day or in three of five livers of sheep dosed at the rate of 3 mg/kg/day. Sheep treated with albendazole had a mean weight gain of 2.7 kg, 4.0 kg, and 4.0 kg greater than the controls for the dosages of 1, 3, and 5 mg/kg/day, respectively. Determination of bile duct damage by measurement of serum gamma-glutamyl transpeptidase activity at 9 weeks after final cyst inoculation revealed increases of 3.0X, 1.0X, and 1.1X for the dosages of 1, 3, and 5 mg/kg/day, respectively, and 2.3X for the control, as compared with 7 weeks after final cyst inoculation.     

Evaluation of lasalocid as a coccidiostat in calves: titration, efficacy, and comparison with monensin and decoquinate

Two experiments were conducted to evaluate lasalocid as a coccidiostat in Holstein calves and to compare lasalocid with monensin and decoquinate. In experiment 1, calves in 3 groups (6 calves/group) were each inoculated with 500,000 sporulated oocysts, 88% of which were Eimeria bovis and 12% were E zuernii. Calves in each group were given lasalocid-medicated feed at 0.50 (group 3), 0.75 (group 4), or 1 mg/kg (group 5) of body weight/day for 45 days. Two control groups (6 calves/group) were also evaluated; calves in control group 2 were inoculated and nontreated, and calves in control group 1 were noninoculated and nontreated. At 0.50, 0.75, or 1 mg/kg/day, lasalocid was equally effective in preventing induced coccidiosis (E bovis and E zuernii) in calves. Compared with inoculated nontreated controls, treated calves had significantly (P less than 0.05) fewer oocysts in feces and had fewer clinical signs of coccidiosis from days 16 to 30 after inoculation. Experiment 2 was conducted to compare the effectiveness of monensin, lasalocid, and decoquinate for the prevention of experimentally induced coccidiosis. Calves (n = 48) were allotted into 4 groups (12 calves/group); each was inoculated orally with 275,000 sporulated oocysts, predominantly E bovis and E zuernii, and each was given nonmedicated feed (group 6) or feed medicated with 33 mg of lasalocid (group 7), decoquinate (group 8), or monensin (group 9)/kg of feed for 46 days. Calves given medicated rations had significantly (P less than 0.05) fewer oocysts in their feces and fewer clinical signs of coccidiosis than did calves given nonmedicated rations.(ABSTRACT TRUNCATED AT 250 WORDS)