伊维菌素与左旋咪唑对犊牛新蛔虫病的疗效对比试验

将30头犊牛新蛔虫病阳性牛随机分为2组,分别投以伊维菌素和左旋咪唑进行驱虫,采集投药后7d、14d、21d犊牛的粪便进行虫卵检查,以对比2种药物对犊牛新蛔虫的驱除效果。试验结果表明,伊维菌素与左旋咪唑对犊牛新蛔虫病具有相同的驱虫效果,用药后21d实验室虫卵检出率为0,说明2种药物对犊牛新蛔虫病的疗效无明显差异(p>0.05)。     

牛场要重视犊牛新蛔虫病的防治

石阡县汤山镇某牛场有能繁母牛80头(水母牛20头、黄母牛60头),年产犊牛70余头。自2003年以来新生犊牛死亡严重,6月龄时年均成活率只有70%,经济损失较大。2006年2月该场犊牛病死就达5头之多,笔者前往就诊。1临床症状该场现有6月龄以下犊牛45头,多数表现营养不良、精神委顿、被毛粗乱,有的腹泻呈白色稀便或血便,腥臭,其他生理指标无显著变化。经当地兽医按肠炎治疗收效不大,死亡依然严重。2剖检变化剖检病死的2月龄黄牛犊一头,小肠内牛新蛔虫68条,小肠呈严重蛔虫性炎症,便稀、恶臭,全身肌肉、可视粘膜苍白呈严重贫血。该牛犊为牛新蛔虫病死亡…     

黔西县城关犊牛新蛔虫病的感染调查及治疗经验

犊牛新蛔虫病的病原体为无饰科牛新蛔虫(NeoaHcearis rieulorum),寄生于犊牛小肠内引起发病,严重影响犊牛发育。为了弄清本病的流行情况及治疗方法,对黔西县城关镇及其附近的甘棠、纸厂和谷里区的六个乡镇、16个村民组的52头犊牛(黄牛犊13头、水牛犊39头)进行了粪检,检出率为36.5%,其中1—7日龄的感染率最高,占66.6%,可见本病生前感染较为严重,即新蛔虫侵袭性虫卵感染怀孕中后期母牛后,经胎盘进入胎体内发育而     

不同药物组合对山羊肝片吸虫及消化道线虫驱除效果的试验

作者应用4组不同药物对放牧的浏阳黑山羊进行了驱虫试验，结果表明：应用硝碘酚腈 左旋味唑组(Ⅰ组)，以及硫双二氯酚 左旋咪唑组(Ⅱ组)肝片吸虫和线虫减卵率均为100％，剖检查虫肝片吸虫和线虫均为阴性。应用硝氯酚 驱虫精组(Ⅲ组)肝片吸虫和线虫减卵率分别为90.5％和81.0％，剖检查虫肝片吸虫为阴性，线虫18条。应用肝蛭净 驱虫精组(Ⅳ组)肝片吸虫和线虫减卵率分别为59.1％和91.6％，剖检查虫肝片吸虫和线虫分别为12条和6条。因而认为Ⅰ组与Ⅱ组的药物组合对驱除山羊肝片吸虫及消化道线虫效果较好。     

江西省抚州市人群蛔虫和猪蛔虫感染调查

为了解江西省抚州市人群蛔虫和猪蛔虫感染情况,及时掌握蛔虫病的流行动态,为蛔虫病的防控提供依据。用直接涂片法对该市幼儿园、低年级小学生、大学生、村民1 619例人群粪样进行显微镜检,猪蛔虫感染调查是在抚州市孝桥屠宰场收集25头猪的肠内容物。1 619例人群粪样中,5例为蛔虫卵阳性,且阳性样本均在幼儿园和低年级小学生群体检出,人群蛔虫感染率为0.31%。共收集到猪蛔虫198条,其性比为0.664,被检的25头猪荷虫数为1~16条,平均荷虫数为7.92条,最适荷虫数为每头猪7~10条。江西省抚州市人群蛔虫感染率已明显下降,但猪蛔虫的防控应引起重视。     

云南贯众化合物2对猪蛔虫驱除作用效果观察

考察云南贯众化合物2对猪蛔虫驱除作用。以感染虫卵量约为6×105个/头的自然感染蛔虫病猪作为试验动物,试验过程中每天观察其临床表现,并于感染后2个月对粪便进行蛔虫卵检查和记数,60 d后粪检虫数达7 000个/g则可作为猪蛔虫病模型的供试动物;云南贯众化合物2作为供试药物。结果表明,云南贯众化合物2驱除猪蛔虫作用效果明显,且具有吸收分布快、消除缓慢和生物利用率高等特点,其驱虫效果确实可靠。     

一例犊牛蛔虫病的诊治与体会

一养牛户犊牛出现下痢,排灰白色稀粪,引发1头犊牛死亡。经现场调查,观察临床症状、剖检病理变化、实验室鲜粪检查等方法分析,确诊为牛群蛔虫感染,发生犊牛蛔虫病。采取综合防治措施,取得良好治疗效果。并对犊牛蛔虫病的预防、诊治方法进行总结。     

依威咪克亭(Ivermectin)对犊牛胎生网尾线虫等的驱虫试验

本试验选择自然感染肺园虫及胃肠寄生虫的12头乳牛犊作驱虫试验:6头用依威咪克亭(Ivermectin),按200μg/kg的剂量皮下一次给药;另8头只给予赋形药。治疗后7日进行剖检时,治疗组均未分离到肺园虫,而对照组每头都感染肺园虫1—46条。该药对奥氏奥斯特他线虫成虫的驱虫效力为99％,能全部驱除少量存在的第四期奥斯特他线虫、毛园线虫及成熟的艾氏毛园线虫。从治疗牛犊的粪便虫卵计数中看出,除少数细颈线虫外,可驱除全部胃肠寄生虫。有1头犊牛于治疗后在注射部位出现短时疼痛,另1头则于剖检时发现注射部位轻度硬结。     

水牛犊新蛔虫病的综合防治

犊牛蛔虫病的病原体为无饰科新蛔属的犊牛蛔虫,寄生于5月龄内的犊牛小肠而引起的疾病。笔者参加了南涧县公郎镇、南涧镇、宝华镇、无量山镇等地5月龄以内的水牛犊新蛔虫病感染情况抽样检查。共检查水牛犊96头,检出感染犊新蛔虫的水牛犊18头,感染率为18.75%,结果反映南涧县水牛犊新蛔虫病感染率高,由此提出相应的防治措施。     

犊牛大肠杆菌病的防治

本文主要介绍了犊牛大肠杆菌病的病原、流行特点、症状、剖检病变和诊断,并提出加强妊娠母牛、哺乳犊牛的饲养管理,改善产房、牛舍的环境卫生,注意产房和牛舍的防寒保暖工作等措施,有效防控犊牛大肠杆菌病的发生。     

Effect of ivermectin on performance of beef cattle on Georgia pastures

A total of 469 cows and calves from 2 herds, each on 6 pastures, was used to evaluate the anthelmintic efficacy and animal-performance benefits of ivermectin given subcutaneously at a dosage of 200 micrograms/kg to nursing beef calves and their dams during a grazing season. Pastures were paired across the 2 herds. Three pasture groups from 1 herd were randomly assigned to either a nonmedicated control or to a medicated group. Treatment assignments were reversed in the other herd. The control groups comprised 110 cows and 108 calves, whereas 127 cows and 124 calves were treated with ivermectin (200 micrograms/kg). The cows were treated once, in late spring, and the calves were treated twice, once in late spring and again in midsummer. Cattle from one herd were weighed on days - 12, 21, 49, 77 (day of 2nd treatment for calves), and 105, and the other herd was weighed on days - 6, 23, 57, 86 (day of 2nd treatment for calves), and 113. Rectal fecal samples for nematode egg counts were obtained from approximately 25% of the cattle in each pasture on weighing days; usually, the same cattle were sampled each time. Calves treated with ivermectin gained (P less than 0.05) more weight than control calves up to the 2nd treatment date and up to the termination of the study. There was no significant difference between treated and control cows, with regard to weight gain over either interval. Treated calves had fewer positive fecal egg counts (P less than 0.01) and passed fewer eggs (P less than 0.05) after both treatments than did control calves. There were no differences in either number of eggs or number of negative cows between treatment groups. Adverse reactions attributable to treatment were not seen.     

Effect of a single strategically timed dose of fenbendazole on cow and calf performance

A 168-day study was conducted to evaluate the effect of a strategically timed treatment with fenbendazole on anthelmintic efficacy and performance of beef cows and calves. Eight groups of 10 Angus cow/calf pairs were allotted on 7 May 1987 to eight similarly managed 4.86-ha pastures (bermudagrass/tall fescue) on the basis of cow age, and calf sex and weight. At that time, four groups of cows received a dose of fenbendazole (5 mg kg-1) with their calves receiving fenbendazole at the same dosage 28 days later. Treated calf average daily gain (ADG) was 0.04 kg greater (P less than 0.05) than control calves (0.82 vs. 0.78 kg) during the 168-day study. Treated cow ADG was 0.09 kg greater (P less than 0.05) than control cows (0.40 vs. 0.31 kg). Although there was a reduction (P less than 0.05) in fecal egg counts following treatment of the cows, the numbers of eggs generally were low compared with egg counts of calves. From Day 28 through Day 112 post-treatment, fecal egg counts of treated calves were lower (P less than 0.05) than those of control calves. However, fecal egg counts from treated calves increased post-treatment until there were no differences (P greater than 0.05) between treated and control calves at the end of the study. The pregnancy rate tended to be higher (P = 0.12) for treated cows (98%) than for untreated control cows (75%). The actual calving rate was higher (P = 0.03), for treated cows (90%) than for untreated control cows (68%). Results indicated that a strategic anthelmintic treatment can improve cow and calf performance, but that calves born in late winter or early spring may need more than one therapeutic dose during the nursing period on pasture.     

Supplementation of suckling beef calves with different levels of crude protein on tropical pasture

The effects of supplementation with different levels of crude protein on performance, intake and nutrient digestibility and efficiency of microbial protein synthesis in suckling beef calves on pasture were assessed. Fifty-five calves, with an average age of 100 days and an initial average body weight of 110?±?7.5 kg and their respective dams, were used. The experimental design was completely randomised with five treatments and 11 replications. The experimental treatments for calves were as follows: control = calves received only mineral mixture; supplementation levels = calves received supplement containing 8, 19, 30 or 41 % of crude protein (CP, at a rate of 0.5 % of body weight (BW)). The cows received only mineral mixture ad libitum. Supplemented calves had higher (P?<?0.1) average daily gain (ADG). Protein levels showed a quadratic effect (P?<?0.1) on average daily gain (ADG) of calves. There was no difference in total dry matter (DM) intake (P?>?0.1). However, intake of dry matter forage (DMF) presented cubic profiles (P?<?0.1), with CP levels in the supplements. Supplementation increased (P?<?0.1) the digestibility of nutrients, except for the digestibility of neutral detergent fibre. Supplementation increased (P?<?0.1) the production of microbial nitrogen and N losses in urine. It can be concluded that multiple supplementations optimise the performance of beef calves on creep feeding. The intake of supplements with CP levels between 8 and 30 % partially replaces of the pasture ingested by calves and increases the digestibility of the diet.     

Composition and Nutrient Deficiencies of Arkansas Forages for Beef Cattle

A database was compiled to determine the nutrient composition, variability, and nutrient deficiencies of 11,592 forage samples (10,246 hay, 1,001 pasture, and 345 silage) collected from 1985 to 1999. Samples were analyzed for 1 to 15 nutrients: DM, N, ADF, NDF, P, K, Ca, Mg, Na, S, Fe, Mn, Zn, Cu, and Se. Mean (±SD) CP and TDN levels (% DM) of bermudagrass, fescue, and mixed grass (blends of bermudagrass, fescue, orchardgrass, ryegrass, and cheat) hays were 12.4 ± 3.5, 60.0± 6.2; 11.2± 3.0, 53.8± 4.7; and 11.1 ± 3.1, 52.9± 4.7, respectively. For beef cows and calves, TDN was deficient in a greater percentage of hays (P < 0.05) than was CP. Bermudagrass hays contained greater levels of CP and TDN than fescue or mixed grass hays (P < 0.05). Fescue and mixed grass hays did not differ (P > 0.05) in CP, ADF, NDF, or TDN concentrations. Only 6 to 10% of the hays analyzed for Na contained adequate levels for beef cows and calves. Selenium, Cu, and Zn were deficient in 62, 52, and 41% of the hay samples, respectively. For lactating beef cows, a lesser percentage of the hays were deficient in P (16%), Ca (7%), Mg (30%), and S (8%). Iron, Mn, and K were deficient in 2% or less of the hays. Bermudagrass, corn, and sorghum-sudan silages contained greater (P < 0.05) levels of TDN than silages composed of fescue, mixed grass, ryegrass, sorghum silage types, or wheat. With the exception of bluestems and orchardgrass, the pasture samples contained greater concentrations of CP and TDN than the same forage species harvested as hay. In general, forages were highly variable in nutrient content, and most hays were deficient in one or more nutrients for beef cattle.     

Evaluation of the parasitological and production responses of a cow/calf operation to an anthelmintic program with ivermectin

The efficacy of a treatment schedule using ivermectin, given subcutaneously at the rate of 200 micrograms kg-1, to control gastrointestinal parasitism and its effect on liveweight gains was assessed. Two herds with a total of 466 Hereford X Brangus cow/calf pairs were used. Each herd was on six pasture plots of comparable size, stocking rate, and quality and quantity of forage. Pasture groups were paired across the two herds. Pasture groups from one herd were randomly assigned to nonmedicated control and the other three to ivermectin treatment. Treatment assignments per pasture group were reversed in the other herd. The control group contained 118 cows and 112 calves and the medicated group 121 cows and 115 calves. Cows were treated in early July and the calves in late July or early August. Cattle from one herd were weighed on Days -28, 0 (day of cow treatment), 30 (day of calf treatment), 58, and 86, while the other herd was weighed on Days -29, 0 (day of cow treatment), 27 (day of calf treatment), 61, and 89. Day 0 was not the same calendar day for the two herds. Fecal samples for parasite egg counts were obtained from the rectum on weight days from five cows and six calves from each pasture; in most cases the same cattle were sampled each time. Calves treated with ivermectin gained (P less than 0.05) more weight than control calves between day of treatment for cows and the end of the trial.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of a once-daily suckling program on gastrointestinal parasitism in Angus cows and calves

Over a 2-year period involving a total of 168 Angus cows and their calves, 2 studies were conducted to evaluate the effect of once-daily suckling on cow reproduction, calf growth, and gastrointestinal parasitism. Experiment I compared 2 restricted suckling (RS) groups with 1 normal suckling (NS) group. Each group consisted of 24 cows with their calves (24 cows-calves/group = 24 cows and 24 calves/group). In the RS groups, suckling by the calves was restricted to once a day for 45 days, and then the calves were allowed to suckle normally throughout the remainder of the experiment. In the NS group, the calves suckled normally throughout the experiment. Experiment II compared 2 groups of RS cow-calves (24 cow-calves/group) with 2 groups of 24 NS cow-calves/group. In experiment I, there were no differences (P less than 0.05) in pregnancy rate or in the average number of nematode eggs/g of feces (epg) between the cows from the 2 treatment groups. The RS calves consistently had higher epg counts than did the NS calves during the 45 days of RS (169 vs 62 epg, P less than 0.05) and from the time of their return to pasture until weaning (266 vs 186 EPG, P = 0.27). The RS calves also had a higher average coccidia oocyst count during the RS period only. In experiment II, RS cows had a higher pregnancy rate (87.6% vs 66.0%, P less than 0.05) and a shorter postpartum interval (83 vs 101 days, P less than 0.05) than did NS cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of trainer animals to improve performance and health of newly arrived feedlot calves

Four trials were conducted to determine the efficacy of using trainer animals to improve the health and performance of newly arrived feedlot calves. For all trials, trainer animals were given 3 wk to adapt to the feedlot before arrival of the feeder calves and initiation of the trials. Trainer animals were present with newly received feedlot calves for 14 d after arrival and then were removed from the pens for the remaining 14 d of the experiments. In Trial 1, trainer animals were six crossbred beef steers and six mature cull beef cows. Newly received calves were allotted to 18 pens with 10 calves/pen. Six pens contained a trainer steer and six pens contained a trainer cow. Similar procedures were used for the subsequent three trials, except 12 trainer cows and 24 pens were used, and in Trial 4 half of the calves were allotted to pasture paddocks for 14 d before placement in their feedlot pens. During wk 1 of Trial 1, calves with trainer cows and steers gained weight more rapidly (P < .10) than those without a trainer animal (1.12 vs .67 kg/d, respectively). During wk 2, this trend was reversed and overall gains did not differ (P > .20) among treatment groups. Morbidity was 16.7 for control calves, 28.3% for calves with trainer steers, and 8.3% for calves with trainer cows. Four of six trainer steers required antibiotic treatment for respiratory disease. On d 1, a greater (P < .05) percentage of calves in the trainer cow group (81.7%) were observed eating during the first 30 min after feeding compared with either the steer trainer group (60%) or the control group containing no trainer animal (48.3%). This trend continued on d 2 but was not evident on d 3 or 7. In Trial 2, overall gains were 10% greater (P < .06) and final BW was higher (P < .01) for calves with trainer cows than for those without trainers. Trainer cows resulted in a substantial reduction (P < .01) in calf morbidity compared with calves housed alone. In Trial 3, trainer cows did not improve performance or health of newly received calves. More (P < .07) calves with trainers than without were eating 5 min after feeding on d 1, 2, 4, and 8. In Trial 4, the presence of trainer cows the first 2 wk did not affect (P > .27) gains. However, calves placed on pasture after arrival had lower (P < .03) gains during wk 1 than those housed in the feedlot. Calves placed in pasture paddocks upon arrival had more than twice (P < .01) the incidence of morbidity of those placed directly in the feedlot. In these trials, trainer cows had a significant effect on eating behavior of newly received calves, but health and performance benefits were variable.     

4. The development of a production system for beef animals on cenchrus ciliaris pasture

The results obtained in the first season of a five‐year project to develop a production system for a breeding herd of beef animals, are presented. The trial area consisted of 30 ha of Cenchrus ciliaris pasture growing under dryland conditions in the Northern Transvaal. The pasture provided 8 500 grazing days for 30 cows and their calves. In addition 80,7 tonnes of hay were made of which 42,4 tonnes were fed to the cows in the winter. Bull calves gained 0,826 kg per head daily and heifer calves gained 0,777 kg.     

The effect of turn-out to pasture on blood plasma iron concentrations in beef cattle

Beef cows, bred to calve in the spring, were housed indoors over the winter. On May 25, 48 of the cows, and their calves, were put out to pasture while the other 24 cows and calves remained confined.Plasma iron concentrations in the pasture cows were higher (P<0.01) than the levels of the barn cows for several weeks after turn-out, but in September there was no difference (P>0.05). In contrast, the pasture calves showed significantly lower (P<0.01) levels than did the barn calves during the first two weeks, however, there was no difference (P>0.05) in September. No difference in plasma iron levels between male and female calves was found.     

Vigilance in Cattle: The Influence of Predation,Social Interactions,and Environmental Factors

Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% ± 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% ± 0.46%) as those without calves (2.0% ± 0.27%). Single cattle and groups of two to five exhibited higher vigilance rates (4.2% ± 0.79%) than groups of six to 20 (2.5% ± 0.32%) and groups of > 20 (3.0% ± 0.41%). Cattle in groups of > 20 increased vigilance as visual obstruction increased. Mother cows whose calves were preyed upon (n = 5) exhibited a 3% to 48% increase in vigilance within 3 d after their calves were killed; this rate returned to near baseline levels after 10 d. Conversely, mother cows reduced foraging after their calves were killed from 88.5% ± 1.69% to 43.5% ± 11.4%; foraging rate also returned to near baseline levels after 10 d. Cattle exhibit vigilance at lower levels compared to wild ungulates, but this behavior appears to be at least partially an antipredatory behavior. Our findings provide support that predators can influence cattle behavior.