Exploring the limitations of pathophysiological indicators used for targeted selective treatment in sheep experimentally infected with Haemonchus contortus

Identifying which sheep to treat as part of a Targeted Selective Treatment approach to gastro-intestinal nematode control relies entirely on the efficacy of the indicators. Indicators such as FAMACHA© (anaemia), DISCO (diarrhea) and reductions in weight gains were designed specifically to reflect those sheep experiencing symptomatic consequences of infection. Using the gastro-intestinal nematode Haemonchus contortus as a model species, this study explored the utility and sensitivity of these indicators under controlled experimental conditions on 63 adult sheep. The potential effect of sheep with different H. contortus resistance phenotypes on indicator efficacy was compared in three different phenotypes, i.e. high (Blackbelly females), medium (Blackbelly rams) and low resistance (Romane rams). The potential effect of the H. contortus isolate on indicator efficacy was also explored by using four different isolates, with varying anthelmintic resistance capacities, to infect the sheep. We limited the study to the first month of infection to evaluate the interest of these indicators as an early predictive means for controlling infection. The pathophysiological indicators FAMACHA© and DISCO do not reflect infection intensity based on Faecal Egg Counts, nor do reductions in weight gains. FAMACHA© was however a good indicator of anaemia with strong correlations to haematocrit. There was little agreement among the three indicators to identify the same animals in need of treatment and even combining them did not increase their predictive value of infection intensity or relative host damage from infection. The indicator sensitivity was influenced by the H. contortus isolate and sheep resistance phenotype in which they were tested. One isolate was poorly infective but induced high levels of anaemia (FAMACHA©) and diarrhea (DISCO) compared to the three others. The FAMACHA© and DISCO had higher values in the sheep group with a medium resistance phenotype (Blackbelly rams) indicating higher levels of damage compared to the high and low resistance phenotypes. We conclude that there is no ‘one size fits all’ approach to the use of indicators for Targeted Selective Treatment and the indicators should be calibrated to farm-specific conditions to increase their efficacy.     

浅析猪舍通风设计与靶向通风介绍

文章分析了目前在猪场设计中常用的几种通风模式的优缺点，指出了猪舍通风需要解决的问题和方法。并提出了靶向通风系统在猪舍特别是楼房猪舍通风中的应用。提出靶向通风可以很好地解决目前楼房猪舍中存在的空气过滤和除臭两个问题。     

Nematode control in suckler beef cattle over their first two grazing seasons using a targeted selective treatment approach

Background

With concerns over the development of anthelmintic resistance in cattle nematode populations, we must re-examine our approach to nematode control in cattle. Targeted selective treatments (TST), whereby individual animals are treated instead of entire groups, are being investigated as an alternative. The study objective was to determine if anthelmintic usage could be reduced using a TST-based approach to nematode control in spring-born suckler beef cattle over their first and second grazing seasons (SGS) without affecting performance. In the first grazing season (FGS), 99 calves with an initial mean (s.d.) calf age and live weight on day 0 (June 28^th 2012) of 107 (23.1) days and 160 (32.5) kg, respectively, were used. The study commenced on day 0 when calves were randomised and allocated to one of two treatments; 1), standard treatment (control) and 2), TST. Control calves were treated subcutaneously with ivermectin on days 0, 41 and 82 in the FGS. All calves were treated with ivermectin on day 124 and housed on day 133. In the SGS, only heifer calves from the FGS were used and control heifers were treated with ivermectin on day 393. Animals were weighed, blood and faecal sampled every three weeks. The TST animals were treated with ivermectin if thresholds based on a combination of plasma pepsinogen concentrations, faecal egg count and/or the presence of Dictyocaulus viviparus larvae in faeces (FGS only) were reached.

Results

No TST calves reached the treatment threshold criteria in the FGS. The FGS average daily live weight gain (ADG ± s.e.m.) for control and TST group calves was 0.89 ± 0.02 kg and 0.94 ± 0.02 kg day⁻¹, respectively (P = 0.17). In the SGS, all heifers were treated with ivermectin on day 431 due to clinical signs of respiratory disease. The ADG for control and TST heifers from turnout on day 321 to day 431 was 0.90 ± 0.04 and 0.80 ± 0.04 kg day⁻¹, respectively (P = 0.03).

Conclusions

Spring-born FGS suckler beef calves require minimal anthelmintic treatment to maintain performance. In contrast, clinical parasitic disease may develop in the SGS unless appropriate anthelmintic treatment is provided.     

秸秆处理方法的研究进展

作者主要论述了现阶段秸秆处理的主要方法,从物理、化学和生物处理3个方向进行了阐述,分析了优劣,为秸秆的综合利用提供方法,并结合文献进一步提出了未来秸秆综合利用的方向。     

帕金森病的治疗进展

帕金森病(Parkinsondisease,PD)是以中脑黑质多巴胺能神经元的变性与消失及纹状体中多巴胺(Dopamine,DA)水平降低的一种疾病,长期困扰着中老年人,虽然病因比较明确,但目前还没有一种特别的治疗方法或药物能彻底根治PD。本文就PD治疗以及神经营养因子的应用等方面作了简要的阐述。     

提高秸秆饲料营养价值的方法

主要综述提高秸秆饲料营养价值的化学处理方法、物理处理方法和生物学处理方法等。     

一例犬耳血肿的诊治

耳血肿多发生在耳郭内侧,偶尔也发生在外侧。就1例犬耳血肿病例,阐述了其治疗、护理的过程,以期为该病的诊治提供参考。     

实蝇检疫处理的研究进展

主要对实蝇的检疫处理方法作简要介绍.同时对各种处理方法的利弊进行了简要分析,并对检疫处理技术的发展进行了思考与展望.     

Risk factors associated with bacteriological cure, new infection, and incidence of clinical mastitis after dry cow therapy with three different antibiotics

Factors affecting bacteriological cure rates (BCR) and new intramammary infections (IMI) during the dry period as well as clinical mastitis (CM) during early lactation were investigated in 414 German Holstein dairy cows receiving dry cow therapy. Cows were treated with either benethamine benzylpenicillin (300,000 IU), penethamate hydriodide (100,000 IU), and framycetin sulphate (100 mg, n = 136), or cefquinome (150 mg, n = 135), or benzathine cloxacillin (1,280 mg, n = 143). Overall BCR, IMI, and CM at parturition were 86.4%, 20.7%, and 4.3%, respectively. The three antibiotic treatments differed only in BCR, with cloxacillin yielding better results than the others. Udder quarters from cows with > 4 lactations had a higher risk of IMI and CM at calving. Chronic changes in udder tissues were linked to a lower BCR and were associated with a higher risk of CM during early lactation. The risk of CM at calving was higher in udder quarters with unspecific or subclinical mastitis before drying off. In conclusion, with antibiotic dry cow therapy, age and health status of the udder appear to be major determinants of IMI and CM during the dry period and early lactation, while BCR was associated with the antibiotic type and udder tissue status.     

Effect of Cooking on Residues of the Quinolones Oxolinic Acid and Flumequine in Fish

Steffenak, I., V. Hormazabal and M. Yndestad: Effect of cooking on residues of the quinolones oxolinic acid and flumequine in fish. Acta vet. scand. 1994,35,299-301.– The effect of cooking on residues of the quinolones oxolinic acid and flumequine in fish was investigated. Salmon containing residues of oxolinic acid and flumequine was boiled or baked in the oven. Samples of raw and cooked muscle, skin, and bone, as well as of the water in which the fish was boiled and juice from the baked fish, were analysed. Oxolinic acid and flumequine did not degrade at the temperatures reached when cooking the fish. However, fish muscle free from drug residues may be contaminated during boiling and baking due to leakage of the drug from reservoirs in the fish.     

Description of a technique for orthograde endodontic treatment of equine cheek teeth with apical infections

An orthograde endodontic method, similar to that used in human dentistry, is described for use on endodontically diseased permanent cheek teeth in horses. The technique has been adapted to meet the anatomical and physiological differences between hypsodont and brachyodont teeth and is performed in sedated horses. The techniques of debriding the pulp cavity and use of dental materials which fulfil the requirements for equine teeth are presented here. The results of this technique appear to be promising but have yet to be evaluated in a peer‐reviewed study. By using orthograde endodontic therapy on sedated horses it is now possible to save endodontically diseased permanent cheek teeth.     

马骡便秘疝临床诊断与治疗

本文在总结多年临床经验的基础上，具体论述了针对马骡便秘疝的临床综合诊断方法，提出了以掏结、捶结为主，配合投给泻药和补液强心等治疗措施的治疗方案。     

A REVIEW OF TREATMENT PLANNING AND DOSE CALCULATION IN VETERINARY RADIATION ONCOLOGY

Because radiation cell killing follows Poisson statistics, radiation dose response curves for tumors and normal tissue response are sigmoidal in shape. This shape implies that small errors in delivery of radiation dose can result in large changes in the probability of normal tissue necrosis or tumor control. Thus it is important for veterinarians involved with radiation oncology to be familiar with the basic aspects of radiation physics and dose calculation as they relate to radiation therapy. In this paper, we present a review of pertinent physics and treatment planning relative to orthovoltage and cobalt irradiation. The usefulness of radiation treatment planning computers is emphasized for improving the radiation oncologist's knowledge of dose distribution and selection of the optimum treatment plan.     

低精料水平下氨化微贮稻草育肥西镇牛试验研究

本试验以广泛分布于秦巴山区的西镇牛为研究对象，进行低精料水平下稻草经不同处理舍饲饲养试验。结果表明，稻草经过氨化、微贮加工可提高牛采食量、日增重，提高饲料转化率。氨化、微贮组日增重较干稻草组分别提高124％和l11％。在低精料水平下饲喂氨化、微贮稻草能显著提高经济效益。试验90d，氨化组较干稻草组每头牛增收94元。     

畜禽养殖废水脱氮除磷研究进展

笔者介绍了SBR、上流式活性污泥床、fiehl prototype工艺等几种目前国内外较典型的集约化养殖场废水处理方法,比较了它们在脱氮除磷方面的优缺点及其应用和研究情况,简述了畜禽养殖废水脱氮除磷现状.最后对畜禽养殖废水脱氮除磷存在的问题进行了探讨,同时对其发展趋势进行了展望.     

极端干旱区骆驼刺对水氮条件变化的生长响应

采用盆栽试验,研究了不同水氮处理下骆驼刺（Alhagi sparsifolia）的形态特征、生物量累积和分配特征,并探讨了适合骆驼刺生长的最佳水氮条件。经过2年的水氮处理发现,水分和氮素处理对骆驼刺的株高、冠幅、基茎、地上和地下生物量累积均有显著影响,对生物量分配还存在着明显的交互作用,但在不同生长年份影响也不同。在第1个生长年份,综合评价结果为干旱低氮（田间持水量30%~35%,施氮51 mg N·kg^-1）处理下生长表现最好,主要表现在株高、基茎、根系生物量和根冠比均有明显增加。在第2个生长年份,则为中水中氮处理（田间持水量60%~65%,施氮102 mg N·kg^-1）下综合生长表现最好,主要表现在地上、地下生物量和根冠比均有显著增加。因此,在骆驼刺幼苗生长早期应推荐干旱低氮处理,随株龄增加则为中水中氮处理更合适。