The repeatability of faecal egg counts in Polish Wrzosówka sheep

The number of nematode eggs in the faeces was estimated in Polish Wrzosówka sheep, in the spring and autumn of 1993 and again in 1994. The sheep had been naturally infected. The dominant species were Haemonchus contortus and Teladorsagia circumcincta, but Trichostrongylus spp., Cooperia curticei, Nematodirus spp. and Chabertia ovina were also present. Anthelmintics were not used. Egg counts were skewed, with a range of 0–4100 eggs g⁻¹ (EPG); most sheep had egg counts below 100 EPG. Egg counts were approximately four times higher in spring than in autumn. Repeatability values within a season were all significant and positive. The repeatability of egg counts between seasons was estimated from the correlation between the mean transformed value in spring and in autumn, and was 0.52 in 1993 (P < 0.001) and 0.41 in 1994 (P < 0.05). The results show that animals with higher than average values in spring are likely to have higher than average values in autumn, and suggest that similar mechanisms regulated egg counts in both seasons even though egg counts were much lower in autumn.     

Genetic parameters for strongyle and Nematodirus faecal egg counts in lambs and their relationships with performance traits

Genetic resistance to the gastro-intestinal parasites of lambs can contribute to sustainable systems of parasite control with associated benefits for health and welfare. This study reports estimates of the genetic parameters of strongyle egg counts (FEC), Nematodirus egg counts (NEM), faecal consistency scores (FCS) and their associations with growth and ultrasonic measurements of muscle (UMD) and fat (UFD) depths in lambs. The lambs were the progeny of 45 Bluefaced Leicester sires from Scottish Blackface and Hardy Speckled Face dams. Faecal samples were taken from lambs at 10, 14, 18, 22 and 26 weeks of age, giving 1024 to 3055 records per trait. Live weight was recorded for all lambs at 16 weeks and live weight, UMD and UFD were recorded in female lambs at 28 weeks. Mean FEC and NEM were significantly higher for twin versus single reared lambs, for male castrate versus female lambs and for the offspring of Scottish Blackface versus Hardy Speckled Face ewes. Heritability estimates for FEC were low (0.04 ± 0.02 to 0.20 ± 0.08) and showed a non-significant trend to increase with age. The phenotypic correlations between measures of FEC at different ages were low (0.06 to 0.34) but genetic correlations were not significantly different from one in most cases. Heritability estimates of NEM ranged from 0.05 ± 0.03 to 0.09 ± 0.05 and genetic correlations among counts at different ages were not significantly different from zero. FEC and NEM were strongly correlated genetically (0.62 to 0.93) and estimates of the genetic correlations between FEC and NEM with live weights (− 0.36 to 0.23), UMD (− 0.35 to 0.25) and UFD (0.08 to 0.55) were variable in sign, though not significantly different from zero. Heritability estimates for faecal consistency scores (FCS) were 0.06 ±0.03 to 0.11 ± 0.04, with strong genetic correlations between successive measures. FCS was not significantly correlated with FEC or lamb performance traits. It is concluded that selection for reduced strongyle egg counts in lambs at around 5–6 months of age will give favourable correlated responses in NEM in lambs, with limited correlated response in lamb performance or faecal consistency scores.     

Accuracy and Precision of Mini-FLOTAC and McMaster Techniques for Determining Equine Strongyle Egg Counts

The use of fecal egg count techniques to indirectly assess intestinal parasite burdens and determine anthelmintic efficacy is common in parasitological research and veterinary practice. The McMaster method is one of the most widely used techniques in veterinary practice, but recently, the Mini-FLOTAC technique has been introduced as a possible alternative. Studies comparing the two methods in precision and accuracy are needed. This study aimed at evaluating the Mini-FLOTAC technique for determining equine strongyle egg counts through a two-part procedure. First, a set of fecal counts was executed using both methods. Next, blind counts were performed on spiked fecal samples with true egg counts at 0, 5, 50, 500, and 1,000 eggs per gram. All counts were performed in triplicates, and each sample was counted using both methods. Mini-FLOTAC and McMaster had 83.2% and 53.7% precision, respectively. The accuracy was found to be 42.6% and 23.5% for Mini-FLOTAC and McMaster, respectively. In conclusion, this study found that Mini-FLOTAC exhibited both higher precision and accuracy than the McMaster technique and appears to be a more reliable alternative. Using a more precise egg-counting method can help assure that changes in egg counts before and after treatment reflect a genuine reduction and are not due to chance variability.     

Novel insights into the pathogenic importance,diagnosis and treatment of the rumen fluke (Calicophoron daubneyi) in cattle

Recently, sharp increases in the prevalence of rumen fluke infections have been recorded throughout Western Europe. However, scarce information is available on the diagnosis, pathogenic importance and control of this parasite. We undertook 3 pilot studies to gain more insights into these aspects of rumen fluke biology in cattle. First, we evaluated the diagnostic performance of mini-FLOTAC to detect adult rumen fluke infections based on faecal egg count in an abattoir survey and found high sensitivity (0.94) and specificity (0.98). Moreover, there was an association between ruminal fluke burden (assessed by visual scoring) and faecal egg count and a cut-off of 200 eggs per gram is proposed to detect highly infected animals (>200 flukes present in the rumen and/or reticulum). There was also a significant association between ruminal fluke burden and faecal consistency. However, in a second study, we performed a case-control field survey to investigate the association between rumen fluke infection and herd-level problems with diarrhoea and no association was found. Finally, we evaluated the use of closantel (Flukiver^®, Elanco Animal Health, subcutaneous administration at 10 mg/kg) to treat rumen fluke infection on 3 herds, but no significant reduction in egg output post-treatment was found. Because this result is in contrast with a previous study using an oral dose of closantel, more research is required into the effect of administration route on the efficacy of closantel on rumen fluke.     

A quantitative trait locus for faecal worm egg and blood eosinophil counts on chromosome 23 in Australian goats

Three microsatellite markers on goat chromosome 23 adjacent to the MHC were used to test for quantitative trait loci (QTL) affecting faecal worm egg count (WEC) and leukocyte traits in ten Australian Angora and twelve Australian Cashmere half‐sib families (n = 16–57 per family). Data were collected from 280 Angora and 347 Cashmere kids over a 3‐ and 4‐year period. A putative QTL affecting trichostrongyle WEC was found in two small families at the 5% chromosome‐wise threshold level. The biggest QTL effect for WEC of 1.65 standard deviations (σ_p) was found within the region of OarCP73‐BM1258. A significant QTL affecting blood eosinophil counts at the 1% chromosome–wise threshold level was detected at marker BM1258 (at 26 cM) in two Angora and Cashmere families. The magnitude of the putative QTL was 0.69 and 0.85 σ_p in Angora and Cashmere families, respectively. Due to the comparatively low power of the study these findings should be viewed as indicative rather than definitive.     

Fasciola hepatica: A comparative survey of adult fluke resistance to triclabendazole,nitroxynil and closantel on selected upland and lowland sheep farms in Northern Ireland using faecal egg counting,coproantigen ELISA testing and fluke histology

In order to investigate the incidence and distribution of adult fluke resistance to the fasciolicide tricalbendazole (TCBZ) amongst populations of Fasciola hepatica in sheep flocks in Northern Ireland (NI), individual rectal faeces samples were collected from 3 groups of 20 sheep, before (pre-dose), and 21 days after (post-dose) treatment of the animals with TCBZ, nitroxynil or closantel, on each of 13 well-managed sheep farms distributed across the province. The efficacy of each flukicide was determined for each farm, using faecal egg count reduction (FECRT) and F. hepatica coproantigen ELISA testing. In certain flocks, 2 sheep with high pre-dose faecal egg counts (FEC) were killed 3 days and 21 days respectively after TCBZ treatment, and the histology of the fluke reproductive organs was compared with that of flukes from untreated sheep, and from sheep treated with nitroxynil or closantel 2 days prior to death, using haematoxylin and eosin (H&E) staining and an in situ hybridisation method (TdT-mediated dUDP nick end labelling [TUNEL]) to demonstrate apoptosis. Results from FECRT revealed that in all flocks with a high fluke burden, TCBZ was ineffective in treating chronic fasciolosis, and this finding was generally supported by the results of the coproantigen reduction test (CRT). The histology of reproductive organs of flukes from TCBZ-treated sheep in these flocks was normal, when compared with untreated flukes, and this, together with the FECRT and CRT findings, indicated a likely diagnosis of TCBZ resistance in all the flocks with a high fluke burden. In contrast, nitroxynil and closantel were found to be fully effective against TCBZ-resistant flukes in each of the flocks bearing a high chronic fluke burden. All of the flocks with a high fluke burden and TCBZ resistance were managed on lowland in the South and East of NI. Upland flocks, in the North and West, had low fluke burdens, or were clear of infection; and FECs were too low to allow valid resistance testing. The study highlights the high level of penetration of TCBZ resistance throughout F. hepatica populations in areas of intensively managed sheep production with a high level of fluke challenge. Further, it emphasises the importance of pre-emptive chemotherapeutic action against chronic fasciolosis, using flukicides effective against the egg-producing adult flukes to minimise pasture contamination for the next season's lamb crop. This study also exemplifies the use of several complementary methods (FECRT; CRT; fluke histology; comparative anthelmintic efficacy testing) for confirmation of a diagnosis of fluke drug resistance.     

绵羊夏伯特线虫外生性发育的研究

把绵羊夏伯特线虫虫卵置于消毒粪便培养基内，于２５℃温箱内及及室内进行培养。结果表明：在２５℃下经４０－４４ｈ第一期幼虫逸出卵壳，６２－６９ｈ完成第一次蜕皮成为第二期幼虫，１６２－１８９ｈ完成第二次蜕皮成为第三期幼虫，第三期幼虫肠细胞呈矩 ，共３２个，尾鞘长０．１７５－０．２２０ｍｍ，生殖原基距头端０．３４５－０．３８１ｍｍ；在室内培养的虫卵发育缓慢，经经１０ｄ才发育为第三期幼虫。     

不同品种蛋鸡鸡蛋品质的比较分析

针对当前市场对高品质鸡蛋需求增加的现状,本试验比较了在相同饲养管理条件下的几个主要品种蛋鸡的鸡蛋品质,结果表明:不同品种蛋鸡的鸡蛋品质存在许多差异,综合考虑,柴鸡、绿壳蛋鸡在生产优质鸡蛋方面具有一定的遗传优势。     

An evaluation of anthelmintic properties,assessed using faecal nematode egg counts,of New Zealand native flax (Phormium tenax)

AIM: To investigate the anthelmintic properties of New Zealand native flax (Phormium tenax) for cattle, using a faecal egg count reduction test (FECRT).

METHODS: Twenty-six heifer calves with high (>300 epg) faecal nematode egg counts (FEC) were paired into two groups and fed either chopped flax leaves ad libitum, or barley straw at an equivalent dry matter (DM) rate, from Day 0–7; all were supplemented with 1.5 kg/head/day cereal feed supplement. On Days 8–10, all heifers were fed a common diet of 3.5 kg DM/ head/day barley straw and 1.5 kg/head/day cereal feed supplement. Heifers were weighed and faecal samples were collected on Days —6, 0, 7, and 10; samples were analysed in triplicate for FEC. The nutritive value of the flax and straw was analysed.

RESULTS: Both the flax and straw had low dry matter digestibility (DMD) and protein content. Although the flax-fed claves grew more than the controls, this may have been related to gut fill. Total daily faecal egg output was similar for flax and straw groups on Day 7 (14.7 vs 15.0 x 10⁶ eggs/day, respectively) and Day 10 (14.9 vs 15.1 x 10⁶ eggs/day, respectively). There was no difference in the change in FEC with time between the calves fed flax or straw diets.

CONCLUSION: Consumption of flax leaves did not reduce FEC in calves with a mixed nematode infection.     

鸡蛋、乌鸡蛋、鹌鹑蛋营养成分的测定比较

禽蛋是人们生活中的重要营养源,是天然食物中最理想的蛋白质。本试验测定了鸡蛋、乌鸡蛋和鹌鹑蛋中的水分、脂肪、蛋白质、磷脂、胆固醇、维生素B2和氨基酸的含量,通过数据对比分析,得到如下结果:乌鸡蛋具有较高的营养价值,鹌鹑蛋由于含有很高的胆固醇,并不适合老年人的食用。鸡蛋的蛋白质、磷脂和氨基酸含量均低于乌鸡蛋和鹌鹑蛋,其营养价值最低。     

Epidemiology of nematodosis in Romney lambs selectively bred for resistance or susceptibility to nematode infection

Field trials were undertaken to compare nematode population dynamics, lamb productivity and levels of breech soiling in experimental flocks of Romney lambs selectively bred for increased resistance or susceptibility to nematode infection. In each year of the 2 year study, spring-born ewe lambs derived from Wallaceville Animal Research Centre's divergent nematode-resistant and nematode-susceptible breeding lines were grazed as separate flocks on matched farmlets from weaning (at 3 months old) until they were approximately 10–11 months old. Allocation of farmlets was reversed between Years 1 and 2 of the study to account for any possible paddock-related effects. Within each year both flocks were subjected to identical management conditions, including anthelmintic treatment (which was administered only when the overall mean faecal worm egg count measured across both genotypes reached 1500 eggs g⁻¹). In both years, by mid-autumn (April) nematode larval infestation levels on pasture were approximately 5–6-fold greater on the farmlet grazed by susceptible (S) genotype lambs than on that grazed by their resistant (R) counterparts (Year 1: 2506 cf. 544 larvae Kg⁻¹ herbage; Year 2: 431 cf. 74 larvae kg⁻¹ herbage). This led to 51-fold and 56-fold differences in faecal egg count between R and S lambs by late autumn (May) and winter (July) in Years 1 and 2, respectively. Although mean growth rates were similar in the R and S lambs over summer (while pasture infestation levels on the farmlets were still in the process of diverging), significantly higher growth rates occurred in the R than in the S lambs over autumn-winter in both years of the study (P < 0.01). In contrast, no significant differences in growth rate occurred in either year between male lambs derived from the nematode-resistant and nematode-susceptible breeding lines which were grazed together on another area of the Wallaceville farm from weaning until late autumn. Despite the substantially lower pasture infestation levels encountered by the R ewe lambs, they nevertheless temporarily suffered more breech soiling (dags) than their S counterparts (P < 0.01) in both years. Yearling fleece-weights of the R and S genotypes did not differ significantly in either year. Although the results of our study confirmed that there are potentially significant epidemiological benefits to be derived from breeding sheep for resistance to nematode infection, these benefits did not appear to be associated with large advantages in animal performance. Further work is needed to establish how these results should be interpreted with respect to anthelmintic drench requirements of genetically resistant animals.     

Comparison of in vitro methods and faecal egg count reduction test for the detection of benzimidazole resistance in small strongyles of horses

The objective of the study was to compare the in vitro egg hatch test (EHT), larval development test (LDT) and in vivo faecal egg count reduction test (FECR test) for the detection of benzimidazole resistance in equine strongyles. The presence of resistant or susceptible strongyle populations was determined in 25 stud farms using the in vivo FECR test and in vitro EHT. On the basis of the FECR values, resistance to fenbendazole was detected on 15 of the 25 farms (60%). The ED₅₀ value (anthelmintic concentration producing 50% inhibition of hatching) for suspected resistant populations varied from 0.110 to 0.222 g/ml thiabendazole (TBZ). Final LD₅₀ values (anthelmintic concentration inhibiting development of 50% of eggs into L₃ infective larvae) above 0.029 g/ml TBZ in the in vitro larval development test on samples from 11 stud farms revealed the presence of populations of small strongyles suspected of being benzimidazole-resistant.     

A survey on anthelmintic resistance in nematode parasites of sheep in the Slovak Republic

The prevalence of anthelmintic resistance on 27 sheep farms in Slovakia was investigated in 2003 and 2004 using the faecal egg count reduction test (FECRT) according to the WAAVP guidelines. Resistance to albendazole was detected on one farm (3.7%) and suspected on two farms (7.4%) out of 27 sheep flocks. Resistance to ivermectin was tested on 26 farms. On six (23.1%) farms, results indicated the presence of ivermectin resistance. Resistance to ivermectin was suspected on eight farms (30.8%). However, it is also possible that generic ivermectin anthelmintics used in survey have a lower efficacy against sheep nematodes.     

Further comparison of faecal egg count reduction test procedures: Sensitivity and specificity

Extract

In a recent communication (McKenna2006 McKenna, PB. 2006. A comparison of faecal egg count reduction test procedures. New Zealand Veterinary Journal, 54: 202–3. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), a comparison was made between four different methods for calculating results from faecal egg count reduction (FECR) tests (FECRTs). The first and most complex of these, referred to as FECRT₁, involved the use of the formula: FECR = 100 × (1?[T2/T1][C1/C2]), where T1 and T2 represented the mean pre- and post-treatment faecal nematode egg counts (FECs) of a treated group, and C1 and C2 represented the mean pre- and post-treatment FECs of an untreated control group, respectively. The other three formulae consisted of more simplified versions of this procedure. In one of them (FECRT₂), only post-treatment samples were considered, whereas the other two were based on comparisons between the FECs of groups of animals sampled at the time of anthelmintic treatment (pre-treatment) with those sampled several days later (post-treatment). Thus, FECRT₂ was determined according to the formula: FECR = 100 × (1?[T2/C2]), while FECRT₃ was calculated from FECR = 100 × (1?[T2/T1]). The fourth procedure (FECRT₄) was based on a further simplification of FECRT₃ where pre-treatment FECs from only one treatment group were used for comparison with all post-treatment results. This base-line pre-treatment group thus effectively functioned as an untreated control group and hence the formula for FECRT₄ was FECR = 100 × (1?[T2/C1]).     

Further comparison of faecal egg count reduction test procedures: sensitivity and specificity

In a recent communication (McKenna 2006), a comparison was made between four different methods for calculating results from faecal egg count reduction (FECR) tests (FECRTs). The first and most complex of these, referred to as FECRT1, involved the use of the formula: FECR = 100 x (1-[T2/T1][C1/C2]), where T1 and T2 represented the mean pre- and post-treatment faecal nematode egg counts (FECs) of a treated group, and C1 and C2 represented the mean pre- and post-treatment FECs of an untreated control group, respectively. The other three formulae consisted of more simplified versions of this procedure. In one of them (FECRT2), only post-treatment samples were considered, whereas the other two were based on comparisons between the FECs of groups of animals sampled at the time of anthelmintic treatment (pre-treatment) with those sampled several days later (post-treatment). Thus, FECRT2 was determined according to the formula: FECR = 100 x (1-[T2/C2]), while FECRT3 was calculated from FECR = 100 x (1-[T2/T1]). The fourth procedure (FECRT4) was based on a further simplification of FECRT3, where pre-treatment FECs from only one treatment group were used for comparison with all post-treatment results. This base-line pre-treatment group thus effectively functioned as an untreated control group and hence the formula for FECRT4 was FECR = 100 x (1-[T2/C1]). The study was based on an analysis of 210 previously published FECRTs performed in sheep or goats. In each case, FECRs were calculated using all four of these FECRT formulae, and their results compared. The results of these comparisons indicated that the use of any one of them was likely to result in similar estimates of anthelmintic efficacy and the detection of comparable numbers of cases of anthelmintic resistance continued.     

蛋鸡饲喂芽孢杆菌制剂对鸡蛋蛋品质及营养成分的影响

本试验旨在研究芽孢杆菌制剂对"京粉一号"蛋鸡蛋品质及蛋营养成分的影响。选择健康、产蛋均匀的259日龄的"京粉一号"蛋鸡3 600只,随机分为2组,每组6个重复,每个重复300只鸡。对照组饲喂基础日粮,试验组在基础日粮中添加3%的芽孢杆菌制剂,进行为期40 d的试验。结果表明:与对照组相比,试验组蛋壳硬度、哈夫单位以及蛋黄颜色均有不同程度地提高(P>0.05);在反映蛋的物理指标上,试验组蛋黄重和蛋黄相对重显著高于对照组(P<0.05),蛋清相对重显著低于对照组(P<0.05),蛋黄蛋白比有升高的趋势(P>0.05);同时,试验组蛋黄中脂肪和水分含量显著降低(P<0.05),蛋白含量显著升高(P<0.05)。试验表明:在蛋鸡日粮中添加芽孢杆菌制剂,对蛋品质具有一定的改善作用;可显著提高蛋黄重、蛋黄相对重,降低蛋清相对重。同时,可减少蛋黄中脂肪和水分含量,增加蛋白的含量。     

Anthelmintic resistance in sheep in Europe: A selected review

Intensive use of anthelmintics to control gastrointestinal nematodes selects for anthelmintic resistance, which has become an important issue in many European countries. Presence of nematode strains resistant to benzimidazoles, imidazothiazoles and/or macrocyclic lactones has been repeatedly reported, particularly for the three most important genera, Haemonchus, Teladorsagia and Trichostrongylus. Additionally, multiple drug-resistant populations of these parasites have also been detected. Examples are given for the situation in European countries with differing climatic conditions and management systems of small ruminants. The widespread emergence of multi-resistant nematodes proves that the past intensive suppressive chemical control strategies may not be a successful approach any longer. Experience from the up to now development of anthelmintic resistance suggests that modern control schemes should not rely on sole use of anthelmintics, but employ other, more complex and sustainable recipes, combing chemical, environmental and immunological control.