Department of Veterinary Medicine and Animal Production, University of Napoli Federico II, CREMOPAR, Napoli, Italy.
BIOEPAR, INRA, Oniris, 44307, Nantes, France.
Parasit Vectors. 2019 Jul 16;12(1):353. doi: 10.1186/s13071-019-3601-x.
Faecal egg counts (FEC) and the FEC reduction test (FECRT) for assessing gastrointestinal nematode (GIN) infection and efficacy of anthelmintics are rarely carried out on ruminant farms because of the cost of individual analyses. The use of pooled faecal samples is a promising method to reduce time and costs, but few studies are available for cattle, especially on the evaluation of different pool sizes and FECRT application.
A study was conducted to assess FEC strategies based on pooled faecal samples using different pool sizes and to evaluate the pen-side use of a portable FEC-kit for the assessment of FEC on cattle farms. A total of 19 farms representing 29 groups of cattle were investigated in Italy and France. On each farm, individual faecal samples from heifers were collected before (D0) and two weeks after (D14) anthelmintic treatment with ivermectin or benzimidazoles. FEC were determined individually and as pooled samples using the Mini-FLOTAC technique. Four different pool sizes were used: 5 individual samples, 10 individual samples, global and global on-farm. Correlations and agreements between individual and pooled results were estimated with Spearman's correlation coefficient and Lin's concordance correlation coefficients, respectively.
High correlation and agreement coefficients were found between the mean of individual FEC and the mean of FEC of the different pool sizes when considering all FEC obtained at D0 and D14. However, these parameters were lower for FECR calculation due to a poorer estimate of FEC at D14 from the faecal pools. When using FEC from pooled samples only at D0, higher correlation and agreement coefficients were found between FECR data, the better results being obtained with pools of 5 samples. Interestingly, FEC obtained on pooled samples by the portable FEC-kit on-farm showed high correlation and agreement with FEC obtained on individual samples in the laboratory. This field approach has to be validated on a larger scale to assess its feasibility and reliability.
The present study highlights that the pooling strategy and the use of portable FEC-kits on-farm are rapid and cost-effective procedures for the assessment of GIN egg excretion and can be used cautiously for FECR calculation following the administration of anthelmintics in cattle.
由于个体分析的成本，评估胃肠道线虫（GIN）感染和驱虫剂效果的粪便卵计数（FEC）和 FEC 减少试验（FECRT）很少在反刍动物养殖场进行。使用混合粪便样本是一种减少时间和成本的有前途的方法，但针对牛的研究很少，尤其是在评估不同的样本大小和 FECRT 应用方面。
本研究旨在评估基于不同样本大小的混合粪便样本的 FEC 策略，并评估便携式 FEC 试剂盒在牛场评估 FEC 的现场使用情况。在意大利和法国，共调查了 19 个农场的 29 个牛群。在每个农场，在使用伊维菌素或苯并咪唑类药物驱虫前后（D0 和 D14），从小母牛中采集个体粪便样本。使用 Mini-FLOTAC 技术分别和作为混合样本进行 FEC 检测。使用了四种不同的样本大小：5 个个体样本、10 个个体样本、总体样本和农场总体样本。使用 Spearman 相关系数和 Lin 一致性相关系数分别评估个体和混合结果之间的相关性和一致性。
当考虑所有在 D0 和 D14 获得的 FEC 时，个体 FEC 的平均值与不同样本大小的 FEC 的平均值之间存在高相关性和一致性系数。然而，由于粪便样本在 D14 时对 FEC 的估计较差，因此在计算 FECR 时这些参数较低。仅在 D0 时使用混合样本的 FEC 时，FECR 数据之间的相关性和一致性系数更高，5 个样本的混合样本的结果更好。有趣的是，在实验室中用便携式 FEC 试剂盒在现场获得的混合样本的 FEC 与在实验室中用个体样本获得的 FEC 具有高度相关性和一致性。需要在更大的范围内验证这种现场方法，以评估其可行性和可靠性。
本研究表明，混合策略和在牛场使用便携式 FEC 试剂盒是快速且具有成本效益的方法，可用于评估 GIN 卵排出量，并且在牛群中使用驱虫剂后谨慎地用于 FECR 计算。
