Effect of LongRange™ eprinomectin on Anopheles arabiensis by feeding on calves treated with the drug

Background Misuse of long-lasting insecticidal nets together with resistance of vectors to most of the insecticides for indoor residual spraying and impregnated nets threaten malaria vector control interventions, requiring search for alternative control methods. Reports have shown that Anopheles mosquitoes die when they feed on endectocidal drugs used to treat humans and animals. A study was designed to investigate the efficacy of LongRange™ (eprinomectin 5%) on laboratory reared Anopheles arabiensis fed on treated calves. Methods Anopheles arabiensis from insectary colony was fed on three calves treated with therapeutic dose of LongRange™ eprinomectin (1 ml/50 kg) and on non-treated three other calves as control arm. For the feeding, mosquitoes were placed in paper cups covered with nylon cloth mesh and then allowed to feed on the necks of calves. Subsequently, mosquito survival, fecundity, egg hatchability, larval development and adult emergence were recorded. Data were entered and analysed by using SPSS version 20. The Kaplan–Meier survival analysis and independent sample t-test were used. Results All mosquitoes that fed on LongRange™ Eprinomectin treated calves died within 7 days following blood ingestion. The drug also slightly affected fecundity and hatchability of An. arabiensis. Conclusion Treating livestock with LongRange™ (eprinomectin 5%) may serve as a supplementary control method for zoophagic An. arabiensis.

Performance Analysis of Magnetorheological Rubber Reinforcing Cord Fabric

Magnetorheological rubber material is a kind of composite material of magneto elastic coupling with multi functions, which is composed of magnetic particles and the mixed rubber films with the magnetic properties of the material, but because of its mechanical properties has limited practical use, and nylon cloth which has the advantages of high strength, dimensional stability, can be the ideal framework of magnetorheological rubber. The results show that for the magnetorheological rubber made from the NR/SBR blend, the tensile strength of the magnetorheological rubber with the cord fabric can greatly improve, the tensile strength can reach 17.8MPa, but also can improve the shear modulus of magnetorheological rubber and zero field storage shear modulus.

A comparison of parameters of the passage of nylon capsules and digesta calculated from faecal excretion data obtained in lactating cows

The aim of the study was to compare parameters of passage of nylon capsules and digesta represented by Cr-labelled maize silage through the digestive tract of dairy cows. The capsules were made of nylon cloth (42 µm pore size, 10 mm outside diameter) and applied orally. The evaluation was carried out in dairy cows with milk yield of 19.0 kg/day. The diet (17.6 kg DM/day) consisted of maize silage, lucerne hay and concentrate. Total mean retention time (TMRT), delay time (τ), summarised compartmental mean retention time (CMRTS), and mean individual compartmental retention times (CMRT1 and CMRT2) were calculated. TMRT, τ, CMRTS, CMRT1 and CMRT2 values of nylon capsules and Cr-labelled silage were 36.2 and 45.4 h (P < 0.01), 16.2 and 8.3 h (P < 0.01), 20.1 and 37.2 h (P < 0.01), 7.8 and 8.5 h, 12.2 and 28.7 h (P < 0.05), respectively. The calculated mean retention time of nylon capsules in the reticulo-rumen (CMRTS) was shorter and in the intestines (τ) was longer than that of digesta. For this reason the estimation of digestibility using the nylon capsule method can be questionable.  

Comparison of apparent and true digestibility of nutrients determined in dairy cows either by the nylon capsule or in vivo method

In this study the values of true digestibility of DM, OM, CP, NDF and starch determined either by the nylon capsule method or conventional in vivo method were compared. Four intact crossbred dairy cows (mean milk yield 21.9 kg/d) were used in two experimental periods. TMR consisted of maize silage, lucerne hay and concentrate. Nylon capsules (external diameter 10 mm) were made of nylon cloth (pore size 42 µm). Capsules were filled with TMR and at the beginning of the in vivo trial they were administered orally as a paper bolus into the cows. The values of true digestibility (after washing loss correction) of DM and OM, as determined by means of the nylon capsule method were lower than those estimated by the in vivo method. The respective differences were –6.9 and –7.3% (P < 0.05).  Insignificant differences were found in CP, NDF and starch.