A new duplex real-time RT-PCR assay for sensitive and specific detection of African horse sickness virus.

A new real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for a simple and rapid diagnosis of African Horse Sickness (AHS) was developed. Primers and FAM-labeled TaqMan-MGB probes specific for African horse sickness virus (AHSV) were selected from the consensus sequence of the segment 8 of all 9 serotypes of AHSV reference strains. For the determination of the analytical sensitivity, an in vitro transcript (AHS_ns2T7) of the target region was constructed and tested. Furthermore, the AHS_ns2T7 transcript was used either as positive control or as a standard for quantifying target copies. A commercial heterologous Armored RNA was used as an internal positive control (IPC) for both RNA isolation and RT-PCR steps. The qRT-PCR AHS_ns2 was able to amplify the target sequence up to 0.71 copies/reaction. Its flexibility allowed to amplify a wide dynamic range of RNA copies from 1.5 to 0.001fg. Within this range, the Ct values varied from 18 to 38 cycles with SD values always lower than 0.5 confirming their strong and constant linear correlation with the RNA target. Furthermore the newly designed duplex real-time RT-PCR proved to be strictly AHSV-specific as it did not amplify close related viruses.

Electronic identification of cattle: interference in the reading of ceramic bolus transponders in the presence of ruminal magnets.

The authors assess the reading performances of electronic transponders encased in ceramic boluses, utilised as identification (ID) instruments for production ruminants, and the possible influence of the magnet, which is located in the fore-stomach of ruminants. Research has been conducted in free-range Friesian dairy herds in the Teramo Province. The use of the electronic bolus to identify cattle appears to provide better guarantees than the traditional methods used and meets the requirements of identifying individual animals at the farm level. Results demonstrate how the presence of both the magnet and the ceramic bolus, equipped with a transponder, makes it difficult, and sometimes impossible, to read the code. However, the electronic ID system is the best instrument currently available. The authors confirm the validity of this method and highlight some problems that still need to be solved.

Iodine supplementation restores fertility of sheep exposed to iodine deficiency.

The aims of the study were to monitor sheep iodine intake in different sheep breeding farms in Abruzzo and to evaluate the effects of iodine supplementation on ovine fertility. The urinary iodine concentrations (UIC) in animals of 8 out of the 11 breeding farms analyzed were borderline (UIC 100-150 microg/l) or very low (UIC < or = 50 microg/l). Only animals bred in 3 farms showed an adequate iodine intake with a mean UIC > or = 300 microg/l. Animals with very low iodine intake had lower T4 and T3 (p < 0.01) serum levels, compared to those with adequate iodine intake. To investigate the effects of iodine supplementation on ovine fertility, 32 ewes and 20 rams, characterized by low UIC, were randomly divided into 2 groups. One group (16 ewes and 10 rams) received a sc injection of 1 ml of Lipiodol, containing 480 mg of iodine, while the remaining animals were employed as control. This treatment was able to maintain UIC above 300 microg/l for 3 months and to increase T4 and T3 serum levels (p < 0.01). After 9 months, the fertility of control and treated animals was assessed by monitoring the rate of successful matings by ultrasonography. The results showed that 100% of treated ewes mated with treated rams were pregnant vs 37% of the control ewes mated with control rams (p = 0.007). The iodine content was 4-fold higher in milk from treated ewes (2393 +/- 453 microg/l), compared to controls (675 +/- 154 microg/l). The results demonstrated that iodine supplementation restores fertility of sheep living in iodine deficient areas and may represent a means to achieve a silent iodine prophylaxis of local populations.