No abstract

In Ireland, surveys in the 1970's have shown calving rates to first service of 60-69%. Since then genetic merit and milk yield per cow have increased significantly. The objectives of this study were to determine calving rates in Irish dairy herds for the period 1991-1996 and if these had declined over time. Breeding records for 58 Spring calving commercial dairy herds maintained on the computerised DAIRYMIS System were analysed. Inseminations were categorised as either DIY AI (DIY), commercial AI (COM) or Natural Service (NAT). Between 1991 and 1996 there was a significant trend towards DIY (P<0.01) and away from NAT (P<0.01) with no consistent trend in COM usage. In 1991, roughly one third of services were to each of the three service methods but by 1996 DIY accounted for nearly 50% of all services. A subset of 34 herds, which had been present for at least five of the six years between 1991 and 1996, was used in the calving rate analysis. Calving rates to first service for DIY (48.4%) and NAT (46.0%) were not significantly different although both were significantly lower (P<0.001) than those for COM (54.5%). For small (<65), medium (65-128) and large herds (˃128) the respective proportion of services in each category were 22%, 44% and 34%. The respective calving rates of 55.2%, 51.6% and 45.7% declined significantly as herd size increased For all service types, there was a significant (P<0.001) decline in first service calving rate over time. The increased usage of DIY, combined with its lower fertility rates, would appear to be one factor responsible for the reduction in calving rate for 1991-1996 period.

Abstracts / International Journal of Infectious Diseases 79(S1) (2019) 1-150 129 particles were able to harmonise data received from the participants and reduce the inter-laboratory variation. Based on these results, the WHO Expert committee on Biological Standardisation established the material as an International Reference Reagent.Conclusion: The lentiviral packaging system represent an enabling technology to assist the development and calibration of diagnostic kits. It is a safe alternative to handling a high containment level pathogen and obviates the issues related to bioterrorism law. Furthermore, this type of reference material can be prepared contemporaneously or in advance of any viral outbreak to assist calibration of sensitive and specific assays and their harmonisation through standardisation at the time of the emergency when they are most urgently needed.

No abstract

The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories.