Survival and dispersal of a defined cohort of Irish cattle

An understanding of livestock movement is critical to effective disease prevention, control and prediction. However, livestock movement in Ireland has not yet been quantified. This study has sought to define the survival and dispersal of a defined cohort of cattle born in Co. Kerry during 2000. The cohort was observed for a maximum of four years, from January 1, 2000 to December 31, 2004. Beef and dairy animals moved an average 1.31 and 0.83 times, respectively. At study end, 18.8% of the beef animals remained alive on Irish farms, including 6.7% at the farm-of-birth, compared with 48.6% and 27.7% for dairy animals respectively. Beef animals werae dispersed to all Irish counties, but mainly to Cork, Limerick, Tipperary and Galway. Dairy animals mainly moved to Cork, Limerick, and Tipperary, with less animals going to Galway, Meath and Kilkenny. The four-year survival probability was 0.07 (male beef animals), 0.25 (male dairy), 0.38 (female beef), and 0.72 (female dairy). Although there was considerable dispersal, the number of moves per animal was less than expected

Impact of foot-and-mouth disease on mastitis and culling on a large-scale dairy farm in Kenya

Foot and mouth disease (FMD) is a highly transmissible viral infection of cloven hooved animals associated with severe economic losses when introduced into FMD-free countries. Information on the impact of the disease in FMDV-endemic countries is poorly characterised yet essential for the prioritisation of scarce resources for disease control programmes. A FMD (virus serotype SAT2) outbreak on a large-scale dairy farm in Nakuru County, Kenya provided an opportunity to evaluate the impact of FMD on clinical mastitis and culling rate. A cohort approach followed animals over a 12-month period after the commencement of the outbreak. For culling, all animals were included; for mastitis, those over 18 months of age. FMD was recorded in 400/644 cattle over a 29-day period. During the follow-up period 76 animals were culled or died whilst in the over 18 month old cohort 63 developed clinical mastitis. Hazard ratios (HR) were generated using Cox regression accounting for non-proportional hazards by inclusion of time-varying effects. Univariable analysis showed FMD cases were culled sooner but there was no effect on clinical mastitis. After adjusting for possible confounders and inclusion of time-varying effects there was weak evidence to support an effect of FMD on culling (HR = 1.7, 95% confidence intervals [CI] 0.88-3.1, P = 0.12). For mastitis, there was stronger evidence of an increased rate in the first month after the onset of the outbreak (HR = 2.9, 95%CI 0.97-8.9, P = 0.057)

The productivity of holstein-friesian dairy cattle in different farming systems of Kenya

Information on performance of various breeds within different farming systems of Kenya would be useful in determining a breeding programme that would enable selection of appropriate animals for improved production. This study investigated the performance of Holstein-Friesian cows in small-scale farms (SSF), medium scale farms (MSF) and large-scale farms (LSF) and the factors which influenced performance in a range of milk production and fertility traits. Mean performance of animals for total lactation milk yield was 4540kg (LSF & MSF) and 2151kg (SSF). The age at first calving was lower on LSF and MSF (31.8 months)than on the SSF (45.0 months). Lactation lengths were lower on SSF (255 days) than on the MSF and LSF (301 days). Calving intervals in all systems were long, 404 days on MSF and LSF, and 429 days on SSF. Milk yield was highly influenced by seasonal effects, parity and lactation length, however lactation length, age at first calving and calving interval were only affected by seasonal effects on some of the LSF and MSF. Trends in performance over the years showed that between 1986 and 1996 there was little change in performance on SSF and MSF. On three LSF that altered the management of animals and introduced total-mixed-ration feeds, there was a marked increase in milk production. When comparing the performance of Holstein-Friesian cows on SSF with Ayrshire, Guernsey and Jersey, their level of performance was the lowest for total milk yield, calving interval and age at first calving. Further improvements and research on production systems are required in the country.International Journal of Agricultural and Rural Development Vol. 5 2004: 145-15