NADIS Veterinary Report and Forecast – September 2008
UK - This is a monthly report from the National Animal Disease Information Service (NADIS), looking at the data collected from their UK farm inspections.NADIS BPEX Commentary – September 2008
Farrowing rate data is collected by NADIS reporting veterinary surgeons quarterly and the overall picture is summarised over a 19-month period in graph 1. In general, farrowing rate has remained remarkably consistent over the time, with an average figure of approximately 82.5%. Over the time measured, the 3-month rolling averages show a dip in farrowing rate in late summer 2007 and again at the turn of this year. Whilst the former can be explained by summer infertility, the drop in mid winter is more difficult to explain. It remains to be seen whether farrowing rate dips again in late summer this year, following a 6-month period of little change.

Within and between systems there is small difference in farrowing rate achieved between indoor and outdoor farms (82.8% v 82.3%) and whilst straw and slats as the predominant sow bedding seem to have little bearing on results, it is interesting to see that continuous production breeding has achieved a full percentage point benefit over batch systems, reflecting reports received over more than a year of stockpeople struggling to come to terms with the demands of serving large numbers of sows within a batch (graph 2).

When measured against herd type, the best results are achieved by the small number of breeding only units, with breeder/weaner farms achieving slightly better results than breeder/feeder farms. It can be speculated that where attention is distracted by the pressure of weaners and growers results in breeding may suffer but this observation could equally implicate the presence of growing pigs as a source of reproductive infectious agents for sows, especially PRRS (fig 3).

Finally, there is a small but steady increase in farrowing rate results as herds get larger, with small (<100 sows) herds achieving less than 81% farrowing rate, whilst large herds (>700 sows) exceed 84% (graph 4).

Whilst farrowing rate is a measure of herd fertility and not directly a measure of productivity, the farrowing index (litters/sow/year) is itself influenced by fertility and therefore, all efforts to improve farrowing rate would be expected to be rewarded by increasing overall output from the breeding herd.
Further Reading
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