Читать книгу Veterinary Treatment of Pigs - Graham R Duncanson - Страница 104

The farrowing rate tells you the number of sows that farrow as a percentage of the number of sows and gilts that are served. The target should be 85% (more in an elite herd). This means that for every 100 sows and gilts which are served, 85 have gone on to farrow, while the remaining 15 have returned to service, been culled or died. It is vital that there is a record kept of all farrowings over a 12-month period. This figure is then divided by the total number of sows and gilts served. The answer is then multiplied by 100. The farrowing rate can be tracked monthly by deleting data from the earliest month and adding data from the latest month. For a real-time farrowing rate record, draw up a fertility chart and record weekly services, subsequent failures and expected farrowing rate percentage. This will allow a quicker response if things start to go wrong.

Obviously any new disease problems will lower the farrowing rate. However, there are other factors which will affect the farrowing rate and will need to be addressed in a diplomatic manner with the management and the pig keepers:

• Sow and gilt management (stable body conditions and social environments are particularly important).

• Nutrition and feeding regimens.

• Stockmanship (heat observation, heat recording, service/artificial insemination (AI) management and handling techniques are very important).

• Physical environment (thermal environment and hygiene are very important).

• Culling decisions.

The farrowing rate gives a guide to how many sows you need to serve to run the farrowing accommodation at optimum capacity. This is important not only from the viewpoint of physical use of the farrowing house or the farrowing arks, but also maximizing the output from the labour force. As an example, if the farrowing accommodation is sufficient for 160 sows and there is a farrowing rate of 85%, then there will be a need to serve 190 sows each week.