the pig cannot be slaughtered within 7 days, has no breeding future and cannot be used for home consumption:
• The pig should be destroyed humanely.
All needles, syringes and containers should be disposed of according to legal requirements.
Herd Recording
Introduction
Recording and measuring the performance of pig herds, particularly breeding herds, is vital to gauge herd performance and subsequent profitability. Key indicators include: number born alive, piglet survival and kilograms of meat sold per sow per year. These need to be compared with the national average and hopefully with the top 10% of the national pig herds.
More specific indicators, which should be linked to targets, need to be recorded in breeding herds.
Farrowing rate
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.
Farrowing index
The farrowing index is literally the number of litters per sow per year. The target should be 2.25. This can be raised to 2.4 in really elite herds. The farrowing index is determined by four key factors:
• The length of pregnancy (this could be as short as 114 days but might creep up to 117 days).
• The length of lactation (this is problematic in the UK as the legal age for weaning of piglets is 28 days).
• The length of time it takes for normal sows to return to oestrus after weaning (this is normally 6 days but may be shorter particularly with the correct use of hormone injection; see Chapter 10).
• The so-called non-productive days.
Non-productive days
Realistically, the main target to improve the farrowing index is to reduce the number of non-productive days. The factors to concentrate on are:
• To avoid any delay after weaning for the sow returning to oestrus (e.g. thin sows or poor boar exposure).
• To avoid missing a service. Services may be missed if the sow actually comes on heat in the farrowing accommodation or if there is poor oestrus detection.
• To avoid sows returning to service at the normal/expected time. This is easy to say but very hard to prevent. Obviously there may be a pathogen involved (see Chapter 10), which will need addressing after a diagnosis, but this is unlikely if the return is at the expected time. There may be a poor service environment. Timing of service is important whether this is natural service or AI.
• To avoid sows having a return to service at a longer time than expected. This is most likely to be caused by a pathogen. A diagnosis and a treatment plan is then a priority.
• To avoid culling or dying. This is a crass statement but actually with careful planning this is possible with various disease control strategies, e.g. reducing lameness by attention to the flooring, reducing deaths by vaccination. It is therefore very important that the reason for culling is recorded and obviously with any deaths the reason is recorded.
Pre-weaning mortality
This should be less than 10% and mortality due to scour in sucking pigs, less than 0.5%. Different diseases typically affect piglets at different ages; hence it is important to record the ages at which pigs are noted to be scouring, are treated and die. Many of the causes of scour in sucking piglets will damage or destroy the all-important villi in the small intestine, which are responsible for absorption of nutrients. Loss of these villi will predispose piglets to post-weaning scours because nutrients which should be absorbed in the small intestine can end up feeding the bacteria present in the large intestine, leading to bacterial proliferation there and scour.
2 Nutrition
Introduction
Pigs are omnivores. Wild species in their natural environment eat a very wide variety of foodstuffs. Domesticated pigs are kept in very varied environments from extremely large commercial breeding and fattening units through to smallholder units with pigs living very closely with humans in rural environments, to pet pigs living very close to their owners. Their nutrition will vary in a similar manner, with very high scientific diets and at the lower range ad hoc diets. In all situations it should be stressed that pigs should NEVER be fed any household scraps containing meat products because of the danger of the spread of pandemic infectious diseases, e.g. FMD, classical swine fever (CSF) and African swine fever (ASF). In most countries these diseases are notifiable and there is legislation banning not only the feeding of household scraps but also the feeding of commercial waste products called swill.
The full nutritional requirements for all types, ages and breeds of pig are beyond the scope of this book. Diseases of the neurological system and the skin as they are related to nutrition are listed below and also will be cross-referenced in Chapters 11
