Growth Promoters: Replacing Antimicrobials
By Livestock Knowledge Transfer, UK - This article looks at the alternatives to antimicrobials and the strategy for replacing them.
The EU Scientific Steering Committee (SSC) has recommended that the use of antibiotics as growth promoters should be phased out. However, the SSC has recognised that the phase-out process should be planned and co-ordinated since rapid changes might affect animal health. Management and husbandry practices will need to be optimised so that health and welfare are
maintained.
From September 1999 the only antimicrobials licenced for use as zootechnical feed additives in pig diets are avilamycin (‘Maxus’), salinomycin (‘Salocin’) and flavophospholipol (‘Flavomycin’). None of these are related to any of the antibiotics used in human medicine.
Alternative feed additives
In a comprehensive review of the scientific literature commissioned by MLC no single group of feed additives could be considered to improve consistently either growth rates or feed conversion efficiency.Even when antibiotics are used as feed additives it has been shown that they do not provide a consistent return on all farms at all times. A small number of feed additives may be useful when problems are being experienced in the early stages after weaning.
Some organic acid preparations and some probiotics may prove useful in certain situations. Some enzyme preparations may prove useful in specific diet formulations.
Management and husbandry
The benefits from antibiotic feed additives are achieved through many different effects on the gut, so the strategy for replacing them will depend on a combination of nutritional, hygiene, housing and husbandry factors.There is no substitute for good management and hygiene when it comes to achieving the performance potential of pigs. Management after weaning can have significant effects on lifetime performance and health. Costs of production need to be minimised while still striving to unlock the potential growth rates and food conversion efficiency of the pigs. Veterinary advice will also be needed when there are health problems.
Potential effect on performance of alternatives to antibiotic feed additives
Antibiotics | +++++ |
Zinc oxide | ++++ |
Copper sulphate | +++ |
Organic acids | + |
Enzymes | +++ |
Pre-fermentation of feed | ? |
Probiotics | + |
Prebiotics | ++ |
All-in all-out production | ++++ |
Hygiene | ++++ |
Later weaning | ? |
Outdoor production | + |
Colostrum quality & intake | ++ |
Immunisation | +++ |
Drinking water quality | ++ |
Training of staff | ++++ |
Alternative feed additives
Always insist on seeing the results of independent tests before using. Check effectiveness when used on your farm because most vary a lot between farms.- Organic acids
In general results inconsistent. Greatest benefits are seen in the younger weaned piglet. Some may be useful against Salmonella. - Probiotics
Widely promoted but only mixtures of bacteria likely to be effective as must compete with resident population in gut.
- Prebiotics
Fermentable substrates such as slow release lactose can encourage favourable bacteria. Most are unproven.
- Pre- fermentation
Pre-fermenting the diet with an appropriate culture may prove effective at combining probiotics and organic acids to give a stable gut environment.
- Enzymes
Improve digestibility of nutrients. May help improve gut health.
- Immune enhancers
Some could make a useful contribution but require independent testing.
- Chemical probiosis
Some show promise but still unproven.
Management and Husbandry
The change from sow milk to a dry diet at weaning is a major challenge to the digestive system of pigs. Management and nutrition after weaning is critical to the success of a pig farm.- Provide suitable easily digested diet
- Maximise feed intake – change feed frequently, provide extra feed points at weaning, consider gruels
- Control environment – no draughts, match temperature to age, good ventilation
- Good quality flooring or straw
- Clean fresh water at all times
- Consider later weaning
- Minimise mixing to reduce stress and disease transfer
- All in/All out systems - all pens in a room or house should be emptied and then cleaned and disinfected properly before being filled again with pigs
- Identify diseases early and treat effectively. Use vaccines where appropriate
Source: Livestock Knowledge Transfer - First published 2001. Added to this site 2003.