5 September 1997


Product assurance pressures to exclude animal protein from livestock rations must recognise the highly beneficial and cost-effective contribution of top quality fishmeal in pig diets. Harry Hope reports

CONCERN that specifications now being launched by retailers might include an arbitrary no-fishmeal clause, is expressed by independent animal nutritionist, Caroline Bevan, Lyneal, Shropshire.

"Producers have little option but to comply with supermarket requests on feed use to protect their outlets. But I see no justification for a ban on fishmeal, particularly in rations for young growing pigs and sow suckler diets," says Mrs Bevan.

She cites scientific evidence showing that fishmeal in balanced sow diets can produce an extra half a pig a litter.

Its inclusion at the grower stage is equally beneficial. She also suggests that weaner-growers are unable to tolerate the allergenic properties in vegetable proteins supplied by soya, peas and beans.

When used at high level to compensate for the absence of fishmeal, such ingredients can aggravate problems including nutritional scours and colitis.

Much of Mrs Bevans consultancy work is with pig producers who mill and mix their own feeds and who also recognise the high biological value of fishmeal. Its value as a protein source has been reinforced further by the ban on meat and bonemeal.

While alternatives to fishmeal are available, her calculations show them to be more expensive in terms of ingredient cost and pig performance.

"When you replace 5% fishmeal with 2.5% skim milk powder this adds £20/t to ration costs at present prices. Alternatively, dried whey powder used at the 5% level adds £10/t to the cost a balanced ration, and 60% protein maize gluten, included as a fishmeal substitute at the 5% level, adds £7/t to costs.

"Blends of milk-based ingredients including whey concentrates and by-products are available from baby food manufacturers. These could prove more cost-effective than straight milk products, to provide a suitable fishmeal alternative in pig starter diets, but they are likely to remain too expensive for finisher rations. While finishers certainly tolerate higher levels of soya and other legume proteins, fishmeal is hard to beat for the younger pigs," says Mrs Bevan.

Formulations including synthetic protein might compete if the recent steep decline in cereal prices continues. In this respect she accepts detailed trials evidence that pigs will finish satisfactorily on rations based on cereals and the synthetic amino acids lysine, methionine and tryptophan.

Low wheat and barley prices might also tempt more arable-pig producers to move into home mill and mixing if compound feed manufacturers do not reduce their prices accordingly, she says.

Any increased reliance on cereals should also be accompanied by an accurate analysis of feed value for, dependent on variety, the protein content of wheat in particular can vary from 9-14%, advises Mrs Bevan.

Obtaining analyses

She acknowledges the difficulty in obtaining representative analyses on farms where a spread of varieties are grown to reduce crop disease risks. Accurate analysis is complicated still further when facilities for separate storage are limited.

While fishmeal is recognised mainly as a competitive source of highly digestible and balanced protein, its contribution to the minerals fraction of the diet is also valuable. Its exclusion in predominantly cereal diets requires the inclusion of more dicalcium phosphate, which is of inferior availability to the same minerals in fishmeal. That in turn can lead to higher levels of phosphate in dung and slurry. This potential pollutant might be ameliorated by the use of phytase enzymes in the feed.

Mrs Bevan anticipates lower cereal prices and a rough harvest with less grain meeting milling and malting standards, leading to an increased use in pig rations. This could occur despite similar reductions in the cost of alternative ingredients including a wide range of food industry by-products.

Though competing farm assurance and traceability schemes could discourage the use of various animal by-products as protein sources in pig feeds, she pleads for the continued recognition of the pig as a uniquely efficient omnivorous animal.

"Pigs have a traditional capability for turning relatively cheap by-products from a wide variety of sources into high quality meat. That function should not be impeded or prevented by questionable rules and regulation on permitted feed ingredients," she says.

There is no justification for a ban on fishmeal particularly for young pigs, according to Banbury Agriculture nutritionist Caroline Bevan.

Extra costs of replacing 5% fishmeal


rate (%) (£/t)

Skim milk powder2.520

Dried whey powder510

maize gluten(60% protein)57


&#8226 Adds up to £20/t.

&#8226 Could cause digestive upsets.

&#8226 Will reduce sow performance.

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