Alternatives to maize & fishmeal

6 March 1998

Alternatives to maize & fishmeal

By Emma Penny

INCREASING cost of straights, and retailer and public pressure about ration components has led one researcher to investigate alternative rations for finishing pigs.

According to pig specialist Violet Beattie, based at the Agricultural Research Institute for Northern Ireland, the traditional finishing diet, which includes maize and fishmeal, is just too expensive.

"Also, alternative crops are now being grown within the EU for oil and protein. The by-products of these industries are available for use in animal feed, and in our trial we looked at rapeseed meal, pollard – the bran by-product from wheat milling – and copra, which is derived from coconut shells."

Trials at Hillsborough compared three diets with similar declared analyses – 21% protein and 13.7DE – but made from a wide range of raw materials.

The first was a traditional Northern Irish finishing ration – 70% cereals, and including maize and fishmeal. Diet two contained 70% wheat/barley but no maize or fish, with diet three comprising 30% cereals and the by-products.

All diets were pelleted and offered in single space wet and dry feeders to finishing pigs in the weight range 40-100kg.

"We found that pigs on all diets performed in a similar way – there was no significant difference in daily liveweight gain or feed conversion," says Dr Beattie.

However, killing out percentage was affected by ration choice. "The killing out percentage dropped from 77%, where 70% cereals were fed, to only 76%, where the low cereal/high by-product ration was fed. When pigs are killed at about 100kg liveweight thats a loss of about £1 a pig."

Dr Beattie thinks that the lower killing-out percentage reflects the effect of less cereal but more fibre in the ration. "It could be argued that a higher fibre diet leads to the gut wall thickening as it is more difficult to move feed through the pig."

The best ration was found to be the second option – 70% cereals but no maize or fishmeal. "The results show that there is no benefit whatsoever from including maize and fishmeal – which are expensive – in finishing pig rations. Removing these two products reduced feed costs by £1.50 a pig."

Traditionally, maize is included in pig rations to encourage pigs to eat, with fishmeal as a concentrated source of protein. Neither of these is needed in finishing rations, explains Dr Beattie.

"Intake is not an issue with finishing pigs – the only type of pig which really needs encouragement to eat is a lactating sow. Concentrated sources of protein are only required by young pigs, and even then, fishmeal is expensive."

The low cereal/high by-product ration did offer some benefits – pigs tended to have less fat and the fat was more unsaturated, she says.

"But unsaturated fat has a poorer appearance, and is more likely to go off in storage. This can lead to concerns at the retail stage, where the healthier product may look less attractive on the shelf."

The conclusion of the trial is that finishing pigs should be fed on a cereal-based ration – without maize or fishmeal.

"The low cereal/high by-product ration performed equally well, but is only worth considering if it is £15/t cheaper than cereals. Given cereals are so cheap this year that is unlikely to be the case."


&#8226 High cereal diet best.

&#8226 By-products performed well.

&#8226 No reason for feeding maize or fishmeal.

Finishing pigs should be fed on a cereal-based ration, without maize or fishmeal, says Hillsboroughs Violet Beattie.


&#8226 High cereal diet best.

&#8226 By-products performed well.

&#8226 No reason for feeding maize or fishmeal.

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