Future of feed for pigs and poultry: A British view

In a special workshop during the biannual show, Dr Mike Bedford, AB Vista, aimed to explain the use of the enzyme phytase and how it can help improve digestibility in an animal’s gut.

 

He focused on the subject of phytic acid, also known as phytate – an ‘anti-nutrient’. This feed ingredient is a source of phosphorus (P), binds minerals and proteins and can strongly irritate the gut, he explained.

 

For nutritionists and feed experts, degrading the phytic acid would be very useful for more than one purpose, he explained, as it would mean that more P would become available and it is thought that protein digestibility is reduced by about 10% by non-digested phytic acid.

 

Animal performance will increase when adding phytase to low-phytate ingredients, he explained. Apart from additional P release, more minerals are released, Bedford said, leading to more magnesium in animal bones. In addition, since animals do not have to spend energy on destroying phytic acid, more energy is taken up.

 

Next came Prof Helen Miller, Leeds University, answering questions around the principle of nutrigenomics. The method, applied by some companies in the animal nutrition industry as well, can help providing answers as to what is the exact effect of certain nutrients on metabolism in animals.

 

She explained that a ‘genome’ describes all genes in an organism; genomics is the mapping, sequencing and analysis of all genes in a given species; this can be done structurally (mapping and sequencing) and functional (what does the gene do?).

 

Pigs are known to have at least 24,000 different proteins in their DNA, but as always the proteins are made up of four bases: tymine, adenine, cytosine and guanine. Length and number of bases determine what protein you get.

 

The genes constantly replicate through a principle called ‘gene expression’. This is where the effect of different diets can be measured, Miller explained, as here it can be seen if every gene is still expressed – or whether these are changing here.

 

This requires careful comparison to known databases – and these are widely available on microchips of 1.28 x 1.28 cm. Through colour analysis, it can be seen whether e.g. zinc oxide inclusion in feed has any effect on the proteins in the genome – and on which genomes.

 

“Nutrigenomics gives a much clearer idea as to what is exactly happening in the gut. We know more how it is operation,” Miller said. She added that the effect of probiotics and prebiotics can be further investigated, how gut bacteria can affect an animal’s immunostatus, fatness levels and growth rates.

 

In addition, it is possible to determine a selection of ingredients for particular situations, for specific environments or for specific genotypes.