Over-processed feeds can reduce pig herd efficiency

Take-home message: Over-processed feed materials can reduce the efficiency of pig herds if their nutrient values aren’t properly calculated and accounted for.

Feed ingredients used in pig diets are often processed to improve their nutritional value.

But over-processing can result in chemical reactions with amino acids which can affect their digestibility, and in turn affect the way pigs grow.

In a study by scientists at Waginingen University, researchers wanted to understand how proteins with lower quality protein sources are used by pigs, and what effect they have on productivity, lean mean production, and nitrogen excretion.

By secondary toasting soybean and rapeseed in the presence of sugars to create differences in protein quality, the researchers found that over-processing ingredients drastically reduced the utilisation and retention of dietary protein in pigs.

They also saw small changes in amino acid pattern of body protein, due to a shortage and imbalance in amino acids absorbed during digestion.

As a result, there was too much energy in the pigs diets, meaning animals grew slower, were fatter and used their diet less efficiently. They also excreted more nitrogen in faeces.

However the team discovered that by compensating for the loss in amino acids by supplementing diets with free amino acids, growth performance could be restored.

Free amino acid supplementation also restored protein deposition, amino acid pattern of body protein and amino acid utilisation, although this effect was not complete for over-processed soybean meal.

“In general, this study shows that the use of over-processed feed materials, for example co-products of the human food production may reduce the efficiency of pig production if their nutritive value is not adequately taken into account,” the researchers wrote.

“The effects of processing could be substantial and should be taken into account when using processed protein sources in diets for growing pigs.

“It is essential to adequately asses the protein quality of over-processed feed ingredients and supplement required the amino acids to optimise growth performance, feed utilisation, lean meat in the carcass, and reduce nitrogen excretion. 

“This may contribute to a more sustainable food supply and optimal use of available biomass.”

Taken from: Amino acid utilization and body composition of growing pigs fed processed soybean meal or rapeseed meal with or without amino acid supplementation
Authors: T.G. Hulshof, A.F.B. van der Poel, W.H. Hendriks, and P. Bikker

  • Animal Journal articles are available for free for BSAS members - simply login to your account and visit our publications section
  • Animal’s ‘Article of the month’ is freely available for one month for non-BSAS members.