Improvements urged for feed ammoniation

Individual producers have ammoniated feed on their farms for years, but “it’s been in limited use because of safety, environmental and technical concerns and economical constraints.” | File photo

Livestock researcher says the process for boosting low-quality feed’s palatability must be industrialized to make it safer

Ammoniation of low quality feed isn’t new, but research at the University of Saskatchewan is looking at how to make the process easier and safer as the world looks toward feeding more people.

Dr. Gabriel Ribeiro, the Saskatchewan Beef Industry Chair, said the process has to be industrialized if it is to be of use to the industry.

He said the world population is growing in Africa and Asia particularly and so is the demand for meat.

Projections suggest 43 percent more beef will be needed in 2050 than was produced in 2010, he told the Animal Nutrition Conference of Canada. But land resources are limited and pressure to reduce degradation of natural resources is increasing. There is always the food-versus-feed discussion and increasing emphasis on beef production’s contribution to greenhouse gas emissions.

“I think the only way to be sustainable is to focus on the advantage of ruminant production, (namely) its ability to use forages and fibre rich byproducts that other animals can’t use well,” Ribeiro said.

Cereal crop residue such as straw and corn stover is widely available and cheap. However, producers are reluctant to use too much of these for feed because of their low digestibility.

Studies have shown that less than 50 percent is digested and crude protein is low.

Ammonia fibre expansion technology, or AFEX, can break down the residue to make it more easily digested.

Individual producers have ammoniated feed on their farms for years.

“However, it’s been in limited use because of safety, environmental and technical concerns and economical constraints,” said Ribeiro.

AFEX was developed for cellulosic ethanol production to pretreat biomass.

The straw is ground and put into a reaction chamber where it receives steam and ammonia at high pressure. This is followed by a quick pressure release and ammonia recovery.

Ribeiro said this process is much safer than that of traditional ammoniation on farms.

The result of AFEX is crude protein increases of between 81 and 312 percent compared to untreated feed.

“The greater CP content with AFEX treated forages can reduce the need for protein supplementation in the diet of ruminants, as this non-protein nitrogen can be used to meet the soluble N requirement of the rumen microbes and contribute to microbial protein synthesis,” said the conference proceedings on this research.

The neutral detergent fibre in crops treated with AFEX drops by 15 to 24 percent without changing the acid detergent fibre content.

When feed is ingested, rumen microbes then colonize it. Ribeiro said the colonizers replace the feed’s own microbes within 30 to 60 minutes to aid digestion.

Then secondary colonizers take over.

Ribeiro said AFEX treated feed alters the early colonizers but not the later ones.

“We hugely increase the potentially degradable fraction of NDF,” he said.

That percentage can go from 50 percent to 80 to 90 percent, Ribeiro said.

He also outlined research into fibrolytic enzymes and how combining their use and AFEX technology could lead to better fibre digestion.

“That AFEX technology can dramatically improve fibre digestion is really interesting but now we need to take this larger scale,” Ribeiro said.

Moving to an industrial model would be more expensive than what some producers do on their farms but if it can be done cheaply enough and provide nutritional value it may make sense, he said.

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