"The majority of the phosphorus in plant feed ingredients is bound in phytate," said U of I animal sciences professor Hans Stein. “It is difficult for pigs to utilize that phosphorus because they cannot hydrolyze that phytate molecule. There is an exogenous enzyme called phytase that helps the pigs hydrolyze that phosphorus bond from phytate so the digestibility is increased.”
However, there are no data on the response to different levels of phytase in the diet. “It's not known if we need to add 500, or 1,000, or 1,500 units of phytase to get a maximum response, and it's also not known if the response is the same when we use different feed ingredients,” Stein said.
Stein's team tested the digestibility of phosphorus in conventional corn grain, corn germ, distillers dried grains with solubles (DDGS), and high-protein distillers dried grains (DDG). They tested each ingredient with no phytate and with 500 units, 1,000 units, and 1,500 units of added phytate.
Supplementation with 500, 1,000, and 1,500 units of phytate increased phosphorus digestibility from 40.9 percent in corn grain with no added phytate to 67.5, 64.5, and 74.9 percent, respectively. Phosphorus digestibility in corn germ increased from 40.7 percent to 59.0, 64.4, and 63.2 percent, respectively. Digestibility of phosphorus in DDGS increased from 76.9 percent to 82.9, 82.5, and 83.0 percent, respectively, but the increase was not significant. Phosphorus digestibility in high protein DDG increased from 77.1 percent to 88.0, 84.1, and 86.9 percent, respectively.
"What we discovered was that for corn and corn germ, we had a low digestibility without phytase, but as we added phytase to the diet, we increased the digestibility quite dramatically," Stein said.
For DDGS and high-protein DDG, the result was quite different. Because these two ingredients have been fermented, some of those phytate bonds are hydrolyzed in the ethanol plant and therefore, less of the phosphorus is bound to phytate in DDGS and high-protein DDG.
“When we added phytase to DDGS, we did not see a significant increase in digestibility because the digestibility was already very high. And the same was true for HP DDG,” said Stein. “What this tells us is that the effect of phytase depends on the particular ingredient. If it's an ingredient that has a lot of phosphorus bound to phytate, we see a nice response, but if it doesn't have much phosphorus bound to phytate, we don't see nearly as much of a response.”
The second finding was that the response to phytase is not linear. “The response to the initial 500 units of phytase is much greater than if we add another 500 units or another 500 units after that,” said Stein. “It's a curvilinear response, even for the ingredients where a good response is obtained.”
The researchers developed equations to predict the response to every level of phytase supplementation up to 1,500 units.
This research will help producers and feed companies to increase the digestibility of phosphorus in ingredients they are already feeding, thus avoiding the expense of adding dicalcium phosphate or monocalcium phosphate to swine diets.
"With current prices, it's less expensive to use phytase than it is to use dicalcium phosphate or monocalcium phosphate," Stein pointed out. Use of phytase to improve phosphorus digestibility also reduces the amount of phosphorus excreted in feces, which in turn reduces the environmental impact of swine production.
Stein's lab is continuing its research into phytase supplementation and is currently testing different sources of canola meal and soybean meal. He and his team plan to conduct similar research for all major feed ingredients used in U.S. swine diets.
The study was published in a recent issue of the Journal of Animal Science and was co-authored with doctoral candidate Ferdinando Almeida.
Susan Jongeneel | EurekAlert!
Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München
Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences