Page 5 - National Poultry Newspaper

Fibre in poultry rations and
its relationship with broiler
performance and gut health
MINGAN Choct is a professor of animal nu- trition at the University of New England and is well-known for his work in carbohydrate chemis- try and nutrition, feed enzymes, necrotic enter- itis and net energy.
from the use of ‘fibre ad- ditives’ that come under the term ‘structural fibre’ or components.
phased out because it is not accurate, nor is the representation of true fi- bre contents in feed in- gredients.
For instance, the chemi- cal structures of the enti- ties making up each frac- tion will be essential for determining the suscep- tibility of each entity to the digestive process of the animal, as well as to exogenous enzymes.
Mingan led the Austral- ian Poultry Cooperative Research Centre as chief executive officer for 14 years and was then ap- pointed pro vice-chancel- lor for external relations at the University of New England in 2017.
This particular class of ‘fibre’ consists mainly of non-starch polysac- charides and lignin, and is used as an additive in poultry feed to enhance gut development in birds that have little or no ac- cess to a sufficient amount of coarse material in their feed or environment.
To achieve this goal, the development of an NSP database may initially fo- cus on the total insolu- ble and soluble NSP and their relationship with the crude fibre levels used in commercial diets, fol- lowed by techniques that enable rapid determina- tion of these fractions.
This in-depth under- standing of the physical and chemical character- istics of NSP will inform future nutritional strate- gies that target specific fractions and types of fibre in ingredients to pro- duce desired nutritional and health outcomes in pigs and poultry.
With over 400 articles published, Mingan sub- mitted the following re- search excerpt on fibre in relation to broiler health for the recent 2022 Aus- tralian Poultry Science Symposium.
Examples of such addi- tives are tree fibres, cereal hulls, straws, bagasse and woody grass that have a reasonable level of coarse- ness and can stimulate the gizzard first and foremost.
Then, concerted ef- forts should be directed to producing a data- base that provides not only NSP values but also physiochemical and nu- tritional characteristics.
Mingan Choct mchoct@une.edu.au
Fibre is a nutrient that has been largely ignored in feed formulation – not because it is unimportant, but because of what ‘fibre’ actually stands for.
Fibre is a nutrient that has been largely ignored in feed formulation – not because it is unimportant, but because of what ‘fi- bre’ actually stands for.
Second, the feed indus- try currently does not have a reliable and ap- plicable fibre database for feed ingredients common- ly used in poultry feed formulation.
First, the terms used to describe fibre in feed are confusing and the values they represent are inac- curate.
The true fibre content of feed is well represented by the sum of non-starch polysaccharides and lignin.
For instance, ‘crude fi- bre’ is a 19th century relic that does not mean much in monogastric animal nu- trition.
However, it is impor- tant to highlight that even when some nutritionists have access to NSP values for commonly used feed ingredients, they have dif- ficulty applying them to feed formulation.
Its continued use in feed formulation perhaps rep- resents the single largest source of inaccuracy in so-called ‘least cost feed formulation’, which relies on the additivity of all nu- trients present in a given diet.
This is because:
This is because crude fi- bre values are highly vari- able and miss up to a third of the fibre constituents in key ingredients, such as soybean meal.
• The physical properties of fibre to a significant de- gree dictate its nutritional roles in poultry diets – it is not only solubility or vis- cosity, rather it is the way the NSP are associated with various components of cell walls – that is, how they are embedded in cell wall architectures – and such information is not readily available
Furthermore, two other terms that came into ex- istence in the 1960s – acid detergent fibre and neu- tral detergent fibre – refer to the arbitrary extracts of feed constituents that do not represent unique classes of chemically defined molecules, and these values are not used in feed formulation.
• NSP come
ous chemical structures – meaning their digest- ibility naturally differs widely.
They are also not ac- curate.
The chemical structures also influence the nutri- tional properties of NSP, be it the digestion by the animal consuming them, or by feed additives such as exogenous enzymes targeting them.
As an example, NDF ig- nores up to a quarter of the true fibre components – mainly soluble hemicel- lulose and pectic polysac- charides.
Third, nutritionists need to have the awareness that the use of crude fibre in feed formulation must be
Further confusion has arisen in recent years
Mingan Choct is a professor of animal nutrition at the University of New England.
www.poultrynews.com.au
National Poultry Newspaper, March 2022 – Page 5
• There is no clear cor- relation between the levels of crude fibre and NSP, hampering the ability of nutritionists to set a mini- mum or maximum value in feed formulation
in vari-