The Effect of Insoluble Fibre and Intermittent Feeding on Gizzard Development, Gut Motility, and Performance in Broiler Chickens
Published:May 14, 2012
Summary
Summary A trial was conducted to test the following hypothesis; broiler exposure to coarse insoluble fibre in the diet or litter will result in enhanced gizzard function and performance, improved adaptability to an intermittent feeding program and an increase in the occurrence of reverse peristalsis. Ross 308 broiler chickens were either intermittent or ad libitum fed a basal diet, a basal di...
Interesting paper, would you then recommend a min. of insoluble fiber in broiler diets?, from what age?, which would be the best source, ...also wheat bran could play similar role as oat/barley hulls or not?. And last but not least, you don´t mention what basal diet was used (corn-soya?), would you then, if following your advice, avoid using exogenous enzymes?. Many thanks from Rafa.
Me too think that it is a very good piece of information.Now I can understand the reason why in practical life the signs of severe reflux are constantly seen in the gizzard of dead broilers suspected cause of death for poor quality ( adultration of feed raw materials such as rice brawn with high propertion of finely ground rice hulls/saw dusts and soybean meals with high propertion of soybean plant steam parts and leaves,maize with high propertion of cobs) feed supply. Thank you so much for the sharing the information. Dr K B Bohara Valley grop of Poultry industry Nepal
Use of appropriate insoluble fibre / high B-value ingredients in broiler feed and intermittent feeding practice in broiler would be an interesting exposer to broiler farmers comparing with conventional broiler feeding practice. However, maintaining low pH (<5pH) in hind gut would be key to reduce B-value for nutrient digestibility.
Thank you for your comments. It appears that the gizzard works as a "pace-maker" organ for nutrient digestibility, where it controls the particle size of the digesta entering the small intestine, tailoring the amount of nutrients for the endogenous enzymes to properly and effectively digest them down stream. However, if the gizzard has been rendered functionless by the provision of finely ground feed, this will not happen. Thus, the provision of coarse, structural material, such as hardwood shavings, oat hulls, or whole grains, will enhance gizzard development.
It is difficult to recommend a minimum level of insoluble fibre at this stage because it is often not the amount alone but the type and particle size of the fibre that matters more. For example, if coarsely ground oat hulls are used, their effect on gizzard development is obvious, but if the same oat hulls are finely ground (pass through 2-3mm screens), they have no effect on gizzard development.
Thank you all very much for the comments. I think Mingan has explained the situation very well: the gizzard is a grinding organ and therefore requires a substrate for its own development. A well-developed gizzard will not only result in a more homogenised particle size of digesta entering the lumen but reductions in pH in the gizzard as a result of up regulation of HCL secretions coming from the proventriculus - this may have numerous beneficial effects, namely presenting optimal conditions for pepsin activity. A well-developed gizzard is a powerful, muscular organ and creates intra luminal pressure changes with each contraction-relaxation, this has an effect on the pattern of motility in the small intestines and most likely promotes mixing of digesta that will aid optimal enzyme/substrate contact.
The diets used in the trial were corn/wheat/soya based without enzymes but inclusion of coarse fibre does not necessarily eliminate the need for NSPases, optimal performance in broilers will be achieved by including both.
Another co-author on this paper, Prof Birger Svihus recently published a comprehensive review on the topic of gizzard development and fibre, in that you may find some recommendations: SVIHUS, B. (2011) The gizzard: function, influence of diet structure and effects on nutrient availability. World's Poultry Science Journal. 67: 207-224.
In answer to Silas´s question, I think this much more dependent on the water holding capacity of the raw materials than the retention of dry matter in the foregut.
Thank you Adam and Coautors for this realy great work.
I would like just to add some more caracteristics of insoluble fiber in this case crude fibre concentrates:
- creates a fibre network in the intestinal tract which swells and loosenes the digesta. So that enzymes can penetrate the digesta easier and work more efficient. Therefore improved fat and protein digestion is observed.
- longer retention of digesta in the gizzard
- binds water in the upper paro of intestinal tract and releases it in the lower part
-high swelling capacity (water binding)
-Accelerates the intestinal transit and thus minimizes risk of colonization of harmfol bacteria that cause wet litter
-since the fibre concentration is higher than in traditional fibre sources, they are a good tool to enrich formulations with crute fibre withou consuming too much space in the formula if required
- also they are fee of soluble non starch polysaccharides (NSP)
Best Regards and go a head with a good researche like this
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