Influence of maize particle size and phytase supplementation on the performance of broiler starters
Published:November 18, 2009
By:A.M. AMERAH and V. RAVINDRAN
Paper from the Australian Poultry Science Symposium
The degree of grain grinding may influence the efficacy of exogenous enzymes in poultry diets, but published data on this aspect are limited. Amerah et al. (2008) reported that the effectiveness of exogenous xylanase in broiler diets is influenced by the particle size (PS) of wheat. The aim of the present experiment was to examine the interaction between maize PS and phytase supplementation on the performance and toe ash contents of broilers. The experimental design was a 2 x 2 factorial arrangement of treatments evaluating two maize PS (medium and coarse) and phytase supplementation (without or with 500 FTU/kg diet). The two PS were achieved by grinding the whole maize in a hammer mill to pass through 3 and 7 mm sieves, respectively. The geometric mean diameter (GMD) of the coarse and medium maize were determined to be 0.611 and 0.849 mm, respectively. Broiler starter diets, based on maize and soybean meal, were formulated to meet or exceed the requirements for major nutrients for broiler starters, except calcium and phosphorus (P). Each diet was fed to six pens of eight male broilers (Ross 308) each from day 1 to 21 post-hatching.
Phytase supplementation increased (P < 0.001) the feed intake and, improved (P < 0.05 to 0.001) weight gain and feed per gain in both medium and coarse PS diets. Coarse grinding improved (P < 0.05) weight gain, but had no effect (P > 0.05) on feed intake and feed per gain. No interactions (P > 0.05) between phytase supplementation and PS were observed for the performance parameters. However, a phytase x PS interaction (P < 0.01) was observed for the toe ash contents. Phytase supplementation increased the toe ash contents of birds fed the coarse PS diet but had no effect in those fed the medium PS diet. Interestingly, the toe ash content of birds fed the coarse PS diet was higher (P < 0.01) than those fed the medium PS diet, suggesting that grinding the maize coarsely has a beneficial effect on P bioavailability. Similar positive effects of coarse grinding of maize have been reported by Kasim and Edwards (2000). The present data suggest that, unlike xylanase supplementation in wheatbased diets, the response of broilers to phytase supplementation in maize-based diets is not influenced by maize PS.
Amerah AM, Ravindran V, Lentle RG, Thomas DG (2008) British Poultry Science 49, 455- 462.
Congratulation for the work about maize particle size and phytase in broiler starters. Concern about the Corn and the total diet quality regarding toxins. As everybody knows toxins can interfer strongly in the performance.
As we know Particle size reduction increases the surface area of the grain, thus allowing for greater interaction with digestive enzymes. However, fine grinding will increase the energy costs of feed processing and may result in dust problems, and increase the incidence of gastric ulcers in swine.
Kilburn and Edwards (2001) have shown that in phosphorus deficient practical-type corn-soybean meal (SBM) diets, the utilization of Ca, P, and phytate P is increased by increasing the particle size of corn in the diet. Kilburn and Edwards (2004) have shown that coarse SBM improved bone ash, gain:feed ratios and plasma P levels.
As phytate p utilization is increase by increasing the particle size of corn and soybean meal there is need to study the effect of particle size on NSP utilization. There is also need to study Is there any advantage of increasing particle size in palletize feed on nutrient utilization without enzyme addition and with enzyme addition?
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Firas
29 de diciembre de 2009
Great study about maize particle size and phytase in broiler starters and this need more study and more research.
Very interesting article about maize particle size and phytase in broiler starters ! I agree with Dr.Ramzee that more research would validate the concept.
This is very interesting article about maize particle size and phytase in broiler starters, authors did a good study on particle size of corn and effect of phytase. This definitely need more attention and more research.
