Effect of storage time and dietary enzyme on the metabolizable energy and digesta viscosity of barley-based diets for poultry

Abstract

The effect of barley storage time and dietary enzyme addition on the energy value of barley-based broiler diets was studied in two experiments. A two-rowed winter barley (Beka cultivar) was stored at room temperature for 0, 3, 6, 16, and 32 wk after harvesting. At these dates, diets were formulated using 50% barley with and without the addition of a commercial beta-glucanase-based enzyme product. In Experiment 1, 320 Arbor Acres chickens (eight replicates of three 10-d-old birds and eight replicates of one 30-d-old bird, per treatment) were fed the experimental diets to determine the AMEn following a 2 x 2 x 5 (age by enzyme by barley storage time) factorial design. At the end of the metabolism trial, viscosity of the intestinal contents was determined in 30-d-old broilers. Total beta-glucan, nonstarch polysaccharides (NSP), in vitro viscosity, and endogenous enzyme activity of barley grain decreased with increasing storage time. Dietary AMEn increased with barley storage time (from 2,755 to 2,939 kcal/kg DM, P < 0.001, for 0 and 32 wk of storage, respectively), with enzyme addition (2,861 vs 2,919 kcal/kg DM, P < 0.003), and with the age of animals (2,826 and 2,958 kcal/kg DM for 10- and 30-d-old chickens, respectively, P < 0.001). Interactions of enzyme and age by barley storage time (P < 0.02 and P < 0.001, respectively) were also detected. These data indicate that the minimum time of barley storage before its inclusion in broiler feed depends on the animals' age (more than 6 wk for 10-d-old chickens and 3 wk for 30-d-old chickens), and that the use of enzymes allowed a reduction in the time of barley storage. Digesta viscosity decreased with barley storage time (P < 0.001), and with enzyme addition (P < 0.001), an interaction of storage time by enzyme addition was shown (P < 0.007). Digesta viscosity was also negatively related to the dietary AMEn content (r = -0.68, P < 0.01). In vitro barley viscosity explained 53 and 90% of the variation in gut viscosity produced by unsupplemented and enzyme supplemented diets, respectively. In Experiment 2, the same diets as Experiment 1 and the barley grain were intubated into 120 adult roosters (Hy-Line) to determine TMEn. Dietary and barley TMEn values were not affected by barley storage time or enzyme addition (3,237 and 3,037 kcal TMEn/kg DM for diets and barley, respectively).

Effect of wheat cultivar and enzyme supplementation on nutrient availability and performance of laying hens

“…The AME value of wheat is likely to differ when fed to layers as compared to broilers because energy extraction from feed varies among birds of different types and ages (Zelenka 1997). Fuente et al (1998) Abbreviations: AIA, acid-insoluble ash; AME, apparent metabolizable energy; AME n , nitrogen-corrected apparent metabolizable energy; CP, crude protein; DM, dry matter; FCR, feed conversion ratio; FI, feed intake; GE, gross energy; LSD, least significant difference; NSP, non-starch polysaccharide Can. J. Anim.…”

“…The AME value of wheat is likely to differ when fed to layers as compared to broilers because energy extraction from feed varies among birds of different types and ages (Zelenka 1997). Fuente et al (1998) reported that the nitrogen-corrected apparent metabolizable energy (AME n ) of barley-based broiler diets increased as birds aged. The negative effects of NSP in broiler diets, such as increased intestinal viscosity and reduced performance (Bedford 1995), tend to be greater for younger birds than older birds.…”

The effect of storage of cereal grain and enzyme supplementation on measurements of AME and broiler chick performance

“…Huyghebaert and Schöner (1999) reported that storage of eight newly harvested wheat samples for 5 mo did not affect the ME levels measured, nor did storage change the relative rank for ME, or the individual wheat sample response to enzyme supplementation. However, Fuente et al (1998) reported that a newly harvested barley was not as well utilized by broilers, and young (10 d of age), as compared to older (30 d of age) broilers were negatively impacted for a longer time after the grain was harvested. These reports did not indicate changes of ad libitum feed intake and performance due to storage of cereal grain.…”

Enzymic Digestion of Walls Purified from the Starchy Endosperm of Barley

“…We have shown previously that of the four activities present in barley that possessed the capability of solubilising β-glucan, the one with highest specific activity appeared to be a "pentosan solubilase" 8 . From the present work we infer that supplementing β-glucanases with pentosan-degrading enzymes (and perhaps feruloyl and acetyl esterases) would allow the most efficient degradation of barley-based feedstocks, whether for fermentation or for animal feed 15 . However there remains a need to explain why the majority of the β-glucan present in the walls remains unsolubilised after treatment with a range of enzymes of diverse specificity.…”