poster-linked

Adjusting Roller Settings Based On Kernel Size Improved Starch Digestibility Of Dry-Rolled Barley Grain M. Ahmad 1 , M. Oba 1 , D. Gibb 2 , and T. A. McAllister 2 University of Alberta, Edmonton, Alberta, Canada 1 , Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada 2 Background Methods Results Objective Conclusion To evaluate the effect of adjusting roller settings based on kernel size on in situ starch digestibility of dry rolled barley. Figure 1. The in situ starch digestibility of dry-rolled barley with two different roller setting methods; multiple roller setting (MRS) vs. single roller setting (SRS). Samples were incubated in the rumen of cow for six time points (0, 3, 6, 12, 24, and 48 h). The in situ starch digestibility was greater (P < 0.01) for MRS method compared with SRS method (Table. 1). Starch digestibility at 48 h incubation time was not affected (P = 0.76) by treatment. The rate of in situ starch digestion was also greater (P = 0.05) for MRS method (18.6 vs. 11.9 % h -1 ) than SRS method. Screening of barley grain prior to processing, and adjusting roller settings based on its kernel size improve the rate of starch digestion in the rumen and may improve the efficiency of grain utilization possibly by reducing unprocessed grains in the diets. References: Karkallas, J. 1985. An improved enzymatic method for the determination of native and modified starch. J. Sci. Food Agric. 36: 1019–1027. Khorasani, G. R., J. Helm, and J. J. Kennelly. 2000. In situ rumen degradation characteristics of sixty cultivars of barley grain. Can. J. Anim. Sci. 80: 691-701. Table 1: The in situ Starch digestibility of dry-rolled barley at two different roller settings methods MRS SRS SEM P value 0h digestibility % 22.8 14.9 1.09 <0.01 3h digestibility % 55.0 38.6 1.8 <0.01 6h digestibility % 62.6 54.4 1.94 0.01 12h digestibility % 78.9 69.7 1.24 <0.01 24h digestibility % 85.3 83.1 0.75 0.05 48h digestibility % 93.1 93.4 0.54 0.76 Rate of digestion (k) %/h 18.6 3 11.9 0.82 <0.01 MRS = Multiple roller settings method; SRS = Single roller setting method; SEM = Standard error mean Whole barley is hardly digested due to its hard pericarp. Processing increases microbial attachment to starch content of the grain. Barley grain naturally varies in kernel size (Khorasani et al., 2000). Single roller setting may not be effective for various kernel sizes. Dry rolling with single roller setting; May not provide uniform particle size. Large kernel may shatter and produce more fines. Small kernels may pass as unchanged. May decrease efficiency of the roller mill. Restrict ruminal micro flora to act on starch. Decrease starch digestibility in the rumen. May decrease animal performance. Adjusting roller settings based on kernel size; May decrease variation in particle size. Decrease percentage of unprocessed grains. Decrease percentage of fines. Increase surface area for microbial attachment. Increase starch digestibility in the rumen. Twenty cultivar lots of barley samples were dry-rolled using two methods; Multiple-roller-setting (MRS) method with Processing index (77%). Single-roller-setting (SRS) method with Processing index (87%). In MRS method, grain samples were screened through 7, 6 , and 4 mm sieves. Spaces for roller mill were set at 1.487, 1.194, and 1.000 mm for large (> 7 mm), medium (> 6 mm), and small kernels (> 4 mm), respectively. In SRS method, the samples were dry- rolled through the roller space of 1.194 mm. Samples in Nylon bags were placed in the rumen of cow for 6 time points. Samples were analyzed for starch using Karkallas et al. (1985) procedure. 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 Incubation Tim e (h ) S tarch D igestibility % MRS SRS Statistical analysis: Data were statistically analyzed using ANOVA procedure of JMP Rolled barley

Upload: manzoor-ahmad

Post on 08-Jan-2017

47 views

Category:

Documents

0 download

Report

Download

Embed Size (px):

TRANSCRIPT

Adjusting Roller Settings Based On Kernel Size Improved Starch Digestibility Of Dry-Rolled Barley Grain

M. Ahmad1, M. Oba1, D. Gibb2, and T. A. McAllister2

University of Alberta, Edmonton, Alberta, Canada1, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada2

Background Methods Results

Objective

Conclusion

To evaluate the effect of adjusting roller settings based on kernel size on in situ starch digestibility of dry rolled barley.

Figure 1. The in situ starch digestibility of dry-rolled barley with two different roller setting methods; multiple roller setting (MRS) vs. single roller setting (SRS). Samples were incubated in the rumen of cow for six time points (0, 3, 6, 12, 24, and 48 h).

The in situ starch digestibility was greater (P < 0.01) for

MRS method compared with SRS method (Table. 1). Starch digestibility at 48 h incubation time was not

affected (P = 0.76) by treatment.The rate of in situ starch digestion was also greater

(P = 0.05) for MRS method (18.6 vs. 11.9 % h-1) than SRS method.

Screening of barley grain prior to processing, and adjusting roller settings based on its kernel size improve the rate of starch digestion in the rumen and may improve the efficiency of grain utilization possibly by reducing unprocessed grains in the diets.

References: Karkallas, J. 1985. An improved enzymatic method for the determination of native and modified starch. J. Sci. Food Agric. 36: 1019–1027. Khorasani, G. R., J. Helm, and J. J. Kennelly. 2000. In situ rumen degradation characteristics of sixty cultivars of barley grain. Can. J. Anim. Sci. 80: 691-701.

Table 1: The in situ Starch digestibility of dry-rolled barley at two different roller settings methods

MRS SRS SEM P value

0h digestibility % 22.8 14.9 1.09 <0.01

3h digestibility % 55.0 38.6 1.8 <0.01

6h digestibility % 62.6 54.4 1.94 0.01

12h digestibility % 78.9 69.7 1.24 <0.01

24h digestibility % 85.3 83.1 0.75 0.05

48h digestibility % 93.1 93.4 0.54 0.76Rate of digestion (k) %/h 18.63 11.9 0.82 <0.01MRS = Multiple roller settings method; SRS = Single roller setting method; SEM = Standard error mean

Whole barley is hardly digested due to its hard pericarp.

Processing increases microbial attachment to starch content of the grain.

Barley grain naturally varies in kernel size (Khorasani et al., 2000).

Single roller setting may not be effective for various kernel sizes.

Dry rolling with single roller setting;May not provide uniform particle size.Large kernel may shatter and produce more fines.Small kernels may pass as unchanged. May decrease efficiency of the roller mill.Restrict ruminal micro flora to act on starch.Decrease starch digestibility in the rumen. May decrease animal performance.

Adjusting roller settings based on kernel size;May decrease variation in particle size.Decrease percentage of unprocessed grains.Decrease percentage of fines.Increase surface area for microbial attachment.Increase starch digestibility in the rumen.

Twenty cultivar lots of barley samples were dry-rolled using two methods;

Multiple-roller-setting (MRS) method with Processing index (77%).

Single-roller-setting (SRS) method with Processing index (87%).

In MRS method, grain samples were screened through 7, 6 , and 4 mm sieves.

Spaces for roller mill were set at 1.487, 1.194, and 1.000 mm for large (> 7 mm), medium (> 6 mm), and small kernels (> 4 mm), respectively.

In SRS method, the samples were dry-rolled through the roller space of 1.194 mm.

Samples in Nylon bags were placed in the rumen of cow for 6 time points.

Samples were analyzed for starch using Karkallas et al. (1985) procedure.

100

0 10 20 30 40 50 60

Incubation Time ( h )

Sta