Abstract
Gas production (GP) and starch degradation (STAD) from
starchy feedstuffs were measured simultaneously by in-vitro incubation
in buffered rumen fluid after 0, 4, 6, 8, 12, 16 and 24 h incubation
to explore the possibility to estimate STAD via GP technique for
starchy feedstuffs. The results showed the ranking in the initial degree
of starch degradation and gas production. Potato starch and maize
had the slowest initial rate, and tapioca, corncob mix and barley had
the fastest ones in STAD. Starch degradation of Over 75% took place
after 6-h incubation and nearly finished completely in 24-h incubation. Potato starch and maize, likewise, had the slowest initial rate
of gas production, and however the fastest initial rate was found in
the samples with smallest total starch content (TSC) such as pea and
barley. Gas production was in line with the starch degradation, but
the linking degree between GP and STAD varied with the samples
with different TSC, especially in the initial incubation. Overall regression indicated a strong correlationship between GP and STAD with
R2 0.88 and for individual sample, R2 ranged from 0.93 1.00. The
regression relationship was affected by TSC of the sample. A larger
TSC displayed a higher coefficient and constant as well. R2 for the
constant and coefficient regression with TSC was 0.88 and 0.91 respectively. The multiple linear regression was made via TSC and GP as
two main predictors: STAD=-318.14+0.427*TSC+1.876*GP(R2=0.95,
RSD=48.71, P=0.0000). The estimation equation was further modified by using GP as main predictor and its constant and coefficient
was, however, indirectly estimated by incorporating the regressions
of constant and coefficient with TSC instead of direct estimation:
STAD=(0.2088*TSC+168.55)+GP*(0.00136*TSC+0.9654)(R2=0.97, RSD=41.2, P=0.0000). R2 and RSD in both equations were well improved if compared with the values of 0.88 and 76.15 of the regression
using GP as unique predictor. The much higher in R2 and RSD of
the second equation indicated the modified equation was more accurate
and robust. Gas production technique can be used to estimate the rate
and extent of starch degradation in rumen fluid, as long as the starch
content is taking into account.
starchy feedstuffs were measured simultaneously by in-vitro incubation
in buffered rumen fluid after 0, 4, 6, 8, 12, 16 and 24 h incubation
to explore the possibility to estimate STAD via GP technique for
starchy feedstuffs. The results showed the ranking in the initial degree
of starch degradation and gas production. Potato starch and maize
had the slowest initial rate, and tapioca, corncob mix and barley had
the fastest ones in STAD. Starch degradation of Over 75% took place
after 6-h incubation and nearly finished completely in 24-h incubation. Potato starch and maize, likewise, had the slowest initial rate
of gas production, and however the fastest initial rate was found in
the samples with smallest total starch content (TSC) such as pea and
barley. Gas production was in line with the starch degradation, but
the linking degree between GP and STAD varied with the samples
with different TSC, especially in the initial incubation. Overall regression indicated a strong correlationship between GP and STAD with
R2 0.88 and for individual sample, R2 ranged from 0.93 1.00. The
regression relationship was affected by TSC of the sample. A larger
TSC displayed a higher coefficient and constant as well. R2 for the
constant and coefficient regression with TSC was 0.88 and 0.91 respectively. The multiple linear regression was made via TSC and GP as
two main predictors: STAD=-318.14+0.427*TSC+1.876*GP(R2=0.95,
RSD=48.71, P=0.0000). The estimation equation was further modified by using GP as main predictor and its constant and coefficient
was, however, indirectly estimated by incorporating the regressions
of constant and coefficient with TSC instead of direct estimation:
STAD=(0.2088*TSC+168.55)+GP*(0.00136*TSC+0.9654)(R2=0.97, RSD=41.2, P=0.0000). R2 and RSD in both equations were well improved if compared with the values of 0.88 and 76.15 of the regression
using GP as unique predictor. The much higher in R2 and RSD of
the second equation indicated the modified equation was more accurate
and robust. Gas production technique can be used to estimate the rate
and extent of starch degradation in rumen fluid, as long as the starch
content is taking into account.
Original language | English |
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Pages (from-to) | 286-286 |
Journal | Journal of Dairy Science |
Volume | 84 |
Issue number | suppl. 1 |
Publication status | Published - 2001 |