Ruminal digestion kinetics of temper-rolled hulless barley

1996 ◽  
Vol 76 (4) ◽  
pp. 629-632 ◽  
Author(s):  
W. Z. Yang ◽  
K. A. Beauchemin ◽  
L. M. Rode

In situ ruminal digestion kinetics of temper-rolled hulless barley were affected by the moisture content of grain prior to processing. A moisture content of 21% resulted in optimum ruminal digestion of temper-rolled hulless barley. Key words: Hulless barley, grain processing, temper-rolling, in situ digestion, ruminal degradability

1998 ◽  
Vol 11 (2) ◽  
pp. 128-132 ◽  
Author(s):  
M. Sarwar ◽  
Mahr-un-Nisa ◽  
S. A. Bhatti ◽  
C. S. Ali

2005 ◽  
Vol 57 (2) ◽  
pp. 223-228 ◽  
Author(s):  
O.N. Di Marco ◽  
M.S. Aello ◽  
S. Arias

The in situ dry matter (DM) disappearance of corn silages in two maturity stages (milk grain and half milk line) of known in vivo and in vitro digestibility was determined, with the main purpose of comparing digestibility values with the ruminal disappearance at 24 and 48h of incubation. A secondary goal was the description of their ruminal digestion kinetics, from which the effective degradability was calculated at an assumed passage rate of 4%/h. Data of in vivo, in vitro and in situ degradability at 24 and 48-h were analyzed with a linear model that included as fixed effects the maturity and the methodology of evaluation, and the kinetic data were described by the exponential model of McDonald. There was a significant effect (P<0.05) of methodology in the estimation of digestibility, but not of maturity or interaction maturity × methodology. The in vivo digestibility (52.9%) was not different from the 24-h in situ degradability (55.6%) with numerical values in the range of the effective degradability. The in vitro digestibility (61.6%) was not different from the 48-h in situ degradability (61.9%), being both estimates higher than the in vivo digestibility. The 24-h in situ degradability was a closer estimator of the in vivo digestibility and the 48-h in situ degradability and the in vitro digestibility overestimated the in vivo parameter by 15-20%.


2016 ◽  
Vol 38 (2) ◽  
pp. 171 ◽  
Author(s):  
Renê Ferreira Costa ◽  
Daniel Ananias de Assis Pires ◽  
Marielly Maria Almeida Moura ◽  
José Avelino Santos Rodrigues ◽  
Vicente Ribeiro Rocha Júnior ◽  
...  

This study aimed to evaluate in situ degradability and degradation kinetics of DM, NDF and ADF of silage, with or without tannin in the grains. Two isogenic lines of grain sorghum (CMS-XS 114 with tannin and CMS-XS 165 without tannin) and two sorghum hybrids (BR-700 dual purpose with tannin and BR-601 forage without tannin) were ensiled; dried and ground silage samples were placed in nylon bags and introduced through the fistulas. After incubation for 6, 12, 24, 48, 72 and 96 hours, bags were taken for subsequent analysis of fibrous fractions. The experimental design was completely randomized with 4 replicates and 4 treatments and means compared by Tukey’s test at 5% probability. As for the DM degradation rate, silage of CMSXS165without tannin was superior. Silages of genotypes BR700 and CMSXS 114 with tannin showed the highest values of indigestible ADF (59.54 and 43.09%). Regarding the NDF, the potential degradation of silage of CMSXS165 line without tannin was superior. Tannin can reduce ruminal degradability of the dry matter and fibrous fractions. 


2019 ◽  
Vol 20 (6) ◽  
pp. 1366 ◽  
Author(s):  
Baoli Sun ◽  
Luciana L. Prates ◽  
Peiqiang Yu

The aim of this study was to reveal an interactive curve-linear relationship between altered carbohydrate macromolecular structure traits of hulless barley cultivars and nutrient utilization, biodegradation, as well as bioavailability. The cultivars had different carbohydrate macromolecular traits, including amylose (A), amylopectin (AP), and β-glucan contents, as well as their ratios (A:AP). The parameters assessed included: (1) chemical and nutrient profiles; (2) protein and carbohydrate sub-fractions partitioned by the Cornell Net Carbohydrate and Protein System (CNCPS); (3) total digestible nutrients (TDN) and energy values; and (4) in situ rumen degradation kinetics of nutrients and truly absorbed nutrient supply. The hulless barley samples were analyzed for starch (ST), crude protein (CP), total soluble crude protein (SCP), etc. The in situ incubation technique was performed to evaluate the degradation kinetics of the nutrients, as well as the effective degradability (ED) and bypass nutrient (B). Results showed that the carbohydrates (g/kg DM) had a cubic relationship (p < 0.05), with the A:AP ratio and β-glucan level; while the starch level presented a quadratic relationship (p < 0.05), with the A:AP ratio and cubic relationship (p < 0.05), with β-glucan level. The CP and SCP contents had a cubic relationship (p < 0.05) with the A:AP ratio and β-glucan level. The altered carbohydrate macromolecular traits were observed to have strongly curve-linear correlations with protein and carbohydrate fractions partitioned by CNCPS. For the in situ protein degradation kinetics, there was a quadratic effect of A:AP ratio on the rumen undegraded protein (RUP, g/kg DM) and a linear effect of β-glucan on the bypass protein (BCP, g/kg DM). The A:AP ratio and β-glucan levels had quadratic effects (p < 0.05) on BCP and EDCP. For ST degradation kinetics, the ST degradation rate (Kd), BST and EDST showed cubic effects (p < 0.05) with A:AP ratio. The β-glucan level showed a cubic effect on EDST (g/kg DM) and a quadratic effect on BST (g/kg ST or g/kg DM) and EDST (g/kg DM). In conclusion, alteration of carbohydrate macromolecular traits in hulless barley significantly impacted nutrient utilization, metabolic characteristics, biodegradation, and bioavailability. Altered carbohydrate macromolecular traits curve-linearly affected the nutrient profiles, protein and carbohydrate fractions, total digestible nutrient, energy values, and in situ degradation kinetics.


1997 ◽  
Vol 68 (3-4) ◽  
pp. 247-257 ◽  
Author(s):  
A.G. Silva ◽  
R.C. Wanderley ◽  
A.F. Pedroso ◽  
G. Ashbell

2000 ◽  
Vol 80 (4) ◽  
pp. 691-701 ◽  
Author(s):  
G. R. Khorasani ◽  
J. Helm ◽  
J. J. Kennelly

Our objectives were to determine the extent of genetic variability in the rate and extent of ruminal digestion among 60 cultivars of barley, and to evaluate the correlations between ruminal digestion characteristics and chemical composition and test weight of barley cultivars. Barley samples were ground through a 2-mm screen, and bags containing 1 g of ground grains were incubated in the rumen of three late-lactation Holstein cows with rumen cannulae for 0, 1, 2, 4, 8, 12, 16, and 24 h. The rate and extent of ruminal digestion were estimated. The insoluble DM fraction ranged from 33.4 to 56.4%, the degradable DM fraction ranged from 34.1 to 60.2%, and the rate of degradation of DM ranged from 0.200 h−1 to 0.624 h−1. Hulled barley cultivars had lower (P < 0.05) soluble and degradable fractions than hulless cultivars. The soluble fraction was positively correlated to starch content of barley cultivars (P = 0.01) and the degradable fraction was correlated to the test weight and CP content (P < 0.01). The observed variability in the ruminal digestion characteristics of barley cultivars indicates that genetic selection holds promise as a means of enhancing the nutritional quality of barley for ruminants. We also observed that 70% of the variation in digestibility could be explained by measures of bulk density, starch content, and kernel weight. Key words: Barley cultivars, in situ degradability


1988 ◽  
Vol 68 (3) ◽  
pp. 779-786 ◽  
Author(s):  
P. H. ROBINSON ◽  
J. J. KENNELLY

High-moisture barley (HMB) was ensiled in polyethylene silage bags. Treatments applied to 30% moisture HMB as a percentage of dry matter (DM) were: none, 1% ammonia, 2% ammonia, and 1.5% sulphur dioxide. A fifth treatment was the addition of 1.5% sulphur dioxide to 20% moisture HMB. Barley samples were ruminally incubated to estimate degradability of DM and nitrogen (N). Ruminally incubated bags were also introduced to the duodenal cannulae and collected in feces to estimate true whole-tract digestion. Sulphur dioxide treatment, or moisture content, had no influence on ruminal degradability, with the exception of increased degradation rate of potentially degradable N for 20 vs 30% HMB, or whole-tract true digestion. Ammoniation resulted in net reduction in rate of ruminal DM release due to shift of soluble DM to the potentially degradable fraction, and decrease in the potentially degradable fraction degradation rate. Ammoniation increased barley N content up to 44% with no change in rate of ruminal N release. Whole-tract true DM digestion was higher for ammoniated barley but N digestion was not influenced. Sulphur dioxide appears to offer no advantages beyond grain preservation, whereas ammoniation offers potential by reducting rate of ruminal DM release, and providing a source of slow release nonprotein N, without affecting post-ruminal digestibility. Key words: High-moisture barley, ammonia, sulphur dioxide


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