scholarly journals Effect of varying the proportion of concentrate with the same starch content in the diet on passage rate and on ruminal digestion in dairy cows

1993 ◽  
Vol 42 (2) ◽  
pp. 154-154 ◽  
Author(s):  
BP Widyobroto ◽  
JL Peyraud
Keyword(s):  
Dairy Cows ◽  
Starch Content ◽  
Passage Rate ◽  
Ruminal Digestion

Fermentation and degradation in the rumen of dairy cows fed on diets consisting of silage from an intensively managed sward and silages from semi-natural grasslands

2004 ◽  
Vol 142 (1) ◽  
pp. 79-88 ◽  
Author(s):  
M. H. BRUINENBERG ◽  
H. VALK ◽  
P. C. STRUIK ◽  
A. M. VAN VUUREN
Keyword(s):  
Fatty Acids ◽  
Dairy Cows ◽  
Clearance Rate ◽  
Volatile Fatty Acids ◽  
Grassland Management ◽  
Pool Size ◽  
Passage Rate ◽  
Natural Grasslands ◽  
Intensively Managed ◽  
Ruminal Digestion

To assess the effect of grassland management on the ruminal digestion of silages, four lactating dairy cows, fitted with a rumen cannula, were fed diets consisting of concentrates and different grass silages. The grass silages consisted of intensively managed grass (IM) in variable proportions replaced by silages harvested from a ‘species-poor’ grassland managed to stimulate nesting of birds (SPP) or from a grassland managed to increase plant species diversity (SPR). The roughage part of the diets was composed completely of IM (100IM), or 200 g/kg (in dry matter) of IM replaced by SPP (20SPP) or 600 g/kg of IM replaced by SPP (60SPP), or SPR (60SPR). The pH in the rumen was highest on 60SPR and lowest on 100IM and 20SPP (P<0·05), whereas volatile fatty acids (VFA) concentrations were lowest on 60SPP and 60SPR and highest on 100IM (P<0·05). No differences in the ratio non-glucogenic: glucogenic volatile fatty acids were observed among the diets. The NH3 concentration was highest on 100IM and 20SPP and lowest on 60SPR (P<0·05), reflecting differences in CP intake. The concentration of uric acid in the urine (mg per kg metabolic body weight) was highest on 100IM (P<0·05). Rumen pool size of OM and DM did not differ among treatments, but pool size of NDF and IADF were highest on 60SPR (P<0·05). Passage rate was high on 100IM and 60SPR, but no significant differences with the other treatments were established. Also, no significant differences were observed in rates of degradation. Clearance rate of large particles was highest on 60SPP and differed significantly from 60SPR (P<0·05) only. No differences were observed in clearance rate of small particles. In conclusion, for most rumen fermentation characteristics measured in the study, no noticeably aberrant behaviour of the silages from semi-natural grassland was observed.

1404 Effects of replacing soybean meal with canola meal or treated canola meal on ruminal digestion, and omasal nutrient flow in lactating dairy cows

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 680-680
Author(s):  
E. Marostegan de Paula ◽  
M. A Camargo Danes ◽  
N. E Lobos ◽  
F. L. Drago ◽  
G. I. Zanton ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Soybean Meal ◽  
Canola Meal ◽  
Nutrient Flow ◽  
Lactating Dairy Cows ◽  
Ruminal Digestion

scholarly journals In situ rumen degradation of kernels from short-season corn silage hybrids as affected by processing1,2

2018 ◽  
Vol 2 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Renan L Miorin ◽  
Lucia Holtshausen ◽  
Vern Baron ◽  
Karen A Beauchemin
Keyword(s):  
Particle Size ◽  
Degradation Kinetics ◽  
Starch Content ◽  
Beef Cows ◽  
Passage Rate ◽  
Corn Hybrids ◽  
Rumen Degradation ◽  
Randomized Design ◽  
Short Season

Abstract The objective of this in situ study was to evaluate the rumen degradability of kernels from short-season corn hybrids grown for silage in Western Canada (Lacombe, AB) and determine whether decreasing kernel particle size would enhance ruminal degradability in a similar manner for all hybrids. The study was a completely randomized design with 3 beef cows (replicates) and a 6 (hybrid) × 3 (particle size) factorial arrangement of treatments. Kernels were processed to generate three different particle sizes: large (2.3 mm), medium (1.4 mm), and small (0.7 mm). Processed samples were incubated in the rumen for 0, 3, 6, 12, 24, and 48 h using the in situ method and degradation kinetics of DM and starch were determined. Effective rumen degradability (ED) was estimated using a passage rate of 0.04 (ED4), 0.06 (ED6), and 0.08/h (ED8). Hybrids exhibited a range in whole plant DM content (23.7 to 25.0%), starch content (15.9 to 28.1% DM), kernel hardness (21.9 to 34.4 s/20 g) and density (3.57 to 4.18 g/mL), and prolamin content (8.24 to 11.34 g/100 g starch). Differences in digestion kinetics among hybrids were generally more pronounced for starch than DM. The hybrids differed in starch degradability (P &lt; 0.05), with earlier maturing hybrids having lower A fraction, lower kd, and lower ED, with hybrid effects on ED being accentuated with faster passage rate. Kernel DM content (r = −0.85, −0.87), hardness (r = −0.89, −0.86), and density (r = −0.84, −0.85) were negatively correlated with ED4 and ED8 of starch, respectively, due mainly to decreased kd of fraction B. Reducing the particle size of kernels increased ED of starch due to increased A fraction and kd of the B fraction. A tendency (P = 0.09) for hybrid × processing effects for ED6 and ED8 indicated that processing had greater effects on increasing ED of starch for earlier maturing hybrids. We conclude that short-season hybrids that mature early may have lower ED of DM and starch and would benefit from prolonged ensilage time. Kernel processing during silage making is recommended for short-season corn hybrids as a means of enhancing rumen availability of starch.

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