1239 Sources of variation in dry matter content and particle size distribution in total mixed rations in dairy farms in Argentina

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 596-597
Author(s):  
P. Turiello ◽  
M. Ruiz de Huidobro ◽  
F. Bargo ◽  
A. Larriestra ◽  
A. Relling
1997 ◽  
Vol 1997 ◽  
pp. 197-197
Author(s):  
R. Sanderson ◽  
S.J. Lister ◽  
A. Sargeant ◽  
M.S. Dhanoa

The objectives of this study were a) to examine the effect of particle size and silage dry matter (DM) content on the rate and pattern of fermentation of fresh silages in vitro as an aid to modelling the in vivo situation and b) to compare the rate and pattern of fermentation of fresh silage samples with those obtained for freeze-dried material.


2020 ◽  
Author(s):  
Cristina Contreras ◽  
Sara Acevedo ◽  
Sofía Martínez ◽  
Carlos Bonilla

<p>Typical information in soil databases is the soil texture and particle size distribution. These properties are used for soil description or predicting other soil properties such as bulk density or hydraulic conductivity. Measuring particle size distribution with standards methods such as the pipette or hydrometer is time-consuming because of the sample pre-treatment used to remove organic matter or iron and the sample post-treatment. Nowadays, there are new methodologies for determining soil particle size distribution, such as the Integral Suspension Pressure (ISP) method, which measures the silt content in a semi-automatized process. Thus, the main objective of this study was to evaluate the suitability of the ISP method compared to standard techniques used in soil analysis and evaluate the effect of organic matter content in the ISP measurements. The main results showed that the ISP method is equivalent in accuracy to the pipette, especially for soils rich in silt or sand content. Also, the results demonstrate the convenience of removing the soil organic matter when using the ISP for soils with more than 1.5% organic matter.</p>


1982 ◽  
Vol 62 (4) ◽  
pp. 631-639 ◽  
Author(s):  
G. T. PATTERSON ◽  
G. J. WALL

Replicate soil samples (2–20) from the A, B and C horizons of 41 pedons were collected to measure within-pedon variability of particle size distribution, organic matter content, calcium carbonate equivalent and pH. Variability in soil properties was examined in relation to the mode of origin of the soil material, soil horizonation and soil drainage. Variance in particle size distribution was significantly influenced by mode of deposition as well as by soil horizons, while soil drainage had no significant influence on the variation in particle size distribution. Variance in calcium carbonate equivalent and organic matter content was not influenced by soil drainage or mode of deposition. The number of replicate samples required for statistically reliable evaluation of a pedon at given confidence limits was determined for the soil properties studied. The results of these calculations indicate the need for up to five replicate samples to achieve satisfactory levels of accuracy at the 95% confidence level for some of the soil properties studied.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1085
Author(s):  
Elizabeth M. Buckhaus ◽  
Dathan T. Smerchek ◽  
Zachary K. Smith

Background:  Differing fractions of a batch of feed, differing ingredient characteristics, and inadequate mix time can lead to non-uniformity within a mix of feed.  Methods: The experiment was designed as a 5 x 2 x 2 factorial arrangement with seven replications per simple treatment mean. Factors included: 1) batch fraction (BF; n = 5); 2) corn silage inclusion level (CSLVL; n = 2) 15% or 30% inclusion (dry matter basis); and 3) mixing duration (DR; n = 2) of 20 or 25 mixer revolutions. Data were analyzed as a completely randomized design using a binomial approach. The Penn State Particle Separator was used to separate fractions of the total mixed ration (TMR). Results: No interactions between BF, CSLVL, and DR were detected (P ≥ 0.31) for any dependent variables. There was an increase (P = 0.01) in retention on the 19 mm sieve from the first BF compared to the last BF. CSLVL altered (P = 0.01) retention on the 19 mm sieve. Increasing DR from 20 to 25 revolutions had no appreciable influence (P = 0.23) on particles greater than 19 mm.  CSLVL (P = 0.01) and DR (P = 0.01) altered particle retention on the 8 mm sieve. BF (P = 0.01), CSLVL (P = 0.01), and DR (P = 0.02), influenced particle retention on the 4 mm sieve. CSLVL impacted (P ≤ 0.01) particles remaining in the bottom pan and particles greater than 4 mm. BF (P = 0.01) and CSLVL (P = 0.01) altered particles greater than 8 mm. Conclusions: These data indicate that BF and CSLVL fed alters particle size distribution that in turn could alter dry matter intake, dietary net energy content, and influence daily gain. Mixing DR had no appreciable influence on particle size distribution of the TMR.


2014 ◽  
Vol 63 (1) ◽  
pp. 9-18
Author(s):  
Hilda Hernádi ◽  
A. Makó

The obtained results of the present study showed the good applicability of the van Genuchten equation for parameterizing NAPL retention data of soils (R2 = 0.99).Sufficient applicability of continuous PTFs for estimating the parameters of NAPL retention curves was found (R2 for α, n and θs was 0.47, 0.84 and 0.86, respectively).The accuracy of parametric and point PTFs increased in case derived values of the independent variables in addition to the PSD (particle size distribution) fractions, bulk density, CaCO3 and organic matter content (R2 = 0.57–0.90 and RMSE = 2.43–5.67 vol%) were used, as compared to PTFs using only the original values of basic soil parameters as predictor variables (R2 = 0,48–0.86; RMSE = 3.56–6.83 vol%).According to the gained results, PTFs seem to be similarly accurate if the particle size distribution of soils — determined by different standard methods — are applied as independent variables.


1988 ◽  
Vol 39 (4) ◽  
pp. 671 ◽  
Author(s):  
RH Weston

Lactating and non-pregnant, non-lactating ewes were compared with respect to voluntary consumption of a medium quality roughage and various aspects of digestion of the roughage as fed at intakes near ad libitum. The lactating ewes, relative to their control counterparts (i) consumed more roughage, (ii) ate more rapidly, (iii) maintained higher levels of digesta in the rumen, omasum, abomasum, and caecum + proximal colon, (iv) showed no difference in particle size distribution in rumen digesta, (v) exhibited enhanced rumination activities and (vi) on average, cleared a particulate marker more rapidly from the rumen. It was estimated that the lactating ewes had a higher energy deficit than the controls. It was concluded that (i) the greater rate of removal of feed dry matter from the reticula-rumen (mass/time) during lactation was largely attributable to the enhancing effect of the prevailing higher reticulo-rumen digesta load on rumination, digestion and propulsion, (ii) neither capacity to use energy nor physiological capability of the reticula-rumen played a primary limiting role in the regulation of roughage intake, with the control of animals, (iii) the comparative data are consistent with a concept that energy metabolism and digesta load interact in the regulation of roughage intake, and (iv) scope exists for increasing consumption of the roughage by appropriate physiological manipulation of the animal.


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