Relationship between in vivo, in situ and in vitro techniques for evaluation of tropical forages in Brazil

2002 ◽  
Vol 2002 ◽  
pp. 141-141
Author(s):  
Ives C.S. Bueno ◽  
Sergio L.S. Cabral Filho ◽  
Liliana L. Oetting ◽  
Mariana C. Machado ◽  
Sarita P. Gobbo ◽  
...  

In vivo experiments are the preferred method for ruminant feed evaluation, but they are very expensive, laborious and time-consuming. In situ and in vitro techniques are commonly used as a routine all over the world as a predictor of in vivo results. In situ assays have been the basis of many feed evaluation systems due to its ease of use and low cost. In vitro techniques, such as gas production, give an opportunity to get similar information plus a better description of fermentative kinetics. The aim of this work was to compare data obtained from in vivo, in vitro and in situ assays for the evaluation of three tropical forages used in ruminant nutrition in Brazil.

2020 ◽  
Vol 158 (1-2) ◽  
pp. 150-158 ◽  
Author(s):  
B. C. Silva ◽  
M. V. C. Pacheco ◽  
L. A. Godoi ◽  
F. A. S. Silva ◽  
D. Zanetti ◽  
...  

AbstractAn experiment was conducted to evaluate: (1) the effects of ensiling maize or sorghum grains after reconstitution on readily soluble fraction (a), potentially degradable fraction in the rumen (b) and rate constant for degradation of b (c) of dry matter (DM), organic matter (OM) and starch (STA); and (2) an appropriate incubation time for in situ or in vitro procedures to estimate in vivo digestibility. Four rumen-cannulated Nellore bulls (body weight = 262 ± 19.6 kg) distributed in a 4 × 4 Latin square were used. Diets were based on dry ground maize (DGM); or dry ground sorghum (DGS); or reconstituted ground maize silage; or reconstituted ground sorghum silage. In vitro and in situ incubations of the individual grains and diets were simultaneously performed with in vivo digestibility. In general, reconstituted grains and diets based on reconstituted grains presented greater (P < 0.05) fraction a and lower (P < 0.05) fraction b of DM, OM and STA compared to dry grains and diets based on dry grain. However, the magnitude of response of the reconstitution and ensiling process on DM and OM degradability parameter was greater for maize than that for sorghum. Moreover, no differences (P > 0.05) were observed between DGM- and DGS-based diets for c estimates. The results suggest that the reconstitution process promotes grains protein matrix breakdown increasing STA availability. The incubation times required for in vivo digestibility estimations of DM, OM and STA are 24 h for in situ and 36 h for in vitro procedures.


Author(s):  
M.T. Dentinho ◽  
K. Khazaal ◽  
J.M. Ribeiro ◽  
E.R. Ørskov

By using separated values of kinetics of in situ dry matter (DM) degradation or in vitro gas production (Menke and Steingass, 1988) of leguminosae hays, Khazaal et al, (1993) reported high correlation with intake (r= 0.88; r= 0.79) and in vivo DM digestibility (DMD) (r= 0.94; r= 0.88). The aim of the present study was to extend the range of samples used and compare the ability of the 2 stages in vitro digestibility (Tilley and Terry, 1963), the in situ DM degradation or the gas production techniques to predict daily intake (g DM/ kgW0.75) and in vivo DM digestibility (DMD) of 19 leguminous and graminaceous hays fed to sheep.Three harvesting stages (early bloom EB, mid bloom MB or in seed IS) made from lucerne (Medicago sativa), sweet clover (Melilotus segetalis), Persian clover (Trifolium resupinatum), Rye (Secale cereale), Triticale (Triticale hexaploid), oat (Avena stativa) and a pre-bloom (PB) Italian ryegrass (Lolium multiflorum ). Each hay was fed ad libitum to 4 Merino male sheep and their intake and in vivo DMD recorded. Gas production (ml/ 200 mg DM) or in situ DM degradation (g/ 100 g DM) were determined as described by Khazaal et al, (1993) after 6, 12, 24, 48, 72 or 96 h incubation. Measured gas production or DM degradation values were fitted to the equation p=a+b(l-e-ct)(McDonald, 1981) where p is gas production or DM degradation at time t and a, b and c are constants. For nylon bag the washing loss (soluble fraction) was defined as A, the insoluble but fermentable matter was defined as B=(a+b)-A, and c is the rate of fermentation or degradation (Ørskov and Ryle, 1990).


2010 ◽  
Vol 148 (6) ◽  
pp. 723-733 ◽  
Author(s):  
H. KHALILVANDI-BEHROOZYAR ◽  
M. DEHGHAN-BANADAKY ◽  
K. REZAYAZDI

SUMMARYThe current study was conducted to determine chemical composition, nutrient content and availability, metabolizable energy (ME) content and nutritive value of sainfoin hay for ruminants. Three ruminally cannulated Holstein cows were used forin situandin vivoexperiments, to determine rumen degradability and digestibility of sainfoin hay. Apparent total tract digestibility of nutrients was determined with feeding of sainfoin hay as the sole diet to achieve 10% more than maintenance energy requirements. Six Zandi ewes were used in the palatability experiment. Means for dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and condensed tannins (CTs) of sainfoin hay were: 940·4 g/kg and 93·43, 12·13, 47·87, 43·33 and 2·13 g/kg DM, respectively.In situeffective degradability of CP and DM were 0·38 and 0·54 g/g with a ruminal outflow rate of 0·05/h, respectively. OM apparent digestibility was in the range of 0·592–0·689, respectively, for Tilley & Terry and total faecal collection assays. ME content of sainfoin hay, according to different methods (gas production,in vitroandin vivodetermined digestible organic matter in dry matter (DOMD)) was in the range 6·87–10·11 MJ/kg DM. Metabolizable protein (MP) content was 483·4 g/kg CP. Sainfoin was more palatable than alfalfa for sheep. It was concluded that sainfoin has a potential use in ruminant rations, especially if environmental conditions are not suitable for alfalfa production.


1999 ◽  
Vol 50 (5) ◽  
pp. 825 ◽  
Author(s):  
S. Kitessa ◽  
G. G. Irish ◽  
P. C. Flinn

Digestibility is a very useful index of the energy content of ruminant feeds, but cheaper and quicker laboratory methods are required as an alternative to the ultimate measure of in vivo digestibility using animals. These methods involve either prediction of digestibility from chemical composition or in vitro and in situ simulation of the digestion process. This review presents a range of chemical and in vitro techniques for predicting digestibility, together with an assessment of their advantages and limitations, particularly the degree to which they account for the sources of variation in in vivo digestibility in ruminants. In situ digestion of feed samples in the actual rumen environment is probably the most accurate of the non in vivo procedures, but is not suitable for routine application. Thein vitro gas production technique offers no advantages in prediction of total tract digestibility, but is useful for screening cereal grains for rate of starch hydrolysis in the rumen. The preferred procedure for routine laboratory prediction of digestibility is the pepsin-cellulase technique, provided amylase is included or high temperature digestion is used for samples high in starch content. Prediction of digestibility from chemical composition is not recommended. The optical technique of near infrared reflectance spectroscopy can be calibrated against any of the methods outlined in this review, and is unsurpassed in terms of speed and repeatability. Direct NIR prediction of in vivo digestibility is also possible, but is limited by the lack of adequate numbers of feed samples with known in vivo values. Future work should be aimed at filling this gap and also improving the accuracy of laboratory methods for predicting the digestibility of low quality feeds.


1996 ◽  
Vol 1996 ◽  
pp. 223-223
Author(s):  
A. Pendong ◽  
J.H.T. Barbi ◽  
E. Owen ◽  
E.R. Deaville

During the past twenty years the in vitro, two-stage digestibility method of Tilley and Terry (1963) has been widely used to predict the in vivo digestible organic matter content (DOMD) of forage dry matter. Recently in vitro gas production methods have attracted considerable research interest because of their potential to simulate the fermentation kinetics of forages in the rumen. However the potential of gas production methods to assess DOMD, as well as fermentation kinetics, has not been reported.


1998 ◽  
Vol 22 ◽  
pp. 1-11 ◽  
Author(s):  
S. Tamminga ◽  
B. A. Williams

AbstractIn vitro techniques are widely used to predict the nutritive value of foods for farm animals. However, food evaluation systems are moving towards systems based on nutrient flows rather than on energy or protein. Nutrients are supplied via the digestive tract and presently available in vitro methods are inadequate to simulate the complicated and non-steady-state processes in this tract. This is partly due the lack of adequate in vivo reference values and partly due to a too-high degree of standardization and simplification. Future developments should therefore aim to develop in vitro systems which closely monitor the dynamics of the digestive processes. Adequate interpretation of the results may require sophisticated mathematical models.


1998 ◽  
Vol 22 ◽  
pp. 33-35
Author(s):  
A. T. Adesogan ◽  
E. Owen ◽  
D. I. Givens

Several published reports on the nutritive value of whole-crop wheat (WCW) have been based on estimations from laboratory techniques, some of which were developed for grass silage. However, there is little information on the accuracy of such estimations. Therefore the aim of this study was to evaluate the suitability of predicting the in vivo digestibility of WCW from various less animal-dependent techniques.


2004 ◽  
Vol 116 (1-2) ◽  
pp. 35-51 ◽  
Author(s):  
J.M.J Gosselink ◽  
J.P Dulphy ◽  
C Poncet ◽  
J Aufrère ◽  
S Tamminga ◽  
...  
Keyword(s):  

1996 ◽  
Vol 1996 ◽  
pp. 227-227 ◽  
Author(s):  
A.H. Murray ◽  
D. Daalkhaijav ◽  
C.D. Wood

In Mongolia animal performance is very much dependent on the quality and quantity of natural grassland available, since certain pastoral animals may obtain as much as 98% of their annual intake from pasture. There have been few studies to date on either in vivo or in vitro degradation of native Mongolian pastures. This paper seeks to investigate the degradation characteristics of native pastures from 2 regions in Mongolia, high mountain and forest steppe. It also investigates the relationship between the in vitro gas production technique and the in sacco technique.


1998 ◽  
Vol 22 ◽  
pp. 13-19
Author(s):  
D. J. Minson

AbstractRegressions relating in vivo digestibility to chemical composition of the food have residual standard deviations that are unacceptably high. The development of the two-stage in vitro technique inoculated with rumen liquor (Tilley and Terry, 1963) allowed dry-matter digestibility to be predicted with greater accuracy. This success was followed by a series of developments which replaced rumen liquor with inoculum produced from fresh or preserved faeces collected from sheep or cattle. Other methods used inoculum from a continuous fermentation containing rumen micro-organisms and enzymes produced by fungi. Another modification was to use gas production as a measure of in vitro digestion. The range of nutritional problems that could be measured by in vitro techniques was extended to include the estimation of voluntary food intake and protein degradation. All these in vitro techniques require standardization using food samples that have previously been analysed in vitro or offered as the sole diet to animals. The relative merits of these two calibration methods are discussed. Special facilities are required for storing and distributing these standard foods.


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