The use of dairy cow faeces rather than rumen liquor in the gas pressure transducer technique for assessing digestion kinetics in vitro

1995 ◽  
Vol 1995 ◽  
pp. 113-113 ◽  
Author(s):  
D M Harris ◽  
A Barlet ◽  
A T Chamberlain

The pressure transducer technique has been proposed as a method of evaluating feed degradation characteristics (Theodorou, 1993) and it has been shown to predict the in vivo and in sacco degradability of forages (Blummel and Orskov, 1993). However the original technique requires rumen liquor and hence access to surgically prepared animals. Faecal material is generally easier to obtain and this work assessed it's suitability as an alternative source of microbes.Rumen liquor (R) and faeces (F) were collected simultaneously from a rumenally fistulated lactating dairy cow. R was mixed 1:1 with modified van Soest medium and F 1:2 to obtain similar dry matter contents. Homogenised strained 20 ml aliquats were inoculated into vented 250 ml bottles containing 180 ml of modified van Soest medium and 1.5g DM of a 7:3 mixture of milled air dried grass silage and 180 g CP / kg DM concentrates. The 7:3 ratio of silage and concentrates was chosen to reflect the diet the donor cow was consuming.

1995 ◽  
Vol 1995 ◽  
pp. 113-113
Author(s):  
D M Harris ◽  
A Barlet ◽  
A T Chamberlain

The pressure transducer technique has been proposed as a method of evaluating feed degradation characteristics (Theodorou, 1993) and it has been shown to predict the in vivo and in sacco degradability of forages (Blummel and Orskov, 1993). However the original technique requires rumen liquor and hence access to surgically prepared animals. Faecal material is generally easier to obtain and this work assessed it's suitability as an alternative source of microbes.Rumen liquor (R) and faeces (F) were collected simultaneously from a rumenally fistulated lactating dairy cow. R was mixed 1:1 with modified van Soest medium and F 1:2 to obtain similar dry matter contents. Homogenised strained 20 ml aliquats were inoculated into vented 250 ml bottles containing 180 ml of modified van Soest medium and 1.5g DM of a 7:3 mixture of milled air dried grass silage and 180 g CP / kg DM concentrates. The 7:3 ratio of silage and concentrates was chosen to reflect the diet the donor cow was consuming.


2009 ◽  
Vol 22 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Marina Vranić ◽  
Mladen Knežević ◽  
Goran Perčulija ◽  
Krešimir Bošnjak ◽  
Josip Leto

1996 ◽  
Vol 126 (2) ◽  
pp. 235-248 ◽  
Author(s):  
I. V. Nsahlai ◽  
N. N. Umunna

SUMMARYThis study (conducted in Debre Zeit, Ethiopia in 1993) examined (i) the effect of source of inoculum on in vitro dry matter (DM) digestibility (1VDMD) and gas production (GP) and (ii) the IVDMD, GP and in sacco degradability as predictors of in vivo DM digestibility (DMD) and intake. Six ruminally cannulated male sheep (used in the degradability studies and from which rumen fluid was harvested for the in vitro studies) and six intact sheep (from which faeces for reconstitution was obtained) were given teff straw ad libitum supplemented with 200 g/day of concentrate (1:1 mixture of noug (Guizotia abyssinica) cake and wheat middlings). In determining IVDMD on 26 feeds, pepsin-HC1 digestion was replaced with neutral detergent extraction. Microbial GP was measured on these feeds incubated with rumen fluid or reconstituted faeces inocula at various time periods. The degradability of each feed was determined by the nylon bag technique in three sheep. Eighty-eight intact male Ethiopian Menz type sheep (mean liveweight 256 (S.D. = 1·98) kg) were used in a randomized complete block experiment to determine intake and digestibility.Gas production using faeces inoculum (GP-F) was strongly related to GP using rumen fluid inoculum (GP-R) particularly at 48 h (R2 = 0·85; P <0·001) of incubation. The IVDMD obtained with reconstituted sheep faeces inoculum (IVDMD-F) had a strong positive relationship (R2 = 0·88; P <0·0001) with IVDMD measured using rumen fluid (IVDMD-R). The IVDMD values obtained by centrifugation were positively related to those obtained by filtration for the rumen fluid (R2 = 0·61) and reconstituted faeces (R2 = 0·47) inocula.The relationship between degradability and in vivo DMD was generally poor for roughages but improved with the length of incubation for forage legumes, being strongest at 24 h (R2 = 0·54). The in vivo DMD had the strongest relationship with GP-R at 24 h of incubation for roughages (R2 = 0·64) and legumes (R2 = 0·84). Dry matter degradability was poorly related to DM intake for roughages (R2 <0·10), while these were closely related for legumes particularly at 6 h of incubation (R2 = 0·55). The relationship between GP-R and intake was strongest at 12 h of incubation for roughages (R2 = 0·41) but was generally weak for legumes. The IVDMD accounted for a very low proportion of the variation in intake of roughages and legume forages. The gas production method was the best among the methods tested in predicting voluntary roughage intake, but not the intake of legumes. The nylon bag technique gave the best predictors (solubility, rate constant ‘c’ and Lag phase) of legume intake (R2 = 0·98).The discussion suggests explanations for why the nylon bag technique predicted performance from forage legumes better than from roughages, why the technique was much better as a predictor of intake than of in vivo DMD, and why the gas production technique predicted in vivo DMD and not the intake of legumes. Reconstituted faeces inoculum may replace rumen fluid inoculum in in vitro procedures. The IVDMD method is a less accurate predictor of in vivo DMD than GP and rumen degradability constants. Both feed factors and practices inherent in the methodologies may modify the predictiveness of indirect digestibility methods.


2015 ◽  
Vol 93 (3) ◽  
pp. 187-195 ◽  
Author(s):  
L.L. VanSomeren ◽  
P.S. Barboza ◽  
D.P. Thompson ◽  
D.D. Gustine

Ruminant populations are often limited by how well individuals are able to acquire nutrients for growth, maintenance, and reproduction. Nutrient supply to the animal is dictated by the concentration of nutrients in feeds and the efficiency of digesting those nutrients (i.e., digestibility). Many different methods have been used to measure digestibility of forages for wild herbivores, all of which rely on collecting rumen fluid from animals or incubation within animals. Animal-based methods can provide useful estimates, but the approach is limited by the expense of fistulated animals, wide variation in digestibility among animals, and contamination from endogenous and microbial sources that impairs the estimation of nutrient digestibility. We tested an in vitro method using a two-stage procedure using purified enzymes. The first stage, a 6 h acid–pepsin treatment, was followed by a combined 72 h amylase–cellulase or amylase–Viscozyme treatment. We then validated our estimates using in sacco and in vivo methods to digest samples of the same forages. In vitro estimates of dry matter (DM) digestibility were correlated with estimates of in sacco and in vivo DM digestibility (both P < 0.01). The in vitro procedure using Viscozyme (r2 = 0.77) was more precise than the in vitro procedure using cellulase (r2 = 0.59). Both procedures can be used to predict in sacco digestibility after correcting for the biases of each method. We used the in vitro method to measure digestibility of nitrogen (N; 0.07–0.95 g/g), which declined to zero as total N content declined below 0.03–0.06 g/g of DM. The in vitro method is well suited to monitoring forage quality over multiple years because it is reproducible, can be used with minimal investment by other laboratories without animal facilities, and can measure digestibility of individual nutrients such as N.


2020 ◽  
pp. 1-14
Author(s):  
Shelby Shrigley ◽  
Fredrik Nilsson ◽  
Bengt Mattsson ◽  
Alessandro Fiorenzano ◽  
Janitha Mudannayake ◽  
...  

Background: Human induced pluripotent stem cells (hiPSCs) have been proposed as an alternative source for cell replacement therapy for Parkinson’s disease (PD) and they provide the option of using the patient’s own cells. A few studies have investigated transplantation of patient-derived dopaminergic (DA) neurons in preclinical models; however, little is known about the long-term integrity and function of grafts derived from patients with PD. Objective: To assess the viability and function of DA neuron grafts derived from a patient hiPSC line with an α-synuclein gene triplication (AST18), using a clinical grade human embryonic stem cell (hESC) line (RC17) as a reference control. Methods: Cells were differentiated into ventral mesencephalic (VM)-patterned DA progenitors using an established GMP protocol. The progenitors were then either terminally differentiated to mature DA neurons in vitro or transplanted into 6-hydroxydopamine (6-OHDA) lesioned rats and their survival, maturation, function, and propensity to develop α-synuclein related pathology, were assessed in vivo. Results: Both cell lines generated functional neurons with DA properties in vitro. AST18-derived VM progenitor cells survived transplantation and matured into neuron-rich grafts similar to the RC17 cells. After 24 weeks, both cell lines produced DA-rich grafts that mediated full functional recovery; however, pathological changes were only observed in grafts derived from the α-synuclein triplication patient line. Conclusion: This data shows proof-of-principle for survival and functional recovery with familial PD patient-derived cells in the 6-OHDA model of PD. However, signs of slowly developing pathology warrants further investigation before use of autologous grafts in patients.


1977 ◽  
Vol 57 (2) ◽  
pp. 279-288 ◽  
Author(s):  
S. O. THORLACIUS

Digestibility and intake of diets containing 8, 28, 48 or 68% ground wheat straw plus ground crested wheatgrass and rapeseed meal, and diets containing 33, 48, 63 and 78% ground crested wheatgrass plus barley and rapeseed meal was measured with four yearling wethers per diet. Digestible energy (DE) content ranged from 2.07 to 2.95 kcal/g dry matter (DM) and dry matter digestibility (DMD) (%) from 48.7 to 71.1%. Regression of DE intake y (kcal/w0.75kg/d) on DE content (x) was curvilinear; y = −2,133 + 1,626x − 277.9x2, r = 0.996, P < 0.01, SE = ± 7.3. There was also a curvilinear relationship between diet density, as fed, (x) g (DM)/ml and DMD (%), y = 9.057 + 364.1x − 530.0x2, r = 0.970, P < 0.01, SE = ± 2.4. A linear regression equation was calculated over the DE range (2.07–2.52) for which there was an obvious increase in DE intake with increasing diet DE content; y = −700.6 + 361x, r = 0.994, P < 0.01, SE = ± 9.4, y = DE intake (kcal/w0.75kg/d), x = DE [kcal/g (DM)]. Using this regression equation and assuming a linear increase in DE intake with increase in diet DE content up to a point at which the apparent energy demand of the animal is satisfied gave a more accurate prediction of DE intake than when the curvilinear regression equation, y = −2,133 + 1,626x − 277.9x2, was used empirically. Accuracy of the prediction was further improved by expressing DE/unit ration volume instead of per unit DM. The sheep used in the present experiments had an apparent energy demand of 230 kcal/w0.75kg/day which was met at diet DE contents above 0.48 kcal/ml or 2.6 kcal/g (DM). There was a high correlation between in vivo DE content of the diet, y [kcal/g (DM)] and in vitro (x) digestible organic matter content, x, (%), r = 0.991, P < 0.01, y = 0.38 + 0.037x, SE = ± 0.04.


2016 ◽  
Vol 88 ◽  
pp. 199-206 ◽  
Author(s):  
Cecilie Toft Vangsøe ◽  
Anne Krog Ingerslev ◽  
Peter Kappel Theil ◽  
Mette Skou Hedemann ◽  
Helle Nygaard Lærke ◽  
...  

2020 ◽  
Vol 14 (2) ◽  
pp. 209-229
Author(s):  
Jorge Alberto Elizondo-Salazar ◽  
Cynthia Rebeca Monge-Rojas
Keyword(s):  

La calidad nutritiva de los alimentos o ingredientes utilizados para la alimentación de los rumiantes está en función del nivel de consumo, de la degradabilidad a nivel ruminal, de la digestibilidad, de la concentración de nutrientes y de la eficiencia con que estos pueden ser metabolizados y utilizados. Una vez ingeridos los alimentos, la degradabilidad hace referencia a la cantidad de alimento que desaparece en el rumen por acción de los microorganismos presentes. La degradación ruminal es crucial en el suministro de nutrientes de la dieta para satisfacer las demandas de los microorganismos y de los tejidos corporales de los animales. Por lo tanto, es esencial estudiar la dinámica de la degradación ruminal de los alimentos antes de su uso potencial para formular raciones apropiadas para los rumiantes. Entre los muchos métodos que se han utilizado en el pasado, el método in sacco ha sido el método más eficaz para estudiar la degradación del rumen; sin embargo, el uso de este método es cada vez menos frecuente debido a sus implicaciones para el bienestar animal. Si bien se han probado muchos métodos in vitro como posibles alternativas al método in sacco, no se ha podido eliminar la necesidad de utilizar animales fistulados para obtener el licor o líquido ruminal. La canulación del rumen se puede realizar en un animal sano con un gasto mínimo. La cirugía no es más difícil que la mayoría de los otros procedimientos quirúrgicos de rutina realizados por veterinarios. Un animal canulado o fistulado proporciona además una fuente de contenido ruminal a largo plazo que se puede utilizar fácilmente para transfaunar compañeras del hato que han sufrido diversos trastornos digestivos. El objetivo de este trabajo es presentar, de manera resumida, los diferentes pasos en la fistulación de una vaca y detallar el uso de la técnica in vivo o in sacco para determinar la degradabilidad ruminal de los alimentos o ingredientes.


1975 ◽  
Vol 23 (1) ◽  
pp. 3-9
Author(s):  
S. Tamminga ◽  
C.J. van der Koelen

1. Grass from the same sward was ensiled without additive, with 14.6 g formic acid/100 g crude protein or 10.8 g formic acid and 10.6 g formaldehyde/100 g crude protein. Similar grass was dried and pelleted. Drying or ensiling with the mixture reduced solubility of N in the preserved grass but formic acid increased it, and ensiling without additive increased it even more. Apparent digestibility of N in the rumen of cows tended to decrease with decrease in solubility. Digestibility in vitro of the mixed diet given to the cows, calculated from digestibility of the separate components, agreed well with the values in vivo for diets with silages, but was high for that with dried grass. (Abstract retrieved from CAB Abstracts by CABI’s permission)


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