A comparison of three techniques to determine the herbage intake of dairy cows grazing kikuyu (Pennisetum clandestinum) pasture

1996 ◽  
Vol 36 (1) ◽  
pp. 23 ◽  
Author(s):  
M Reeves ◽  
WJ Fulkerson ◽  
RC Kellaway ◽  
H Dove
Keyword(s):  
Quality Parameters ◽  
Pennisetum Clandestinum ◽  
Concentrate Supplementation ◽  
Herbage Intake ◽  
Time Period ◽  
The Difference ◽  
Standard Energy

Two studies were conducted to compare the precision of estimating kikuyu grass (Pennisetum clandestinum) intake by Friesian cows fed 0, 3 or 6 kg of cereal-based concentrate/cow.day, using a rising plate meter (RPM), standard energy requirements in reverse (RS) and plant wax alkanes as internal markers. Study 1 compared herbage intake estimates obtained using the RPM and RS techniques over a 45-day period. RS estimates were based on the metabolisable energy (ME) of ration components derived from in vitro organic matter digestibility (OMD) values. Pregrazing calibration equations for the RPM determined at 2-weekly intervals differed significantly (P<0.01) from postgrazing calibrations; consequently separate equations were used to determine pasture intake as the difference in pre- and post-grazing pasture mass. Estimates of total intake were lower using the RPM than the RS technique for the groups fed 0 kg (12.5 v. 14.8 kg dry matter (DM)/cow.day) and 3 kg (10.4 v. 12.9 kg DM/cow.day) of concentrate, and higher for those receiving 6 kg (10.5 v. 7.8 kg DM/cow.day). In study 2 (12 days duration), intakes derived using alkanes were compared with intakes estimated using the RS and RPM techniques. The C32/C33 alkane pair gave the closest estimate of herbage intake to that obtained using the RPM and RS techniques. Whole diet in vivo DM digestibility (DMD), determined by the alkane method, was not significantly different between the 3 groups (mean 70%), suggesting that digestibility of the kikuyu declined with increasing concentrate supplementation. The in vivo DMD of kikuyu alone (determined in the non-concentrate-supplemented cows) was considerably higher (69.5%) than the OMD determined in vitro (63.9%). By using in vivo rather than in vitro digestibilities for kikuyu in the RS calculations, the intake estimates were reduced by 17%, and for the 0 kg concentrate group, intake estimates aligned closely to predictions of the RPM and alkanes. Concentrates in the diet resulted in lower intake estimates using the RS technique compared with the RPM and alkane techniques. This was most evident at the 6 kg level of supplementation where RS predicted kikuyu intake to be 6.5 kg DM/cow.day using in vivo-derived DMD and this was substantially lower than either the RPM (12.4 kg DM/cow.day) or alkanes (9.2 kg DM/cow.day). The alkane technique provided a direct and precise method of measuring the intake of individual cows grazing tightly-managed kikuyu pasture. With the use of accurate animal production and feed quality parameters, the RS technique can provide sensible pasture intake estimates over an extended time period. The RPM technique is useful for obtaining herd estimates of pasture intake and for the determination of pasture parameters associated with intake.

The nutrition of grazing ewes during pregnancy and lactation: a comparison of alkane-based and chromium/in vitro-based estimates of herbage intake

2000 ◽  
Vol 51 (6) ◽  
pp. 765 ◽  
Author(s):  
H. Dove ◽  
M. Freer ◽  
J. Z. Foot
Keyword(s):  
Late Pregnancy ◽  
In Vitro Digestibility ◽  
Faecal Output ◽  
Stage Of Lactation ◽  
Herbage Intake ◽  
Faecal Samples ◽  
Pregnancy And Lactation ◽  
The Difference

The n-alkane and chromium/in vitro procedures for estimating herbage intake were compared in grazing ewes during late pregnancy, early lactation, and mid-lactation. To ensure differences in herbage intake, the ewes were grazed in 4 plots of phalaris-dominant pasture at 2 levels of stocking: 17.1 ewes/ha and 30.8 ewes/ha. To investigate whether either procedure for estimating herbage intake was influenced by supplement consumption, half of the ewes at each stocking level received 500 g/day air-dry of a pelletted supplement (1 : 1 milled oat grain : sunflower meal). Supplement intakes were estimated using tritiated gypsum as a marker. During intake measurement periods, ewes were dosed twice daily with both alkane capsules and capsules containing chromium sesquioxide. For the last 6 days of the 12-day dosing period, rectal faecal samples were taken twice daily, immediately before the dosing. Over these same periods, wether sheep fitted with faecal collection harnesses were similarly dosed and sampled, and their total faecal output collected to establish the faecal recovery of chromium and the alkanes. Herbage intakes were estimated using the C27/C28, C29/C28, C31/C32, and C33/C32 alkane pairs. Estimates of intake based on the shorter alkane pairs were lower than those estimated with the C33/C32 alkane pair, by amounts which differed between the periods. Evidence is presented that estimates based on the last pair of alkanes (C33/C32) are the most accurate and are also more accurate than those based on the chromium/in vitro procedure. The relationship between these 2 methods for estimating intake was different in mid-pregnancy compared with either stage of lactation. The consumption of supplement did not interfere with any of the methods for estimating herbage intake. Estimates of faecal output based on the use of chromium, C28 alkane, or C32 as an external marker were statistically identical, indicating that the difference between the 2 methods for estimating herbage intake was not related to a failure to accommodate the incomplete recovery of any of the markers used or to the failure of rectal grab samples to be representative of total faeces. Our results indicate that herbage collected by oesophageally fistulated (OF) sheep was representative of that grazed by the ewes and could thus be used to provide the herbage alkane data needed to estimate herbage intake by the alkane method. However, the in vitro digestibility values obtained from the OF samples did not represent the digestibilities actually occurring in vivo. This was the main cause of the observed difference between the 2 methods for estimating intake. Possible reasons for the differences between the in vitro and in vivo estimates of digestibility are discussed.

scholarly journals Modern Approaches to Determination of the Biological Activity of Insulin and its

2019 ◽  
Vol 9 (2) ◽  
pp. 85-92
Author(s):  
T. A. Batuashvili ◽  
L. V. Simutenko ◽  
P. V. Shadrin ◽  
N. P. Neugodova
Keyword(s):  
Biological Activity ◽  
Animal Models ◽  
Insulin Analogues ◽  
Quality Parameters ◽  
The Body ◽  
Animal Testing ◽  
Biological Potency

The paper considers insulin’s specific action on the patient’s body, types of insulin preparations and insulin analogues which are used for the treatment of diabetes, as well as applicable requirements for these products. It was demonstrated that determination of biological activity is one of the key quality parameters of this type of medicines. The paper summarises the methods used for evaluation of insulin and its analogues, which are based both on the hormone’s general action on the body (in vivo: double crossing, euglycemic clamp, etc.), and on certain aspects of the hormone’s interaction with the body systems (in vitro: receptor-binding assay, phosphorylation, metabolic methods). Due to the appearance of insulin biosimilars on the pharmaceutical market, the article raises the issue that the «Biological potency» parameter tested in animals should be kept as part of the product specification. The analysis of the in vivo and in vitro methods of biological activity determination convincingly demonstrates that animal models can not be replaced with the modern analytical methods based on cell cultures. Consequently, animal models are still necessary, as they allow for an adequate assessment of the quality of insulins in terms of «Biological potency». Taking into account the global trend towards reduction of animal testing, the authors point out the need to develop modern methods, the results of which will be comparable to the results of in vivo determination of the biological activity.

scholarly journals A method to quantify glucose utilization in vivo in skeletal muscle and white adipose tissue of the anaesthetized rat

1985 ◽  
Vol 228 (1) ◽  
pp. 103-110 ◽  
Author(s):  
P Ferré ◽  
A Leturque ◽  
A F Burnol ◽  
L Penicaud ◽  
J Girard
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Glucose Utilization ◽  
Correction Factors ◽  
Arterial Blood ◽  
Time Period ◽  
Anaesthetized Rat

A quantitative method allowing determination of glucose metabolism in vivo in muscles and white adipose tissue of the anaesthetized rat is presented. A tracer dose of 2-deoxy[3H]glucose was injected intravenously in an anaesthetized rat and the concentration of 2-deoxy[3H]glucose was monitored in arterial blood. After 30-80 min, three muscles, the soleus, the extensor digitorum longus and the epitrochlearis, periovarian white adipose tissue and brain were sampled and analysed for their content of 2-deoxy[3H]glucose 6-phosphate. This content could be related to glucose utilization during the same time period, since (1) the integral of the decrease of 2-deoxy[3H]glucose in arterial blood was known and (2) correction factors for the analogue effect of 2-deoxyglucose compared with glucose in the transport and phosphorylation steps were determined from experiments in vitro. Glucose utilization was then measured by this technique in the tissues of post-absorptive rats in the basal state (0.1 munit of insulin/ml of plasma) or during euglycaemic-hyperinsulinaemic glucose clamp (8 munits of insulin/ml of plasma) and of 48 h-starved rats. Results corresponded qualitatively and quantitatively to the known physiological characteristics of the tissues studied.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Fusobacterium Nucleatum ◽  
Living Cells ◽  
First Time ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

Sign in / Sign up

Export Citation Format

Share Document