Estimation of intake and digestibility of silage by beef steers using a controlled release capsule of n-alkanes

2003 ◽  
Vol 83 (4) ◽  
pp. 761-768 ◽  
Author(s):  
E. Charmley ◽  
D. R. Ouellet ◽  
D. M. Veira ◽  
R. Michaud ◽  
J. L. Duynisveld ◽  
...  
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
High Standard ◽  
Standard Errors ◽  
Beef Steers ◽  
Release Rates ◽  
Significant Difference ◽  
Fecal Recovery ◽  
Ad Libitum ◽  
Predicted Values

Twelve beef steers were fed a grass-legume silage either ad libitum or at 70% of ad libitum feeding. Intake and digestibility were measured directly or predicted using the alkane ratio technique. The C32 and C36 alkanes were delivered via a controlled release capsule (CRC) in the rumen. Level of feeding had no effect on digestibility (P > 0.05) but dry matter (DM) intake tended to be greater for steers fed ad libitum (P = 0.08). The release of alkanes from the CRC was erratic and 20% greater than expected. This influenced the exogenous to endogenous alkane ratios. Estimates of intake were therefore derived using both the expected and actual (determined from total collection of feces and their alkane analysis) exogenous alkane release rates. Estimated intakes based on the manufacturers’ release rate were underestimated and associated with high standard errors. For cattle fed restricted silage, estimated intakes obtained with C31:C32, C33:C32 and C33:C36 alkane pairs and using actual measured release rates of exogenous markers were associated with lower standard errors and averaged 87, 102 and 103% of actual values, respectively. For ad libitum-fed cattle the corresponding values were 81, 96 and 96% of actual values. There was no significant difference between actual and estimated DM intake when the C33:C32 and C36:C32 alkane pairs were used. The precision of intake estimates using manufacturers release rates for exogenous alkanes was poor, as evidenced by significant discrepancies (P < 0.05 for four of six estimates) between observed and predicted values averaging 2.26 kg or 30% of DM intake. However, when measured exogenous alkane release rates were used, standard errors were reduced and discrepancies for estimates using C33:C32 and C33:C326 were only 0.4 kg or 6% of DM intake. Fecal recovery of C27, C29, C31 and C33 alkanes was 73.4, 92.7, 85.6 and 100%, respectively. Both C29 and C33 gave good estimates of digestibility because of high recovery. Observed and estimated values were not significantly different. It is concluded that exogenous alkane release from CRCs was not satisfactorily consistent. Reliable estimates of intake could only be made if actual release rate was known. Endogenous alkanes can be used for determination of digestibility, provided fecal recovery is known. Key words: Beef, silage, alkane, intake, digestibility

Performance of Controlled Release Dispensers for Grandlure, the Pheromone of the Boll Weevil (Coleoptera: Curculionidae)2

1990 ◽  
Vol 25 (3) ◽  
pp. 414-426 ◽  
Author(s):  
B. A. Leonhardt ◽  
W. A. Dickerson ◽  
R. L. Ridgway ◽  
E. D. DeVilbiss
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Emission Rate ◽  
Boll Weevil ◽  
Emission Rates ◽  
Release Rates ◽  
Cigarette Filter ◽  
Temperature Changes

Comparison of laboratory-measured release rates with boll weevil captures showed that dispensers containing 10 mg of grandlure with a release rate of 10 μg/hr or higher generally produced weevil captures which were at least 50% as high as those with the reference, fresh cigarette filter. Emission rates of ca. 3 μg/hr or lower and amounts of residual grandlure of ≤ 2 mg generally resulted in weevil captures below the 50% threshold. Comparisons of commercial dispenser formulations containing 10 mg of grandlure showed that a Hereon orange plastic laminate (H-OL-T) was most effective in prolonging the release of grandlure in both field and laboratory evaluations. Its emission rate was least affected by temperature changes. Scentry PVC dispensers (S-T-T, S-C-T, S-S-T, and S-YS-T) and the Consep membrane (C-M-T) lost grandlure more rapidly than did the laminate; however, differences in weevil captures were often not significant. Fermone black PVC squares (F-S-T and F-OS-T), AgriSense polymeric rods, (A-50R-T and A-35R-T) and the cigarette filter (CF-T) were less effective in extending the release of grandlure. Dispensers mounted in the capture cylinder lost grandlure more rapidly than did similar dispensers mounted in the cooler trap base. A layer of stickum on one side of flat dispensers to facilitate attachment to the trap resulted in a somewhat lower release rate of grandlure.

Lipid-Based Implants: Impact of Formulation Parameters

2014 ◽  
Vol 1060 ◽  
pp. 87-90
Author(s):  
Marisa Nicolai ◽  
Vanessa Amaral ◽  
Cátia Antunes ◽  
Duangratana Shuwisitkul ◽  
Joana Portugal Mota
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Release Rates ◽  
Drug Release Rate ◽  
Blend Ratio ◽  
Drug Type ◽  
Formulation Parameters ◽  
Blend Ratios ◽  
Aqueous Solubilities

Lipid implants have been attracting attention in recent years. However, to better understand these systems, more fundamental studies are required. The objective of this work was to evaluate the effect of some formulation parameters, namely lipid and drug type, implant shape/surface area and lipid blend ratio, on drug release rate. The developed implants were cylindrical or spherical in shape with an even surface. Caffeine release from glycerol-trimyristate implant was very fast when compared with glycerol-tristerate matrix. The latter allowed a 4 month controlled release in contrast with glycerol-trimyristate matrix (~ 5 days). Caffeine and theophylline presented similar release rates, despite their different aqueous solubilities. In addition, different lipid blend ratios provided different release profiles for caffeine.

scholarly journals Estimation of feed intake by cattle using controlled-release capsules containing n-alkanes or chromium sesquioxide

2004 ◽  
Vol 142 (2) ◽  
pp. 225-234 ◽  
Author(s):  
L. M. M. FERREIRA ◽  
M. OLIVÁN ◽  
M. A. M. RODRIGUES ◽  
K. OSORO ◽  
H. DOVE ◽  
...  
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Feed Intake ◽  
Dry Weight ◽  
Average Weight ◽  
Release Rates ◽  
Grab Sampling ◽  
Holstein Friesian ◽  
The Mean ◽  
Friesian Cows

An experiment was carried out to evaluate the utilization of the n-alkane technique and the chromium sesquioxide (Cr2O3)/acid insoluble ash (AIA) procedure to estimate feed intake of meadow hay by two breeds of cattle. The animals were housed in individual pens, and offered known amounts of meadow hay as the sole diet component. One group of 4 Barrosã cows (average weight, 457±24 kg) and another group of 4 Holstein–Friesian cows (average weight, 635±148 kg) were dosed with intra-ruminal controlled-release capsules (CRC) that contained alkane markers or Cr2O3 in separate capsules. During intake estimation, meadow hay and faeces were sampled twice daily. There was no significant effect of grab sampling time on the meadow hay intake estimation, due to the fact that no differences were observed in the faecal marker concentrations.The mean real intakes, measured as the difference between the dry weight of feed offered each day and the dry weight of daily feed refusal, were 5·64 and 7·76 kg DM/day for Barrosã and Holstein–Friesian cows, respectively. For Barrosã cows the mean estimated intakes when using the CRC release rates documented by the manufacturer (MRR) were 5·66, 6·59 and 6·90 kg DM/day, using the Cr2O3/AIA procedure, C31[ratio ]C32 and C33[ratio ]C32 n-alkane pairs, respectively. For Holstein–Friesian cows the same markers gave values of 7·72, 8·51 and 8·95 kg DM/day, respectively. Mean daily intake estimation was improved when the release rate calculated as the reduction rate in CRCs payload performed in a additional experiment (CRR), was used. The differences from the real intake values, obtained using C31[ratio ]C32 and C33[ratio ]C32 alkane pairs, decreased from 950 and 1260 g/day to 140 and 420 g/day, respectively, for Barrosã cows and from 750 and 1190 g/day to 290 and 90 g/day for Holstein–Friesian cows. The intake estimation using the Cr2O3/AIA procedure was not affected by correcting the CRC release rate, because the release rates of both MRR and the CRR were similar.The results indicate that controlled-release capsules provide a uniform marker release in cattle, but also suggest that to obtain accurate estimates of intake, it is better to measure release rates within the context of particular experiments.

scholarly journals Effect of various surfactants and their concentration on controlled release of captopril from polymeric matrices

2008 ◽  
Vol 58 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Ali Nokhodchi ◽  
Davoud Hassan-Zadeh ◽  
Farnaz Monajjem-Zadeh ◽  
Nita Taghi-Zadeh
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Hydroxypropyl Methylcellulose ◽  
Water Soluble ◽  
Partial Replacement ◽  
Polymeric Matrices ◽  
Control Drug ◽  
Significant Difference ◽  
Release Data

Effect of various surfactants and their concentration on controlled release of captopril from polymeric matricesVarious methods are available to formulate water soluble drugs into sustained release dosage forms by retarding the dissolution rate. One of the methods used to control drug release and thereby prolong therapeutic activity is to use hydrophilic and lipophilic polymers. In this study, the effects of various polymers such as hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC) and sodium carboxymethylcellulose (CMC) and surfactants (sodium lauryl sulphate, cetyltrimethylammonium bromide and Arlacel 60) on the release rate of captopril were investigated. The results showed that an increase in the amount of HPMC K15M resulted in reduction of the release rate of captopril from these matrices. When HPMC was partly replaced by NaCMC (the ratio of HPMC/NaCMC was 5:1), the release rate of the drug significantly decreased. However, there was no significant difference in release rate of captopril from matrices produced with ratios of 5:1 and 2:1 of HPMC/NaCMC. The presence of lactose in matrices containing HPMC and NaCMC increased the release rate of captopril. It was interesting to note that although partial replacement of HPMC by EC reduced the release rate of the drug (ratio of HPMC/EC 2:1), the release rate was increased when the ratio of HPMC/EC was reduced to 1:1. The effects of various surfactants on the release rate of captopril from HPMC/EC (1:1) matrices were also investigated. The results showed that the surfactants did not significantly change the release rate of the drug. Release data were examined kinetically and the ideal kinetic models were estimated for the drug release. The kinetic analysis of drug release data from various formulations showed that incorporation of surfactants in HPMC/EC matrices did not produce a zero-order release pattern.

Evaluation of a Soil Incubation Method to Characterize Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers

2014 ◽  
Vol 97 (3) ◽  
pp. 643-660 ◽  
Author(s):  
L Carolina Medina ◽  
Jerry B Sartain ◽  
Thomas A Obreza ◽  
William L Hall ◽  
Nancy J Thiex
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Nutrient Release ◽  
Soil Incubation ◽  
Release Rates ◽  
N Release ◽  
Production And Distribution ◽  
Slow Release Fertilizers ◽  
Incubation Temperatures ◽  
Controlled Release Fertilizers

Abstract Several technologies have been proposed to characterize the nutrient release patterns of slow- release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35°C increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (Iowa&gt;California&gt;Pennsylvania&gt;Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.

Factors influencing the release rate of alkanes from an intra-ruminal, controlled-release device, and the resultant accuracy of intake estimation in sheep

2002 ◽  
Vol 53 (6) ◽  
pp. 681 ◽  
Author(s):  
H. Dove ◽  
R. W. Mayes ◽  
C. S. Lamb ◽  
K. J. Ellis
Keyword(s):  
Controlled Release ◽  
Release Rate ◽  
Feeding Frequency ◽  
Release Rates ◽  
Castrate Male ◽  
Once Daily ◽  
Faecal Output ◽  
Factors Influencing ◽  
Herbage Intake ◽  
Release Devices

Two experiments were conducted to evaluate factors influencing the release rate of octacosane (C28) and dotriacontane (C32) synthetic alkanes from controlled-release devices (CRD) inserted into the rumen of sheep, and the resultant accuracy of alkane-based estimates of herbage intake. In the first experiment, estimates of the rate of release of alkanes from CRD suspended in the rumen of 7 rumen-fistulated ewes were obtained by directly measuring the rate of CRD plunger travel. In the second experiment, CRD were administered orally to 24 castrate male sheep to evaluate the effects of level of feeding (1200 v. 600 g DM/day), frequency of feeding (continuous v. once-daily), and number of CRD inserted (1 v. 2) on temporal trends in faecal alkane concentrations and ratios and on the accuracy of estimation of intake. In both experiments, animals were also dosed orally, once daily with paper pellets containing 56 mg hexatriacontane (C36). In Expt 1, linear alkane release from the CRD commenced after a lag period of 2-3 days, at mean rates of 40.1 mg/day (C28) and 41.7 mg/day (C32), close to the desired rates of 40 mg/day. There was no evidence of curvilinearity, and differences in release rate between sheep were small (CV 4.1%). Alkanes attributable to the CRD appeared in faeces after 2-3 days and reached plateau concentrations by 6-7 days. Data are presented to indicate that the release rate was not affected by the removal of CRD from the rumen for measurement, and that the release rates in fistulated (Expt 1) and intact sheep (Expt 2) were similar. In Expt 2, there was no effect of level of feeding on CRD release rates and faecal alkane concentrations were consistent with the differences in faecal output caused by feeding level. As a result, the accuracy with which known intakes were estimated was unaffected by level of feeding. Similarly, there were no effects of feeding frequency on the accuracy of estimated intake, implying that in this study, feeding frequency had no effect on CRD release rates. The administration of 2 CRD to half the animals in this experiment increased faecal concentrations of C28 and C32 and the synthetic : herbage alkane ratios associated with these alkanes [e.g. faecal C32 : tritriacontane (C33)] but these changes were not significantly different from those expected from the release rates estimated in Expt 1. As a result, the accuracy with which known intakes were estimated was not influenced by the number of CRD administered. In both experiments, once-daily dosing with C36 alkane resulted in a more rapid rise in faecal C36 concentrations and faecal C36 : pentatriacontane (C35) ratios to maximal levels (3-4 days), compared with alkanes derived from the CRD (6-7 days), but thereafter, faecal C36 concentrations were much more variable, especially in the fistulated sheep. As a result, intake estimates based on the C36 : C35 alkane pair significantly over-estimated known intakes by 13% (Expt 1) and 8% (Expt 2). Data are presented to indicate that C36 alkane functioned satisfactorily as a faecal output marker and, with C32 : C33 estimates of intake, provided accurate estimates of herbage digestibility. The results indicate that intra-ruminal controlled-release devices provide a satisfactory means of delivering an accurate, daily dose of alkanes for the estimation of herbage intake, faecal output, and digestibility in sheep.

Formulation Development and Characterization of controlled release core in cup matrix tablets of venlafaxine HCl

2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Rate ◽  
Zero Order ◽  
Water Soluble ◽  
Matrix Tablets ◽  
Drug Dissolution ◽  
Crystalline Cellulose ◽  
Hydrophobic Polymers

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.

scholarly journals The nitrogen topdressing mode of indica-japonica and indica hybrid rice are different after side-deep fertilization with machine transplanting

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaodan Wang ◽  
Yaliang Wang ◽  
Yuping Zhang ◽  
Jing Xiang ◽  
Yikai Zhang ◽  
...  
Keyword(s):  
Single Dose ◽  
Controlled Release ◽  
Nitrogen Uptake ◽  
Dry Matter ◽  
Hybrid Rice ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Quick Release ◽  
Significant Difference ◽  
Spikelets Per Panicle

AbstractDetermination of the optimal fertilization method is crucial to maximize nitrogen use efficiency and yield of different rice cultivars. Side-deep fertilization with controlled-release nitrogen, in conjunction with machine transplanting and subsequent topdressing, was applied to Indica–japonica hybrid rice ‘Yongyou1540’ (YY1540) and indica hybrid rice ‘Tianyouhuazhan’ (TYHZ). Four nitrogen treatments were applied in 2018 and 2019: traditional nitrogen application with quick-release nitrogen (T1), single-dose deep fertilization at transplanting with 100% controlled-release nitrogen (T2), and deep fertilization of 70% controlled-release nitrogen and topdressing of 30% quick nitrogen at tillering (T3), or at panicle initiation (T4). Side-deep fertilization reduced the fertilizer application frequency without causing yield loss, T4 enhanced the yield of YY1540 by increasing the number of productive tillers and number of spikelets per panicle compared with T1, T2 and T3. The yield of TYHZ showed no significant difference among treatments. The T4 treatment decreased the number of tillers at the tilling peak stage and increased the percentage productive tillers and number of differentiated spikelets. Compared with the other treatments, T4 increased dry matter accumulation and leaf area index during panicle initiation and grain ripening, and contributed to enhanced nitrogen uptake and nitrogen utilization in YY1540. On average, nitrogen uptake and utilization in YY1540 were highest in T4, but no significant differences among treatments were observed in TYHZ. Dry matter accumulation and nitrogen uptake from panicle initiation to heading of YY1540 were correlated with number of spikelets per panicle, but no significant correlations were observed for TYHZ. Supplementary topdressing with quick-release nitrogen at the panicle initiation stage was required to increase yield of indica–japonica hybrid rice, whereas single-dose deep fertilization with controlled-release nitrogen is satisfactory for the indica hybrid cultivar.

scholarly journals PSXII-3 Rumen microbiome from beef steers undergoing grain adaptation with steam-flaked corn varying in bulk density

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 446-447
Author(s):  
Kaue Tonelli Nardi ◽  
Kaliu G Scaranto Silva ◽  
Igor Gomes Favero ◽  
Jordan K Hinds ◽  
Carly A Hoffmann ◽  
...  
Keyword(s):  
Bulk Density ◽  
Block Design ◽  
Order Effects ◽  
Beef Steers ◽  
Post Feeding ◽  
Rumen Microbiome ◽  
Randomized Complete Block Design ◽  
Ad Libitum ◽  
Microbiome Data ◽  
Adaptation Phase

Abstract The effects of steam-flaked corn bulk density during grain adaptation phase on ruminal microbiome were evaluated. Crossbred-Angus ruminally cannulated steers (n = 6; BW = 405 ± 42 kg) were assigned to a randomized complete block design (block = body weight) to 1 of 2 grain adaptation strategies: 1) steam-flaked corn (SFC) bulk density of 335 g/L; and 2) 412 g/L. Steers were ad libitum fed, individually, during 6-7d phases, consisting of: HAY, followed by the STEP-UP1 through STEP-UP4, diets, respectively, in which roughage was gradually replaced with grain until FINISHER diet was fed. Respective SFC bulk densities were fed throughout STEP-UP diets, while the FINISHER diet consisted of 335 g/L strategy only for both groups. Ruminal fluid samples (100 mL) were collected on d-5 of each step, at 6h post-feeding for DNA extraction. Microbiome data were sequenced by Illumnia® NovaSeq™ 6000 (16S rRNA). The SFC bulk density did not affect (P &gt; 0.50) the relative abundance (RA) for any taxonomy classification. Regardless of SFC bulk density, inclusion of grain throughout adaptation phases affected domain (P ≤ 0.03) when initial phases were compared to FINISHER. Phylum RA were affected (P ≤ 0.05) for Actinobacteria (27%), Bacteroidetes (11%), and Euryarchaeota (2%). Within Class RA were affected (P ≤ 0.04) for Clostridia (46%), Actinobacteria (27%), and Bacilli (5%). Order effects on RA were observed (P ≤ 0.04) for Clostridiales (45%), Coriobacteriales (25%), and Lactobacillales (4%). Within Family RA was affected (P ≤ 0.03) for Coriobacteriaceae (25%), Lachnospiraceae (27%), Ruminococcaceae (6%), and Lactobacillaceae (4%), while a tendency (P = 0.09) was observed for Veillonellaceae (1%). In Genus, RA was affected (P ≤ 0.01) for Olsenela (22%), Pediococcus (3%), and Butyrivibrio (3%). As steers advance through subsequent grain adaptation phases until the FINISHER, more meaningful ruminal microbiome changes are observed than SFC density change.

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