Activity In Feed Research Articles

Survey of estrogenic activity in fish feed by YES assay

Survey of estrogenic activity in fish feed by YES assay

Determination of Phytase Activity in Feed by a Colorimetric Enzymatic Method: Collaborative Interlaboratory Study

Fourteen laboratories participated in a collaborative study (coded fyt9404) and 13 laboratories participated in a study (coded fyt9410) to validate a colorimetric assay for determination of microbial phytase activity in feed. For each study, all laboratories received 6 laboratory samples provided by one commercial supplier (phytase activity levels within the range of 200-400 per kg) to be analyzed in duplicate. Method performance was calculated and statistical calculations were executed according to AOAC guidelines. Results from 3 laboratories for study fyt9404 and from one laboratory for study fyt9410 were excluded from statistical analysis because of invalid data determined during initial review by Youden pair, value versus laboratory. For study fyt9404, repeatability relative standard deviation (RSDr) values ranged from 6.2 to 8.6%, and reproducibility relative standard deviation (RSDR) values ranged from 14.1 to 27.6%. No outliers were identified. For study fyt9410, RSDr values ranged from 3.9 to 7.9%, and RSDR values ranged from 14.0 to 20.5%. With outliers excluded, RSDr values ranged from 2.5 to 7.9%, and RSDR values ranged from 14.0 to 20.5%.

Modelling heat production and energy balance in group-housed growing pigs exposed to low or high ambient temperatures.

The effects of ambient temperature (T; 12-29 degrees C), body weight (BW; 30-90 kg) and metabolisable energy intake (ME) on components of energy balance were studied in seven groups of Piétrain x Large White barrows kept in a respiratory chamber. In Expt 1 (groups 1, 2 and 3), T varied in a cyclic way from 22 degrees C to 12 degrees C and then from 12 degrees C to 22 degrees C with three or four consecutive days at each of 22, 19, 16, 14 and 12 degrees C. Similarly, in Expt 2 (groups 4, 5 and 6), T varied from 19 to 29 degrees C and then from 29 to 19 degrees C with three or four consecutive days at each of 19, 22, 25, 27 and 29 degrees C. In both experiments, pigs were offered feed ad libitum. In Expt 3, pigs (group 7) were exposed to the thermic conditions of Expt 1 but their feed allowance was adjusted on a BW basis to the ad libitum intake recorded at 19 and 22 degrees C in Expt 1. Groups 1, 2, 4, 5 and 7 were used over two successive cycles with initial average BW of 37 kg at cycle 1 (four pigs per group) and 63 kg at cycle 2 (three pigs per group). Groups 3 and 6 were studied at an intermediary stage of growth; their initial BW was 45 kg. The O2 and CO2 concentrations, physical activity and feed intake were continuously and simultaneously measured and used to calculate total heat production (HP; HPtot), HP due to physical activity (HPact), activity-free HP (HP0), and thermic effect of feed. HP was modelled as a non-linear function with T, BW and ME as predictors. Results indicate that all components of HP were proportional to BW(0.60). Physical activity was minimal between 19 and 27 degrees C (8 % ME). The estimated lower critical temperature was 24 degrees C. Between 24 and 12 degrees C, total thermic effect of feed decreased from 31 to 16 % ME, but the short-term thermic effect of feed (5.1 % ME) remained constant. Equations for prediction of HPtot, HPact and HP0 according to BW, T and ME are proposed and evaluated according to literature values; values for the feed cost of thermoregulation in pigs are proposed.

Design of a vapor permeation membrane for VOC removal by the filling membrane concept

The concept of a filling-type membrane is used to design a membrane for removing volatile organic compounds from emissions. Solvent solubility is predicted by the GCLF-EOS model, and compared with the previously used UNIFAC-FV model. For the various polymer systems studied, the GCLF-EOS model provides better accuracy, and this is attributed to the correct prediction of the effect of excess volume on solubility. The flux of benzene, toluene and ethylbenzene is measured by vapor permeation experiments through filling-type acrylate membranes, and the prediction from this approach agrees well with the VOC vapor permeation experiments. The influence of such operating conditions as solvent activity in feed and permeate is also discussed.

An Investigation of Odors and Volatile Organic Compounds Released during Composting

ABSTRACT The emissions of odors and volatile organic compounds produced from a commercial composting operation have been studied using a laboratory-scale composting system. The composting activity of a typical commercial compost feed was followed by monitoring the composting temperature, as well as the respiratory rate. Using a controlled aeration system, the gaseous volatiles produced were tested for odors using the "dilution-to-threshold" method, as well as gas composition, as determined by gas chromatography-mass spectrometry. The results indicated that while there may be a reasonable correlation between the release of volatile organic compounds (VOCs) and odors, care has to be taken when trying to identify offensive odors with specific chemical species. However, the data obtained suggests that offensive odors formed during commercial composting may be due to sulfurous and nitrogenous compounds, although their concentrations in the compost gases may not be very high. The major release of VOCs occurred during the first two weeks of composting, after which the gaseous releases fell dramatically as the composting process proceeded and temperatures started to fall.

Exposure Pathways and Dose Calculations in RODOS: Improvement of Predictions by Measured Data

All radiation exposure pathways which are considered in the RODOS food chain and dose modules are described. For each of them, the principal processes controlling the exposure are discussed, showing up the input data requirements. Emphasis is put on those data which vary from region to region and thus require the adaptation of model parameters of RODOS is to be used for regions with different conditions. Calculation of individual doses as well as estimation of collective doses are reflected. Possibilities for improving the dose estimations by consideration of measured data are discussed. The deposition onto different kinds of surfaces (e.g. soil, plant canopies, urban areas) can be improved by means of gamma dose rate measurements, vegetation samples, in situ gamma spectrometry etc. Measurements of concentrations of activity in feed and foodstuffs, whole-body burdens, personal dosemeters etc. can help to improve the predicted internal and external doses.

Energy metabolism in pregnant sows and newborn pigs.

Measurements of heat production(HP; indirect calorimetry) and its partition between maintenance, physical activity, thermoregulation, and thermic effect of feed or energy gain were carried out in sows maintained in different situations: primiparous or multiparous; pregnant or nonpregnant; thermoneutral or cold conditions; varied feeding levels; and varied body weights (BW). Metabolizable energy requirements for maintenance average 420 kJ/kg BW.75 at thermoneutrality and moderate physical activity. This value is not significantly affected by parity, pregnancy, and stage of pregnancy. Physical activity is a major factor causing differences in energy balance between sows because activity is variable and its energy cost (27 kJ.kg BW-.75.100 min-1 standing) is four to five times higher than in other species. Lower critical temperature (LCT) is approximately 20 degrees C in pregnant and individually housed sows, and daily HP is increased by approximately 15 kJ/kg BW.75 for each degree Celsius decrease of ambient temperature below LCT. Efficiencies of utilization of ME for meeting energy requirements for maintenance, maternal gain, and uterine gain are 77, 75, and 50%, respectively. Equations for predicting energy deposition in the uterus and mammary gland are proposed. In addition to activity and thermoregulation, energy requirements of pregnant sows depend on body reserves of energy. Studies with newborn pigs indicate that they are quite sensitive to ambient temperature (i.e., +25 J.kg BW-.75.min-1 for each degree Celsius decrease of temperature), and their LCT is 32 to 34 degrees C. The energy demand of pigs for thermoregulation just after birth relies mainly on carbohydrates from glycogen reserves or colostrum. Survival of newborn pigs is highly dependent on the supply of colostrum.

Viscometric Determination of p-Glucanase and Endoxylanase Activity in Feed

Abstract A method is described for viscometric determination of enzymatic activity of β-glucanase and endoxylanase in feed samples. The method is based on determination of the decrease in viscosity as a result of hydrolysis of glycosidic bonds in β-glucan and xylan at pH 3.5. This method does not require a blank sample (feed without enzyme addition), and it does not need standard addition for reliable quantitation.

Wood-Derived Estrogens: Studiesin Vitrowith Breast Cancer Cell Lines andin Vivoin Trout

The wood-derived compound, β-sitosterol (purity >90%), was shown to be estrogenic in fish. It induced the expression of the vitellogenin gene in the liver of juvenile and methyltestosterone-treated rainbow trout. Structural similarities to β-sitosterol notwithstanding, cholesterol, citrostadienol, β-sitostanol, and 5-androstene-3β,17β-diol, an estrogenic member of the androstenic steroid group, were inactive. An abietic acid mixture (37% abietic acid, 6% dehydroabietic acid, and a remainder of unknown compounds) showed slight hormonal activity in feed, but it was completely inactive when given intraperitoneally in implants. The estrogenic component of the abietic acid preparation was not identified. In addition to β-sitosterol and abietic acid, several other wood-derived compounds including betulin, isorhapontigenin, isorhapontin, and pinosylvin were estrogenic in breast cancer cells (MCF-7 or T-47D). However, betulin and pinosylvin, available in sufficient amounts forin vivotesting, did not induce the expression of the vitellogenin gene. Differences in the primary sequences of human and fish estrogen receptors (hormone as well as DNA-binding regions) or uptake and metabolism of the compounds may explain the discrepancy between the two estrogen bioassays. Wood-derived compounds such as β-sitosterol, present in pulp and paper mill effluents, may account for the weak estrogenicity of debarking effluent seen at the vitellogenin expression bioassay.

Technical note: detection and quantification of supplemental fungal beta-glucanase activity in animal feed.

Selected hydrolytic enzymes are added to animal feeds in order to degrade specific antinutritional factors and(or) to increase availability of certain components of feedstuffs to the animal. A method is described that allows detection and quantification of beta-glucanase activity in complex feedstuffs. The method is based on radial diffusion of an enzyme-containing feed extract through an agar gel in which lichenan substrate (a relatively inexpensive glucan of mixed beta 1-->4 and beta 1-->3 linkages) has been dissolved. A linear relationship between the diameter of the zone of substrate hydrolyzed and the log of enzyme activity present was observed. The assay described is technically straightforward and requires no specialized equipment. At typical commercial inclusion levels (1 kg/t), the activity of a supplemental beta-glucanase, added to feed in a commercial mill was determined by averaging several measurements, with a precision of +/- 4%, variation between individual readings of +/- 11.3% (SD), and recovery of 109%. By using high-concentration feed extracts, the method was sensitive enough to detect background and(or) supplemental beta-glucanase activities as low as .05 kg/t supplement equivalent. This method allows consumers, producers, and regulatory authorities to measure the activity of beta-glucanase in feed at commercial inclusion levels and, hence, study the effects of processes such as pelleting and extrusion on such supplements.

Spoilage and pathogenic microorganisms in animal feed

Fungi are the principal cause of spoilage of animal feed, particularly cereals and legumes. In addition, some fungal species may elaborate toxins which cause serious disease in animals consuming the feed. Bacterial spoilage may also occur although the problem is relatively uncommon because the water activity of dry feed is too low to permit bacterial multiplication. Animal feed may be the source of several pathogens. The virus diseases such as classical swine fever, foot and mouth disease, Newcastle disease and swine vesicular disease, together with bovine spongiform encephalopathy, are notifiable in the UK and legislation exists to minimise the risk of the causal organisms being spread by animal feed. Anthrax, listeriosis and salmonellosis are examples of bacterial diseases that may be contracted following the consumption of contaminated feed, and botulism is associated with the ingestion of preformed toxin.

Effects of water activity on morphology, growth and blastospore production of Metarhizium anisopliae, Beauveria bassiana and Paecilomyces farinosus in batch and fed-batch culture

Metarhizium anisopliae, Beauveria bassiana and Paecilomyces farinosus were grown in submerged liquid culture on glucose- and polyethylene glycol (PEG)-adjusted media of different initial water activities. The initial glucose or PEG concentration of the medium affected the morphology, biomass and blastospore production of M. anisopliae and P. farinosus in shake flask culture. At 80 mg glucose ml−1 or 0·15 M PEG (initial water activity (aw), 0·980), M. anisopliae grew filamentously, but at 10 mg glucose ml−1 or in the absence of PEG (initial aw, 0·986), pellet growth occurred. Similarly, less mycelial aggregation occurred in cultures of P. farinosus grown at low (aw, 0·982) than at high (aw, 0·990) initial water activities. Conditions which favoured a filamentous morphology were correlated with increased blastospore production. Blastospore yield of fed-batch cultures of B. bassiana was increased when the water activity of the nutrient feed was reduced by the incorporation of 2·4 M PEG.

Specific activity measurements to determine phosphorus turnover in bluegill, Lepomis macrochirus

The biological turnover constant for phosphorus was determined in muscle and five other sections of bluegill. Bluegill of average weight 121 g were maintained in a large flowthrough system at 22°–16°C and fed worms, Eisenia foetida, at two feeding levels, ad lib. (which averaged 2.6 g/d per 100-g fish, wet weight), and 1.5 g/d per 100-g fish. The daily phosphorus intakes at the two levels per 100-g fish were 3.1 and 1.8 mg. The average phosphorus concentration was 2.4 mg/g in muscle and 15.4 mg/g in the whole fish. Worm food was spiked with P-32 at increasing daily increments to balance radioactive decay. The radioactive worms were fed daily to the bluegill during the P-32 accumulation period of 51 days. For the next 28 days of depuration, nonradioactive worms were fed. Sets of three bluegill were collected at approximately weekly intervals, sectioned and analyzed for P-32 and phosphorus. All data were reported as specific activity in tissue relative to specific activity in feed, with P-32 count rates corrected for its 14.3-day half life. Phosphorus turnover constants were obtained by three approaches: (1) from the relative specific activity measured near steady state; (2) by fitting an equation for a 1-compartment model to the accumulation and depuration data; and (3) by fitting an equation for a simplified 2-compartment model to the depuration data. The biological turnover constant calculated with all three approaches was 0.004 d−1 for phosphorus in muscle of bluegill fed ad lib.

Factors Influencing Antifungal Activity of Gentian Violet in Poultry Feed and Ingredients ,

The inhibition of fungal activity in poultry feed and ingredients by gentian violet was investigated by measuring respiratory CO2 liberated into the headspace gas above samples of feed and ingredients. Inhibition by gentian violet depended on 1) the lot of com meal, 2) the concentration of gentian violet, 3) the moisture of the substrate, 4) time of incubation, 5) particle sizes of corn meal and gentian violet, and 6) temperature of a short heating episode mimicking the feed-pelleting process. These same factors were reported earlier to control and limit the activity of organic acid mold inhibitors. These results imply that differences between gentian violet and other mold inhibitors used in poultry feed are quantitative rather than qualitative.

Prophylactic activity of flubendazole-medicated feed on Brugia pahangi infection of multimammate rats.

Prophylactic activity of flubendazole-medicated feed on Brugia pahangi infection of multimammate rats.

ENZYME PURIFICATION AND CONCENTRATION BY SIMULATED MOVING BED CHROMATOGRAPHY: AN EXPERIMENTAL STUDY

Abstract A new continuous affinity chromatography for enzyme purification and concentration was proposed. It combined the features of pH-parametric pumping and simulated moving bed operations. Adsorption and desorption were taking place simultaneously in the system. Regeneration of adsorbent was performed by successively shifting the adsorption and desorption sections from one column to another with a time controller. Performance tests for enzyme separation and purification were carried out by devising six-staged affinity chromatographic columns, 16 cm ID × 40 cm Ht, packed with 10 cm height chitin-CHOM each for trypsin purification. Factors affecting the successful operations of the systems and separation efficiency of enzyme were investigated. The system was applied to the purification of trypsin from extract of porcine pancreas. It was found that fairly high separation efficiency can be achieved, SAR (specific activity ratio = specific activity of product/specific activity of feed) of eluam was as high...

Thiaminase activity in fish silage and moist fish feed

Experiments were performed to examine the effects of spoilage and ensilation on the thiamine-destructive properties of whole sprats, Sprattus sprattus L.. The thiaminolytic factor was shown to be heat-labile, with pH optima of 4.5 and 6.4. This confirmed that the factor was an enzyme, thiaminase. Thiaminase activity was found to persist during spoilage and immediately after ensilation, but was significantly reduced by extended storage of silage at ambient temperature. The effect of mixing thiaminolytic silage into a moist pellet with a dry binder meal was investigated. This was shown to suspend thiamine destruction, suggesting that thiaminase-containing silage may be used safely to produce moist feeds for fish, given that an adequate supplement of thiamine is included in the binder meal.

Radiocarbon Dating of Fossil Eggshell

Controlled feeding experiments demonstrate that the 14C content of the carbonate fraction of fossil avian eggshell should reliably reflect the 14C activity of feed and contemporary atmospheric CO2 regardless of amounts of 14C depleted scratch injested. Consideration of biochemical pathways and exchange rates across lung membranes leads to the possibility that the carbonate fraction may, in some instances, be slightly 14C depleted. 14C dates on eggshell carbonate should require little or no correction. As with marine shell carbonate, normal soil-forming processes may alter the surficial carbon isotopes in eggshell carbonate. 14C dates on the protein fraction should be even more reliable than those on the carbonate fraction, but only if special precautions or separation techniques exclude non-indigenous carbon from the sample. Original protein contents are likely to be too low for conventional 14C dating techniques.

DYSPROSIUM, CERIUM AND CHROMIUM MARKER DETERMINATION BY INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS

An instrumental neutron activation analysis (INAA) procedure has been developed for the measurement of dysprosium (Dy), cerium (Ce) and chromium (Cr) using the Canadian SLOWPOKE nuclear reactor. These elements were included in animal feed at 25 ppm, 61 ppm and 0.34%, respectively. Concentrations in feed and digesta samples were determined by measuring, with a Ge(Li) detector coupled to a 4096 multichannel analyzer, the radioactivity induced by neutron irradiation. Quantitative analysis procedures based on 165mDy (half-life:T1/2 = 1.26 min), 51Cr (T1/2 = 27.8 days) and 141Ce (T1/2 = 32.6 days) were developed after a study of the major contributions to induced background activity in both feed and fecal materials. For short irradiations, 28Al is the dominant induced background activity; for longer irradiations (> 2 h), 38Cl, 56Mn and 24Na dominate. Inert markers with radioisotopes of half-lives less than several minutes (165mDy) or longer than several days (51Cr and 141Ce) are most amenable to instrumental analysis. The application of the methods developed to routine analysis is discussed from the viewpoint of sample throughput and analysis time.

Propionic Acid Is An Alternative To Antibiotics In Poultry Diet

Propionic acid (PA) is a fungicide and bactericide, registered to control fungi and bacteria in stored grains, hay, grain storage areas, poultry litter, and drinking water for livestock and poultry. European Union (EU) certifies PA as the great of grain preserver and most efficient in controlling Salmonella and other pathogens. Recently it is used as feed additive in poultry and non-ruminant production. Suitable inclusion level of PA is 0.2 to 0.4% which can improve the overall performances of poultry. The preservative effect of PA is due to its antibacterial and mould inhibitory effect. High bacteriostatic property of PA is due to its pH reduction activity both in feed and gastrointestinal tract through pharmacogenic action on microflora. Propionic acidA with its growth promoting, health enhancing and antimicrobial effect has proven to be an effective alternative to antibiotic growth promoters in food animal production. DOI: http://dx.doi.org/10.3329/bjas.v38i1-2.9920 BJAS 2009; 38(1-2): 115-122