Output of selenium in milk, urine, and feces is proportional to selenium intake in dairy cows fed a total mixed ration supplemented with selenium yeast

Fifteen rumen fistulated Holstein cows in late lactation and fed a total mixed ration offered ad libitum were supplemented with Se yeast to provide 0, 11, 20, 30, or 42 mg of supplemental Se/day to test the hypothesis that amounts of Se secreted in milk, excreted in urine and feces, and apparently retained in tissues would increase in direct proportion to Se intake. One-half of the yeast supplement was placed directly into the rumen through the fistula of each cow just before milking in the morning and again in the evening, and estimates of average daily excretion of Se were made using total collections of urine and feces from 25 to 31 d after treatments commenced. Amounts of Se secreted daily in milk and apparently retained in tissues increased linearly with average daily intake of Se. The amount of Se excreted in feces and total excretion of Se in urine plus feces increased curvilinearly with Se intake, such that proportionately less Se was excreted as the amount of Se fed increased. On average, total Se excretion accounted for 66%, Se secretion in milk accounted for 17%, and Se apparently retained in tissues accounted for 17% of total Se intake by cows. Thus, in herds fed large amounts of Se yeast, most of the Se will be excreted and retained on-farm. High concentrations of Se will be found where urine and feces accumulate (e.g., yards and effluent ponds), and effluent management practices must be tailored to avoid environmental issues.     

The protective ability of Mediterranean dietary plants against the oxidative damage: The role of radical oxygen species in inflammation and the polyphenol,flavonoid and sterol contents

Ten hydroalcoholic extracts of edible plants from the Calabria region (Italy) were evaluated for their in vitro antioxidant and antiradical properties and in vivo topical anti-inflammatory activity. All the extracts had radical-scavenging and/or antioxidant properties, the most active plants being hawkweed oxtongue and viper’s bugloss. The best free radical (DPPH·)-scavenging activity was found in hawkweed oxtongue and chicory leaves extracts (IC₅₀ = 25 and 26 μg/ml, respectively). Hawkweed oxtongue, poppy and viper’s bugloss extracts showed the greatest inhibition of linoleic acid oxidation (IC₅₀ = 3 μg/ml). Viper’s bugloss and hawkweed oxtongue extracts had the greatest antioxidant effect on bovine brain peroxidation (IC₅₀ = 11 and 22 μg/ml). All the extracts also showed an anti-inflammatory effect: 300 μg/cm² provoked oedema reductions ranging from 18% to 43%. Cress was the most active plant. Chicory leaves contained the highest amount of phenolics (190 mg/g) whilst Rush crimps contained the highest amount of flavonoids (32.9 mg/g), followed by hawkweed oxtongue (15.8 mg/g). Cress contained the highest number of sterols. Among them, γ-sitosterol (12.2%) and ergost-5-en-3-ol (3β) (4.5%) were found to be the major constituents. Moreover, three of the identified molecules (stigmasta-5,23-dien-3β-ol, stigmasta-5,24(28)-dien-3-ol (3β,22E) and 9,19-cyclolanost-24-en-3-ol (3β)) were found in this plant only.     

Effectiveness of modified yeast cell wall extracts to reduce aflatoxin B1 absorption in dairy ewes

This study investigated the effect of a modified yeast cell wall extract preparation (YCW) on the excretion of aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1) in feces, urine, and milk of dairy ewes fed an aflatoxin-contaminated diet. Sixteen ewes in mid-lactation were assigned to 4 treatment groups: control, AF (60 μg of AFB1/kg of feed), YCW (2 g/kg of feed), and AF+YCW. The trial consisted of a short-term (3-d) exposure period followed by a long-term (21-d) exposure period. At the end of each exposure period, milk, urine, and feces were collected over 72 h. The treatments did not affect feed intake, milk production, milk composition, or body weight. The presence of AFM1 was detected in all matrices, whereas AFB1 was only present in feces. Daily excretion was higher following long-term exposure and reached 26.9 μg of AFB1/d in feces, 37.2 μg of AFM1/d in feces, and 10.7 μg of AFM1/d in urine. Supplementation with YCW was effective in increasing aflatoxin excretion in feces in the long-term exposure (up to 156% increase). The effect was accompanied by a trend of decreasing urinary excretion of AFM1. In contrast, the addition of YCW to the contaminated diet did not affect the transfer of aflatoxins from feed to milk under the present experimental conditions with low-producing ewes. The transfer rates of AFM1 in milk ranged from 0.24 to 0.54%. In conclusion, feed supplementation with YCW reduced the absorption of AFB1 and increased the elimination of AFB1 and AFM1 in ewe feces. Yeast cell wall extract could be used to protect ruminants from chronic exposure to aflatoxins present in feeds.     

Optimizing production of in vivo-matured oocytes from superstimulated Holstein cows for in vitro production of embryos using X-sorted sperm

The present study aimed to establish an efficient system for the production of female embryos from dairy cows by in vitro fertilization (IVF) using X-sorted sperm and in vivo-matured oocytes collected by ovum pick up (OPU). Nonlactating Holstein cows (n = 36) were administered a controlled intravaginal progesterone-releasing (controlled internal drug release) device (d 0), underwent dominant follicle ablation (DFA) or ovulation by administration of 100 μg of GnRH on d 5, and were superstimulated with FSH and PGF_2α, following standard procedures. Controlled internal drug release devices were removed on the evening of d 8 or on the morning of d 9, depending on the experiment. For LH surge induction, 200 μg of GnRH was administered on the morning of d 10 (0 h). In experiment 1, the peak (48.1%) of ovulating follicles was detected at 29 to 32 h after GnRH injection (0 h), and the range in the timing of the initiation of ovulation was less by timing from GnRH administration (30.0 ± 2.8 h) rather than by timing the onset of estrus (32.7 ± 4.7 h). Only 0.9% of total ovulated follicles were recorded before 26 h after GnRH injection. Therefore, OPU was carried out at 26 h and IVF occurred at 30 h after GnRH in experiments 2 and 3. In experiment 2, 83.3 ± 10.8% of oocytes with expanded cumulus cells had extruded the first polar body at 30 h after GnRH injection. The aim of experiment 3 was to compare the effect of either DFA or GnRH-induced LH surge before superstimulation on the efficiency of embryo production by IVF following superstimulation. Progesterone concentrations from d 10 to 12 in the DFA group were lower than those in the GnRH group. A greater proportion of recovered oocytes with expanded cumulus cells from ≥8-mm follicles was observed in the DFA group than in the GnRH group (95.9 and 77.4%, respectively). Blastocyst rates in the DFA and GnRH groups (58.0 and 52.8%, respectively) did not differ from those of oocytes collected from nonstimulated OPU and matured in vitro (49.9%). However, the proportion of high-quality blastocysts was higher in the DFA group compared with the GnRH group (54.9 vs. 21.5%). Our results demonstrate that high rates of good-quality blastocysts can be produced by IVF with X-sorted frozen sperm using in vivo-matured oocytes collected by OPU from cows after DFA and superstimulation combined with ovulation induction.     

Galactooligosaccharides derived from lactose and lactulose: influence of structure on Lactobacillus, Streptococcus and Bifidobacterium growth

The effect of structure on the fermentative properties of potential prebiotic trisaccharides derived from lactulose like 6′-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 6)-β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranose), 4′-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 4)-β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranose), and 1-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranosyl-(1 → 1)-β-d-galactopyranose); and from lactose like 4′-galactosyl-lactose (β-d-galactopyranosyl-(1 → 4)-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranose) and 6′-galactosyl-lactose (β-d-galactopyranosyl-(1 → 6)-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranose), has been assessed in vitro. Fermentations with twelve pure strains of Lactobacillus, Streptococcus and Bifidobacterium were carried out using the purified trisaccharides as the sole carbon source, and bacteria growth was evaluated at 600 nm by means of a microplate reader during 48 h. Maximum growth rates (μ_max) and lag phase were calculated. In general, all the strains tested were able to utilize lactulose and pure trisaccharides derived from lactulose and lactose when they were used as sole carbon source. Nonetheless, glycosidic linkage and/or the monosaccharide composition of the trisaccharides affected the individual strains lag phase, cell densities and growth rates. A general preference towards β-galactosyl residues β(1-6) and β(1-1) linked over those β(1-4) linked was observed, and some strains showed higher cell densities and speed of growth on 6′-galactosyl-lactulose than on 6′-galactosyl-lactose. This is the first study of the effect of lactulose-derived oligosaccharides on pure culture growth which shows that transglycosylation of lactulose allows for obtaining galactooligosaccharides with new glycosidic structures and would open new routes to the synthesis of compounds with potential prebiotic effects.     

Technical note: Effects of forage protein-binding polyphenols on chemistry of dairy excreta

Forage chemistry can affect intake, digestion, milk production, and manure excretion. Although information is available on the effects of forage protein-binding polyphenols on small ruminant production and manure excretion, little information is available for dairy cattle. The objective of this study was to compare fecal and urinary N excretion of diets formulated with alfalfa (Medicago sativa L.) silage versus condensed tannin-containing birdsfoot trefoil (Lotus corniculatus) or o-quinone-containing red clover (Trifolium pratense L.) silages. Significantly higher concentrations of N were excreted in urine by lactating Holstein dairy cows fed red clover and low-tannin birdsfoot trefoil (8.2 g/L) than by cows fed high-tannin birdsfoot trefoil or alfalfa (7.1 g/L). Fecal N concentrations were similar (33.6 g/kg) among all diets. Dairy cows fed red clover had lower rates of urinary N excretion (5.0 g/h) compared with other forages (6.6 g/h). Fecal N excretion rates were lowest for red clover (4.1 g/h), intermediate for alfalfa (5.8 g/h), and greatest for cows fed high- and low-tannin birdsfoot trefoil (6.4 g/h). The ratio of fecal N to urinary N was highest for high-tannin trefoil, lowest for alfalfa and red clover, and higher in excreta collected in morning than evening. Concentrations of neutral detergent fiber (NDF) in feces, of N in NDF (NDIN) and acid detergent fiber (ADIN), and relative amounts of NDIN and ADIN excreted in feces were significantly higher from cows fed high-tannin birdsfoot trefoil than the other silage types. Study results imply that collection of excreta for environmental studies needs to consider forage polyphenol and diurnal effects on chemistry of dairy excreta.     

Spirostane and cholestane glycosides from the bulbs of Allium nigrum L

A phytochemical investigation of the fresh bulbs of Allium nigrum L. led to the isolation of new spirostane-type glycosides as two inseparable isomer mixtures, nigrosides A1/A2 (1a/1b) and nigrosides B1/B2 (2a/2b), two new cholestane-type glycosides, nigrosides C and D (3 and 4), together with the known compounds, 25(R,S)-5α-spirostan-2α,3β,6β-trio1-3-O-β-d-glucopyranosyl-(1 → 2)-O-[β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (5a/5b) and 25(R,S)-5α-spirostan-2α,3β,6β-trio1 3-O-β-d-glucopyranosyl-(1 → 2)-O-[4-O-(3S)-3-hydroxy-3-methylglutaryl-β-d-xylopyranosyl-(1 → 3)]-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside (6a/6b), isolated from this plant for the first time. All structures were elucidated mainly by spectroscopic analysis (1D and 2D NMR experiments, FABMS, HRESIMS) and by comparison with literature data. Cytotoxicity of the isolated compounds was assessed against human colon carcinoma (HT-29 and HCT 116) cell lines. Compounds 5a/5b and 6a/6b were found to be the most active with IC₅₀ values 1.09 and 2.82 μM against HT-29 and 1.59 and 3.45 μM against HCT 116, respectively.     

Corn oil and milk enhance the absorption of orally administered allyl isothiocyanate in rats

Allyl isothiocyanate, a chief component of mustard oil, exhibits anticancer effects in both cultured cancer cells and animal models. The accumulation of the N-acetylcysteine conjugate of allyl isothiocyanate, the final metabolite of allyl isothiocyanate, in urine was evaluated in rats that were orally coadministered allyl isothiocyanate with fluids (e.g., water, green tea, milk, and 10% ethanol) or corn oil. The N-acetylcysteine conjugate of allyl isothiocyanate content in urine when allyl isothiocyanate (2 or 4 μmol) was coadministered with corn oil or milk showed a greater increase (1.4 ± 0.22 or 2.7 ± 0.34 μmol or 1.2 ± 0.32 or 2.5 ± 0.36 μmol, 1.6- to 1.8-fold or 1.5-fold, respectively) than when allyl isothiocyanate (2 or 4 μmol) was coadministered with water (0.78 ± 0.10 or 1.7 ± 0.17 μmol). This result demonstrates that corn oil and milk enhance the absorption of allyl isothiocyanate in rats.     

Part-time grazing improves sheep milk production and its nutritional characteristics

The positive effect of part-time grazing with three different amounts of indoor-supplied concentrate on milk production and quality was studied in an experimental flock of latxa sheep in mid-lactation. The group that received the highest amount of concentrate (group 3) ingested the least amount of grass during the 4 h the animals were on the pasture. Milk production increased by 30% (p ? 0.05) in the three groups that were allowed to graze as compared with the milk produced by the control group (group 0; always fed indoors). No change in the milk gross composition among the four experimental groups was observed. The milk from group 1 (which received the lowest amount of concentrate) had the highest concentration (p ? 0.05) of unsaturated fatty acids (FA), both total and polyunsaturated (PUFA), and the highest percent (56%) of non-atherogenic saturated FA (p ? 0.05) as compared to 49% in the control group. Consequently, the atherogenicity index of the milk from group 1 was the lowest (p ? 0.05) of all groups. In addition, the concentration of CLA isomer c9t11 in this milk was 50 μg/g fat, but only 15 μg/g fat in the control group and around 33 μg/g fat in groups 2 and 3. Changes in milk triglyceride composition were also observed between control group and grazing animals. The Trolox equivalent antioxidant capacity (TEAC) value of milks from groups 1 and 2 was higher than those of milks from groups 0 or 3. Curd firmness to compression was lowest (p ? 0.05) in milk from group 1. These results clearly indicate that part-time grazing is a viable alternative to intensive indoor sheep milk production which allows the use of locally available resources and improves the nutritional quality of the milk.     

Antioxidant,anticholinesterase and antimicrobial constituents from the essential oil and ethanol extract of Salvia potentillifolia

The essential oil of Salvia potentillifolia was analysed by GC and GC–MS. Totally, 123 components were detected in both hydrodistilled and steam-distilled oils, α- and β-pinenes being major compounds. The antioxidant activities were determined by using complementary tests, namely, DPPH radical-scavenging, β-carotene-linoleic acid and reducing power assays. The ethanol extract also showed better activity (IC₅₀ = 69.4 ± 0.99 μg/ml) than that of BHT in the DPPH system, and showed great lipid peroxidation inhibition in the β-carotene-linoleic acid system (IC₅₀ = 30.4 ± 0.50 μg/ml). The essential oil showed meaningful butyrylcholinesterase activity (65.7 ± 0.21%), and α-pinene showed high acetylcholinesterase inhibitory activity (IC₅₀ = 86.2 ± 0.96 μM) while β-pinene was inactive. Antimicrobial activity was also investigated on several microorganisms, and the essential oil showed high activity against Bacillus subtilis and B. cereus. It also exhibited remarkable anticandidal activity against Candida albicans and C. tropicalis with MIC values of 18.5 and 15.5 μg/ml, respectively, while α- and β-pinenes showed moderate activity.     

Contribution to explanation of the effect of supplemented creatine in human metabolism

Simple voltammetric determination of thiodiglycolic acid (TDGA) offers the possibility to follow individual deviations in metabolism of thiocompounds and one-carbon (1c) and two-carbon (2c) units, which take part in endogenous synthesis of creatine (CR). In three groups of young men the levels of TDGA in urine were followed after application of CR given as food supplement in 5 g daily doses. In the first group (7 men) it was found that the level of TDGA increased independently of the day time of application of CR. In the second group (9 men) the level of TDGA increased within an interval of 3–8.5 h after CR application and then dropped during 2 h to the normal level (20 mg L⁻¹). In the third group (11 men), in 4 days’ study the effects of CR were compared in alternation to vitamin B₁₂. Vitamin B₁₂ was given in the evening of the 1st and 3rd day and CR in the morning of the 3rd and 4th day. CR increased the excretion of TDGA in all men, while B₁₂ only in four men independently of CR application.     

The microstructure of almond (Prunus dulcis (Mill.) D.A.Webb cv. ‘Nonpareil’) cotyledon

Microstructure of almond (Prunus dulcis (Mill.) D.A. Webb cv. ‘Nonpareil’) cotyledon was observed with light, scanning and transmission electron microscopy. The objective of this study was to characterise almond cotyledon surfaces as well as to describe internal and subcellular organisation. The testa has an outer epidermis, which consists of relatively large thin-walled cells, which range from 100 to 300 μm in width. The major portion of the testa consists of approximately 14-20 layers of flattened parenchymal cells with the total thickness of the layers ranging from 80 to 120 μm. The remainder of the testa was comprised of a small amount of vascular tissue. The embryo consisted primarily of parenchymal tissue with relatively thin cell walls (1-3 μm in thickness) and a small amount of provascular tissue. Protein bodies up to 12 μm in width and spaces once occupied by lipid bodies up to 3 μm in width were present in all cells of the embryo.     

Two unusual minor 18,19-seco-ursane glycosides from leaves of Ilex cornuta

The leaves of Ilex cornuta is traditionally used as a functional tea in China. Two new minor 18,19-seco-ursane glycosides, named cornutaoside A (1) and B (2), were isolated from leaves of I. cornuta, along with two known compounds (3 and 4). Their structures were elucidated as (3β,12β)-3-[β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-12,21-dihydroxy-19-oxo-18,19-secours-13(18)-en-28-oic acid (1) and (3β,12β)-3-[β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranosyl]-12,19,21-trihydroxy-18,19-secours-13(18)-en-28-oic acid (2), by chemical methods, 1D and 2D NMR experiments, and by comparison with known analogues. This is the first report of E-seco triterpenoids and diterpene skeletons (4) from this plant. In a preliminary cytotoxic test against U937, L1210, and B16 cell lines, 1 and 2 had no significant activities as compared to controls, with concentrations up to 443.61 and 346.25 μM/plate, for 1 and 2, respectively.     

Determination of catechins in green tea infusions by reduced flow micellar electrokinetic chromatography

A sulfated-β-cyclodextrin (s-β-CD) modified reduced flow micellar electrokinetic chromatography (RF-MEKC) method was developed and validated for the determination of catechins in green tea. The optimal electrolyte consisted of 0.2% triethylamine, 50 mmol/L SDS and 0.8% s-β-CD (pH = 2.9), allowing baseline separation of five catechins in 4 min. The samples and standards were injected at 0.6 psi for 5 s under constant voltage of −30 kV. Sample preparation simply involved extraction of 2 g of tea with 200 mL water at 95 °C under constant stirring for 5 min. The method demonstrated excellent performance, with limits of detection (LOD) and quantification (LOQ) of 0.02–0.1 and 0.1–0.5 μg/mL, respectively, and recovery percentages of 94–101%. The method was applied to six samples of Brazilian green tea infusions. Epigallocatechin gallate (23.4–112.4 μg/mL) was the major component, followed by epigallocatechin (18.4–78.9 μg/mL), epicatechin gallate (5.6–29.6 μg/mL), epicatechin (4.6–14.5 μg/mL) and catechin (3.2–8.2 μg/mL).     

Studies on cytotoxic triterpene saponins from the leaves of Aralia elata

Aralia elata has long been used as a tonic, anticancer and antidiabetic agent in China and Japan, and is widely consumed as food. Phytochemical investigation of the leaves of A. elata has led to the isolation of four new compounds, 3-O-[β-d-glucopyranosyl(1 → 3)-β-d-glucopyranosyl] echinocystic acid 28-O-β-d-glucopyranosyl ester (congmuyenoside I, 1), 3-O-[β-d-glucopyranosyl(1 → 2)-β-d-glucopyranosyl] hederagenin 28-O-β-d-glucopyranosyl ester (congmuyenoside II, 2), 3-O-{[β-d-glucopyranosyl(1 → 2)]-[β-d-glucopyranosyl(1 → 3)-β-d-glucopyranosyl(1 → 3)]-β-d-glucopyranosyl} echinocystic acid 28-O-β-d-glucopyranosyl ester (congmuyenoside III, 3) and 3-O-β-d-glucopyranosyl caulophyllogenin 28-O-β-d-glucopyranosyl ester (congmuyenoside IV, 4), and eight known triterpene saponins (5–12). The structural determination was accomplished with spectroscopic analysis, in particularly ¹³C NMR, 2D NMR and HR-ESI-MS techniques. In addition, compounds 5–10 were found for the first time in the genus Aralia. Compounds 1–12 were tested for their inhibition of the growth of HL60, A549 and DU145 cancer cells. In addition, compound 8 showed significant cytotoxic activities against HL60, A549 and DU145 cancer cells with IC₅₀ values of 15.62, 11.25 and 7.59 μM, respectively.     

Post-column on-line photochemical derivatization for the direct isocratic-LC-FLD analysis of resveratrol and piceid isomers in wine

Resveratrol is a stilbene produced by plants, e.g. grapes, in response to stress. Resveratrol is extracted during winemaking, being present in wine as 3-O-β-d-gluocoside (piceid) and as aglycone. Both, resveratrol and piceid exist in two isomeric forms, trans and cis. Resveratrol and piceid are weakly fluorescent in both of their isomeric forms, but highly fluorescent compounds are obtained when the original molecules are UV-irradiated. A chromatographic method with post-column on-line photoderivatization, has been developed for the analysis of resveratrol and piceid isomers. The four analytes are firstly separated in a C18 column (150 mm × 3.9 mm i.d., 4 μm) by isocratic elution, at 15 °C, with a mobile phase consisting of a mixture acetonitrile:o-phosphoric acid (0.04%), 18:82, v:v, at 0.9 mL min⁻¹, and secondly they are on-line phototransformed into their fluorescent photoproducts in a 3 m PTFE tube coiled around a 4 W xenon lamp. The elution conditions have been chemometrically optimized by means of the experimental design and the response surface methodology. Linearity ranges from 0.10 to 1.50 and from 0.10 to 1.00 μg mL⁻¹ and LOD around 0.001 and 0.01 μg mL⁻¹ have been calculated for trans- and cis-isomers, respectively. The method has been satisfactorily applied to red and white wine samples by standard addition and external calibration, respectively.     

Pathway for the elimination of melamine in lactating dairy cows

Melamine might be degraded into cyanuric acid and some other analogs by the rumen microorganism. Thus, the metabolism of melamine in ruminants may be different from that in monogastric animals. The objective of this study was to investigate the pathway for the elimination of melamine in lactating dairy cows. Four late-lactation dairy cows (body weight=524±17 kg, days in milk=265±14 d) fitted with ruminal cannulas were dosed with melamine (purity ≥99.5%) at 800 mg/d per cow that divided into 2 equal daily doses. The trial lasted for 20 d (13-d preliminary period, followed by a 7-d sample-collecting period). The method of liquid chromatography and tandem mass spectrometry was used to determine melamine and cyanuric acid contents simultaneously. Before the trial started, no melamine or cyanuric acid was detected in samples of total mixed ration, milk, plasma, urine, and feces. The melamine concentration in rumen fluid (Y, mg/L) decreased exponentially after the morning feeding (X, h) (Y=3.85591e(-X/9.25674)+1.35924, R(2)=0.99), but no cyanuric acid was detected. Plasma melamine concentration (0.296±0.014 mg/L) was relatively stable in the 3 different sampling times. The percentages of melamine excreted through milk, urine, and feces were 0.48±0.06, 44.07±10.79 and 10.98±3.88%, respectively. It could be inferred that 44.47±7.98% of ingested melamine was degraded in the rumen, because cyanuric acid was detected in plasma, urine, and feces on the condition that no melamine was contained in the total mixed ration fed to the dairy cows. The results of the present study implied that the elimination pathway of melamine in lactating dairy cows was different from that in monogastric animals. A high percentage of melamine was degraded into cyanuric acid gradually by rumen microorganisms. Most ingested melamine was excreted in urine and feces, which are the main elimination pathways for melamine in lactating dairy cows.     

Detection of Clinical Mastitis with the Help of a Thermal Camera

Increasing dairy farm size and increase in automation in livestock production require that new methods are used to monitor animal health. In this study, a thermal camera was tested for its capacity to detect clinical mastitis. Mastitis was experimentally induced in 6 cows with 10 μg of Escherichia coli lipopolysaccharide (LPS). The LPS was infused into the left forequarter of each cow, and the right forequarters served as controls. Clinical examination for systemic and local signs and sampling for indicators of inflammation in milk were carried out before morning and evening milking throughout the 5-d experimental period and more frequently on the challenge day. Thermal images of experimental and control quarters were taken at each sampling time from lateral and medial angles. The first signs of clinical mastitis were noted in all cows 2 h postchallenge and included changes in general appearance of the cows and local clinical signs in the affected udder quarter. Rectal temperature, milk somatic cell count, and electrical conductivity were increased 4 h postchallenge and milk N-acetyl-β-D-glucosaminidase activity 8 h postchallenge. The thermal camera was successful in detecting the 1 to 1.5°C temperature change on udder skin associated with clinical mastitis in all cows because temperature of the udder skin of the experimental and control quarters increased in line with the rectal temperature. Yet, local signs on the udder were seen before the rise in udder skin and body temperature. The udder represents a sensitive site for detection of any febrile disease using a noninvasive method. A thermal camera mounted in a milking or feeding parlor could detect temperature changes associated with clinical mastitis or other diseases in a dairy herd.     

Protein deposition on contact lenses: The past, the present, and the future

Proteins are a key component in body fluids and adhere to most biomaterials within seconds of their exposure. The tear film consists of more than 400 different proteins, ranging in size from 10 to 2360 kDa, with a net charge of pH 1-11. Protein deposition rates on poly-2-hydroxyethyl methacrylate (pHEMA) and silicone hydrogel soft contact lenses have been determined using a number of ex vivo and in vitro experiments. Ionic, high water pHEMA-based lenses attract the highest amount of tear film protein (1300 μg/lens), due to an electrostatic attraction between the material and positively charged lysozyme. All other types of pHEMA-based lenses deposit typically less than 100 μg/lens. Silicone hydrogel lenses attract less protein than pHEMA-based materials, with <10 μg/lens for non-ionic and up to 34 μg/lens for ionic materials. Despite the low protein rates on silicone hydrogel lenses, the percentage of denatured protein is typically higher than that seen on pHEMA-based lenses. Newer approaches incorporating phosphorylcholine, polyethers or hyaluronic acid into potential contact lens materials result in reduced protein deposition rates compared to current lens materials.