BACKGROUND: Colostrum is the first milk produced after birth and is particularly rich in immunoglobulins, growth factors and antimicrobial peptides. Therefore, maintenance and storage of bovine colostrum has always been considered due to benefits of colostrum for the calf. Microbial contamination of colostrum is a concern because it is thought that bacteria in colostrum may interfere with passive absorption of colostral antibodies. OBJECTIVES: The aim of this study was to evaluate the effects of chemical preservatives and natural fermentation on quality and storage of colostrum. METHODS: Colostrum from the first milking of five Holstein cows was stored separately. Then colostrum samples were studied at days 1, 10, 20, and 30 of storage after treatment. All samples underwent microbiological culture for total plate count and detection of Escherichia coli, Coliforms, mold and yeast. Then whey was provided from untreated and treated samples at the end of 30th day and SRID (single radial immune diffusion) test was performed for assaying IgG antibody. Then the effect of treatments on colostrum antibody level was studied. RESULTS: The results showed that potassium sorbate did not have a role in reducing E.coli and coliforms count. However, it has prevented an increase in E.coli and coliform count during 30 days. Formic acid and propionic acid reduced the number of E. coli and coliform (p<0.05). In addition, the two organic acids promoted the growth of mold and yeasts compared with potassium sorbate. Nonetheless, the mentioned three treatments did not have an important role in reducing total count (p>0.05). The natural fermentation contributed to the decline of E. coli and coliform count while total count increased one day after treatment compared with other treatments, however among the treatments, formic acid and potassium sorbate were more effective than propionic acid and natural fermentation treatment for maintaining hygienic quality of colostrum. The result of measuring IgG antibody indicated that potassium sorbate has had more protective effect than other treatments. CONCLUSIONS: The results exposed that potassium sorbate and formic acid are better than other treatments to maintain colostrum quality with regard to increasing shelf life of colostrum.

Some azo dyes, including Sudans I–IV and Para Red, are genotoxic and may be biotransformed to cancerogenic aromatic amines. They are banned as food and feed additives, but their presence has been detected in food. Aromatic amines are also considered potentially toxic. Online EC–MS is a promising tool to study the transformation mechanisms of xenobiotics such as azo dyes. The aim of the study was to investigate emulation of how azo dyes are enzymatically transformed to amines with EC–MS. The reduction reactions of five azo dyes (Sudans I–IV and Para Red) were conducted using a glassy carbon working electrode and 0.1% formic acid in acetonitrile. Reduction results were compared with the literature and in silico to select preliminary candidates for metabolites. The LC-MS/MS method was used to confirm results obtained by electrochemical reactor. A limited number of pre-selected compounds were confirmed as azo dyes metabolites – aniline for Sudan I, aniline and 4-aminoazobenzene for Sudan III, o-toluidine for Sudan IV, and 4-nitroaniline for Para Red. No metabolites were found for Sudan II. Electrochemistry–mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation.

Introduction: Quercetin is a polyphenolic flavonoid which has been used in traditional Chinese medicine as a natural therapeutic agent with a broad spectrum of activities (antioxidant, anticancer, neuroprotective, anti-inflammatory, antiviral and antibacterial). The aim of this study was to develop and validate a rapid and simple ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for the determination of quercetin in milk. Material and Methods: Sample preparation was based on a liquid-liquid extraction with 0.5% formic acid in acetonitrile. The chromatographic separation was performed on a ZORBAX SB-C18 column with methanol and 0.5% formic acid as a mobile phase. Results: The procedure was successfully validated. The mean recovery of the analyte was 98%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively, and the repeatability and reproducibility were in the range of 3%–7.2% and 6.1%–12%, respectively. The lowest level of quantification was 1.0 μg/kg. Conclusion: The proposed method was successfully applied in evaluating the pharmacokinetics of quercetin in milk obtained from dairy cows with clinical mastitis after intramammary administration.

Introduction: The paper presents the method of simultaneous determination of 10 illegal azo dyes in feed by ultra-high performance liquid chromatography coupled with tandem mass spectrometry technique. Material and Methods: The dyes were extracted with hexane, evaporated to dryness, and analysed. Separation was achieved in 7 min in a gradient elution using acetonitrile (A) and 0.1% formic acid (B) as a mobile phase. Results: The validation results showed the repeatability of the method, which was evaluated at three levels (50, 500, and 5,000 μg/kg). All the matrix calibration curves for the working ranges were linear (R² 0.9904 to 1.0), the repeatability was between 2.1% and 24%, and recoveries ranged from 77.9% to 120%. The LOD and LOQ were at 1-2 and 5-10 μg/kg for different dyes, respectively. Furthermore, the method was applied in the homogeneity tests of the in-house prepared feed containing Sudan I at the levels of 0.5, 5, and 50 mg/kg. Conclusions: A sensitive, selective, and fast multiresidue method was successfully developed and validated. Its robustness was confirmed by the analysis of an experimental feed containing Sudan I.

Salicylic acid is a derivative of benzoic acid and occurs in nature. The main target of this study was to develop the liquid chromatography coupled with tandem mass spectrometry technique as a method for determination of salicylic acid in feed materials and compound feed. Salicylic acid was extracted from feed with 0.1% hydrochloric acid in methanol. Separation was achieved in 8 min in a gradient elution using 0.1% formic acid and acetonitrile. The analyte was detected using negative electrospray tandem mass spectrometry. The procedure was validated to the specifications of the European Commission Decision No. 2002/657/EC. The validation results showed the repeatability of the method, which was evaluated at three levels (0.25, 0.5, and 1.0 mg/kg). Calibration curves for the working ranges were linear (R² 0.9911 to 0.9936), and recoveries ranged from 98.3% to 101%. The LOD and LOQ for compound feed were 0.02 and 0.05 mg/kg, respectively. Salicylic acid was found mostly in corn, and its concentrations differed depending on whether it was young or fully grown (5.30–12.8 mg/kg and 0.13–1.01 mg/kg, respectively). A sensitive and reliable method for the determination of salicylic acid in feed and compound feed using LC-MS/MS was developed.

OBJECTIVE To describe histologic changes in the temporomandibular joints (TMJs) of horses of various ages. SAMPLE 22 TMJs from cadavers of 11 horses. PROCEDURES Horses were categorized into 3 age groups (group 1, 2 to 10 years old [n = 3]; group 2, 11 to 20 years old [3]; and group 3, > 20 years old [5]). Each TMJ was sectioned into 5-mm slices, preserved in formalin, decalcified in formic acid, and routinely processed for histologic analysis. Joints were systematically assessed by use of previously described methods. Multilevel mixed-effects models were used to examine the data. RESULTS The number of changes was significantly fewer and degree of changes was significantly less within the TMJs of group 1 horses, compared with those of group 3 horses. Comparison among groups revealed that the combination of temporal and mandibular scores for group 1 was significantly lower than for groups 2 or 3. Disk score did not differ significantly between groups 1 and 2, but disk scores of groups 1 and 2 were significantly lower than the disk score of group 3. CONCLUSIONS AND CLINICAL RELEVANCE The assessed lesions were associated with osteoarthritis, and they accumulated in the TMJs as horses aged. In the absence of signs of pain manifested as changes in mastication, behavior, or performance, it would be difficult to determine the point at which accrued pathological changes represented the onset of clinically important osteoarthritis of the TMJs.

Edible bird's nest (EBN)is made from the saliva of swiftlet from the Aerodramus species. It is one of the most widely consumed traditional health food by the Chinese community due to its claimed medicinal value. EBN contains glycoproteins with abundance of sialic acid (SA). EBN with higher SA content has a potential to command for higher price. The objective of this study was to determine and compare free SA content of EBN collected from Johor and Kelantan. A total of 23 and 30 of raw and unprocessed EBN samples were obtained from Kelantan and Johor, respectively. SA from EBN samples were analysed using LC-MS/MS. Johor showed higher content of free SA with the value of 135.04 ± 29.60 mg/kg compared to Kelantan which has a value of 95.55 ± 25.6 mg/kg. Highest content of free SA was found in EBN from Pontian district, Johor.