Effects of copper and zinc sources and inclusion levels of copper on weanling pig performance and intestinal microbiota

A 42-d experiment was conducted to evaluate the effect of Cu and Zn source and Cu level on pig performance, mineral status, bacterial modulation, and the presence of antimicrobial-resistant genes in isolates of Enterococcus spp. At weaning, 528 pigs (5.9 ± 0.50 kg) were allotted to 48 pens of a randomized complete block design in a 2 × 2 factorial arrangement with two Cu and Zn sources (SF: sulfate and HCl: hydroxychloride) and two Cu levels (15 and 160 mg/kg). As a challenge, the pigs were reared in dirty pens used by a previous commercial batch. Two-phase diets were offered: the pre-starter (PS) phase from day 1 to 14 and the starter phase (ST) from day 14 to 42. At days 14 and 42, pigs were individually weighed and blood samples from one pig per pen were taken. At the end of the experiment, one pig per pen was euthanized to collect the samples. Feeding high levels of Cu increased body weight (BW) from 16.6 to 17.7 kg (P < 0.001). Furthermore, average daily gain, gain to feed (G:F) ratio, average daily feed intake (ADFI), and mineral status were enhanced with Cu at 160 mg/kg (P < 0.05) compared with Cu at 15 mg/kg. There was no effect of the interaction between source × level on any of the growth performance responses except for ADFI (P = 0.004) and G:F (P = 0.029) at the end of the ST period and for G:F (P = 0.006) for entire nursery period (day 0 to 42). At the end of the ST period, pigs fed Cu at 160 mg/kg as HCl had not only higher ADFI but also lower G:F than those fed Cu as SF at 160 mg/kg. Meanwhile, for the entire nursery period, G:F did not differ between pigs fed Cu at 160 mg/kg as HCl or SF. In colonic digesta, the relative abundance of Streptococcus, Enterobacter, Escherichia, among others, decreased (P-adjust < 0.05), while Lachnospira and Roseburia tended (P-adjust < 0.10) to increase in pigs fed Cu at 160 mg/kg as HCl compared with those fed Cu SF at 160 mg/kg. An increase (P-adjust < 0.05) in Methanosphaera and Roseburia was observed in pigs fed Cu at 160 mg/kg. From colon digesta, Enterococcus spp. was isolated in 40 samples, being E. faecalis the most dominating (65%) regardless of the experimental diet. Genes of ermB (7.5%) and tetM (5%) were identified. No genes for Cu (tcrB) or vancomycin (vanA, vanB, vanC1, and vanC2) were detected. In conclusion, European Union permissible levels of Cu (160 mg/kg), of both sources, were able to increase performance, mineral status, and bacterial modulation compared with nutritional level. Different effects on growth performance, mineral tissue content, and microbial modulation were observed between Cu and Zn sources.

QUANTIFICATION OF HYDRAZINE HYDRATE IN IMATINIB MESYLATE AT GENOTOXIC LEVEL BY CHROMATOGRAPHIC METHOD

Hydrazine hydrate has genotoxic effect in nature and so it should be controlled down as Potential Genotoxic Impurity (PGI). Being polar molecule, hydrazine hydrate (N2H4.H2O) has no chromophores present in structure which can follow Lambert beer law, thus it is difficult to analyze. The present work described an accurate and highly sensitive reversed-phase liquid chromatography-UV derivatization method for determination of hydrazine in imatinib mesylate drug substance. The method of quantification was developed by attaching chromophores to hydrazine with derivatization, which helped to increase sensitivity. The derivatization of hydrazine hydrate was performed using 1% methanolic solution of benzaldehyde which acts as derivatizing agent. The derivatized product 1,2-dibenzylidenehydrazine gives maximum absorbance at 300 nm and at this wavelength no interference of solvents and other impurities are noted. Limit of detection for developed method was 0.002 μg/g. The developed method was validated to determine hydrazine content and can be used in quality control for commercial batch release of imatinib mesylate drug substances with a genotoxic specification limit level 1.87 μg/g by HPLC.

ANALYTICAL METHOD DEVELOPMENT AND VALIDATION: A REVIEW

The development of sound Analytical method is of supreme importance during the process of drug discovery, release to market and development, culminating in a marketing approval. The objective of this paper is to review the method development, optimize and validation of the method for the drug product from the developmental stage of the formulation to commercial batch of the product.The purpose of this validation is to show that processes involved in the development and manufacture of drug, production and analytical testing can be performed in an effective and reproducible manner. This review article provides guidance on how to perform validation characteristics for the analytical method which are utilized in pharmaceutical analysis. Keywords: Analytical method validation, Pharmaceutical analysis, Specificity, Precision, Accuracy.

pH: a promising indicator of feed waste in piggery effluent?

Feed waste in pork production sheds can amount to substantial economic losses. No simple methods exist to quantify this waste, which commonly ends up in the effluent stream. Monitoring piggery effluent might offer producers a practical alert solution for feed waste losses. We investigated piggery effluent pH as a potential marker of feed waste, given that most feed substrates and breakdown products are acidic whereas effluent is alkaline. To explore this prospective relationship, we constructed simulated effluent streams comprising faeces, urine and feed. These waste components were acquired from a commercial batch grower shed, at four different times over the 12-week growth cycle. In laboratory settings (25°C) we used the collected wastes to simulate the two stages of typical flushing piggery effluent systems: (1) Faeces + urine + feed waste accumulation in flushing channels, and (2) flush water mixing with these wastes in an effluent collection sump. We repeated the exercise for a one-off sampling event at a sow facility. For all events, at the grower and sow facility, the pH of the simulated effluents yielded exponentially decreasing relationships with increasing feed waste level (P < 0.05). For the grower facility we applied each of the four laboratory-derived relationships to the farm’s sump effluent pH, which was measured during each of these sampling events. The predicted feed waste levels were commensurate with estimates of feed waste for the same facility derived from alternative, time intensive approaches reported in other studies. Further work is needed to transition the promising results uncovered here into an alert system to help farmers improve profitability and minimise waste.

Evaluation of Alumina-Forming Austenitic Foil for Advanced Recuperators

A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically stable external alumina scale at temperatures up to 900°C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface recuperators, three commercially cast heats have been rolled to ∼100 μm thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675°C and 750°C, showing excellent creep strength compared with other candidate foil materials. Laboratory exposures in humid air at 650–800°C have shown acceptable oxidation resistance. A similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65 kW microturbine for 2871 h. One composition that showed superior creep and oxidation resistance has been selected for the preparation of a commercial batch of foil.

Evaluation of Alumina-Forming Austenitic Foil for Advanced Recuperators

A corrosion- and creep-resistant austenitic stainless steel has been developed for advanced recuperator applications. By optimizing the Al and Cr contents, the alloy is fully austenitic for creep strength while allowing the formation of a chemically-stable external alumina scale at temperatures up to 900°C. An alumina scale eliminates long-term problems with the formation of volatile Cr oxy-hydroxides in the presence of water vapor in exhaust gas. As a first step in producing foil for primary surface recuperators, three commercially cast heats have been rolled to ∼100μm thick foil in the laboratory to evaluate performance in creep and oxidation testing. Results from initial creep testing are presented at 675° and 750°C showing excellent creep strength compared to other candidate foil materials. Laboratory exposures in humid air at 650°-800°C have shown acceptable oxidation resistance. Similar oxidation behavior was observed for sheet specimens of these alloys exposed in a modified 65kW microturbine for 2,871h. One composition that showed superior creep and oxidation resistance has been selected for preparation of a commercial batch of foil.