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Context. Oil palm frond (OPF) is abundantly available throughout Southeast Asia and is a good source of forage for feedlot cattle, particularly during the dry and monsoon seasons when other forage options are limited. However, the use of OPF in ruminants feed is constrained by its complex fibrous structure and low digestibility.Aims. The aim of this study was to investigate the impact of supplementation with bypass fat on growth, meat quality and economic returns in smallholder feedlot systems where Napier grass is replaced with OPF.Methods. Sixteen Brahman • Charolais crossbred steers, 23 AE 2.0 months old and with initial bodyweight of 425 AE 59.9 kg (mean AE s.e.), were randomly allocated in a 2 • 2 factorial randomised complete-block design experiment with the following dietary treatments: (i) fresh chopped Napier grass-based total mixed ration (TMR; Napier grass-fat), (ii) Napier grass-based TMR + 5% bypass fat (Napier grass+fat), (iii) OPF-based TMR (OPF-fat) and (iv) OPF-based TMR + 5% bypass fat (OPF+fat). Feed intake, digestibility of the diets and average daily gain were measured. The cattle were slaughtered to determine carcass dressing percentage and meat quality. Costs and return of fattening cattle were estimated.Key results. Despite higher intake, cattle fed OPF-fat had a lower bodyweight gain than did cattle fed grass-based diets due to lower digestibility. Bypass-fat supplementation increased the bodyweigh of cattle fed OPF but not of cattle fed Napier grass. Fat supplementation enhanced colour, backfat thickness, and fat content of meat in both the Napier grass-and OPF-based diets. However, replacing Napier grass with OPF reduced the net profit of smallholder feedlot systems, even with fat supplementation. Conclusion.While fat supplementation increased liveweight gain and enhanced some aspects of meat quality, the increased feeding cost reduced net profit. Therefore, supplementation of OPF with bypass fat is not recommended for smallholder feedlots in developing countries.Implications. Appropriate technology to reduce the feeding cost of OPF needs to be developed to make it an economically viable option for smallholder farmers.

PVA is biodegradable plastic and a water-soluble synthetic polymer that plays a significant role in industry. A large amount of PVA in wastewater causes heavy environmental pollution in terms of accumulation, disposal, and long-term degradation; therefore it must be removed from wastewater before the water is discharged. In this study, NS3 mixed microbial culture, capable of completely degrading 5 g.L-1 polyvinyl alcohol (PVA), was isolated from landfill soil using the enrichment culture method. It completely degraded PVA at an initial concentration in the range 1 - 5 g.L-1 over 5 - 20 days of incubation with continuous shaking at 30 °C. Moreover, mixed microbial cultures were found to remove PVA at a high range concentration of 10 - 25 g.L-1. Urea and glucose added to the medium inhibited PVA degradation by increasing the pH to a strongly alkaline level, which would cause cell viability and enzyme stability. The FT-IR spectra and SEM imaging revealed the mechanisms and the physical degradation of PVA films, respectively. PVA uptake in bacterial cells produced a dent in the cell surface, which represented the consumption of PVA by bacterial cell. The PVA-degrading mixed microbial culture is the first reported in Thailand and can be beneficial in PVA wastewater treatment.

This research aimed to study the effect of solvents, namely n-hexane and ethanol, on the yield of crude rice bran oil extraction. The effects of extraction temperatures of 50, 60, and 70 ºC and extraction times of 1, 3, 6, 12, and 24 h were investigated. Rice bran composition was determined. It was found that protein, lipid, moisture, fiber, ash, and carbohydrate content were 12.65±0.56, 16.32±0.81, 7.65±0.62, 10.25±0.64, 6.38±0.59, and 46.75 %, respectively. From the results, the rice bran oil yield from n-hexane extraction was significantly higher than ethanol extraction, with p < 0.05. The maximum rice bran oil obtained from n-hexane extraction was 16.23±0.34 %. The highest yield of rice bran oil was obtained from extraction temperature of 60 - 70 ºC for 12 - 24 h. After extraction by the optimum conditions at 60 ºC for 12 h, the rice bran oil was kept for 1, 2, 3, 4, and 8 weeks for investigation of its quality changes. It can be concluded that the optimum conditions for rice bran oil extraction was with using n-hexane as a solvent for extraction at a temperature of 60 ºC for 12 h. Storing oil for 0, 1, 2, 4, and 8 weeks resulted in the increase of free fatty acids (FFA) and peroxide value, whereas iodine value and saponification value were relatively constant. HIGHLIGHTS n-Hexane and ethanol effect the yield of crude rice bran oil extraction The rice bran oil yield from n-hexane extraction was higher than ethanol extraction The optimum conditions for rice bran oil extraction were with using n-hexane as a solvent for extraction at a temperature of 60 ºC for 12 h Storing rice bran oil for 8 weeks resulted in the increase of free fatty acids (FFA) and peroxide value, whereas iodine value and saponification value were relatively constant