Peel meals as feed ingredients in poultry diets: Chemical composition,dietary recommendations and prospects

The increase demand for poultry products has had direct effect on the supply and price of feed. This has increased research interest into the potential of locally available, less competed and low cost materials as feed ingredients. Several peels from roots/tubers and fruits have been evaluated in poultry diets but recommendations have not been consistent. High fibre, low nutrient density and likely presence of antinutritional factors limit the efficient utilisation of peel meal by poultry. Plant cultivar, age, agronomic practices, method of peel processing, breed and age of poultry all affect the inclusion level of peel meal in poultry diets. The increase interest in breeding crops for low antinutrients, knowledge in processing technologies and availability of several additives such as enzyme products, amino acids and antinutrients binding agents in the feed market could improve the usefulness of peel meal in on‐farm poultry rations. This study reviews the potential of selected root/tuber and fruit peels as feed ingredients for poultry with regards their composition, dietary recommendation and prospects.     

The Source of Anthropogenic Heavy Metals in Fluvial Sediments of a Rural Catchment: Coxs River,Australia

A serious health scare involving thesupply of drinking water to Sydney, Australia hasrecently focussed attention on the environmentalstatus of river catchments of the main reservoir, LakeBurragorang. Although the Coxs River – a majorcatchment of Lake Burragorang – comprises mainlyforests and grazing land, it supports a moderate sizedtown, power stations and coal mines. The heavy metal content of stream-bed sedimentscharacterises environmental impact in this ruralcatchment and sources of contamination. Sediment in acreek flowing through a country town (population 12 000) is markedly enriched in Cr, Pb and Zn (3×, 18×and 52×, respectively) over background, probably dueto a long history of metal-based industry. The highestCu, Pb and Zn concentrations (204, 332 and2460 μg g^-1, respectively) in fluvialsediment in the town are, however associated withdischarges from a sewage treatment plant. Twocoal-based power stations in the catchment contributeconsiderable Cu and Ni (maximum concentrations 562 and157 μg g^-1, respectively) to ambient fluvialsediments, possibly from cooling towers and coalstorage areas. The highest Co and Cr concentrations(113 and 490 μg g^-1) in fluvial sediments ofthis catchment are associated with coal-miningactivities. Selective extraction indicates that about50% of the anthropogenic fraction may bebioavailable, whereas sequential extraction proceduressuggest that <25% is associated with the easilyexchangeable/adsorbed phase.Two dams restrict the migration of heavy metals downthe Coxs River and sediment discharging into LakeBurragorang is low in metals.     

球状壳聚糖树脂对茶多酚的吸附热力学和动力学研究

采用反相悬浮交联法制备了球状壳聚糖树脂(RCM),通过静态吸附实验,研究了RCM对茶多酚的吸附热力学和动力学特性。结果表明:吸附等温线符合Laugmiur等温曲线,且平衡常数Kb随着温度升高而升高。吸附是非自发的、吸热的、熵增加的过程。吸附过程符合二级动力学吸附模型,吸附过程主要受粒子内扩散模型控制。