The objective of this study was to assess the effect of clinoptilolite (a natural zeolite) on growth and performance of broilers as well as on the quality of their litter. A total of 5,200 one-day old broiler chickens (Cobb 500) were used in two consecutive rounds lasting 42 days each. The broilers were given free and continuous access to a nutritionally non-limiting diet (in meal form) that was either a basal diet (B) or a 'zeolite diet' (Z; the basal diet supplemented with clinoptilolite at a level of 2%). A 2×2 factorial design consisted of two feeding treatments (B and Z) and two bedding types, sawdust (S) and sawdust with zeolite (Sz, which was the result of adding 2 kg zeolite/m 2 ), was used. In each round the broilers were randomly assigned to one of four (n = 650), treatment groups: two fed on the basal diet (B) and had bedding of either sawdust (group BS) or sawdust and zeolite (group BSz) and two fed on the Z diet and had as bedding either sawdust (ZS) or sawdust and zeolite (ZSz). Average growth rates were significantly (p<0.05) different between broilers of different groups; broilers that were fed on the 'zeolite diet' (Z) and were placed either in a compartment with sawdust bedding or sawdust bedding and zeolite (ZS and ZSz) as well those that were fed on the basal diet in a compartment with sawdust bedding and zeolite (BSz) grew at a faster rate (p<0.05) compared with those of the control group (BS). The incorporation of NZ in broilers diets and in their bedding material decreased the organic content in litter samples throughout the experimental period. The lowest organic content was recorded in group ZSz where NZ was added in both feed and litter. Mean ammonia concentration (ppm) was significantly higher in group ZS in comparison to groups BSz and ZSz (27.00 vs. 20.55 and 21.71 respectively). The results of this study showed that the incorporation of the clinoptilolite both in feed and into the litter had a positive effect on broiler growth and also on the quality of their litter.

No abstract

Twenty-five sampling stations were selected in order to monitor persistent organic pollutants (polycyclic aromatic hydrocarbons (PAHs), organochlorine (OC) pesticides and total polychlorinated biphenyls (PCBs)) in surface water from Kerkini Lake, the Strymon River, its main tributaries and estuary in N. Aegean Sea during January to July, 2008, according to recent European Union (EU) guidelines. The data were divided among the high (January to April) and the low flow season (May to July). Generally, the values for organic pollutants were within the range reported worldwide for surface water. Elevated PAHs concentrations were observed compared with other places in Greece. Anthracene and benzo(a)pyrene exceeded maximum allowable concentration (MAC) of the relative EU guideline. Also, concentrations above MAC were observed for OCs, γ-HCH, and a-endosulfan. Despite the fact that it is banned since 1972, Aldrin was detected during the monitoring season (from limit of detection (LOD) to 15 ng L(-1)). Total PCB concentrations ranged from LOD to 162 ng L(-1). In addition, the load of organic pollutants was estimated in April (high flow) and June (low flow) in selected sampling stations. According to this estimation, napthalene, anthracene, and fluoranthene (PAHs), total dichlorodiphenyltrichloroethane (DDT), aldrin, and total PCBs had the highest load. Taking into account the relative EU guidelines concerning the pollutants studied, the water quality in the Strymon River catchment could be characterized as poor, which can lead to negative impacts to its biota.

In 2000, the Water Framework Directive (WFD) came into force in the European Union with the aim of protecting and improving water quality. The priority substances established to be monitored are predominantly organic compounds, for which the WFD sets the requirement of ‘whole water sample’ analysis. This legislative requirement poses analytical challenges for the monitoring laboratories as well as technical challenges for reference materials producers. In the past, there were attempts to produce reference materials as quality assurance/quality control tools for measuring organic priority substances in whole water. A critical reflection on the approaches and solutions applied to prepare such kind of matrix reference materials is presented along with a discussion on the difficulties encountered by the analytical laboratories in analysing such complex matrices. The Certified Reference Material (CRM) ERM-CA100 can be considered as a pioneer for a ‘whole water’ CRM (containing humic acids) and has been designed for the analysis of polycyclic aromatic hydrocarbons (PAHs). Further developments seem to be necessary to upgrade the design towards a CRM which will also include suspended particulate matter, another basic constituent of natural surface water samples. Graphical abstract