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This experiment was conducted to determine the digestible and metabolizable energy (DE and ME) content of lipid sources when fed to growing pigs and to establish prediction equations for determining the DE and ME content of the lipid sources based on their fatty acid composition. Eighty-four crossbred growing barrows (Duroc × Landrace × Yorkshire, weighing 39.4 ± 3.5 kg) were randomly allotted to 1 of 14 diets with 6 pigs per diet involving 13 lipid sources and a basal diet composed of corn and soybean meal according to a randomized complete block design. The lipid sources were substituted into the basal diet at a level of 10% at the expense of corn and soybean meal. The barrows were housed in individual metabolism crates to facilitate separate collection of feces and urine, and were fed the assigned test diets at 4% of initial body weight per day. A 5-d total collection of feces and urine followed a 7-d diet adaptation period. The results showed that the DE and ME content of lipid sources were affected by the composition of their fatty acids. The DE and ME content of lipid sources containing more polyunsaturated fatty acids (PUFA) were usually greater. The DE and ME content of the most examined vegetable and animal lipid sources can be predicted by the content of PUFA, oleic acid (C18:1) and stearic acid (C18:0). The best prediction equation is: DE = 34.15 + 0.07 × PUFA + 0.21 × C18:0 − 0.04 × C18:1 ( R 2 = 0.84, P < 0.01); ME = 33.37 + 0.07 × PUFA + 0.20 × C18:0 − 0.04 × C18:1 ( R 2 = 0.85, P < 0.01). [ABSTRACT FROM AUTHOR]

Abstract: Air samples of total suspended particles (TSP, particles less than 30–60 μm), and particles with aerodynamic diameter smaller than 2.5 μm (PM2.5) were collected simultaneously at Guiyu (an electronic waste recycling site), three urban sites in Hong Kong and two urban sites in Guangzhou, South China from 16 August to 17 September 2004. Twenty-two PBDE congeners (BDE-3, -7, -15, -17, -28, -49, -71, -47, -66, -77, -100, -119, -99, -85, -126, -154, -153, -138, -156, -184, -183, -191) in TSP and PM2.5 were measured. The results showed that the overall average concentrations of TSP and PM2.5 collected at Guiyu were 124 and 62.1 μg m−3, respectively. The monthly concentrations of the sum of 22 BDE congeners contained in TSP and PM2.5 at Guiyu were 21.5 and 16.6 ng m−3, with 74.5 and 84.3%, contributed by nine congeners (BDE-28, -47, -66, -100, -99, -154, -153, -183 and -191 respectively). This pattern was similar to Tsuen Wan site of Hong Kong. Two urban sites of Guangzhou had the same congener pattern, but were different from Yuen Long and Hok Tsui sites of Hong Kong. The results also showed that the amount of mono to penta brominated congeners, which are more toxic, accounted for 79.4–95.6% of Σ22PBDEs from all sites. All congeners tested in Guiyu were up to 58–691 times higher than the other urban sites and more than 100 times higher than other studies reported elsewhere. The higher concentration in the air was due to heating or opening burning of electronic waste since PBDEs are formed when plastics containing brominated flame retardants are heated. [Copyright &y& Elsevier]