Herbs, thyme essential oil and condensed tannin extracts as dietary supplements for broilers, and their effects on performance, digestibility, volatile fatty acids and organoleptic properties

International audienceABSTRACT 1. Herbs, thyme essential oil (EO) and condensed tannin (CT) extracts were compared for their effects as dietary supplements, on broiler growth performance, nutrient digestibility and volatile fatty acid (VFA) profiles in the gut. Cooked meat from the birds fed diets with 4 herbs and an EO extract was compared by a taste panel against those fed the control treatment, for organoleptic properties in the meat. 2. Female broiler chicks were fed wheat-soybean meal diets from 0-42 days of age. These chicks were fed either the basal ration (control), or the basal ration with one of rosemary, garlic or yarrow herbs, mimosa, cranberry or grapeseed CT's, or thyme EO supplements (8 treatments in total). Body mass (BM) and feed consumption (AFC) were measured (7, 21 and 42 days of age). 3. The garlic supplement tended (P>0.05) to improve growth rate over the first 7 days, while mimosa CT and thyme EO supplements reduced weight gains. The mimosa supplement in diets lowered (P<0.05) AFC up to study day 21. Meanwhile, the addition of a cranberry supplement reduced the digestibility of DM, OM and N, compared to the controls. Dietary thyme EO, yarrow, rosemary and garlic supplements modified caecal isovaleric and isobutyric acid proportions (Other VFA; P<0.05). Dietary herb supplements affected the intensity of meat flavour (P<0.001), and the potential of observing both garlic (P<0.001) and abnormal (P<0.001) flavours. There were large differences between the consumption of red and white meat samples, while meat temperature affected several flavour attributes. 4. Dietary garlic and grapeseed CT supplements maintained broiler performance and digestibility similarly to those birds fed the control diet, and these supplements appear suitable for dietary inclusion. Careful choices are necessary when selecting dietary plant extract supplements for broilers, but beneficial effects can be observed

Crack growth behavior in ATI 718Plus\uae alloy

ATI 718Plus\uae alloy is a new, cast and wrought, Ni-base superalloy with a maximum use temperature approximately 55\ub0C higher than alloy 718. The mechanical properties have been well characterized by turbine engine OEM's and the alloy has been specified for use as static components and blades in gas turbine engines. Broader use of ATI 718Plus alloy in engine disk applications requires detailed understanding of the damage tolerance under creep and cyclic loading conditions. The results of a large testing program to evaluate the crack growth behavior of ATI 718Plus alloy at temperatures between 649\ub0C and 704\ub0C under conditions of fatigue, dwell-fatigue, and creep are presented. Crack growth rates in ATI 718Plus alloy in this temperature range are lower than alloy 718 and comparable to Waspaloy under non-dwell-fatigue conditions, and comparable to alloy 720 in dwell-fatigue tests. \ua9 2012 Trans Tech Publications, Switzerland.Peer reviewed: YesNRC publication: Ye

Microstructural study of fatigue and dwell fatigue crack growth behaviour of ATI 718Plus alloy

A new superalloy, ATI 718Plus alloy (718Plus), has been developed to have a 55\ub0C higher temperature capability over the traditionally used alloy 718, while maintaining favourable processing characteristics and intrinsic raw material costs. The fatigue and dwell fatigue behaviour of four microstructural variations of 718Plus are evaluated and compared with Waspaloy: standard heat treated condition (HT1), standard heat treated condition with thermal exposure at 732\ub0C (1350\ub0F) for 1000 h (HT2), fine grain condition with a modified d phase (HT3) and fine grain overaged through modified heat treatment (HT4). Fatigue crack growth rate tests were performed at 649\ub0C (1200\ub0F) and 704\ub0C (1300\ub0F) under constant amplitude loading at 10 Hz or with a 100 s tension dwell. The results show that the steady state fatigue crack growth rates of each microstructural variation and both alloys are identical, with all of the 718Plus variations showing a clear advantage over Waspaloy in the fatigue crack threshold regime. The 718Plus variants HT1 and HT3 exhibited the highest fatigue crack growth threshold, followed closely by HT4 and finally HT2. At 649\ub0C (1200\ub0F), the 718Plus alloys had average threshold values ranging from 8\ub78 to 10\ub74 MPa m1/2 whereas the Waspaloy material was 6\ub71-7\ub75 MPa m1/2. At 704\ub0C (1300\ub0F), the advantage increased with the 718Plus alloys having average threshold values ranging from 10\ub71 to 11\ub76 MPa m1/2 compared with Waspaloy, which exhibited average threshold values of 6\ub76-7\ub77 MPa m1/2. Dwell fatigue results show that Waspaloy has better resistance to crack propagation under dwell conditions; however, optimisation of the precipitate phase (HT2) shows vast improvement in the dwell fatigue resistance of 718Plus. \ua9 2011 Canadian Institute of Mining, Metallurgy and Petroleum.Peer reviewed: YesNRC publication: Ye

Activity patterns of insectivorous bats and birds in northern Scandinavia (69° N), during continuous midsummer daylight

Previous studies suggest that many species of insectivorous bats are nocturnal, despite the relatively low availability of their insect prey at night, because of the risk of predation by diurnal predatory birds. We hypothesised that if this was the case bats living above the arctic circle would alter their feeding behaviour during midsummer because there would no longer be any benefit to restricting their activity to the period when their prey are least abundant. Alternatively, if bats were more influenced by competition from aerial insectivorous birds they would continue to feed at &lsquo;night&rsquo; to avoid such competition. In northern Norway (69&deg; N), during continuous midsummer daylight, insectivorous sand martins (Riparia riparia) concentrated their aerial feeding activity when aerial insects were most abundant. The birds stopped feeding between 23:00 and 07:00 when aerial insects were least abundant. In contrast, northern bats (Eptesicus nilssonii), fed mostly between 22:00 and 02:00, coinciding with the lowest aerial insect availability, and with the period when light levels were lowest (ca 1000 lux). Bat activity patterns were closest to those predicted by the avian competition hypothesis. The low densities of both sand martins and Northern bats in the study area, however, were less consistent with this hypothesis. Possibly populations of both species were higher historically and the observed patterns reflected historical competition. Bat activity was most closely correlated to ambient light levels. This raised two alternative explanations that we could not eliminate. Perhaps there was differential predation risk, between the brightest and darkest parts of the day, because the visual capacities of falcons are strongly dependent on luminance. Alternatively the bats may have been entrained to emerge at given light levels by their behaviour at other times of year