Employing a high-resolution (velocity resolution deltanu/nu<1.5%) time-sliced ion velocity imaging apparatus, we have examined the photodissociation of CH2BrCl in the photon energy range of 448.6-618.5 kJ/mol (193.3-266.6 nm). Precise translational and angular distributions for the dominant Br(2P32) and Br(2P12) channels have been determined from the ion images observed for Br(2P32) and Br(2P12). In confirmation with the previous studies, the kinetic-energy distributions for the Br(2P12) channel are found to fit well with one Gaussian function, whereas the kinetic- energy distributions for the Br(2P32) channel exhibit bimodal structures and can be decomposed into a slow and a fast Gaussian component. The observed kinetic-energy distributions are consistent with the conclusion that the formation of the Br(2P32) and Br(2P12) channels takes place on a repulsive potential-energy surface, resulting in a significant fraction (0.40-0.47) of available energy to appear as translational energy for the photo fragments. On the basis of the detailed kinetic-energy distributions and anisotropy parameters obtained in the present study, together with the specific features and relative absorption cross sections of the excited 2A', 1A", 3A', 4A', and 2A" states estimated in previous studies, we have rationalized the dissociation pathways of CH2BrCl in the A-band, leading to the formation of the Br(2P32) and Br(2P12) channels. The analysis of the ion images observed at 235 nm for Cl(2P(32,12)) provides strong evidence that the formation of Cl mainly arises from the secondary photodissociation process CH2Cl + hnu --> CH2 + Cl.

No abstract

Two groups of Atlantic salmon post‐smolts previously fed diets either unsupplemented or supplemented with Zn, Fe, Cu and Mn were fasted for 6 weeks in order to study the reliability of tissue indicators of element status during fasting. The fish were weighed at 2‐week intervals and samples of whole fish liver, vertebrae, serum and eyes were taken for analyses of elements by atomic absorption spectrometry. Body weight, per cent dry matter, condition factor and haematocrit values decreased during the fasting period. The concentration of elements in whole body remained constant, indicating that whole body is a stable indicator of element status during fasting. Other tissues seemed to be more sensitive (i.e. hepatic Fe concentration and vertebrae Zn and Mn concentrations). The serum concentrations of the elements generally decreased during fasting, especially for P and Zn. Element concentrations in whole body and most tissues during fasting were generally more dependent upon initial element status than on the fasting itself. Care should be taken in drawing conclusions about the element status of fish based solely upon the examination of serum concentrations, and more than one tissue indicator should be used in the establishment of the element status of fish.

Phytase was examined as a means to improve turkey performance in diets with high Cl by modifying dietary electrolyte balance. Nicholas turkey toms (10 poults/pen; 10 replicates per pen) were fed corn-soy-distillers dried grains with solubles-canola meal-based diets (DDGS/CM) with varying Cl (0.2, 0.3, 0.4, or 0.5%) and phytase (0 or 500 phytase units/kg of diet), making 8 treatments (4 × 2 factorial). A ninth treatment was a corn-soy based diet (CS) with 0.3% Cl and without phytase (positive control). The diets were formulated to contain similar AMEn and digestible amino acid levels for each of 5 feeding periods (2 to 5, 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age) and fed in mash form. Turkey BW, ADG, ADFI, and feed conversion ratio (FCR) were determined for each pen along with litter moisture, foot pad, and gait scores. An ANOVA was conducted to determine the effects of Cl, phytase, and their interaction. Turkey BW, ADG, and ADFI decreased in a linear or curvilinear manner with increasing diet Cl (P < 05). At 17 wk of age, litter moisture and foot pad score showed a cubic trend with diet Cl (P < 0.05). Phytase improved FCR during 8 to 11 wk and increased litter moisture at 11 wk of age (P < 0.003). Phytase modified the FCR response to Cl during 2 to 5 and 14 to 17 wk of age at the 2 lowest levels of dietary Cl (P < 0.05). Turkeys fed CS had better BW and FCR through 17 wk of age compared with those receiving DDGS/CM at 0.3% Cl. Based on BW, minimum dietary electrolyte balance based on Na, K, and Cl was found to be 247, 217, 200, and 171 mEq/kg during 5 to 8, 8 to 11, 11 to 14, and 14 to 17 wk of age, respectively. The present findings emphasized the importance of considering Cl, phytase, and associated dietary electrolyte balance in turkey diets containing high levels of alternative byproducts.

An experiment was designed to investigate the influence of different levels of dietary inclusion of sunflower meal on broiler's productive performance, serum lipid profile, carcass traits, litter moisture and economic efficiency. One hundred and twenty, day-old Cobb broiler chicks were assigned randomly into 5 equal groups, each contained 24 chicks in three replicate pens (8 chicks/pen). Group 1 was fed on basal diet without sunflower meal and kept as a control group, while groups from 2 to 5 were fed on diets contained 2.5, 5, 7.5 and 10% sunflower meal, respectively. Birds individual weights and pen feed consumed were determined for each feeding period for determining the average body weight (BW), average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). At the trial end, a total of six birds from each group were picked randomly, slaughtered and the visceral organs (liver, gizzard, heart and spleen) plus fat pad were separately weighed for calculating the dressing percentage and the percentage of internal organs relative to carcass weight. Furthermore, litter moisture percentage and economic efficiency were calculated at the trial end. The averages of BW, ADG, ADFI and FCR were not significantly differed among groups. No differences (P>0.05) were observed in the serum lipid parameters and carcass traits among experimental groups. However, the spleen percentage was significantly higher in broilers group that fed on 10% sunflower meal in comparison to those fed on 2.5, 5 and 7.5 sunflower meal, while the litter moisture percentage was not significantly affected. The best economic efficiency was reported in broilers group fed on 10% sunflower meal but the difference did not reach the significance level. It is concluded that levels up to 10% of sunflower meal can be successfully incorporated in broiler chicken diets.