Capillary gas chromatographic determination of methylglyoxal from serum of diabetic patients by precolumn derivatization using meso-stilbenediamine as derivatizing reagent.

Stilbenediamine is used as derivatizing reagent for methylglyoxal (MGo) and dimethylglyoxal for the gas chromatographic (GC) determination of MGo from the serum of diabetic patients and healthy volunteers. The derivatization is obtained at pH 3. GC elution and separation are carried out on an HP5 column (30 m x 0.32 mm i.d.) at column temperature 150 degrees C with a programmed heating rate of 50 degrees C/min up to 250 degrees C, and a total run time of 7 min. The nitrogen flow rate is 5 mL/min and detection is carried out by flame ionization detection. The linear calibration curves are obtained with a range of 0.076-0.760 microg/mL and the detection limit is 25 ng/mL MGo. The amounts of MGo found in the serum of healthy volunteers and diabetic patients are 0.025-0.065 microg/mL and 0.115-0.228 microg/mL, with coefficient of variation 1.3-3.1% and 1.4-3.3%.

Comparative bioefficacy of lysine from L-lysine hydrochloride or L-lysine sulfate in basal diets containing graded levels of canola meal for female broiler chickens.

A broiler growth assay was conducted to compare the efficacy of l-lysine HCl and l-lysine sulfate at a graded addition of canola meal (CM). A total of 1,440 1-d-old female Hubbard broiler chicks were allotted randomly to 6 dietary treatments each in 4 replicates of 60 birds per pen. The 2 lysine sources (l-lysine HCl and l-lysine sulfate) and the 3 CM levels (10, 15, and 20%) were used in 2 x 3 factorial arrangement in isonitrogenous (19% CP) and equicaloric (2,700 kcal of ME/kg) diets containing 0.96% digestible lysine. The experiment lasted for 42 d, and a single mash diet was used throughout the experiment. The feed intake during the starter phase (1 to 28 d) decreased linearly as the dietary CM level increased with diets containing l-lysine HCl, whereas feed intake increased linearly with increasing dietary CM level with that of lysine sulfate. Gizzard weight as percentage of carcass weight increased linearly (P < or = 0.016) as dietary CM level increased. No significant effect of lysine sources or CM was observed on body weight gain, feed:gain, mortality, carcass weight, breast and thigh yield, and abdominal fat. In conclusion, l-lysine HCl can be replaced with l-lysine sulfate for broiler diets, and CM can be used as up to 20% of the starter (1 to 28 d) and finisher (29 to 42 d) diets without having any adverse effects of broiler performance.

Effect and interactions of dietary sodium and chloride on broiler starter performance (hatching to twenty-eight days of age) under subtropical summer conditions.

One-day-old Starbro male broiler chicks (n = 360) were used to determine the effect of increasing levels of Na+ and Cl- above the NRC (1994) recommendations for growing broilers diets (hatching to 28 d) in extremely hot weather. The average maximum and minimum temperatures recorded were 39 and 32 degrees C, respectively. An average relative humidity was 58.2% during the experimental period. Three levels of dietary Na+ (0.20, 0.25, and 0.30%) and Cl- (0.30, 0.40, and 0.50%) were used in 3 x 3 factorial arrangement while maintaining a dietary electrolyte balance (DEB) of 250 mEq/kg. Higher weight gain (P < 0.002) and maximum water consumption (P < 0.05) were observed for birds fed diets containing 0.25 and 0.30% Na+, respectively. Litter moisture was significantly higher (P < 0.05) for birds fed diets containing 0.25% Na+ and 0.40 and 0.50% Cl-. High dietary Na+ (0.30%) tended to increase breast yield (P < 0.003) and decreased abdominal fat (P < 0.001). There was no effect of Na+ on blood pH or serum HCO3-. Diets containing 0.40% Cl- increased the dressing percentage (P < 0.001) and leg yield (P < 0.001) and decreased serum HCO3- (P < 0.001). There was no effect of dietary Cl- on blood pH, feed intake, weight gain, feed:gain, water intake, water:feed intake, or mortality. Significant dietary effect of Na+ x Cl- was noted only for litter moisture (P < 0.001), dressing percentage (P < 0.05), breast (P < 0.05) and leg (P < 0.001) yields, abdominal fat (P < 0.002), and serum HCO3- (P < 0.001). Birds fed diet containing 0.25% Na+ and 0.30% Cl- performed as well as those fed other diets when the cyclic temperature ranged from 32 to 39 degrees C.