Due to the numerous health benefits associated with consumption of antioxidants such as alpha-tocopherol and beta-carotene, an experiment was conducted to determine dietary levels that would significantly enhance their concentration in chicken egg yolks. In the experiment, 127 Single Comb White Leghorn laying hens were divided into treatment groups (n = 40 per treatment group) and fed diets containing 0, 50, 100, 200, or 400 mg/kg beta-carotene, dl-alpha-tocopheryl acetate, or their combination. Yolk alpha-tocopherol increased (P < .05) from the control level of 144 micrograms/g of yolk to 477 micrograms/g of yolk when 400 mg dl-alpha-tocopheryl acetate/kg of diet was supplemented. Yolk retinol levels increased (P < .05) from 11.6 micrograms/g of yolk in controls to 13.9 micrograms/g of yolk at 200 mg beta-carotene/kg of diet. beta-Carotene content in the yolk also increased (P < .05) from .14 micrograms/g of yolk in controls to 5.19 micrograms/g of yolk at 200 mg beta-carotene/kg of diet. Supplemental beta-carotene markedly decreased the yolk deposition of alpha-tocopherol when the two compounds were fed together. Egg production, egg weight, and egg yield were not affected by dietary supplementations. Although the data indicated that it is possible to significantly increase the concentration of all three compounds in chicken eggs, because of the relative expense involved it may not be commercially viable to increase egg yolk concentrations of beta-carotene or retinol by supplementing beta-carotene in the diet.

Fingerling Tilapia aurea were reared for 90 days in three 1.0 m3 floating cages in seawater (36 ppt) at Lee Stocking Island, Bahamas. Fish stocking density (100,200 and 400 fish/m3) apparently did not affect growth rate but it appears salinity inhibited growth. Daily weight gain and specific growth rate ( C ) averaged 0.34 g/day and l.OS%/day, respectively, for Tiiapia cutre0 fingerlings. Infection of the Tilapia aurea by Bacillus sp. was associated with a significant number of mortalities. The relatively low growth rate and the high incidence of disease and mortality of Tilapita our-in seawater indicate that it may not be a good candidate for cage culture in full-strength seawater. I Corresponding author. Current address: 4101 Aspen Street, Bryan, Texas 7780 1.

Two experiments were conducted to determine the dietary requirement for vitamin C of young Tilapia aurea. In the first experiment, best growth and food conversion were obtained over 14 weeks on a diet which contained 50 mg/kg of vitamin C (other levels tested were 0, 100 and 200 mg/kg). In the second experiment, levels of 0, 25, 50, 65, 80, 95 and 110 mg/kg of vitamin C were employed and, again, growth and food conversion did not improve at dietary vitamin C levels above 50 mg/kg. Pathologic changes were observed in fish maintained on rations containing 25 mg/kg or less vitamin C. Gross changes included mild scoliosis and occasional hemorrhages of the fins, mouth and swim bladder. Histologic changes included shortening and thickening of gill lamellae and disorganization of chondrocytes in tips of gill filaments and bases of gill arches.

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A normal phase HPLC method employing a hexane:ethyl acetate mobile phase solvent gradient for the simultaneous separation and quantification of carotenoid pigments and vitamins A and E has been developed. The gradient consists of a 10-min linear change from 1 to 2 mL/min and 95:5 to 70:30 hexane:ethyl acetate mobile phase, which is followed by 7 min of isocratic mobile phase of 70:30 hexane:ethyl acetate at 2 mL/min. The stationary phase consisted of a 4-mu silica column. A photodiode array detector generated simultaneous chromatogram data at three wavelengths (294, 325, and 445 nm) with broad spectrum data at peaks. The method produced good separation of trans-lutein and zeaxanthin.