| Four experiments were performed to evaluate the potential of using turf Bermuda grass as a pigmenting agent for laying hens.;In experiment 1, the carotene and xanthophyll changes during growth of turf Bermuda grass (Cynodon dactylon) were monitored every three days for a total of 18 days. The carotene and xanthophyll concentrations were not proportional to age or length of the grass clippings. Several methods of processing raw turf Bermuda grass to feed-grade materials were also evaluated. Freeze-drying was by far the best method to maintain the maximum carotene and xanthophyll concentrations. Field drying resulted in considerable losses of both carotene and xanthophyll concentrations.;In experiment 2, the effect of diets containing various levels of dehydrated turf Bermuda grass on egg production, feed utilization, yolk color and egg weight was studied. Milo-soybean meal diets were formulated into 4 treatments containing 0, 3, 6, and 9% dried turf Bermuda grass. After 4 weeks the average Roche color score was 1.3, 4.9, 7.0 and 8.7 for treatments 1 through 4, respectively. The maximum egg production and minimum feed consumption were observed in diets containing 3% turf Bermuda grass meal. There was no significant difference of egg weight between control and grass-fed treatments.;In experiment 3, the deposition of xanthophylls in egg yolks from laying hens fed 9% turf Bermuda grass meal was studied. The various carotenoids present in egg yolks were analyzed by open-column, thin-layer and high-performance liquid chromatography (HPLC). Chromatographic analyses suggest that the yolk color was due mainly to the presence of free lutein and zeaxanthin at a ratio of 79:21 respectively.;In experiment 4, a simple, rapid HPLC method was developed to separate and quantify the major carotenoids present in turf Bermuda grasses with minimum isomerization and oxidation. A reversed-phase isocratic solvent system of water-acetonitrile-chloroform (2:83:15) provided a clear separation of neoxanthin violaxanthin, lutein and $beta$-carotene. Separation occurred within 10 min with detection at 470 nm and a sensitivity at 0.01 a.u.f.s. This method was found to be very reproducible with coefficients of variation less than 3% in 5 sample analyses. |
