Xanthophyll bioavailability in dehydrated turf grass.

In a 16-day experiment involving 270 32-week-old laying hens, dehydrated turf grass (DTG) and corn gluten meal (CGM) were compared as xanthophyll sources for egg yolk pigmentation. Experimental diets were formulated to contain, 0, 5, 10, 15 and 20 mg total xanthophyll/kg diet, provided as either DTG or CGM. Neither egg production nor feed consumption was affected by diet. Egg yolk color dominant wavelength increased slightly with increasing dietary xanthophyll and did not differ with source. Egg yolk color excitation purity increased quadratically (P less than .001) with dietary xanthophyll. The response was similar for both DTG and CGM. It was concluded that the xanthophyll in DTG is 100% bioavailable relative to CGM.