Comparison of freeze-dried and extruded Spirulina platensis as yolk pigmenting agents.

Experiment 1 was an 8-wk study with Japanese quail fed 0, .5, 1.0, 2.0, and 4.0% of freeze-dried spirulina or the dry equivalent of fresh spirulina extruded with corn. Experiment 2 was a 16-wk repeat of Experiment 1 using levels of 0, .25, .5, 1.0, and 2.0% spirulina. In the third experiment, corn, barley, and cassava were extruded with fresh spirulina equal to 1% of the dried product, and each feedstuff fed with 1% freeze-dried spirulina. Four replicates of five quail were assigned to each treatment. Yolk color increased with increasing dietary levels of spirulina in Experiment 1. There also was a consistent increase in yolk color with freeze-dried spirulina compared with the extruded spirulina. This pattern was also seen in Experiment 2. In addition, eggs from quail fed the extruded corn control diet had markedly lower yolk scores than those from quail fed the untreated corn control diet. The mean Roche yolk color score of eggs from quail fed corn, barley, or cassava extruded with spirulina was 5.91, 3.55, and 6.70, respectively. These values were respectively 1.41, 1.89, and 4.06 units greater than the corresponding control values.