Abstract:
25A Effect of selenium level and source on egg quality R. King, M. Choct and J.R. Rober ts Animal Science, University of New England, Ar midale NSW 2351 rking@metz.une.edu.au Inclusion of organic sources of selenium in the diet of the layer hen is more effective in enriching eggs with Se than inorganic sources (Surai 2000), and broiler meat enriched with Se has been found to have better quality when this has been achieved with an organic rather than an inorganic source of Se in the diet (Naylor and Choct 2000). An experiment was conducted to observe difference in egg quality over a six_week period from adding various amounts of organic (selenium yeast) and inorganic (sodium selenite) Se to the diets of ISA Brown layers from 20 weeks of age. The experimental treatments were: Diet 1, control without added selenium; Diet 2, 0.1 ppm inorganic Se; Diet 3, 0.3 ppm inorganic Se; Diet 4, 0.1 ppm organic Se; Diet 5, 0.3 ppm organic Se; Diet 6, 0.7 ppm organic Se; Diet 7, 1 ppm organic Se. Eggs from 12 birds per treatment, when they were 50 weeks of age, were collected and kept in a cold room (CR) at 4oC or at room temperature (RT) at 18_25oC for 0, 2, 4 and 6 weeks. The Haugh Unit (HU) was measured as an indicator of the internal egg quality (Figure 1). Haugh Unit of eggs decreased significantly (P<0.01) over time regardless of storage temperature, but the magnitude of the decrease was much larger (P<0.01) in eggs kept at room temperature than at 4oC. No significant effect of either source or level of dietary Se on internal egg quality was found. Surai, P. (2000). Effect of selenium and vitamin E content of the maternal diet on the antioxidant system of the yolk and the developing chick. British Poultry Science 41, 235_243. Naylor, A.J. and Choct. M. (2000). Effects of selenium source and level on performance, mortality and meat quality in male broilers. Proceedings of the Australian Poultry Science Symposium 12, 125_128. 90 80 Haugh Units 70 60 50 40 30 0 2 weeks of storage 4 6 1-CR 1-RT 2-CR 2-RT 3-CR 3-RT 4-CR 4-RT 5-CR 5-RT 6-CR 6-RT 7-CR 7RT Figure 1 Effects of storage and dietar y selenium on the quality of eggs kept in a cold room (CR, 4�C) or at room temperature (RT, 18_25�C). Recent Advances in Animal Nutrition in Australia, Volume 13 (2001)