Abstract: To investigate the long-term effect of feeding flaxseed on the production performance and metabolism of laying hens.48 healthy, approximate weight, fifty-five weeks Hyline Brown hens were divided into four groups, corresponding to treatment 1, 2, 3 and 4 groups were supplemented with 0, 6%, 12% and 18% flaxseed for 10 weeks in the diets respectively. The test results showed that treatment 2 and 3 groups had no effect on weight gain (P>0.05), and treatment 4 group significantly decreased body weight (P<0.05). The excreta moisture content had no significant change with supplement of flaxseed (P>0.05). The treatment 2 and 3 groups could improve laying performance, but treatment 4 group could reduce laying performance. The treatment 2 group did not affect the apparent metabolizable energy and nutrient apparent metabolizable rate of diet, treatment 3 group could reduce the apparent metabolizable energy rate and P apparent metabolizable rate of diet (P<0.05), and treatment 4 group could reduce apparent metabolizable energy and apparent metabolic rate of nutrients. Therefore, supplemented with 6% flaxseed in diet could be used for long-term feeding of laying hens.

Key words: laying hen; flaxseed; apparent metabolic rate; nutrients