부산대학교 도서관

An experiment was carried out to investigate the effect of low CP diets with constant ME:CP ratio on nutrients retention, nitrogen (N) excretion, litter composition and plasma biochemical profile in broilers from 1 to 35 d of age. Four dietary treatments having 4 levels of CP and ME were formulated during starter (23, 22, 21 and 20% CP, and 3,036, 2,904, 2,772 and 2,640 kcal/kg ME), grower (22, 21, 20 and 19% CP, and 3,146, 3,003, 2,860 and 2,717 kcal/kg ME), and finisher (20, 19, 18 and 17% CP, and 3,100, 2,945, 2,790 and 2,635 kcal/kg ME) periods. In total, 1,760 day-old Hubbard broiler chicks were distributed to 16 experimental units of 110 chicks each at random and each dietary treatment was randomly fed to 4 experimental units. Results suggested that 26 d N intake, fat retention, N retention, N excretion and N excretion as percent of N intake were not different among treatments. Similarly, 35 d litter moisture, N and ash contents were not affected by reducing dietary CP and ME levels. However, plasma glucose and triglycerides concentrations increased (P < 0.05) without any treatment effect on plasma uric acid, triiodothyronine and thyroxine concentrations. In conclusion, dietary treatments resulted in similar N retention without any significant increase in fat retention. However, N excretion and litter N contents were not decreased due to similar N intake among treatments, also reflected by plasma parameters. [ABSTRACT FROM AUTHOR]