• Korean Journal of Poultry Science
• /
• v.17 no.4
• /
• pp.303-309
• /
• 1990

In order to study the effect of diet supplemented with 0.015% (150ppm) of L-tryptophan on the performance of broiler breeder, the performance of parent stock of 1768 breeder(Hubbard) fed on the diet supplemented with L tryptophan was compared with those of 1105 breeders fed on the basal (control) diet Henday egg and settable egg production, fertility, hatchability and number of quality chicks per settable egg were recorded during 133 days(34－52 week－old) of experimental feeding period. Also during 28 days of after experimental feeding period(53－56 week－old) the henday egg and settable egg production were recorded. The henday egg production of breeder fed L-tryptophan was similar with that fed the control diet during 7 weeks of the peak laying period(34－41 week－old) after beginning of the experimental feeding but which was significantly(P＜0.05) higher during 84 days of the post peak laying period(41－52 week－old) and 28 days of after experimental feeding period(53－56 week－old) than those of control And birds fed the L-tryptophan layed significantly (P＜0.01) higher numbers of the sellable eggs than those fed control diet during the post peak laying and after experimental feeding periods. While the coefficient of variance for the henday egg and settable egg production were shown lower values in birds fed the diet supplemented with L-tryptophan compared with those fed the control diet Also the diet containing L-tryptophan did not affect fertility and hatchability of settable egg though the number of quality chicks per sellable egg was higher significantly(P＜0.05) in birds fed the L-tryptophan than that fed the control diet.

• Korean Journal of Poultry Science
• /
• v.33 no.1
• /
• pp.15-24
• /
• 2006

This experiment was conducted to investigate the effects of dietary safflower seed (SFS) powder and chitosan on hatching egg production and eggshell qualify in aged egg-type breeder hens. A total of four hundred 54-week-old Hy-Line Brown breeder hens were divided into five the groups and fed experimental diets either with addition of 0.25 and 0.50% SFS powder or 0.10 and 0.20% chitosan or devoid of all for 6 weeks. There were no significant differences in feed intake and laying performances among the groups. The rate of sellable egg in the groups fed diets containing SFS powder or chitosan was significantly increased compared to that of control (P<0.05), irrespective of dose-dependent manner. The addition of SFS powder or chitosan significantly improved the eggshell strength (P<0.01). Eggshell thickness was also significantly increased in the groups 134 diets containing chitosan as compared with that of control (P<0.01). Fertility and hatchability of egg set were significantly improved by dietary chitosan that those of control (P<0.05). ike contents of tibial Ca and P were significantly increased in the groups fed diets containing 0.5% SFS powder, 0.1 and 0.2% chitosan as compared with those of control. The levels of blood estrogen, calcitonin and parathyroid hormone were not affected by the dietary treatments. The overall results indicated that the proper use of some feed additives such as safflower seed powder and chitosan might provide means of improving eggshell quality and reproductive performances in aged egg-type breeder hens.