Production performance of laying hens fed L-tryptophan.
The purpose of this study was to determine whether supplementing L-tryptophan to a nutritionally complete diet would influence egg production rate and egg shell quality in laying hens. One hundred and twenty layers (Rhode Island Red x White Leghorn) were randomly allocated into three groups. Birds were fed a basal diet or diets supplemented with L-tryptophan at 250 or 500 mg/kg for 405 days from 25 wk of age. Hen day egg production and daily egg output were proportionately higher with higher levels of supplemental dietary L-tryptophan; the differences were significant (P less than .05) for layers fed the 500 mg tryptophan/kg diet. The improvement in egg production by dietary L-tryptophan was greatest during the latter part of the laying period. These findings suggest that supplemental L-tryptophan improves the egg production rate in laying hens.
Ohtani
H
H
Fukushima Prefectural Poultry Experimental Station, Koriyama, Japan.
Saitoh
S
S
Ohkawara
H
H
Akiba
Y
Y
Takahashi
K
K
Horiguchi
M
M
Goto
K
K
D000821:Animal Feed; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet; D004528:Egg Shell / Q000648:ultrastructure; D004531:Eggs; D005260:Female; D005298:Fertility; D005527:Food, Fortified; D011897:Random Allocation; D014364:Tryptophan / Q000008:administration & dosage*
D014364:Tryptophan