The present study was conducted to examine effects of long-term graded L-arginine supply on growth
development, egg laying and egg quality in four genetically diverse purebred layer lines. The study comprised a
rearing trial from hatch to week 16 and a following laying performance trial from week 17 to 41. After hatch 150 oneday-old
female chicks of each genotype were distributed to three diets. The experimental diets were equivalent to 70,
100 and 200% L-arginine of age-specific recommended level (National Research Council, 1994) and were offered ad
libitum to chicks (hatch to week 7), pullets (week 8 to 16) and hens (week 17 to 41). However, hens’ diets were quite
low in crude protein. After a pre-laying period from week 17 to 21 thirty-six pullets of each group were used further
in the laying performance trial. Independent of chicken’s genetic background, insufficient L-arginine supply caused
lower body weight, daily weight gain and daily feed intake during the rearing (p<0.001) and induced lower laying
intensity and daily egg mass production in the laying period (p<0.05). Parameters fitted to Gompertz function
suggested higher adult body weight in L-arginine supplemented birds compared to insufficient supplied ones (p<
0.01). Groups fed with insufficient L-arginine reached age of maximum daily weight gain later and showed lowest
maximum daily weight gain (p<0.001). As a consequence of limitations in dietary L-arginine and crude protein, high
performing genotypes decreased strongly in body weight, daily feed intake and performance compared to the low
performing genotypes. In conclusion, L-arginine modified the amount of weight gain and feed intake, especially in
growing chicks and pullets independent of genetic background. The high performing hens were more nutritionally
stressed than the low performing ones, because concentrations of dietary crude protein were relatively low.