Ne. Johnson et al., CHANGES IN DIMENSIONS AND MECHANICAL-PROPERTIES OF BONE IN CHICKS FEDHIGH-LEVELS OF NIACIN, Food and chemical toxicology, 33(4), 1995, pp. 265-271
Tibia dimensions and mechanical properties were determined in White Le
ghorn cockerels that had been fed from 0.1 to 2.0% niacin as a supplem
ent to standard poultry diets. Four experiments of from 20 to 38 days
were conducted. No significant differences due to niacin were found in
weight gain, feed consumed or feed:gain ratios. Decreases in the exte
rior (P < 0.009) and interior (P < 0.015) diameters of the major axes
of the tibiae were found at 0.75-2.0% niacin. Exterior (P < 0.005) aci
d interior (P < 0.001) diameters of the minor axes of the tibia were d
ecreased at levels of 0.75 and 1%. Changes occurred in lateral wall th
ickness of chicks fed 0.75% niacin for 20 days (P < 0.004) and 38 days
(P < 0.023) and in anterior wall thickness of 6-month-old chickens fe
d 1.0% niacin for 28 days (P < 0.001). Ultimate force was decreased in
young chicks fed 1.0 and 1.5% niacin (P < 0.014) and 6-month-old Whit
e Leghorn chickens fed 1.0% niacin (P < 0.004). The addition of high l
evels of niacin to chick rations resulted in changes in dimensions, bo
ne strength and susceptibility to fracture.