Table 3. Effects of dietary vitamin D₃ concentration on growth performance of 1–21-day-old broilers (experiment 2)¹⁾

Vitamin D₃ (IU/kg)	Body weight on day 1 (g/chick)	Body weight on day 21 (g/chick)	Body weight gain (g/chick)	Feed intake (g/chick)	Feed conversion ratio (g/g)	Mortality (%)
0	42.3	452^c	410^c	678^c	1.66^a	1.43
125	42.6	756^b	713^b	974^b	1.37^b	1.43
250	42.6	805^ab	762^ab	1,037^ab	1.36^b	4.29
500	42.3	815^ab	773^ab	1,020^ab	1.32^b	0
1,000	42.8	866^a	823^a	1,070^a	1.30^b	0
2,000	42.6	858^a	815^a	1,034^ab	1.27^b	2.86
SEM	0.16	27	27	25	0.03	0.66
p-value
Linear	0.56	< 0.05	< 0.05	< 0.05	< 0.05	0.92
Quadratic	0.86	< 0.05	< 0.05	< 0.05	< 0.05	0.85

Each value represents the mean of five repetitions (14 broilers per repetition) (n = 5). The negative control feed consisted of 10.0 g/kg calcium and 4.5 g/kg non-phytate phosphorus and did not contain supplemental VD₃.
Values with different superscripts are significantly different (p < 0.05).