Table 5.

Retention (%) in vitamin D₃ activity in different storage periods for vitamin and vitamin/trace mineral (VTM) premixes ¹.

Items	Choline	Cu and Zn	Months (Time)					SEM	p-Time
			1	2	3	6	12
Vitamin premix 1	-	-	96.67	94.65	91.20	91.30	93.14	1.50	0.077
Vitamin premix 2	+	-	97.80	96.31	93.55	95.57	94.45	1.25	0.150
		SEM	1.20	1.32	1.19	2.00	0.95
	p-Choline		0.518	0.393	0.192	0.164	0.353
VTM premix 1	-	Low	98.83 a	97.33 a	95.39 a	91.60 b	86.04 c	0.86	<0.01
VTM premix 2	+	Low	99.15 a	97.50 a	96.43 a	92.73 b	85.24 c	0.83	<0.01
VTM premix 3	-	High	98.79 a	97.33 a	95.17 ab	91.53 b	84.49 c	1.08	<0.01
VTM premix 4	+	High	98.83 a	95.76 a	96.14 a	89.83 b	84.87 c	1.04	<0.01
		SEM	0.47	1.21	1.15	1.03	0.70
	Main effects
	Choline	-	98.81	97.33	95.28	91.57	85.27
		+	98.99	96.30	96.29	91.28	85.06
	Cu and Zn	Low	98.98	97.41	95.91	92.16	85.64
		High	98.81	96.23	95.66	90.68	84.68
	p-value
	Choline		0.713	0.410	0.394	0.784	0.768
	Cu and Zn		0.710	0.339	0.826	0.166	0.191
	Choline x Cu and Zn		0.762	0.338	0.974	0.186	0.412

¹ Vitamin premix 1 contained no choline chloride, while Vitamin premix 2 contained 160,000 mg/kg of choline chloride. VTM premix 1 contained 500 mg/kg of CuSO₄ and 8000 mg/kg of ZnO, and VTM premix 2 contained 40,000 mg/kg of choline chloride, 500 mg/kg of CuSO₄ and 8000 mg/kg of ZnO. VTM premix 3 contained 20,000 mg/kg of CuSO₄ and 225,000 mg/kg of ZnO. VTM premix 4 contained 40,000 mg/kg of choline chloride, 20,000 mg/kg of CuSO₄ and 225,000 mg/kg of ZnO. ^{a, b, c} Means in a row, with different superscripts, are different (p < 0.05).