Table 8.

Retention (%) in niacin 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	-	-	99.67	97.89	99.76	98.90	98.54	0.56	0.130
Vitamin premix 2	+	-	98.60	99.35	98.87	98.54	98.43	0.90	0.954
		SEM	1.18	0.89	0.37	0.66	0.34
	p-Choline		0.557	0.501	0.843	0.149	0.472
VTM premix 1	-	Low	99.58 a	97.46 ab	97.05 ab	95.43 bc	93.66 c	0.69	<0.01
VTM premix 2	+	Low	99.08 a	98.14 a	97.91 a	95.28 b	93.28 b	0.89	<0.01
VTM premix 3	-	High	99.38 a	97.33 a	97.78 a	94.89 b	93.94 b	0.55	<0.01
VTM premix 4	+	High	98.36 a	97.37 ab	96.77 abc	94.53 bc	93.32 c	0.93	<0.01
		SEM	0.38	1.07	0.94	1.39	0.49
	Main effects
	Choline	-	99.48	97.39	97.41	95.16	93.80
		+	98.72	97.76	97.34	94.91	93.30
	Cu and Zn	Low	99.33	97.80	97.48	95.36	93.47
		High	98.87	97.35	97.27	94.71	93.63
	p-value
	Choline		0.059	0.737	0.940	0.859	0.314
	Cu and Zn		0.239	0.679	0.827	0.648	0.745
	Choline x Cu and Zn		0.492	0.767	0.331	0.943	0.807

¹ Vitamin premix 1 contained no choline chloride, and yet 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, while 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).