Table 3.

Effects of prepartum dietary supplementation of rumen-protected choline at 45 g/d (CHOL45, n = 22), 30 g/d (CHOL30, n = 20), or no supplementation (CON, n = 19) on the concentrations and yields of choline metabolites in colostrum

Item	LSM			SE	P-value
	CHOL45	CHOL30	CON		Treatment (T)	Parity (P)	T × P
Metabolite concentration (μmol/L)
Choline1	5.1	5.2	5.1	0.13	0.84	0.05	NS
Betaine	246	250	214	21	0.13	0.04	NS
Trimethylamine N-oxide	10.7a	12.3a	4.7b	0.99	<0.0001	NS	NS
Glycerophosphocholine	4,013	3,958	3,440	219	0.14	NS	NS
Sphingomyelin	523	536	507	48	0.82	NS	NS
Phosphatidylcholine1	5.7	5.8	5.8	0.13	0.79	NS	NS
Phosphocholine	391	393	301	38	0.09	<0.0001	0.05
Total choline2	5,472	5,417	4,815	285	0.15	NS	NS
Methionine	5.2	6.1	9.2	1.2	0.06	0.01	NS
Metabolite yield (μmol/cow)
Choline	963a	1,000a	483b	169	0.02	NS	NS
Betaine	1,401a	1,492a	755b	211	<0.01	0.05	NS
Trimethylamine N-oxide	57.4a	75.8a	16.1b	9.7	<0.0001	NS	NS
Glycerophosphocholine	23,869a	24,262a	11,734b	3,715	<0.01	NS	NS
Sphingomyelin	3,123ab	3,274a	1,694b	509	0.02	NS	NS
Phosphatidylcholine	1,729ab	2,140a	1,181b	297	0.03	NS	NS
Phosphocholine	2,579a	2,958a	1,106b	527	0.01	0.01	NS
Total choline2	32,645a	33,824a	16,116b	5,118	<0.01	NS	NS
Methionine	20.5	25.3	22.2	3.8	0.55	<0.01	NS

^a,bWithin a row, means with different superscripts differ (P ≤ 0.05).

¹Data are presented using a natural logarithmic transformation.

²Sum of all choline-containing biomolecules (choline, glycerophosphocholine, sphingomyelin, phosphatidylcholine, and phosphocholine).