CHOLINE AND CHOLINE ESTER CONCENTRATIONS IN PORCINE MILK THROUGHOUT LACTATION

Choline and choline esters are present in milk and are important for t he suckling neonate. Choline concentrations in porcine milk had not be en previously reported, therefore choline, glycerophosphocholine, phos phatidylcholine, and phosphocholine concentrations in porcine prepartu m mammary secretions, colostrum and milk were determined herein by HPL C and GC-MS. Milk samples were collected from second parity cross-bred sows by manual expression similar to 12 hr prepartum and on day 1 to 28 postpartum. The choline content of prepartum secretions was 5,121 /- 268 mu mol/L. With the onset of lactation, the choline concentratio n initially declined to 2,235 +/- 261 mu mol/L, which was lower than p repartum secretions (P < 0.05). Between d 2 and 28 postpartum, the tot al choline concentration in porcine milk was relatively stable at 3,11 7 +/- 498 mu mol/L, however, the contribution of the individual cholin e compounds varied with lactation. Glycerophosphocholine predominated prepartum secretions (78.9 +/- 1.7%) and on day 1 postpartum (42.9 +/- 11.5%), whereas phosphocholine was the predominant choline and glycer ophosphocholine declined, phosphocholine rose (from 24.3 +/- 20.2% to 78.6 +/- 4.7% of total choline) and phosphatidylcholine remained relat ively constant (6.8 +/- 1.0% of total choline) and phosphatidylcholine remained relatively constant (6.8 +/- 1.0% of total choline) as lacta tion progressed. In summary, the total choline content of mature porci ne milk averaged 3 mM. Assuming milk intake of 800 mL/day and an avera ge body weight of 4 kg between days 1 and 28 postpartum, choline intak e of the suckling piglet would be similar to 600 mu moles/kg/day. (C) Elsevier Science Inc. 1997.