Nucleotides in sow colostrum and milk at different stages of lactation1,2,3

An experiment was conducted with the objective of measuring the concentrations of total milk solids (TMS), CP, and 5′monophosphate nucleotides in sow colostrum and milk. Twelve multiparous sows (Landrace × Yorkshire × Duroc) were used. Litter size was standardized at 11 piglets for all sows at farrowing. Sows were fed an 18.45% CP corn–soybean meal-based diet throughout lactation. The experimental period was the initial 28 d of lactation, with colostrum collected within 12 h of farrowing and milk collected on d 3, 7, 14, 21, and 28. Colostrum and milk samples were analyzed for TMS, CP, adenosine 5′monophosphate (5′AMP), cytidine 5′monophosphate (5′CMP), guanosine 5′monophosphate (5′GMP), inosine 5′monophosphate (5′IMP), and uridine 5′monophosphate (5′UMP). Total milk solids decreased (P < 0.05) from 26.7% on d 0 to 23.1% on d 3. The TMS further decreased (P < 0.05) to 19.3% on d 7, but remained relatively constant thereafter at 18.2, 18.8, and 19.2% on d 14, 21, and 28,