Figure 4.

Net mammary input of carbon (positive value, mol C/d) from plasma metabolites and net mammary output of carbon (negative value; mol C/d) through fat and lactose in colostrum and CO₂ released into plasma during the colostral period (0 to 24 h after the onset of farrowing) in sows fed the control (CON) or fiber-supplemented (FIB) diet during late gestation. The arrows indicate how precursors in plasma are utilized for synthesis of colostral components (fat and lactose) and oxidation, and released as CO₂ into plasma during the colostral period. The blue arrow indicates that ketogenic precursors in plasma (short chain fatty acids, NEFA and triglycerides) were mainly used for colostrum fat synthesis and were also partly oxidized (indicated by carbon dioxide release). The red arrow indicates that glucogenic precursors (glucose and lactate) were likely used for colostrum lactose synthesis and oxidation (indicated by CO₂ release).