A proline-free, chemically defined amino acid basal diet was compared
with this same diet fortified with 4 g L-proline per kg when given to
5-kg pigs. During a 28-day feeding period, daily gain, food intake, an
d gain : food ratio of pigs given the proline-free diet were not diffe
rent (P > 0.05) from those of pigs given the proline-supplemented diet
. Young pigs can apparently synthesize adequate quantities of proline
endogenously to meet their needs for both growth and maintenance.