Table 9.

Effects amino acids of algae on various parameters in piglets.

Amino Acid	Dietary Concentrations a	Effect on Productivity and Gut Health Parameters Observed	Study Period	Refs.
Threonine	11.4 g/kg vs. 9.5 g/kg	Improved FE; increased intestinal mucin synthesis and number of goblet cells	From weaning (d 21) until 3 weeks post-weaning	[275,276]
Threonine	11.1, 7.5 vs. 3.7 g/kg	Improved intestinal morphology and mucosa immune function; beneficial effects in maintaining jejunal morphology and integrity and repairing villous damage caused by E. coli challenge provided day 16 after weaning	From weaning (day 21) until 18 days post-weaning	[276]
Threonine	0.91 vs. 0.79 % in a simple or complex diet b	Greater benefits with a simple vs. complex diet on intestinal morphology; production of gut microbial metabolites and inflammatory status in the jejunum	From week 1 to 3 post-weaning (day 21.	[277]
Tryptophan	0.26 vs. 0.12 %	Increase ghrelin mRNA expression in the gut and plasma	From weaning (day 28) until 21 days post-weaning	[279]
Tryptophan	0.24 vs. 0.18% SID Trp:Lys	Improved ADG and FE	From week 1 to 3 post-weaning (day 21)	[280]
Tryptophan	0.24 vs. 0.16% SID Trp:Lys	Improved FE, but no effect on ADFI	From weaning (day 21) and until 2 weeks post-weaning	[281]

^a Unless specified, each value indicates a supplemental concentration on the top of a basal diet already meeting the dietary requirement for the amino acid. ^b The simple diet contained corn, wheat, and soybean meal, whereas the complex diet also contained fish meal, plasma protein, and dried whey, together with the ingredients of the simple diet.