This study aimed to assess the impact of the identified phenolic, flavonoid, and fat-soluble vitamin compounds found in Caesalpinia coriaria fruits (EC) aqueous extract on growth performance, helminth parasitic load, feeding behavior, and physiological variables in lambs. The fruits were extracted using water, and three doses of the extract as no extract (EC0 mL/lamb/day), 30 mL of aqueous extract of Caesalpinia coriaria fruits (EC30 mL/lamb/day), or 60 mL of aqueous extract of Caesalpinia coriaria fruits (EC60 mL/lamb/day) were orally administered to 24 growing crossbred lambs weighing 18-20 kg for 60 days. The HPLC analysis revealed that ferulic acid, ellagic acid, syringic acid, quercetin, and hesperidin were the predominant compounds in Caesalpinia coriaria fruits. Additionally, water-soluble vitamin compounds such as thiamine, pantothenic acid, and niacin were detected in the Caesalpinia coriaria fruit extract. The dietary administration of EC improved (P < 0.05) average daily gain and feed and water intake. EC30 lambs spent more time (P < 0.03) eating and less time ruminating. The aqueous extract also showed a dose-dependent reduction (P = 0.048) in fecal parasite egg count, with a steady decrease (P = 0.0001) as the extract was applied. EC0 lambs exhibited the highest (P < 0.0001) respiratory frequency and EC30 the lowest. A strong positive correlation was identified between rectal and abdomen temperature in the morning and afternoon measurements. The presence of phenolic and antioxidants in the aqueous extract of C. coriaria, up to 60 mL, demonstrated beneficial effects, including improved productivity, anti-parasitic activity, and mitigation of body temperature. Thus, farmers without access to synthetic drugs can use this plant extract to treat their animals during fattening to reduce gastrointestinal parasites, improve growth rate, and reduce drug residue in animal products. Further studies need to be carried out on the individual components of Caesalpinia coriaria fruits to ascertain their effect on body temperature/physiology and to know if the effects are individualistic or synergistic.
