EFFECTS OF Larrea tridentata ON GROWTH, ORGAN WEIGHTS AND HEPATIC ENZYMES OF BROILERS

Because of the great public scrutiny about using antibiotics as growth promoters in commercial poultry industry, researchers evaluate bioactive compounds of plant extracts as growth promoters. The aim of this study was to evaluate the effects of dietary addition of whole plant, leaves and a powder aqueous extract of Larrea tridentata on growth, organ weights and serum hepatic enzymes of broilers. The hypothesis was that antioxidant capacity of secondary compounds of L. tridentate improve growth. The experimental design was completely randomized with four treatments and 5 cages each. A commercial concentrate was the basal diet to which 20 g t(-1) of L. tridentate (LT) were added (treatments): control (no LT), whole plant, leaves and a powder aqueous extract of LT; these treatments were randomly assigned to 200 Cobb broilers one d old. Feed intake, body weight and organs weight were recorded. Blood serum was collected and hepatic enzyme activity (alkaline phosphatase EC 3.1.3.1, alanine aminotransferase EC 2.6.1.2, and aspartate aminotransferase EC 2.6.1.1) were quantified. Broilers fed LT whole plant, leaves or powder aqueous extract had higher (p <= 0.05) body weight and daily weight gain than control. Because feed intake decreased, and total weight gain increased by whole LT plant, leaves and powder aqueous extract added to diet as compared to control, the feed conversion was reduced (p <= 0.05) in all groups of broilers fed LT. Powder aqueous extract of LT reduced crop, gizzard and liver weights (p <= 0.05) as compared to control, whole plant and leaves. Broilers fed powder aqueous extract of LT had the lowest (p <= 0.05) serum hepatic enzyme concentration as compared to control and those fed whole plant and leaves. Powder LT aqueous extract could be an alternative to growth promoter in broilers.