Efficacy of Supplementing Lemongrass Powder on Growth, Metabolism, Immune and Endo-Parasitic Status of Lambs in the Tropics.

Abstract

BACKGROUND: Parasitic infections are prevalent among lambs in the subtropics, adversely affecting immunity, liver health and growth performance. To efficiently combat these issues, herbs as supplements are an effective approach. OBJECTIVES: The present study aims to evaluate the efficacy of lemongrass powder on growth performance, nutrient digestibility, blood biomarkers, liver enzymes, immune and endo-parasitic status in lambs (Ovis aries). METHODS: Ten lambs (body weight [BW]: 16.67 &#xb1; 3.82&#xa0;kg) were randomly assigned to two diets (5 lambs/diet) in a crossover design, consisting of two 35-days feeding periods separated by a 14-days washout interval. The basal diet had 14.90% crude protein and 10.57 mega joules of metabolizable energy/kg of dry matter (DM) and was considered the control diet (CL-diet), and the lemongrass diet (LS-diet) consisted of the basal diet + 0.50&#xa0;g of lemongrass powder/kg of metabolic BW of a lamb. Feed, faeces and blood samples were collected during each feeding period. RESULTS: Lambs receiving the LS-diet presented a better propensity of DM consumption (p&#xa0;=&#xa0;0.07), greater average daily gain (p&#xa0;=&#xa0;0.06), while showing a better feed conversion ratio (p&#xa0;=&#xa0;0.05) and higher growth velocity (p&#xa0;=&#xa0;0.02) compared to the CL-diet. In addition, lambs given the LS-diet improved nutrient digestibility, serum high-density lipoprotein cholesterol and albumin, while reducing serum triglycerides, low-density lipoprotein cholesterol and globulin compared to the CL-diet (p < 0.05). However, feeding the LS-diet to lambs had no impact on serum total protein, immunoglobulin (Ig)-M, alanine aminotransferase and gamma-glutamyltransferase, while substantially improving serum IgG and reducing aspartate aminotransferase and alkaline phosphatase, thereby improving immunity and liver health. Lambs given the LS-diet effectively suppressed stomach worms, Paramphistomum spp. and Eimeria spp. (p < 0.05). CONCLUSIONS: Lemongrass powder as a supplement with a basal diet had a positive impact on growth velocity, digestibility, serum cholesterol levels, liver health, immunity and endo-parasitic status in lambs.