Abstract
Despite the individual recognition of Indigofera zollingeriana and Spirulina platensis as functional poultry feed ingredients, their synergistic effects remain largely unexplored. In this study, the effects of I. zollingeriana and S. platensis on growth performance, carcass traits, blood biochemistry, and the intestinal environment were evaluated. In a randomized block design, five dietary treatments were administered to local-meat type Muscovy ducks, with five replicates of five birds per treatment. The diets that were tested included the following: T0 (Control): Basal diet without the addition of Spirulina or Indigofera; T1: Basal diet 89.5% + Spirulina 0.5% + Indigofera 10%; T2: Basal diet 89% + Spirulina 1% + Indigofera 10%; T3: Basal diet (84.5% + Spirulina 0.5% + Indigofera 15%); And T4: Basal diet 84% + Spirulina 1% + Indigofera 15%. Compared with the control diet, the combined inclusion of Spirulina and Indigofera significantly decreased the feed conversion ratio (p<0.05), while feed intake (FI) and body weight gain (BWG) remained unaffected. Carcass weight and percentage remained statistically comparable across treatments, with T3 yielding the highest numerical value. In summary, I. zollingeriana and S. platensis were combined to create a beneficial combination that improved feed efficiency and the gut environment without affecting carcass traits or organ development. Among the treatments, the combination consisting of 15% I. zollingeriana showed relatively favorable numerical responses in several measured variables, although these differences were not statistically significant for some variables.