Effects of spirulina (Arthrospira platensis) as feed additive of steers consuming high energy diets: growth performance and nutrient digestion

Two trials were performed in order to evaluate the effects of spirulina platensis (SP) supplemented (0, 0.5, and 1.0% diet DM) high-energy on nutrient digestion growth-performance feedlot cattle. The dose each treatment was top dressed mixed directly with basal at time feeding. In Trial 1, six cannulated Holstein steers (281±2 kg) used a replicated 3×3 Latin square experiment. Supplemental SP did not affect ruminal total tract digestion. Ruminal microbial efficiency (quadratic component, P=0.06), nitrogen (linear P=0.10) pH (linear, P=0.06) tended decrease supplementation, without VFA or estimated methane production. 2, 108 medium-frame crossbred (182±1 211-d study growth performance. feed intake, but linearly (P=0.09) weight gain, gain efficiency, dietary net energy. (P=0.08) increase steer morbidity. Effects supplementation carcass characteristics non-appreciable, (P=0.06) longissimus muscle area. It is concluded that low level (up 1% diet) appreciably digestion, fermentation, health cattle fed diet.