Introduction: Microalgae are increasingly explored as alternative feed ingredients in pig production due to their nutritional value and sustainability potential. However, their
application in practice remains limited, partly because of processing constraints. In the present study, we evaluated the effects of including a minimally processed, liquid microalga supplement in
the diet of post-weaning piglets, focusing on feed acceptance, growth performance, and digestive outcomes.
Material and Methods: A wet feed supplemented with Chlorella vulgaris was produced by incorporating a concentrated microalgal solution (4% DM) into a standard piglet diet in a 1:1 ration.
Feed characteristics were first assessed through aroma profiling and in vitro protein digestibility. Subsequently, 24 post-weaning piglets (initial body weight 18.1 ± 3.55 kg) were fed either a control diet or the microalga-supplemented diet for two weeks. Body weight gain, feed intake, fecal dry matter and total bacteria output were recorded.
Results and Discussion: In vitro analyses showed a 10% increase in protein digestibility of the microalga-supplemented feed compared to the control. Although the inclusion of microalgae
modified the feed aroma profile, this did not negatively affect feed acceptance in vivo. Piglets fed the microalga-supplemented diet exhibited similar (p > 0.05) daily weight gain (0.83 ± 0.17 kg d⁻¹)
and feed intake (6.00 ± 0.66 kg d⁻¹) compared with control animals. Fecal dry matter content was significantly higher in piglets receiving the microalga-supplemented diet (214 ± 18.1 g kg⁻¹ vs. 188 ±
11.8 g kg⁻¹; p < 0.001), indicating an effect on digestive output without compromising growth performance. Overall, these results demonstrate that liquid Chlorella vulgaris can be successfully
included in piglet diets without negative effects on performance or feed acceptance. This approach offers a promising strategy for integrating microalgae into pig production systems while
maintaining animal performance.