Nutritional Value of Biofloc Meal for White Cachama (Piaractus orinoquensis): Effects of Inclusion Level on Digestibility, Growth Performance, and Protein Retention

Abstract

Biofloc technology (BFT) offers a sustainable aquaculture strategy; however, the value of its byproduct, biofloc meal (BFM), as a feed ingredient requires validation for key species. This study evaluated the use of BFM from a tilapia–molasses system as a feed ingredient for white cachama (Piaractus orinoquensis) juveniles. First, the BFM was characterized, revealing a moderate crude protein (CP) content (37.6 ± 5.3%) but high ash content (17.3 ± 3.7%) and with some essential amino acids (methionine and tryptophan) below the limits of detection of the employed analytical procedure. The apparent digestibility coefficients for protein and gross energy were low at 58.3% and 26.8%, respectively. Subsequently, a 45-day feeding trial was conducted to evaluate six isoproteic diets (32% CP) with increasing inclusion levels of BFM, ranging from 0% to 19.0% of the total diet in a BFT system. Although survival was high (>95%) across all treatments, feed efficiency deteriorated significantly with BFM inclusion. The feed conversion ratio (FCR) increased from 2.0 ± 0.1 (control) to 3.2 ± 1.3 (50% BFM), and the apparent protein retention (APR) decreased from 35.3 ± 3.4% to 16.7 ± 6.3% (p < 0.05). Regression analysis indicated that this decline follows a linear trend, suggesting that for every unit increase in BFM inclusion, there is a proportional decrease in performance. This implies that there is no optimal level of inclusion for raw BFM; rather, low levels contribute to a reduction in efficiency. We conclude that raw BFM from a tilapia–molasses system is unsuitable as a major protein replacement under the tested conditions; however, its potential as a functional additive warrants further investigation.