Total mixed rations (TMR) are exposed to aerobic deterioration after mixing, critically accelerated by elevated temperatures. This study evaluates the efficacy of CitroFor stabilizer (citric and formic acid, 95:5 diluted 1:4 with water) across three TMR types (dry cows, lactating cows, post-partum cows) at two temperatures (20 and 30 degrees C) using continuous temperature monitoring (84 h, n = 3). The dry cow TMR showed the highest benefit: at 30 degrees C, CitroFor at 4 l/t fresh matter (FM) reduced the temperature increase from +12.5 to +7.7 degrees C (38%), with a statistically significant ANOVA result (F = 6.39; p = 0.033) and complete elimination of mould and yeast. For lactating cow TMR, even 4 l/t was insufficient to prevent mould and yeast growth. The 2 l/t dose was counterproductive for post-partum TMR (critical time shortened by 10%). Results highlight a fundamental interaction between TMR type, stabilizer dose and temperature regime with practical implications for seasonal feeding management.