• Broilers are less heat tolerant than other poultry species and temperatures over 30°C lead to significantly reduced feed intake and growth depression (Géraert et al., 1993 and 1996).
  • pHorce improved performance of birds when reared under heat stress conditions (average 36°C).
  • pHorce lowered mortality and FCR (feed conversion ratio) and increased bodyweight gain.
  • The inclusion of pHorce across all feed phases gave a return on investment of 1:2.3.


  • pHorce is part of Anpario’s Acid Based Eubiotics (ABE) range and is a blend of concentrated liquid formic and propionic acid on a micropearl mineral carrier; chosen for steady release throughout the gastrointestinal tract.
  • Formic acid is now classified as a bacterial decontaminating agent (including, but not limited to Salmonella) to improve feed hygiene (Feed Additive Register 2017/940).



1,100,040 broilers (Cobb/Hubbard) were placed over a period of 1-2 weeks in 55 houses for large scale commercial evaluation, across São Paulo, in Brazil. The study was divided into 2 treatments in a 4-phase feeding programme conducted until the sheds were cleared at 50 days. All birds received standard diets of either Control (without pHorce) or pHorce (basal diet with a decreasing inclusion of pHorce across the four diet phases (1.0 kg/t, 0.7 kg/t, 0.5 kg/t, 0.3 kg/t)). Management between farms was standardised as far as possible, however environmental conditions differed among the sites. The average environmental temperature during the study across all farms was 30°c (range of 25-36°c).

Graphs Detailing Results

** Production Efficiency Factor = (mean daily gain (g)/10 x FCR) x (100 – % mortality)

  • An 80g increase in bodyweight was seen in the pHorce group and adjusted FCR was 3 points lower (1.81 compared to 1.84), consequently PEF was 14 points higher in birds fed pHorce.
  • A reduction of 0.7% in mortality was observed in the pHorce fed group compared with the control.
  • At average environmental temperature of 36°C, birds were reared under heat stress conditions. This suggests that pHorce can assist in improving performance during periods of environmental and metabolic stress.
  • Feeding pHorce to birds across all production stages improved broiler growth performance compared to the negative control and resulted in a return on investment of 1:2.3.