The positive effects of Progres® on farm animal performance and well-being have been proven over the years for broiler chickens and many other farm animal species. However, for entering the North American markets, Progres® needed to be studied using a specific Target Animal Safety (TAS) protocol.

For Progres®, the TAS broiler study was conducted at Colorado Quality Research in Wellington, Colorado, USA. The study has now been published as an open access article in British Poultry Science, with the title “Tolerability of graded levels of tall oil fatty acids as a nutritional additive for broiler chickens: a 45-day target animal safety study”. The study proved the tolerability of Progres® for up to 5 kg/ton dosing. Typical dosing of Progres® for poultry in commercial operations has been from 500 g/ton to 1.0 kg/ton.

For the TAS experiment, 160 male and 160 female Cobb 500 broiler hatchlings were randomized into pens, 10 birds/pen. On day 7, the birds in each pen were recounted to eight birds per pen. The pens were randomly divided into the following four dietary treatment groups:

  1. Control, Progres® at 0 kg/ton
  2. Progres® at 1.0 kg/ton
  3. Progres® at 3 kg/ton
  4. Progres® at 5.0 kg/ton

The experimental diets were based on corn and soybean meal, and they were free of antibiotic growth promoters and coccidiostats. Different formulations were used for the starter, grower, and finisher phases.

The birds were weighed individually on days 0, 16, 31, and 45. Feed intake, bird weight gain, and feed conversion ratio were calculated for the respective starter, grower and finisher phases, and over the whole study.

On the final day of the study, every bird was sampled for blood for haematology and blood chemistry measurements. Two randomly selected birds from each pen were subjected to gross pathological examination and sampling of several tissues for histopathology, including weighing the liver.

In this study, bird performance was typical for the breed and equal for all diet groups. Mortality was also similar in all treatments. Progres® dosing did not affect any clinical chemistry parameters measured from the blood samples. Likewise, the histopathological examination revealed no diet-associated changes. However, the 5.0 kg/ton dose level of Progres® increased the relative weight of the liver, as a percentage of final body weight, compared to the control group. As no corresponding histopathology findings were observed, this effect was not considered as adverse.

The article concluded that oral administration of Progres® for 45 days in feed was well tolerated by the broiler chickens up to the dietary level of 5.0 kg/ton.

Reference: H. Kettunen, H. Bento, E. Lewis, S. Remington, A. Matthews, S. Hendrix and J. Vuorenmaa (2022) Tolerability of graded levels of tall oil fatty acids as a nutritional additive for broiler chickens: a 45-day target animal safety study. British Poultry Science. Accepted author version published online August 10, 2022. DOI: 10.1080/00071668.2022.2106776.