In previous trials, the resin acids of Progres® have been shown to improve performance and to reduce intestinal disturbances of broilers, turkeys and calves. In sows, the resin acids addition in late gestation diets has increased colostrum yield and its immunoglobulin (IgG) content which supports the growth and well-being of piglets. The basis for these performance benefits seems to be the ability of resin acids to reduce the inflammation-induced degradation of connective tissues in the intestine and to balance the composition of intestinal microbiota.  These properties make Progres® a potential ingredient also for piglets.

A trial at the Faculty of Veterinary Medicine, University of Helsinki, demonstrated that Progres® addition in piglet feeds improved growth and reduced diarrhea incidence post-weaning. The proven benefits are estimated to be caused by the observed effects on intestinal inflammation and microbiota. The study was recently published by Uddin et al. 2021 in Animals. The following summary focuses on the effects in piglets.  


The present study aimed to determine the effects of Progres® supplementation on sow and piglet performance and incidence of post-weaning diarrhea. In the beginning of the trial, 40 sows (Yorkshire × Landrace) were selected based on body condition and parity and allocated to Control (C) and Progres® (P) treatments (Figure 1).

Figure 1. Dietary treatments in the trial

Sows in the test treatment (P) received Progres®, 1.5 kg/ton of feed in their diet from six weeks before the expected date of farrowing until weaning at four weeks.  Litters from both sow feeding treatments were allocated to Control and Progres® creep feed treatments (n=10) creating treatments PP, PV, CP and CC. At weaning, piglets were again allocated to Progres® (P) or Control (C) weaning feed treatments creating eight different treatments. Progres® inclusion in the piglet diets was 1.0 kg/ton and the trial continued until the piglets were seven weeks of age.

Piglets were individually weighted at birth, 24 hours after birth, at weaning (28 days) and three weeks post-weaning. Piglet mortality and incidence of diarrhea pre- and post-weaning were recorded. Fecal samples were collected from six piglets per litter at 4 and 7 weeks of age to study the effect of dietary treatments on intestinal microbiota and concentration of myeloperoxidase, a biomarker of intestinal inflammation.


Piglets from the Progres® fed sows that received it also in creep and weaning feed were 1.6 kg heavier (p <0.05) at 7 weeks of age than piglets from the control (CCC) group. The average daily gain of the PPP piglets post-weaning was 34 g/d higher than CCC piglets (306 vs. 272 g).

Figure 2. Main results in piglets

The incidence of post-weaning diarrhea was significantly lower in piglets that received Progres® in their weaner diet (PPP, PCP, CPP and CCP) than in piglets receiving control diet post-weaning (Figure 3a).  A numerically lower post-weaning mortality was recorded in piglets that received Progres® in their weaner diet (Figure 3b). The weaning weights and the diarrhea incidence and mortality during suckling period did not differ between the dietary treatments.

Figure 3. a) Post-weaning diarrhea incidence % of piglets b) Piglet mortality % post-weaning

The fecal concentration of the inflammation biomarker myeloperoxidase (MPO) at seven weeks was lower in piglets that received Progres® in their weaner diet (Figure 4). Progres® supplementation in the weaner diet also significantly increased the numbers of butyrate producing Lachnospiraceae and Ruminococcaceae bacteria and reduced the numbers of opportunistic pathogens, such as  Bacteroidetes, Streptococcaceae, and Desulfovibrionaceae (results not shown here).

Progres® supplementation in the weaner diet reduced the incidence of diarrhea and decreased mortality by over 50% compared to the control. It also improved the growth of the piglets post-weaning. The resin acids of Progres® have previously shown to reduce the degradation of collagen and infiltration of inflammatory T-cells in the intestinal tissues of broilers.

Figure 4. The concentration of myeloperoxidase (MPO) in feces at 7 weeks

In the present study, Progres® reduced the concentration of inflammation biomarker myeloperoxidase in feces. Thus, anti-inflammatory action of Progres may explain the effects on post-weaning diarrhea, mortality and growth. The observed effects on intestinal microbiota with increased numbers of butyrate producing bacteria and reduced numbers of opportunistic pathogens may also have contributed to improved growth and reduced post-weaning diarrhea.


In conclusion, supplementing diet with Progres® reduced diarrhea incidence by 40% and mortality by over 50% in weaned piglets, simultaneously improving their growth performance. Reduced intestinal inflammation and beneficial modulation of intestinal microbiota were the probable reasons for the improved performance. Altogether the results demonstrated clear beneficial effects of Progres® in piglet feeding.


Uddin, M.K., Hasan, S., Mahmud, M.R., Peltoniemi, O. and Oliviero, C. (2021) In-feed supplementation of resin acid-enriched composition modulates gut microbiota, improves growth performance, and reduces post-weaning diarrhea and gut inflammation in piglets. Animals 11: 2511.