Fermented feed stuff increased orexin level associated with increased food intake and weight gain in weaning pigs

Weaning exposes pigs to various stress factors, leading to growth retardation due to low feed intake, as well as disorders of gastrointestinal function. Fermentation of feed can be beneficial from a health standpoint, especially in the early stages of the pig lives. This study was conducted to investigate the effects of fermented feedstuff on the performance and gastrointestinal hormones involved in feed intake and growth in weaning pigs. A total of 320 Duroc × Landrace × Yorkshire weaning pigs (28 ± 2 d of age with body weight (BW) of 7.38 ± 0.24 kg) were divided into unfermented diet group (UFD) and fermented diet group (FD). Each group consisted of 8 replicates (pens), with 20 piglets per pen. The pigs from the UFD group were fed a basal diet, while the piglets from the FD group were fed a basal diet with 5% feedstuff, which was replaced by the fermented feedstuff for 21 days. Blood samples and tissue samples from the stomach, jejunum and ileum were obtained from six pigs from each group on day 10 of the trial for further analysis.

Pigs fed the fermented diet had higher average daily feed intake (ADFI) and average daily gain (ADG) during the first week, last 2-weeks, and over the entire 3-week period compared with pigs fed unfermented diet. Moreover, feed conversion was only improved by fermentation during the last 2-weeks (P<0.05). Pigs fed fermented diet had a higher serum orexin level and up-regulation in the expression of the prepro-orexin (PPOX) gene in the gastric fundus, jejunum and ileum mucosa (P<0.01), and the expression of IGF-1 (P<0.05) and IGFR (P<0.01) gene in jejunum was compared with pigs fed an unfermented diet. Results indicated that dietary supplementation with fermented feedstuff improved growth performance of weaning pigs by increased orexin, IGF-1 and IGFR levels.

Keywords: Fermented feedstuff, piglet, growth performance, orexin, IGF-1.

Abstract presented at the 3rd International Symposium on Alternatives to Antibiotics 2019.