Med. Weter. 2019, 75 (10), 593-598 593 Praca oryginalna Original paper DOI: dx.doi.org/10.21521/mw.6251 Rye is a one of the best cereal crops; it is easy to grow and not very expensive. However, the use of rye grain in the feeding of livestock (including pigs) is still rather limited due to its lower energy value (when compared with that of other grains) and the presence of so-called “anti-nutritive” substances. In a series of experiments, it was found that population rye grains Expression of serotonin, somatostatin, and glucagon-like peptide 1 (GLP1) in the intestinal neuroendocrine cells of pigs fed with population rye type and hybrid rye type grains 1) ANNA ZACHARKO-SIEMBIDA, MARCIN B. ARCISZEWSKI, JOSE LUIS VALVERDE PIEDRA*, EWA TOMASZEWSKA**, SYLWIA SZYMAŃCZYK**, SIEMOWIT MUSZYŃSKI***, PIOTR DOBROWOLSKI****, SYLWIA MOZEL, TOMASZ SCHWARZ***** Department of Animal Anatomy and Histology, *Department of Pharmacology, Toxicology and Environmental Protection, **Department of Animal Physiology, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland ***Department of Biophysics, Faculty of Production Engineering, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland ****Department of Comparative Anatomy and Anthropology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University in Lublin, Akademicka 19, 20-033 Lublin, Poland *****Department of Swine and Small Animal Breeding, Faculty of Animal Breeding and Biology, University of Agriculture in Kraków, Al. Mickiewicza 24/28, 30-059 Kraków, Poland Received 24.01.2019 Accepted 14.03.2019 1) The study was fnanced by the National Centre for Research and Develop- ment, Poland, under the BIOSTRATEG 2/297910/12/NCBR/2016, ENERGY - FEED research project. Zacharko-Siembida A., Arciszewski M. B., Valverde Piedra J. L., Tomaszewska E., Szymańczyk S., Muszyński S., Dobrowolski P., Mozel S., Schwarz T. Expression of serotonin, somatostatin and glucagon-like peptide 1 (GLP1) in the intestinal neuroendocrine cells of pigs fed with population rye type and hybrid rye type grains Summary Neuroendocrine cells (NEC) are a cell population in the gastrointestinal tract that plays a role in the regulation of the digestion process, satiety and nutrient homeostasis. NE cells express a variety of bioactive hormones that can undergo changes in response to different luminal stimuli, including multiple components, which are present in the diet. In recent years, a modern (hybrid) type of rye grain has been introduced to feed industry. The goal of the present study was to determine immunohistochemically whether the feeding of the pigs with population and hybrid rye grains may evoke adverse changes in the small and large intestines in terms of the expression of serotonin, glucagon-like peptide 1 (GLP1) and somatostatin. Feeding animals with population and hybrid rye grains resulted in a slight increase in serotonin-positive NE cells in the small intestine (but not in the large intestine). After feeding animals with population rye (but not with hybrid rye) grains, there was a decrease in the small intestine GLP1-immunoreactive NE cells was found. No changes in the expression of GLP1 were found in the large intestine of experimental animals. The numbers of somatostatin-IR NEC in the small and large intestines were not affected by feeding with either population or hybrid rye grains. In conclusion, we found that feeding pigs with hybrid and population rye grains started adaptive changes in NEC. However, those changes were not profound, which allows us to speculate that adverse effects of these rye grains have a minor (if any) impact on the gut hormone balance (and indirectly on the health status) of animals. Keywords: rye, grain, feeding, farm animals, neuroendocrine cells, gastrointestinal tract