Extracts of sweet chestnut (Castanea sativa Mill.) which contain hydrolysable tannins are used to prevent diarrhoea in farm animals due to the astringent effect of tannins. The aim of this study was to establish whether long-term treatment with the chestnut extract as a feed additive affects the acetylcholine (ACh)-triggered contractions of isolated rat ileum. Wistar rats of both sexes were divided into 4 male and 4 female groups with 6 animals in each group. The first, second and third groups of both sexes received feed with 3, 15 and 30 g of chestnut extract per kg, respectively. The fourth group of both sexes received feed without the added chestnut extract and served as the control group. After the 90-day trial, the animals were euthanized, and ilea were isolated and placed in an organ bath filled with Tyrode’s solution. Ilea were connected to an isometric transducer. Ileal contractions were triggered by 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, 5.0 and 10.0 mg of ACh, and contractions were recorded. The groups exhibited dose responsiveness to the ACh treatment steps; however, no significant differences in the contraction intensity were observed among the groups at the same ACh dose level. These results suggest that long-term treatment with chestnut extract as an astringent does not influence the intensity of ileal contractions triggered by ACh. Thus, no adverse effect on intestinal motility can be expected during a long-term use of chestnut extract as a feed additive in livestock production; however, further studies in target animal species are needed to confirm the findings.

Background Early maternal separation may have long-lasting physiological effects on different organ systems. Although long-lasting effects of early maternal separation are mostly studied in connection with the development and function of the central nervous system hypothalamic–pituitary–adrenal axis, animal health, behaviour and productivity, there is a lack of information about its impacts on the reproductive system. In the dairy industry, calves are often separated from mothers 1 or 2 days after birth and are not nursed. In the present retrospective study based on data from an artificial insemination (AI) centre, we compared semen parameters and fertility in bulls that were separated from their mothers one day after birth with the semen parameters of bulls that remained with their mothers and were nursed for approximately 2 months. Semen parameters were followed in 3 consecutive years in 52 maternally separated and 22 nursed bulls. Results Ejaculate volume and total sperm count in ejaculate were significantly higher in nursed bulls in comparison to maternally separated bulls at the age 25–36 and 37–48 months, but interestingly, not at the age 12–24 months, during the first year in the AI centre. Non-return rates did not differ between separated and nursed bulls. Conclusion The results suggest that early maternal separation causes long-lasting effects on the functioning of the male reproductive system, evident by reduced production of semen in adult bulls. The data suggest that with a standard of 20 million sperms per straw of frozen semen, 27–78 fewer straws can be obtained from one ejaculate of maternally separated bulls in comparison to the nursed bulls.