Ghrelin Immunoreactive Cell Amounts in the Abomasum in 4-Month-Old Calves by Feeding Different Amounts of Prebiotics and New Synbiotics

The study aim was to determine prebiotic (inulin) and new synbiotic (inulin and Enterococcus faecium) varied dosage effects, during food breakdown-abomasum immunoreactive (IR) cell amount and cold carcass weight. Ghrelin is synthesized in the fundus region of the stomach. In the gastrointestinal system, ghrelin affects multiple functions, including secretion of gastric acid, gastric motility, and pancreatic protein output. The study consisted of 49 Holstein male calves (23 ± 5 days old, 50 ± 5 kg). Control and experimental groups were differentiated only with the additive amount added to the morning food source. Three prebiotic groups were fed Jerusalem artichoke flour (inulin content increased by 50%) in three amounts: 6 g (lowest) PreG₆, 12 g (medium) PreG₁₂, and 24 g (highest) PreG₂₄. Three synbiotic groups were added 0.25 g of prebiotic Enterococcus faecium (2 109 CFU/g) to the respective prebiotic, obtaining a new synbiotic (SynG₆, SynG₁₂, and SynG₂₄). Calves were slaughtered after 56 days to obtain abomasum samples for ghrelin IR cell examination, and carcass weight was determined. It shows that ghrelin IR cell count in the abomasum was (p < 0.05) reduced in 6g and 12g inulin dosage, but carcass weight was significantly (p < 0.05) higher for PreG₁₂ and PreG₂₄ (p < 0.05) and then for CoG (CoG 42.6 kg; PreG₁₂ 51.4 kg; and PreG₂₄ 54.0 kg) and (p < 0.05) for SynG₁₂ and SynG₂₄ (SynG₁₂ 52.3 kg and SynG₂₄ 49.6 kg), which indicates longer satiety and more wholesome breakdown of the food uptake. It was concluded that ghrelin IR cells in 12-week-old calves are more abundant in the fundus region. Medium- and high-dosage prebiotic inulin feeding to the calves improves overall food digestion, allowing for longer satiety and higher cold carcass weight without increasing food amount. Adding synbiotic 0.25 g Enterococcus faecium (2 10⁹ CFU/g (Protexin, UK)) to inulin (produced in Latvia LTD "Herbe") does not improve the results of this prebiotic.