Use of chromium nanoparticles as a protector of digestive enzymes and biochemical parameters for various sources of fat in the diet of calves

Abstract

The gastrointestinal tract acts as a digestive conveyor and carries out a specific stage of food processing throughout its length. A non-traditional approach to feeding cattle unprotected vegetable fats/oils may involve minerals (Ca and/or Mg). In our study, we studied the biological effects associated with the use of chromium nanoparticles at a dose of 200 μg/kg feed, together with soy and sunflower oils, in the diet of 10-month-old Kazakh white-headed breed calves. The calves were surgically fitted with duodenal fistula and pancreatic duct. Results demonstrated that inclusion of chromium nanoparticles in the diet increased the digestibility of crude protein, NDF, ADF and crude fat (p < 0.05). At the same time, inclusion of chromium nanoparticles in the diet led to changes in the blood serum: a 2-fold increase in aspartate aminotransferase (p < 0.05), a 42.2% increase in lactate dehydrogenase and alanine levels similar to control values. We noted that the addition of lipids in the feed led to the mobilisation of triglycerides and cholesterol. At the same time, the inclusion of chromium nanoparticles contributed to a decrease in the level of total lipids in serum and inhibited peripheral metabolic pathways (a 2-fold increase in the de Ritis coefficient). These data may represent additional evidence of the activation of anabolic processes when chromium nanoparticles are introduced into the diet. The increase in the enzyme index was associated with an escalation of lipid peroxidation processes and a decrease in antioxidant defence activity. We showed that vegetable oils enhanced lipolytic and proteolytic activity of pancreatic juice enzymes in the gastrointestinal tract. Adding chromium nanoparticles to the diet reduced lipase activity, especially when used with soybean oil. These data indicate the inhibitory effect of chromium on the activity of pancreatic lipolytic enzymes.