Use of hop cones in growing beef cattle nutrition

Use of hop cones in growing beef cattle nutrition. The objective of this study was to determine the effect of the supplementation of bull diets with hop cones on growing bull performance, the concentrations of blood analytes, including liver enzymes. Twenty-four growing bulls of Slovene autochthonous Cika breed (body weight 373 kg; age 329 days) were randomly allocated to six pens (four animals per pen). Before the start of experiment all animals received the same basic TMR which was afterwards either not supplemented (control; two pens) or supplemented with 50 g per animal (H50; 6 g of hop DM/kg diet DM; two pens) or 100 g of hop cones per animal (H100; 11 g DM/kg diet DM; two pens) daily. Bulls were weighed at the start of the experiment and then again after 30 and 60 days of experiment and average daily gain (ADG), dry matter intake (DMI) and feed to gain ratio (F : G) were calculated. At each weighing day, the blood samples were taken from each bull and plasma glucose and serum non-esterifi ed fatty acids (NEFA), β-hydroxy butyrate (BHBA), urea, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl transferase (GGT) were determined. The inclusion of hop cones in the diet did not have any effects on DMI, ADG or F : G and did not change BHBA, urea and GGT concentrations. Level of ALT was lower (P = 0.025) after 60 days of the experiment compared to control group. In treatments H50 and H100 blood glucose concentrations increased (P < 0.05) after 30 and 60 days of the experiment, while in treatment H100 NEFA concentration decreased (P = 0.022) after 60 days of the experiment. These fi ndings suggest that hop cones and their constituents provoke changes in energy metabolism in ruminants.