Changes in blood profile in sheep receiving raw garlic, garlic oil or monensin

Summary This study aimed to evaluate the effects of supplementing a basal diet ( CTR ) with raw garlic ( GAR ) or garlic oil ( GAO ) on blood profile in sheep. Monensin ( MON , 33 mg/kg DM ) was used as positive control. Four ruminally fistulated rams were used in three experiments each arranged in a 4 × 4 Latin square design with 28‐day periods. Experiments 1 and 2 differed in the dose of GAR (75 vs. 100 g/kg DM ) and GAO (500 vs. 750 mg/kg DM ), while experiment 3 was designed to compare the two doses of each additive ( GAR and GAO ). The animals were fed a basal diet as TMR consisting of 77.83% forage (alfalfa hay and corn silage) and 22.17% concentrate, providing 10.50 MJ/kg DM (metabolizable energy) and 16.5% crude protein to cover maintenance energy and protein requirements. Supplementation of monensin decreased ( P  < 0.05) β ‐hydroxybutyrate ( BHB ) and non‐esterified fatty acid ( NEFA ) concentrations in the blood compared with other treatments. There was no significant effect of additives on serum concentration of glucose, total triglycerides, cholesterol, total protein, albumin and blood urea nitrogen ( BUN ). Although the serum insulin concentration was elevated in sheep receiving MON and GAO ( P  < 0.01), no change was observed in blood glucose concentration. No significant effect of GAO and GAR was observed in key energy and protein‐related blood metabolites. However, administration of monensin had a positive influence on energy indices. In conclusion, whereas parameters characterizing the energy balance did not show a significant effect of GAR supplementation, a higher insulin concentration in GAO ‐treated animals was observed.