Supplementation with plant extracts (carvacrol, cinnamaldehyde and capsaicin): Its effects on acid-base status and productive performance in growing/finishing bull calves

Abstract

This study investigated the in vivo effects of a commercial blend of plant extracts (carvacrol, cinnamaldehyde and capsaicin) on blood acid-base balance and serum lactate levels in a 148-day feedlot experimentwith 24 double-muscled Belgian Blue bull calves. Animals were allotted randomly to one of two experimental groups: 1) a control group (C, no supplementation; n = 10), and 2) a group receiving dietary supplementation with a combination of plant extracts (PE, 100 mg per kg DM of concentrate; n = 14). All animals received a high-grain ration, typical of diets fed commercially to feedlot cattle in Spain, consisting mainly of barley plus other components in proportions depending on the production phase. Production data (weight, DMI, ADG and feed-to-gain ratio) were recorded, and venous blood pH, pCO2, HCO3(-), Base Excess -BE- and serum L-lactate were determined. Apparently, beneficial effects of supplementation on production parameters were observed in both growing and finishing periods, though statistically significant effects were only observed in the finishing period. As regards blood parameters, no significant effects of supplementation (or the supplementation x time interaction) were observed, except for an effect on blood pH in the growing period, when supplemented animals showed significantly higher values than controls. A beneficial supplementation x time interactive effect was observed on serum L-lactate levels: from the first week of the study until the end, supplemented animals showed significantly lower levels than controls. These in vivo results support the utility of this dietary supplement in feedlot cattle receiving a barley-based high-grain diet.