Effect of dietary supplementation with β-hydroxy-β-methylbutyrate on stress parameters in goat kids

Abstract

The objective of this study was to determine the effect of dietary supplementation with β-hydroxy-β-methylbutyric acid (HMB) on live weight loss and selected blood parameters in goat kids after transportation to the slaughterhouse. The study was performed with goat kids that were weaned at 30 days of age and divided into two groups (GK): a control group and an experimental group whose diet was supplemented with HMB (at 50 mg kg-1 of BW) for 60 consecutive days. At the end of the 90-day rearing period, the animals were fasted for 12 h (with access to water) and were transported to the slaughterhouse in the following morning. Blood for analysis was sampled before transportation (BST1) and after unloading in the slaughterhouse (BST2). The animals were weighed on the same dates to determine live weight loss. Red blood cell counts (RBC), white blood cell counts (WBC), hemoglobin concentration (HGB), hematocrit (HCT), neutrophil to lymphocyte (N:L) ratio, and cortisol and glucose concentrations were determined in the sampled blood. The experimental goat kids were characterized by lower weight loss after transportation. Group of kids and BST did not induce variations in RBC, WBC, HGB, and HCT. Cortisol concentration was affected by both GK and BST. Cortisol levels increased after transportation in both groups, but this parameter was significantly higher in the control than in experimental animals at BST2. Glucose levels and the N:L ratio did not differ significantly between GK, but glucose concentration and the N:L ratio were higher at BST2 than at BST1 in both groups. The experimental goat kids were characterized by lower weight loss and lower cortisol concentration after transportation, which could point to the efficacy of HMB in boosting immunity and alleviating transportation stress in goat kids.