Anotace:
The study included 2 groups of lambs (GL): control (C) and experimental (E) which since day 11 of life was receiving an addition of dried Saccharomyces cerevisiae preparation. At the age of 100 days, 12 lambs from each group were weaned from mothers for 12-h pre-slaughter fasting, and transported to a slaughter house. Blood was sampled for analyses: before weaning from mothers (BST 1), before and after transport (BST 2 and 3). Blood samples were assayed for: values of neutrophils and lymphocytes, N:L (neutrophils to lymphocytes ratio), cortisol and glucose. After 24-h chilling of lamb carcasses, musculus longissimus dorsi was subjected to measurements of final acidity (pH24) and colour (CIE Lab), and muscle samples were collected for evaluation of water absorption and shear force. The GL and BST had a significant effect on the N:L ratio. No significant differences were found in the cortisol concentration between groups of lambs. This indicator was significantly different in the analyzed blood sampling time (P < 0.01). In the entire period of pre-slaughter handling, in group C cortisol concentration increased × 8.5, whereas in group E it increased × 4.3 compared to the baseline value. In both groups, the study showed an increase (P < 0.01) in glucose concentration in BST 3 compared to BST 1 and BST 2. Meat of lambs from group E was characterized by lower (P < 0.05) values of pH24, WHC, SF, and indicator a*. The obtained results suggest the advisability of applying a preparation of dried brewer’s yeast in rearing slaughter lambs in order to strengthen their immunity and to alleviate effects of pre-slaughter stress.