High-Condensed Tannin Diet and Transportation Stress in Goats: Effects on Physiological Responses, Gut Microbial Counts and Meat Quality

Abstract

Feeding condensed tannin (CT)-containing diets such as sericea lespedeza (<i>Lespedeza cuneata</i>) and reducing stress have been reported to improve meat quality and food safety in goats. In a completely randomized design with split-plot, thirty-six uncastrated male Spanish goats were assigned to 3 dietary treatments (n = 12/treatment): ground 'Serala' sericea lespedeza hay (SER), bermudagrass (<i>Cynodon dactylon</i>) hay (BG), or bermudagrass hay-dewormed goats (BG-DW; Control) at 75% of intake, with a corn-based supplementation (25%) for 8 weeks. Prior to slaughter, goats were either transported for 90 min to impose stress or held in pens. Basophil counts were lower (<i>p</i> < 0.01) in the SER group compared to BG or BG-DW groups suggesting a better anti-inflammatory capacity due to polyphenols in the SER diet. Compared to BG-DW group, cortisol level was higher (<i>p</i> < 0.05) and norepinephrine was lower (<i>p</i> < 0.05) in the SER group. The SER group had the lowest aerobic plate counts (APC) in both rumen and rectum (<i>p</i> < 0.01). <i>Longissimus dorsi</i> muscle initial pH was not affected by diet or stress. Feeding sericea hay to goats may have beneficial effects, such as enhanced antioxidant and anti-inflammatory properties during stress and reduced gut microbial counts, without changing meat quality characteristics.