Effects of diet supplementation with Trichoderma spp. on structure and ultrastructure of gastric tissues in buffaloes

The effects of supplementing buffalo young bulls with a fibrolytic enzymes mixture derived from Trichoderma harzianum strain T22 on morphostructural and ultrastructural features of the pre-stomachs and abomasum were investigated. Sixteen intact Mediterranean Italian buffalo males (initial body weight 88.2±7.7 kg) were divided into two homogeneous groups (Control and Treatment) and fed the same maize-silage based total mixed ration (TMR). The treatment consisted of spraying the TMR with the liquid fibrolytic enzymes mixture at the dose of 0.7mL/kg of dry matter. Enzyme mixture was prepared weekly and it was applied to TMR, immediately after unloading, diluted in water (1:5 ratio vol/vol). The animals were slaughtered at 350 kg body weight and, for each of them, six samples from rumen, six from reticulum, three from omasum, and five from abomasum were collected. All samples were processed in order to perform scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. The results are a morphostructural description, so that no statistical analysis was performed. Image analysis allowed to highlight some general trends on morphofunctional changes determined by the treatment with Trichoderma. Treated animals showed apparent higher reticular mucosa crests, an apparent increment in number and size of the ruminal papillae, and of the abomasal laminae. Moreover, treatment induced more vascularisation of the superficial layers of the lamina propria, with a greater presence of dilated loops at the abomasal level, as well as an apparent greater number of glands in the different abomasal districts and a widening of the exchange surface between the mucosa and nearby structures. Enhancement of lamina propria vascularisation can improve absorption through the organ wall, as well as it can play an important role in the trophism of mucous membranes. Finally, it was highlighted in both pre-stomachs and abomasum districts a better development of the muscularis mucosae involved in the peristaltic movements. The results of this study showed that fibrolytic enzymes of T. harzianum strain T22 can promote a better growth of both pre-stomachs and abomasum of buffalo young bulls.