This study investigated the effect of preserving wheat and barley grains with an organic acid liquid surfactant mould inhibitor compared to conventioml artificial drying and assessed its effects on the health and performance of pigs post-weaning (PW).
A 2 x 2 factorial arrangement was conducted to investigate the interaction between grain preservation method ( dried vs. pre served) and zinc oxide (ZnO) inclusion (yes vs. no) on growth per formance, diarrhoea scores and incidence, and total tract nutrient digestibility. One hundred and ninety-two pigs (3 pigs/pen; 16 replicates/treatment) were assigned to one of four experimental diets for 35 days: (1) dried grain diet, (2) preserved grain diet, (3) dried grain diet with ZnO and (4) preserved grain diet with ZnO. Diets were formulated to cont’1in similar levels of net energy and standardised ilea! digestible lysine. On day 35 PW, 24 pigs (12 replicates/treatment) from the non-ZnO suppl emented groups were euthanised and digesta was collected for coeffi cient of apparent ilea! digestibility (CAID), gut microbial population and volatile farty acid amlysis. Stomach tissue was also collected for gene expression analysis, as well as small intestine samples for gut morphology.
Notable im provements in grain quality were obsetved in the preserved grain including a reduction in grain p H, mould presence, and contamination by mycotoxins, specifi cally deoxynivalenol in wheat and barley, and ochratoxin A and HT-2 toxin in barley. The preserved grain diet improved average daily gain (ADG; P < 0.01) and body weight (BW; P < 0.01) compared to the dried grain diet The incorporation ofZnO increased average daily feed intake (ADPI; P < 0.01) and BW (P < 0.05) in the dried grain diet, however, ZnO did not affect ADPI (P > 0.05), and reduced ADG and BW in the preserved grain diet (P < 0.05).
Pigs offered the preserved grain diet had reduced faecal scores and diarrhoea incidence compared to those offered the dried grain diet (P < 0.05). Sup plementation of ZnO reduced faecal scores and diarrhoe.a incidence compared to non supplemented pigs (P < 0.001). On day 35 PW, the preserved grain diet had improved CAID of nitrogen and gross energy (P < 0.05), lower levels of colonic branched-cliain volatile fatty acids.