Abstract
To clarify the significance of fecal trimethylamine, lactate, and volatile fatty acids (VFAs) in fermentative development of the hindgut of neonatal calves and the occurrence of diarrhea, 143 fecal samples (47 diarrheic, 93 normal, and 3 meconium) were collected from 58 dairy calves fed milk. An additional 20 fecal samples were taken from 10 weaned calves aged 13–18 weeks. The fecal pH, trimethylamine, ammonia, lactate, and VFAs were analyzed. Compared with weaned calves, trimethylamine level was higher in milk-fed calves and was associated with a large number of cases of diarrhea, but it had little relationship with fecal ammonia level. Feces collected from the youngest (<2 weeks age) calves were more acidic and were associated with higher lactate concentration. Lactic fermentation and fecal acidity were tremendously accelerated particularly in diarrhea. Despite large fluctuations, the VFA concentrations were lower in diarrheic than in normal feces. In diarrheic feces at the youngest stage, the proportion of n-butyrate in the VFAs was lower with accompanying elevation of acetate. However, the fermentative differences between diarrheic and normal feces were less apparent with advancing age. Thus, the fecal lactate and VFA profiles revealed marked changes with advancing age and suffering from diarrhea. Upon comparison with weaned calves, trimethylamine level was clearly higher in milk-fed calves and showed huge elevations in diarrheic cases.
