Effects of proportion of cassava and lactic acid-treated cassava in rations on rumen pH and plasma lipopolysaccharide-binding protein in beef cattle

The objectives of this study were to investigate the effect of the proportion of cassava and lactic acid (LA)-treated cassava in rations on rumen fermentation parameters and plasma lipopolysaccharide-binding protein (LBP) in beef cattle. Four, rumen cannulated, beef cattle were randomly assigned to four experimental rations in a study with a 2 × 2 factorial arrangement in a 4 × 4 Latin square with a 16-day adaptation period, followed by a 5-day experimental period. During the 5 days of experimental period, the cattle were subjected to 4 experimental treatments, i.e. rations that contained either a high proportion or a low proportion (50% versus 35% dry matter) of cassava either untreated or LA treated. Results showed that clinical signs of subacute laminitis were influenced (P = 0.001) by the proportion of cassava, but not by the treatment of cassava. The cow fed the high proportion of untreated cassava tended to reduce (P = 0.058) the mean postprandial rumen pH, increased (P = 0.032) the area under the curve (AUC) of rumen pH less than 5.80 and tended (P = 0.087) to increase the time that rumen pH was lower than 5.80. However, plasma LBP concentrations did not respond consistently to the experimental rations. The outcome of the current study supports the idea that the treatment of cassava with LA reduces the risk of rumen acidosis when cattle are fed rations with a high proportion of cassava.