PATTERNS OF RUMINAL FERMENTATION IN RESPONSE TO ADDITION OF GLUCOGENIC PRECURSOR TO THE DIET OF FEEDLOT STEERS

Abstract

The objective of this study was to evaluate the effect of the addition of a glucogenic precursor on ruminal fermentation patterns. Therefore, four steers with rumen fistulas (700 kg ±100) were fed with four experimental diets; T1: 15% alfalfa hay, 15% oats hay, 20% harinolina, 47% rotated maize, 1% mineral mixture, 2% bicarbonate; for T2, T3 and T4, 20, 40 and 60 g of the glucogenic precursor were added to T1, respectively. Four experimental periods of 11 d were developed. Approximately 100 ml of ruminal liquid was collected in each one of the four experimental periods, when the pH was measured. Aliquots of 10 ml of ruminal liquid were frozen for their later analysis of AGV and N-NH3. The concentrations
of AGV, ammonia and ruminal pH were analyzed with a Latin square with 4X4 factorial arrangement. The interaction treatment per sampling time was significant for the AGVT and N-NH3 concentration (P<0.05). The AGVT concentration increased with the addition of the glucogenic substrate at 4 h, while the concentration of N-NH3 was higher in T2 compared to T1. Therefore, it is concluded that the addition of the glucogenic precursor improves the parameters of ruminal fermentation.