Abstract

This experiment was undertaken to evaluate the potential impacts of supplementing two direct-fed microbial (DFM) products, namely Bactozyme and Ru-max, to the diet of 12 male Barki sheep (live body weight 46.6 ± 2.9 kg) on dry matter intake (DMI), apparent total tract digestibility of nutrients, nitrogen balance and rumen fermentation characteristics. The Bactozyme or Ru-max were supplemented at a rate of 1.0 g/head/day, mixed with the concentrate mixture. Animals were randomly allocated into 3 equal groups (n=4) and were subjected to the digestibility trails.

The results showed that the inclusion of either products of DFM had no positive impact on DMI, but non-significantly improved the apparent total tract digestibility of dry matter (DM), organic matter (OM) and crude protein (CP). However, the Bactozyme addition increased (P<0.05) the apparent total tract digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF). The enhancement of the apparent total tract digestibility of cell wall was not significant for the two of DFM products and a non-significant improvement in cell wall digestion due to the Ru-max supplementation over the control group was found. The DFM products had positive impacts on the average of total digestible nutrients (TDN) and digestible crude protein (DCP) but non significant in comparison with the untreated animals. In addition, the nitrogen balance was improved (P>0.05) by 8 and 13% due to Ru-max and Bactozyme supplementation, respectively in comparison with the control group. The results also revealed that inclusion of DFM products had no impacts on rumen pH 3.0 and 6.0 h after feeding but Bactozyme reduced (P<0.05) the rumen pH 1.0 h after feeding compared to the control group. The inclusion of Bactozyme and Ru-max increased (P>0.05) the NH₃-N concentration in the rumen at 1.0 and 3.0 h after feeding but the Bactozyme decreased (P<0.05) the NH₃-N concentration and increased the volatile fatty acids (VFA) at 6.0 h after feeding compared to the control group. Overall, results indicated that the two DFM products had positive impacts on cell wall digestibility, which in turn improves metabolic energy supply and nutrients utilization in ruminants as well.

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