Evaluation of Activated Effective Microorganisms (EM-2) as Biological Crop Residue Treatment Option Targeted for Feeding Crossbred Dairy Cattle

Abstract

The study was conducted at Holetta Agricultural Research Center with the objective to evaluate the effect of ensiling crop residues (wheat, barley and oat straws) with activated effective micro-organism solution (EM2) on the chemical compositions, in-vitro digestibility and performances of mid lactating Boran-Fresian crossbred cows fed four dietary treatments. These were: ad libtum EM2 treated barley straw basal diet plus on-station formulated dairy concentrate mix supplemented @ 0.3 kg lt^-1 (T1); 0.5 kg lt^-1 (T2); 0.7 kg lt^-1 (T3) and untreated barley straw basal diet plus 0.5 kg lt^-1 milk yield (T4: control groups). Crude protein (CP), digestible organic matter in the dry matter (DOMD), estimated metabolizable energy (EME), total ash, neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin (P<0.05) were significantly (P<0.05) increased by EM2 treatment as compared to the untreated straws. Dry matter (DM) and organic matter (OM) losses as a result of EM-2 treatment were substantial (P<0.05) for all the three crop residues studied. Except for the ash content, interaction effects between the type of crop residue, rate of application and incubation durations were non-significant (P>0.05). Daily intake of EM2 treated barley straw was significantly higher (P<0.05) for all experimental cows compared to cows receiving the untreated residue. Similarly, daily total DM intake followed the same trend as for the basal feed intake. In general, daily intakes and apparent digestibility of all nutrients except DM & OM were higher (P<0.05) for cows fed the EM2 treated barley straw as a basal diet. Daily milk yield and compositions other than milk lactose and total solids were significantly different (P<0.05) among cows receiving the treated barley straw diet. On the other hand, due to high cost of straw treatment, compared to cows on the control diet, the gross and net profit obtained from intervention diets were marginal. In conclusion, EM2 can serve as an alternative biological treatment option for crop residues and thus, can be used on a wider scale among the livestock farming community to alleviate the inherent problems (low intake and digestibility) of most crop residues under local conditions in Ethiopia.