Table 3.
Performance of Bos taurus indicus bulls administered or not Megasphaera elsdenii (Lactipro-NXT; 1 × 1010 CFU/head; MS Biotec, Wamego, KS) and offered an adaptation diet for 14, 6, or 0 d1
| Item | Treatments | SEM | P =2 | |||||
|---|---|---|---|---|---|---|---|---|
| CONT | MEG-14 | MEG-6 | MEG-0 | CONT vs. MEG | L | Q | ||
| Initial BW, kg | 386.6 | 386.7 | 386.6 | 386.6 | 7.66 | 0.89 | 0.81 | 0.80 |
| Final BW, kg | 572.1 | 570.7 | 572.9 | 566.4 | 8.26 | 0.59 | 0.36 | 0.29 |
| Average daily gain, kg/d | 1.59 | 1.58 | 1.60 | 1.54 | 0.26 | 0.59 | 0.24 | 0.26 |
| Dry matter intake, kg | 10.85 | 10.74 | 10.73 | 10.42 | 0.219 | 0.22 | 0.15 | 0.42 |
| Feed efficiency, g/kg | 147 | 147 | 149 | 148 | 2.7 | 0.43 | 0.68 | 0.52 |
| Net energy for maintenance, Mcal/kg | ||||||||
| Observed3 | 1.90 | 1.90 | 1.92 | 1.93 | 0.020 | 0.34 | 0.21 | 0.62 |
| Expected4 | 2.02 | 2.02 | 2.03 | 2.04 | -- | -- | -- | -- |
| Observed: Expected ratio5 | 0.94 | 0.94 | 0.95 | 0.95 | 0.001 | 0.61 | 0.61 | 0.62 |
| Net energy for gain, Mcal/kg | ||||||||
| Observed3 | 1.25 | 1.26 | 1.28 | 1.28 | 0.018 | 0.34 | 0.21 | 0.62 |
| Expected4 | 1.36 | 1.36 | 1.37 | 1.38 | -- | -- | -- | -- |
| Observed: Expected ratio5 | 0.92 | 0.92 | 0.93 | 0.93 | 0.013 | 0.66 | 0.62 | 0.62 |
1Experimental period lasted 119 d. CONT: 14 d adaptation with 2 step-up diets and transition to a high-concentrate finishing diet on d 15 (n = 15), MEG-14: CONT plus oral administration of 20 mL of Lactipro-NXT (M. elsdenii NCIMB 41125, 1 × 1010 CFU/head; MS Biotec, Wamego, KS) on d 0 of the study (n = 15), MEG-6: Six d of adaptation with 2 step-up diets plus oral administration of 20 mL of Lactipro-NXT on d 0 of the study (n = 15), and MEG-0: Finishing diet and oral administration of 20 mL of Lactipro-NXT on d 0 of the study (n = 15).
2Contrast analysis: 1) Megasphaera elsdenii effect = CONT vs. MEG, 2) Linear effect of d of adaptation = L, and 3). Quadratic effect of d of adaptation = Q.
3Calculated using the equation proposed by Zinn and Shen (1998), where estimates of cattle performance were pen averages.
4Calculated using observed NE values based on equation of Zinn and Shen (1998).
5Estimated with the equations proposed by NRC (1996; Level 1) with the addition of ionophore (sodium monensin) and using the TDN values, which had been calculated with equation proposed by Weiss et al. (1992).