| Autor: |
Newbold, J. R., van Zijderveld, S. M., Hulshof, R. B. A., Fokkink, W. B., Leng, R. A., Terencio, P., Powers, W. J., van Adrichem, P. S. J., Paton, N. D., Perdok, H. B. |
| Předmět: |
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| Zdroj: |
Journal of Animal Science; Nov2014, Vol. 92 Issue 11, p5032-5040, 9p |
| Abstrakt: |
Two experiments were conducted to study effects of dietary nitrate on enteric methane production, blood methemoglobin concentration, and growth rate in cattle. In Exp. 1,36 Holstein steers (288 ± 25 kg BW) were fed increasing levels of dietary nitrate (6 levels; 0 to 3.0% of feed DM) in com silage-based total mixed rations. Nitrate was introduced gradually in a 25-d adaptation period before methane production was determined in environmentally controlled rooms. In the rooms, feed intake was restricted and similar among all treatments. Methane production (g/d) decreased linearly as dietary nitrate concentration increased (P < 0.01). The apparent efficiency (measured methane reduction divided by potential methane reduction) with which enteric methane was mitigated was 49%. Blood methemoglobin levels increased with increasing nitrate dose. In Exp. 2,300 Nelore bulls (392 ± 28 kg) were fed increasing levels of nitrate (6 levels; 0 to 2.4% of feed DM) in high-concentrate total mixed rations offered ad libitum. Feed intake decreased linearly with increasing level of dietary nitrate (P < 0.01). However, ADG was not affected by nitrate dose (P = 0.54), resulting in a linear improvement in G:F (P = 0.03) as dietary nitrate level increased. Carcass dressing percentage showed a quadratic response to incremental dietary nitrate, reaching the highest value at 0.96% of NO3/kg DM (P = 0.04). [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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