The effect of incremental levels of dietary nitrate on methane emissions in Holstein steers and performance in Nelore bulls1
| Autor: | H.B. Perdok, W.B. Fokkink, J.R. Newbold, P Terencio, R.B.A. Hulshof, S.M. van Zijderveld, N D Paton, P S J van Adrichem, Wendy Powers, Ronald Leng |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Journal of Animal Science. 92:5032-5040 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.2527/jas.2014-7677 |
| Popis: | 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 corn 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). |
| Databáze: | OpenAIRE |
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