Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep
Nitrate (NO−3) supplementation is an effective methane (CH4) mitigation strategy for ruminants but may produce nitrite (NO−2) toxicity. It has been reported that rumen protozoa have greater ability for NO−3 and NO−2 reduction than bacteria. It was hypothesised that the absence of ruminal protozoa i...
| Autores principales: | , , , , , |
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| Formato: | info:ar-repo/semantics/artículo |
| Lenguaje: | Inglés |
| Publicado: |
Wiley
2020
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12123/7421 https://onlinelibrary.wiley.com/doi/abs/10.1111/jpn.13365 https://doi.org/10.1111/jpn.13365 |
| _version_ | 1855035854743928832 |
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| author | Villar, Maria Laura Hegarty, Roger Stephen Clay, Jonathon William Smith, Katherine Anne Godwin, Ian Robert Nolan, John Vivian |
| author_browse | Clay, Jonathon William Godwin, Ian Robert Hegarty, Roger Stephen Nolan, John Vivian Smith, Katherine Anne Villar, Maria Laura |
| author_facet | Villar, Maria Laura Hegarty, Roger Stephen Clay, Jonathon William Smith, Katherine Anne Godwin, Ian Robert Nolan, John Vivian |
| author_sort | Villar, Maria Laura |
| collection | INTA Digital |
| description | Nitrate (NO−3) supplementation is an effective methane (CH4) mitigation strategy for ruminants but may produce nitrite (NO−2) toxicity. It has been reported that rumen protozoa have greater ability for NO−3 and NO−2 reduction than bacteria. It was hypothesised
that the absence of ruminal protozoa in sheep may lead to higher NO−2 accumulation in the rumen and a higher blood methaemoglobin (MetHb) concentration.
An in vivo experiment was conducted with defaunated (DEF) and faunated (FAU) sheep supplemented with 1.8% NO−3 in DM. The effects of rumen protozoa on concentrations of plasma and ruminal NO−3 and NO−2, blood MetHb, ruminal volatile fatty acid (VFA) and ruminal ammonia (NH3) were investigated. Subsequently, two in vitro experiments were conducted to determine the contribution of protozoa to NO−3 and NO−2 reduction rates in DEF and FAU whole rumen digesta (WRD) and its liquid (LIQ) and solid (SOL) fractions, incubated alone (CON), with the addition of NO−3 or with the addition of NO−2. The results from the in vivo experiment showed no differences in total VFA concentrations, although ruminal NH3 was greater (p < .01) in FAU sheep.
Ruminal NO−3, NO−2 and plasma NO−2 concentrations tended to increase (p < .10) 1.5 hr after feeding in FAU relative to DEF sheep. In vitro results showed that NO−3 reduction to NH3 was stimulated (p < .01) by incoming NO−3 in both DEF and FAU relative to CON digesta. However, adding NO−3 increased (p < .05) the rate of NO−2 accumulation in the SOL fraction of DEF relative to both fractions of FAU digesta. Results observed in vivo and in vitro suggest that NO−3 and NO−2 are more rapidly metabolised in the presence of rumen protozoa. Defaunated sheep may have an increased risk of NO−2 poisoning due to NO−2 accumulation in the rumen. |
| format | info:ar-repo/semantics/artículo |
| id | INTA7421 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | Wiley |
| publisherStr | Wiley |
| record_format | dspace |
| spelling | INTA74212020-06-16T19:21:05Z Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep Villar, Maria Laura Hegarty, Roger Stephen Clay, Jonathon William Smith, Katherine Anne Godwin, Ian Robert Nolan, John Vivian Rumiante Rumen Nitrito Reductasa Digestión Ruminal Oveja Ruminants Nitrito Reductase Rumen Digestion Ewes Nitrate (NO−3) supplementation is an effective methane (CH4) mitigation strategy for ruminants but may produce nitrite (NO−2) toxicity. It has been reported that rumen protozoa have greater ability for NO−3 and NO−2 reduction than bacteria. It was hypothesised that the absence of ruminal protozoa in sheep may lead to higher NO−2 accumulation in the rumen and a higher blood methaemoglobin (MetHb) concentration. An in vivo experiment was conducted with defaunated (DEF) and faunated (FAU) sheep supplemented with 1.8% NO−3 in DM. The effects of rumen protozoa on concentrations of plasma and ruminal NO−3 and NO−2, blood MetHb, ruminal volatile fatty acid (VFA) and ruminal ammonia (NH3) were investigated. Subsequently, two in vitro experiments were conducted to determine the contribution of protozoa to NO−3 and NO−2 reduction rates in DEF and FAU whole rumen digesta (WRD) and its liquid (LIQ) and solid (SOL) fractions, incubated alone (CON), with the addition of NO−3 or with the addition of NO−2. The results from the in vivo experiment showed no differences in total VFA concentrations, although ruminal NH3 was greater (p < .01) in FAU sheep. Ruminal NO−3, NO−2 and plasma NO−2 concentrations tended to increase (p < .10) 1.5 hr after feeding in FAU relative to DEF sheep. In vitro results showed that NO−3 reduction to NH3 was stimulated (p < .01) by incoming NO−3 in both DEF and FAU relative to CON digesta. However, adding NO−3 increased (p < .05) the rate of NO−2 accumulation in the SOL fraction of DEF relative to both fractions of FAU digesta. Results observed in vivo and in vitro suggest that NO−3 and NO−2 are more rapidly metabolised in the presence of rumen protozoa. Defaunated sheep may have an increased risk of NO−2 poisoning due to NO−2 accumulation in the rumen. Estación Experimental Agropecuaria Bariloche Fil: Villar, Maria Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Hegarty, Roger Stephen. University of New England. School of Environmental and Rural Science; Australia Fil: Clay, Jonathon William. University of New England. School of Science and Technology; Australia Fil: Smith, Katherine Anne. University of New England. School of Environmental and Rural Science; Australia Fil: Godwin, Ian Robert. University of New England. School of Environmental and Rural Science; Australia Fil: Nolan, John Vivian. University of New England. School of Environmental and Rural Science; Australia 2020-06-16T19:06:21Z 2020-06-16T19:06:21Z 2020-04 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/7421 https://onlinelibrary.wiley.com/doi/abs/10.1111/jpn.13365 1439-0396 https://doi.org/10.1111/jpn.13365 eng info:eu-repo/semantics/restrictedAccess application/pdf Wiley Journal of Animal Physiology and Animal Nutrition’s : 1-14 (Abril 2020) |
| spellingShingle | Rumiante Rumen Nitrito Reductasa Digestión Ruminal Oveja Ruminants Nitrito Reductase Rumen Digestion Ewes Villar, Maria Laura Hegarty, Roger Stephen Clay, Jonathon William Smith, Katherine Anne Godwin, Ian Robert Nolan, John Vivian Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title | Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title_full | Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title_fullStr | Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title_full_unstemmed | Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title_short | Dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| title_sort | dietary nitrate and presence of protozoa increase nitrate and nitrite reduction in the rumen of sheep |
| topic | Rumiante Rumen Nitrito Reductasa Digestión Ruminal Oveja Ruminants Nitrito Reductase Rumen Digestion Ewes |
| url | http://hdl.handle.net/20.500.12123/7421 https://onlinelibrary.wiley.com/doi/abs/10.1111/jpn.13365 https://doi.org/10.1111/jpn.13365 |
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