Effect of Acclimation to High Nitrate Intakes on Some Rumen Fermentation Parameters in Sheep

Alaboudi, Akram R.; Jones, Graham A.

doi:10.4141/cjas85-099

Cited by 50 publications

(46 citation statements)

References 21 publications

(1 reference statement)

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“…Allison and Reddy (1984) found increased nitrate and nitrite reduction activities by rumen bacteria in vitro after an acclimation. Alaboudi and Jones (1985) also reported from two in vitro experiments that when sheep were acclimated to nitrate (from 0.5 g nitrate kg (1 BW to 2.5 g kg (1 BW over 2 wk), ruminal nitrate and nitrite reduction capacities were increased up to fivefold and the population of nitrate-reducing bacteria was three times greater. Recently, Shi et al (2012) confirmed that the nitrate reduction rate was greater when rumen fluid was used from sheep acclimated to nitrate compared with fluid from sheep not acclimated to nitrate.…”

Section: Figmentioning

confidence: 71%

A review of feeding supplementary nitrate to ruminant animals: nitrate toxicity, methane emissions, and production performance

2014

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Lee, C. and Beauchemin, K. A. 2014. A review of feeding supplementary nitrate to ruminant animals: Nitrate toxicity, methane emissions, and production performance. Can. J. Anim. Sci. 94: 557Á570. The purpose of this review is to discuss the risks and benefits of using supplementary nitrate to reduce enteric methane emissions in ruminants based on the results of a metaanalysis. The meta-analysis confirmed possible nitrate poisoning triggered by higher blood methemoglobin levels with increasing nitrate consumption of ruminants: methemoglobin (%) 041.3)nitrate [g kg (1 body weight (BW) d (1 ]'1.2; R 2 00.76, P B0.001. However, acclimatizing animals to nitrate reduced the toxicity of nitrate: methemoglobin (%)04.2 ) nitrate (g kg (1 BW d (1 )'0.4, R 2 00.76, P 00.002. Animals fed nitrate reduced enteric methane emissions in a doseresponse manner: methane [g kg (1 dry matter intake (DMI)]0(8.3 )nitrate (g kg (1 BW d (1 )'15.2, R 2 00.80, PB0.001. The reduction of enteric methane emissions due to supplementary nitrate was effective and consistent in both in vitro and in vivo studies and also persistent in several long-term studies. Dry matter intake and live weight gain (LWG) of cattle were not affected by nitrate: DMI change, R 2 00.007, P 00.65; LWG change, R 2 00.03, P00.31. It is anticipated that supplementary nitrate as a substitute for urea may change urinary nitrogen composition in a manner that increases ammonia and nitrous oxide emissions from manure. Furthermore, supplementary nitrate may have various physiological roles in nitric oxide metabolism in ruminants. In conclusion, supplementary nitrate is a viable means of mitigating enteric methane emissions due to its consistent and persistent efficacy. Risk of toxicity can be lowered by gradual acclimation of animals to nitrate. However, lowered methane production may not re-direct additional metabolizable energy towards animal production.Abbreviations: BW, body weight; DM, dry matter; DMI, dry matter intake; LWG, live weight gain; NPN, non-protein nitrogen Can.

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Section: Figmentioning

confidence: 71%

A review of feeding supplementary nitrate to ruminant animals: nitrate toxicity, methane emissions, and production performance

2014

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“…Essentially, the NRB and SRB must be concentrated in the biofilm matrix to outcompete the methanogens. The SRB and NRB occur naturally in the rumen (Coleman 1960;Hungate 1966;Howard and Hungate 1976;Cheng et al 1988;Leng 2008) and experiments with sheep and cattle indicate that the population density of these species increases as the concentration of their respective electron acceptors in the ruminant diet increases (Alaboudi and Jones 1985;Hao et al 2009). Which microbial species is the most successful in using the particular oxidised substrate (HCO 3 -, nitrate or sulfate) depends on the distance between the colonies of the organism involved in the interspecies transfer, the partial pressure of H 2 and the Gibbs free-energy change of the reaction.…”

Section: Interspecies H 2 Transfermentioning

confidence: 99%

“…When nitrate replaced urea in the rumen, there was also a tendency for an increased microbial cell yield (cells also represent an electron sink) (Nolan et al 2010). Increased acetate relative to propionate production may result from a channelling of more carbohydrate through pyruvate and acetyl CoA in the fermentative pathways, or it could be a result of acetogenic oxidation of butyrate and propionate by the boosted nitratereducing capacity of rumen contents and increased populations of NRB (Alaboudi and Jones 1985) and SRB. The latter, from animal and human large intestine, have been shown to oxidise propionate and butyrate to acetate (Gibson 1990).…”

Section: The Ruminal Effects Of Promoting Nrb And/or Srb By Supplemenmentioning

confidence: 99%

Interactions between microbial consortia in biofilms: a paradigm shift in rumen microbial ecology and enteric methane mitigation

Leng¹

2014

Anim. Prod. Sci.

132

105

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Abstract. Minimising enteric CH 4 emissions from ruminants is a current research priority because CH 4 contributes to global warming. The most effective mitigation strategy is to adjust the animal's diet to complement locally available feed resources so that optimal production is gained from a minimum of animals. This essay concentrates on a second strategy -the use of feed additives that are toxic to methanogens or that redirect H 2 (and electrons) to inhibit enteric CH 4 emissions from individual animals. Much of the published research in this area is contradictory and may be explained when the microbial ecology of the rumen is considered.Rumen microbes mostly exist in organised consortia within biofilms composed of self-secreted extracellular polymeric substances attached to or within feed particles. In these biofilms, individual colonies are positioned to optimise their use of preferred intermediates from an overall process of organic matter fermentation that generates end-products the animal can utilise. Synthesis of CH 4 within biofilms prevents a rise in the partial pressure of H 2 (pH 2 ) to levels that inhibit bacterial dehydrogenases, and so reduce fermentation rate, feed intake and digestibility. In this context, hypotheses are advanced to explain changes in hydrogen disposal from the biofilms in the rumen resulting from use of anti-methanogenic feed additives as follows.Nitrate acts as an alternative electron sink when it is reduced via NO 2 -to NH 3 and CH 4 synthesis is reduced. However, efficiency of CH 4 mitigation is always lower than that predicted and decreases as NO 3 -ingestion increases. Suggested reasons include (1) variable levels of absorption of NO 3 -or NO 2 -from the rumen and (2) increases in H 2 production. One suggestion is that NO 3 -reduction may lower pH 2 at the surface of biofilms, thereby creating an ecological niche for growth of syntrophic bacteria that oxidise propionate and/or butyrate to acetate with release of H 2 .Chlorinated hydrocarbons also inhibit CH 4 synthesis and increase H 2 and formate production by some rumen methanogens. Formate diffuses from the biofilm and is converted to HCO 3 -and H 2 in rumen fluid and is then excreted via the breath. Short-chain nitro-compounds inhibit both CH 4 and formate synthesis when added to ruminal fluid but have little or no effect in redirecting H 2 to other sinks, so the pH 2 within biofilms may increase to levels that support reductive acetogenesis. Biochar or activated charcoal may also alter biofilm activity and reduce net CH 4 synthesis; direct electron transfer between microbes within biofilms may also be involved. A final suggestion is that, during their sessile life stage, protozoa interact with biofilm communities and help maintain pH 2 in the biofilm, supporting methanogenesis.

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“…When nitrate is drenched at high concentration, there is no accumulation of nitrate in the rumen, it is absorbed by the rumen, a part of it is excreted and a part is recycled through saliva (Wang et al 1961 ). This absorption of nitrate through the rumen will be drastically reduced if the animals are adapted to higher concentration of nitrate in the diet (Alaboudi and Jones 1985 ). The adaptation of the animals increases its ability to use nitrate and nitrite more effi ciently in the rumen, and these are metabolized effi ciently into the body tissue.…”

Section: Adaptation Of Ruminants To High Nitrate Dietsmentioning

confidence: 99%

“…The in vitro results at IVRI, Izatnagar, indicate that an inoculum of nitrate-/ nitrite-reducing bacteria can be an alternative to periodic and slow adaptation for obtaining similar results with nitrate utilizing capacity of the animals. It is very interesting to note that adapted animals return to normal level of its capability to use nitrate in diet within 3 weeks once the nitrate is withdrawn from the ration of sheep (Alaboudi and Jones 1985 ).…”

Section: Adaptation Of Ruminants To High Nitrate Dietsmentioning

confidence: 99%

Nitrate/Nitrite Toxicity and Possibilities of Their Use in Ruminant Diet

Kamra

Agarwal

Chaudhary

2015

Rumen Microbiology: From Evolution to Revolution

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Nitrate is not a normal component of livestock feed due to toxicity of nitrate/nitrite. Sometimes nitrate might enter into the rumen either accidentally or intentionally incorporated in ration as a source of nitrogen, but the nitrate-reducing bacteria present in the rumen (Selenomonas ruminantium, Veillonella parvula and Wolinella succinogenes) take care of it by reducing nitrate to nitrite and further to ammonia, which can be used for synthesis of amino acids in the rumen. The number of such bacteria is not plenty enough to take care of excess nitrate in diet, but slow increase in the level of nitrate might help in the adaptation of the rumen microbes, which give capability of tolerating even toxic levels of nitrate in livestock ration. The incorporation of nitrate in the diet of adapted animals can be as high as 30 % protein requirement of the animals without affecting adversely the rumen fermentation and health of the animals. There was no accumulation of nitrite in the rumen liquor, and methaemoglobin levels in blood were also within safe limits, when the animals were adapted to higher levels of nitrate (Unpublished report from this laboratory). Simultaneously, nitrate inclusion in diet also results in decreased emission of methane, making the process of livestock production eco-friendly. Long-term feeding trials are essential before the technique can be recommended to the farmers for practical application.

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Effect of Acclimation to High Nitrate Intakes on Some Rumen Fermentation Parameters in Sheep

Cited by 50 publications

References 21 publications

A review of feeding supplementary nitrate to ruminant animals: nitrate toxicity, methane emissions, and production performance

A review of feeding supplementary nitrate to ruminant animals: nitrate toxicity, methane emissions, and production performance

Interactions between microbial consortia in biofilms: a paradigm shift in rumen microbial ecology and enteric methane mitigation

Nitrate/Nitrite Toxicity and Possibilities of Their Use in Ruminant Diet

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