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Maigaard M, Weisbjerg MR, Hellwing ALF, Larsen M, Andersen FB, Lund P. The acute effects of rumen pulse-dosing of hydrogen acceptors during methane inhibition with nitrate or 3-nitrooxypropanol in dairy cows. J Dairy Sci 2024:S0022-0302(24)00728-8. [PMID: 38608947 DOI: 10.3168/jds.2023-24343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 03/03/2024] [Indexed: 04/14/2024]
Abstract
Dietary methane (CH4) mitigation is in some cases associated with an increased hydrogen (H2) emission. The objective of the present study was to investigate the acute and short-term effects of acceptors for H2 (fumaric acid, acrylic acid or phloroglucinol) supplemented via pulse-dosing to dairy cows fed CH4 mitigating diets (using nitrate or 3-nitrooxypropanol), on gas exchange, rumen gas and VFA composition. For this purpose, 2 individual 4 × 4 Latin square experiments were conducted with 4 periods of 3 d (nitrate supplementation) and 7 d (3-nitrooxypropanol supplementation), respectively. In each study, 4 rumen cannulated Danish Holstein cows were used. Each additive for CH4 mitigation was included in the ad libitum fed diet within the 2 experiments, to which the cows were adapted for at least 14 d. Acceptors for H2 were administered twice daily in equal portions through the rumen fistula immediately after feeding of the individual cow. In Exp. 1 (nitrate), the treatments were CON-1 (no H2-acceptor), FUM-1 (fumaric acid), ACR-1 (acrylic acid) and FUM+ACR-1 (50% FUM-1 + 50% ACR-1). In Exp. 2 (3-nitrooxypropanol), the 3 treatments, CON-2, FUM-2, and ACR-2, were similar to CON-1, FUM-1 and ACR-1 treatments, however the fourth treatment was PHL-2 (phloroglucinol). Gas exchanges were measured in respiration chambers, while samples of rumen liquid and headspace gas were taken in time series relative to feeding and dosing on specific days. Headspace gas was analyzed for gas composition and rumen liquid was analyzed for volatile fatty acid composition and dissolved gas concentrations. Headspace gas composition and dissolved gas concentration were only measured in Exp. 2. Dry matter intake was reduced upon acrylic acid supplementation. There were no significant effects of any treatments in any experiments on H2 emission, except for a decrease in hourly H2 emission rate (g/h) at 1 h after feeding in both experiments. In Exp. 2, H2 headspace proportions increased by ACR-2 supplementation, whereas dissolved concentrations were unaffected. In Exp. 1, cows on ACR-1 increased propionate proportion at 1 h after feeding. In Exp. 2, both FUM-2 and ACR-2 increased rumen propionate proportion in the hours after feeding and dosing. There was no effect on rumen acetate for cows on PHL-2. There was a strong positive correlation between rumen dissolved CH4 and headspace CH4 (r = 0.84), whereas the equivalent correlation was weaker for H2 (r = 0.41). For the relationship between dissolved concentrations and emissions of CH4 and of H2, there was a moderate positive correlation for CH4 (r = 0.54), whereas it was weak for H2 (r = 0.28) with zero slope. In conclusion, the results suggested that fumaric acid and acrylic acid to some extent was reduced to propionate without associative effects on measures for H2 redirection. Furthermore, phloroglucinol seemed not to be metabolized in the rumen in the present study, as no effects on rumen acetate or measures of H2 were observed. Changes in H2 headspace and emission may be a poor proxy for actual changes in the rumen fluid concentration of H2.
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Affiliation(s)
- Morten Maigaard
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark.
| | - Martin R Weisbjerg
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark
| | - Anne Louise Frydendahl Hellwing
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark
| | - Mogens Larsen
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark
| | - Freja Bylling Andersen
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark
| | - Peter Lund
- Department of Animal and Veterinary Sciences, AU Viborg - Research Centre Foulum, Aarhus University, Blichers Allé 20, 8830 DK-Tjele, Denmark
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Laporte-Uribe JA. Rumen CO 2 species equilibrium might influence performance and be a factor in the pathogenesis of subacute ruminal acidosis. Transl Anim Sci 2020; 3:1081-1098. [PMID: 32704872 PMCID: PMC7200430 DOI: 10.1093/tas/txz144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/19/2019] [Indexed: 12/02/2022] Open
Abstract
This experiment was conducted to explore rumen carbon dioxide (CO2) species equilibrium. Three lactating, fistulated cattle were consecutively exposed to three dietary treatments tailored to produce low rumen pH and increase the risk of subacute ruminal acidosis (SARA) by reducing physically effective neutral detergent fiber (Low peNDF), increasing rumen degradable starch (High RDS) or both (Combined). Under these conditions, high and varied rumen concentrations of the CO2 associated to water or dissolved CO2 (dCO2) were found. The results suggest that the activity of dCO2 and bicarbonate (HCO3−) represents an important component of the rumen environment. Rumen CO2 holdup was associated with high dCO2 and HCO3− activity as well as changes in the viscosity and surface tension of the rumen fluid. All dietary treatments produced low rumen pH, <5.5 for >3 h/d, a condition associated with SARA, but clinical SARA was observed only during CO2 holdup. This pilot study highlights the possible role of CO2 holdup and rumen CO2 species in cattle performance and nutritional diseases. In the future, better estimations of CO2 species might help clarify these findings.
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Longtin M, Price RE, Mishra R, Breidt F. Modeling the buffer capacity of ingredients in salad dressing products. J Food Sci 2020; 85:910-917. [PMID: 32198767 DOI: 10.1111/1750-3841.15018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/21/2019] [Accepted: 11/25/2019] [Indexed: 11/30/2022]
Abstract
The pH of most acid food products depends on undefined and complex buffering of ingredients but is critically important for regulatory purposes and food safety. Our objective was to define the buffer capacity (BC) of ingredients in salad dressing products. Ingredients of salad dressings were titrated individually and in combination using concentrations typical of dressing products. Titration curves from pH 2 to 12 were generated with sodium hydroxide and hydrochloric acid, which were then used to generate BC curves. A matrix of concentration and pK values for a series of monoprotic buffers approximated the pH of each ingredient. Some buffer series required anion or cation corrections for accurate pH prediction, possibly due to the presence of salts of acid or bases. Most buffers had BC values less than 10-fold the BC of acetic acid (0.25 β) typically in dressing formulations and had little influence on the final product pH of the dressings tested. Unexpectedly, we found that sugars in dressing formulations, including sucrose or corn syrup, exhibited buffering at pH values greater than 11 (0.035 β and 0.059 β, respectively), which was likely due to weakly acidic hydroxyl groups on the sugar molecules. However, the concentration and pK for buffers above pH 11 or below pH 2 were difficult to quantify due to the BC of water. The BC data may help to quantify the effects of salad dressing ingredients on the final product pH and benefit regulatory agencies and manufacturers in assessing product pH and safety. PRACTICAL APPLICATION: Buffer capacity data for salad dressing ingredients may help determine the influence ingredient addition will have on the final pH of a salad dressing product. The addition of low acid ingredients with little or no buffering may not significantly alter pH. The modeling method may be useful for regulatory purposes to estimate the effects of low acid ingredients on pH changes for food safety and may also be useful for product development of acid and acidified foods.
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Affiliation(s)
- Madyson Longtin
- U.S. Dept. of Agriculture, Agricultural Research Service, SEA, Food Science Research Unit, NC State Univ., 322 Schaub Hall, Box 7624, Raleigh, NC, 27695-7624, USA
| | - Robert E Price
- U.S. Dept. of Agriculture, Agricultural Research Service, SEA, Food Science Research Unit, NC State Univ., 322 Schaub Hall, Box 7624, Raleigh, NC, 27695-7624, USA
| | - Ritu Mishra
- Clorox Company, 4900 Johnson Drive, Pleasanton, CA, 94588, USA
| | - Fred Breidt
- U.S. Dept. of Agriculture, Agricultural Research Service, SEA, Food Science Research Unit, NC State Univ., 322 Schaub Hall, Box 7624, Raleigh, NC, 27695-7624, USA
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Caushi D, Martens H. Absorption of bicarbonate in sheep omasum. Res Vet Sci 2018; 118:324-330. [PMID: 29601970 DOI: 10.1016/j.rvsc.2018.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 03/07/2018] [Accepted: 03/09/2018] [Indexed: 10/17/2022]
Abstract
Transport of bicarbonate across the isolated epithelium of sheep omasum was studied in vitro in Ussing chambers in combination with the pH-Stat method. The transport of HCO3- occurred in both directions, but Jms HCO3- was significant larger than Jsm. Reducing the activity of the apical Na/H exchanger by a low mucosal Na concentration caused a significant reduction of Jms HCO3-. Mucosal amiloride or short chain fatty acids (25 mmol l-1 SCFA) numerically decreased Jms HCO3-, but their combination (amiloride + SCFA) caused a significant reduction, which was also observed after addition of the carboanhydrase inhibitor ethoxyzolamide. Concentrations of 5 or 15 mmol·l-1 mucosal ammonia did not change transport rates. The obtained results indicate the importance of an undisturbed cytosolic pH for transcellular HCO3- transport, which is probably mediated by an anion exchanger in both the apical and basolateral membranes. Possible impairment of HCO3- transport appears to be an overlooked factor in the pathogenesis of displacement of the abomasum.
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Affiliation(s)
- Driton Caushi
- Freie Universitaet Berlin, Department of Veterinary Physiology, Oertzenweg 19b, 14163 Berlin, Germany.
| | - Holger Martens
- Freie Universitaet Berlin, Department of Veterinary Physiology, Oertzenweg 19b, 14163 Berlin, Germany.
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Stumpff F. A look at the smelly side of physiology: transport of short chain fatty acids. Pflugers Arch 2018; 470:571-598. [PMID: 29305650 DOI: 10.1007/s00424-017-2105-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 12/14/2022]
Abstract
Fermentative organs such as the caecum, the colon, and the rumen have evolved to produce and absorb energy rich short chain fatty acids (SCFA) from otherwise indigestible substrates. Classical models postulate diffusional uptake of the undissociated acid (HSCFA). However, in net terms, a major part of SCFA absorption occurs with uptake of Na+ and resembles classical, coupled electroneutral NaCl transport. Considerable evidence suggests that the anion transporting proteins expressed by epithelia of fermentative organs are poorly selective and that their main function may be to transport acetate-, propionate-, butyrate- and HCO3- as the physiologically relevant anions. Apical uptake of SCFA thus involves non-saturable diffusion of the undissociated acid (HSCFA), SCFA-/HCO3- exchange via DRA (SLC26A3) and/or SCFA--H+ symport (MCT1, SLC16A1). All mechanisms lead to cytosolic acidification with stimulation of Na+/H+ exchange via NHE (SLC9A2/3). Basolaterally, Na+ leaves via the Na+/K+-ATPase with recirculation of K+. Na+ efflux drives the transport of SCFA- anions through volume-regulated anion channels, such as maxi-anion channels (possibly SLCO2A1), LRRC8, anoctamins, or uncoupled exchangers. When luminal buffering is inadequate, basolateral efflux will increasingly involve SCFA-/ HCO3- exchange (AE1/2, SCL4A1/2), or efflux of SCFA- with H+ (MCT1/4, SLC16A1/3). Furthermore, protons can be basolaterally removed by NHE1 (SCL9A1) or NBCe1 (SLC4A4). The purpose of these transport proteins is to maximize the amount of SCFA transported from the tightly buffered ingesta while minimizing acid transport through the epithelium. As known from the rumen for many decades, a disturbance of these processes is likely to cause severe colonic disease.
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Affiliation(s)
- Friederike Stumpff
- Institute of Veterinary Physiology, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
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Molecular hydrogen generated by elemental magnesium supplementation alters rumen fermentation and microbiota in goats. Br J Nutr 2017; 118:401-410. [PMID: 28927478 DOI: 10.1017/s0007114517002161] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We tested the hypotheses that supplementation of a diet with elemental Mg increases ruminal dissolved H2 (dH2) in rumen fluid, which in turn alters rumen fermentation and microbial community in goats. In a randomised block design, twenty growing goats were allocated to two treatments fed the same basal diet with 1·45 % Mg(OH)2 or 0·6 % elemental Mg. After 28 d of adaptation, we collected total faeces to measure total tract digestibility, rumen contents to analyse fermentation end products and microbial groups, and measured methane (CH4) emission using respiration chambers. Ruminal Mg2+ concentration was similar in both treatments. Elemental Mg supplementation increased dH2 at 2·5 h post morning feeding (+180 %, P<0·001). Elemental Mg supplementation decreased total volatile fatty acid concentration (-8·6 %, P<0·001), the acetate:propionate ratio (-11·8 %, P<0·03) and fungal copy numbers (-63·6 %, P=0·006), and increased propionate molar percentage (+11·6 %, P<0·001), methanogen copy numbers (+47·9 %, P<0·001), dissolved CH4 (+35·6 %, P<0·001) and CH4 emissions (+11·7 %, P=0·03), compared with Mg(OH)2 supplementation. The bacterial community composition in both treatments was overall similar. Ruminal dH2 was negatively correlated with acetate molar percentage and fungal copy numbers (P<0·05), and positively correlated with propionate molar percentage and methanogen copy numbers (P<0·05). In summary, elemental Mg supplementation increased ruminal dH2 concentration, which inhibited rumen fermentation, enhanced methanogenesis and seemed to shift fermentation pathways from acetate to propionate, and altered microbiota by decreasing fungi and increasing methanogens.
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Rackwitz R, Gäbel G. Effects of dissolved carbon dioxide on the integrity of the rumen epithelium: An agent in the development of ruminal acidosis. J Anim Physiol Anim Nutr (Berl) 2017; 102:e345-e352. [PMID: 28608583 DOI: 10.1111/jpn.12752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/21/2017] [Indexed: 01/20/2023]
Abstract
The carbon dioxide released and dissolved in rumen fluid may easily permeate across the epithelial cell membrane. Thus, we hypothesized that CO2 may act as proton carrier and induce epithelial damage under acidotic conditions. Ovine ruminal epithelia were mounted in Ussing chambers under short-circuit conditions. The serosal buffer solution had a constant pH of 7.4 and was gassed either with 100% oxygen or with carbogen (95% O2 /5% CO2 ). The mucosal solution was gassed with either 100% oxygen or 100% carbon dioxide. The mucosal pH was lowered stepwise from 6.6 to 5.0 in the presence or absence of short-chain fatty acids (SCFA). The transepithelial conductance (Gt ) as an indicator of epithelial integrity and the short-circuit current (Isc ) as an indicator of active electrogenic ion transfer were continuously monitored. At an initial mucosal pH of 6.6, there was no significant difference in Gt between the treatment groups. In the absence of both SCFA and CO2 , Gt remained constant when the mucosal solution was acidified to pH 5.0. In the presence of SCFA, mucosal acidification induced a significant rise in Gt when the solutions were gassed with oxygen. A small increase in Gt was observed in the mucosal presence of CO2 . However, no difference in final Gt was observed between SCFA-containing and SCFA-free conditions under carbon dioxide gassing during stepwise mucosal acidification. The SCFA+proton-induced increase in Gt could also be minimized by serosal gassing with carbogen. Because of the SCFA+proton-induced changes in Gt and their attenuation by CO2 , a protective role for mucosally available carbon dioxide may be assumed. We suggest that this effect may be due to the intraepithelial conversion of carbon dioxide to bicarbonate. However, the serosal presence of CO2 at a physiological concentration may be sufficient to protect the epithelia from SCFA+proton-induced damage for a certain period of time.
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Affiliation(s)
- R Rackwitz
- Institute for Veterinary Physiology, University of Leipzig, Leipzig, Germany
| | - G Gäbel
- Institute for Veterinary Physiology, University of Leipzig, Leipzig, Germany
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Muñoz-Tamayo R, Giger-Reverdin S, Sauvant D. Mechanistic modelling of in vitro fermentation and methane production by rumen microbiota. Anim Feed Sci Technol 2016. [DOI: 10.1016/j.anifeedsci.2016.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Laporte-Uribe JA. The role of dissolved carbon dioxide in both the decline in rumen pH and nutritional diseases in ruminants. Anim Feed Sci Technol 2016. [DOI: 10.1016/j.anifeedsci.2016.06.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wang M, Ungerfeld EM, Wang R, Zhou CS, Basang ZZ, Ao SM, Tan ZL. Supersaturation of Dissolved Hydrogen and Methane in Rumen of Tibetan Sheep. Front Microbiol 2016; 7:850. [PMID: 27379028 PMCID: PMC4906022 DOI: 10.3389/fmicb.2016.00850] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/23/2016] [Indexed: 01/12/2023] Open
Abstract
Hydrogen (H2) is an essential substrate for methanogens to produce methane (CH4), and also influences pathways of volatile fatty acids (VFA) production in the rumen. Dissolved H2 (H2 (aq)) is the form of H2 available to microbes, and dissolved CH4 (CH4 (aq)) is important for indicating methanogens activity. Rumen H2 (aq) concentration has been estimated by assuming equilibrium with headspace gaseous H2 (H2 (g)) concentration using Henry's law, and has also been directly measured in the liquid phase in some in vitro and in vivo experiments. In this in vivo study, H2 (aq) and CH4 (aq) concentration measured directly in rumen fluid and their corresponding concentrations estimated from their gaseous phase concentrations, were compared to investigate the existence of equilibrium between the gas and liquid phases. Twenty-four Tibetan sheep were randomly assigned to two mixed diets containing the same concentrate mixed with oat grass (OG diet) or barley straw (BS diet). Rumen gaseous phase and contents were sampled using rumenocentesis and oral stomach tubing, respectively. Rumen H2 (aq) and CH4 (aq) concentration and VFA profile differed between sheep fed OG and BS diets. Measured H2 (aq) and CH4 (aq) concentration were greater than H2 (aq) and CH4 (aq) concentrations estimated using gas concentrations, indicating lack of equilibrium between gas and liquid phase and supersaturation of H2 and CH4 in rumen fluid. As a consequence, Gibbs energy changes (ΔG) estimated for various metabolic pathways were different when calculated using dissolved gases concentrations directly measured and when using dissolved gases concentrations assuming equilibrium with the gaseous phase. Dissolved CH4, but not CH4 (g), was positively correlated with H2 (aq). Both H2 (aq) and H2 (g) concentrations were positively correlated with the molar percentage of butyrate and negatively correlated with the molar percentage of acetate. In summary, rumen fluid was supersaturated with both H2 and CH4, and H2 (aq) was closely associated with the VFA profile and CH4 (aq) concentration. The assumption of equilibrium between dissolved gases and gaseous phase affected ΔG estimation.
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Affiliation(s)
- Min Wang
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, South Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of SciencesChangsha, China; Hunan Co-Innovation Center of Animal Production SafetyChangsha, China; Graduate University of Chinese Academy of SciencesBeijing, China
| | | | - Rong Wang
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, South Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences Changsha, China
| | - Chuan She Zhou
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, South Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences Changsha, China
| | - Zhu Zha Basang
- Department of Animal Science and Veterinary Medicine, Tibetan Autonomous Prefecture Academy of Agricultural and Animal Husbandry Science Lhasa, China
| | - Si Man Ao
- Department of Animal Science and Veterinary Medicine, Tibetan Autonomous Prefecture Academy of Agricultural and Animal Husbandry Science Lhasa, China
| | - Zhi Liang Tan
- Key Laboratory for Agro-Ecological Processes in Subtropical Region, South Central Experimental Station of Animal Nutrition and Feed Science, Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of SciencesChangsha, China; Hunan Co-Innovation Center of Animal Production SafetyChangsha, China
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