Can dietary manipulations improve the productivity of pigs with lower environmental and economic cost? A global meta-analysis

Wang, Hongliang; Long, W. Harwood; Chadwick, D. R.; Velthof, G.L.; Oenema, O.; Ma, Wenqi; Wang, Junjun; Qin, Wei; Hou, Yong; Zhang, Fusuo

doi:10.1016/j.agee.2019.106748

Cited by 31 publications

(26 citation statements)

References 72 publications

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“…According to the total odour data (NH 3 + H 2 S production), Xinghua was the best laying hen species (39.94 µg), while Hyline produced the largest amount of odorous gases (92.45 µg). The differences in NH 3 production were also indicated by the concentration of ammonium nitrogen in the fermentation fluid because ammonia nitrogen is consistent with ammonia emissions in animal production [ 32 ]. Interestingly, Jingfen produced the highest total gas volume (39.11 µg), whereas it had low total odorous gas (85.43 µg).…”

Section: Discussionmentioning

confidence: 99%

Effects of Different Laying Hen Species on Odour Emissions

et al. 2020

Animals

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Odour is one of the main environmental concerns in the laying hen industry and may also influence animal health and production performance. Previous studies showed that odours from the laying hen body are primarily produced from the microbial fermentation (breakdown) of organic materials in the caecum, and different laying hen species may have different odour production potentials. This study was conducted to evaluate the emissions of two primary odorous gases, ammonia (NH3) and hydrogen sulphide (H2S), from six different laying hen species (Hyline, Lohmann, Nongda, Jingfen, Xinghua and Zhusi). An in vitro fermentation technique was adopted in this study, which has been reported to be an appropriate method for simulating gas production from the microbial fermentation of organic materials in the caecum. The results of this study show that Jingfen produced the greatest volume of gas after 12 h of fermentation (p < 0.05). Hyline had the highest, while Lohmann had the lowest, total NH3 emissions (p < 0.05). The total H2S emissions of Zhusi and Hyline were higher than those of Lohmann, Jingfen and Xinghua (p < 0.05), while Xinghua exhibited the lowest total H2S emissions (p < 0.05). Of the six laying hen species, Xinghua was identified as the best species because it produced the lowest total amount of NH3 + H2S (39.94 µg). The results for the biochemical indicators showed that the concentration of volatile fatty acids (VFAs) from Zhusi was higher than that for the other five species, while the pH in Zhusi was lower (p < 0.01), and the concentrations of ammonium nitrogen (NH4+), uric acid and urea in Xinghua were lower than those in the other species (p < 0.01). Hyline had the highest change in SO42− concentration during the fermentation processes (p < 0.05). In addition, the results of the correlation analysis suggested that NH3 emission is positively related to urease activities but is not significantly related to the ureC gene number. Furthermore, H2S emission was observed to be significantly related to the reduction of SO42− but showed no connection with the aprA gene number. Overall, our findings provide a reference for future feeding programmes attempting to reduce odour pollution in the laying hen industry.

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Section: Discussionmentioning

confidence: 99%

Effects of Different Laying Hen Species on Odour Emissions

et al. 2020

Animals

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“…Various meta-analyses have been published in recent years to synthesize the extensive literature available on the effect of CP reduction on N excretion for both pigs and broilers. In swine, one estimated from nine trials shows a reduction of N excretion by 7.5% per each 10 g/kg CP reduction ( 28 ); another reported from 59 publications an average reduction of N excretion of 28.5% with low-CP strategies ( 29 ); and the last, based on 27 trials, shows a reduction of N excretion by 8.2% per each 10 g/kg CP reduction ( 8 ) ( Figure 2 ). In broilers, a reduction of N excretion by 9% per each 10 g/kg CP reduction was estimated from 107 trials ( 27 ) ( Figure 3 ).…”

Section: Impact Of Low-cp Diets and Feed-grade Aa Inclusion On Animal Performance And Metabolismmentioning

confidence: 99%

“…It also allows differentiating between organic N, which is a stable form of N, and urea N, quickly degraded into ammonia. A meta-analysis ( 29 ) reports an average reduction of urinary N excretion by 39.6% with low-CP strategies although fecal N excretion was only reduced by 10.4%. Similarly, another meta-analysis ( 8 ) reports a reduction of urinary N excretion by 10% and of fecal N excretion by 3.1% per each 10 g/kg CP reduction ( Figure 2 ).…”

Section: Impact Of Low-cp Diets and Feed-grade Aa Inclusion On Animal Performance And Metabolismmentioning

confidence: 99%

Amino Acid Supplementation to Reduce Environmental Impacts of Broiler and Pig Production: A Review

et al. 2021

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Poultry and swine farming are large contributors to environmental impacts, such as climate change, eutrophication, acidification, and air and water pollution. Feed production and manure management are identified as the main sources of these impacts. Reducing dietary crude protein levels is a nutritional strategy recognized to both decrease the use of high-impact feed ingredients and alter manure composition, reducing emissions of harmful components. For a successful implementation of this technique, feed-grade amino acid supplementation is crucial to maintaining animal performance. Reducing crude protein lowers nitrogen excretion, especially excess nitrogen excreted in urea or uric acid form, improving nitrogen efficiency. At the feed-gate, low–crude protein diets can reduce the carbon footprint of feed production through changes in raw material inclusion. The magnitude of this reduction mainly depends on the climate change impact of soybean meal and its land-use change on the feed-grade amino acids used. Reducing dietary crude protein also lowers the environmental impact of manure management in housing, storage, and at spreading: nitrogen emissions from manure (ammonia, nitrates, nitrous oxide) are reduced through reduction of nitrogen excretion. Moreover, synergetic effects exist with nitrogen form, water excretion, and manure pH, further reducing emissions. Volatilization of nitrogen is more reduced in poultry than in pigs, but emissions are more studied and better understood for pig slurry than poultry litter. Ammonia emissions are also more documented than other N-compounds. Low–crude protein diets supplemented with amino acids is a strategy reducing environmental impact at different stages of animal production, making life cycle assessment the best-suited tool to quantify reduction of environmental impacts. Recent studies report an efficient reduction of environmental impacts with low–crude protein diets. However, more standardization of limits and methods used is necessary to compare results. This review summarizes the current knowledge on mitigation of environmental impacts with low–crude protein diets supplemented with amino acids in poultry and swine, its quantification, and the biological mechanisms involved. A comparison between pigs and poultry is also included. It provides concrete information based on quantified research for decision making for the livestock industry and policy makers.

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“…The feed-to-meat ratio can be reduced by adding exogenous enzymes and reducing feed protein [29] . There are some methods to reduce NH 3 emissions in manure management such as increasing the frequency of manure removal at the housing stage, covering solid manures and acidifying liquid manures at the storage stage, and applying manures according to crop growth requirements [20] .…”

Section: Nutrient Flow Characteristics Of Pig Farmsmentioning

confidence: 99%