Pigs experience biological stress such as physiological, environmental, and social challenges when weaned from the sow. The process of weaning is one of the most stressful events in the pig＇s life that can contribute...Pigs experience biological stress such as physiological, environmental, and social challenges when weaned from the sow. The process of weaning is one of the most stressful events in the pig＇s life that can contribute to intestinal and immune system dysfunctions that result in reduced pig health, growth, and feed intake, particularly during the first week after weaning. Technological improvements in housing, nutrition, health, and management have been used to minimize some of the adverse effects of weaning stress, but a greater understanding of the biological impact of stress is needed to improve strategies to overcome weaning stress. The focus of this review paper is to briefly describe how the biological stress associated with weaning impacts intestinal morphology, structure, physiology, and intestinal immune responses that can impact subsequent production efficiencies such as growth, intake, morbidity, and mortality.展开更多
African swine fever(ASF)is a devastating infectious disease in swine that is severely threatening the global pig industry.An efficacious vaccine is urgently required.Here,we used the Chinese ASFV HLJ/18 as a backbone ...African swine fever(ASF)is a devastating infectious disease in swine that is severely threatening the global pig industry.An efficacious vaccine is urgently required.Here,we used the Chinese ASFV HLJ/18 as a backbone and generated a series of genedeleted viruses.The virulence,immunogenicity,safety,and protective efficacy evaluation in specific-pathogen-free pigs,commercial pigs,and pregnant sows indicated that one virus,namely HLJ/18-7GD,which has seven genes deleted,is fully attenuated in pigs,cannot convert to the virulent strain,and provides complete protection of pigs against lethal ASFV challenge.Our study shows that HLJ/-18-7GD is a safe and effective vaccine against ASFV,and as such is expected to play an important role in controlling the spread of ASFV.展开更多
Gaseous emission （N2O, CH4 and NH3） from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N...Gaseous emission （N2O, CH4 and NH3） from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon （TOC） was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N20 was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 （p = 0.0189）, CH4 （p = 0.0113） and N20 （p = 0.0493） emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N20 losses. C/N ratio could affect the NH3 （p = 0.0442） and CH4 （p = 0.0246） emissions significantly, but not the N20. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.展开更多
文摘Pigs experience biological stress such as physiological, environmental, and social challenges when weaned from the sow. The process of weaning is one of the most stressful events in the pig＇s life that can contribute to intestinal and immune system dysfunctions that result in reduced pig health, growth, and feed intake, particularly during the first week after weaning. Technological improvements in housing, nutrition, health, and management have been used to minimize some of the adverse effects of weaning stress, but a greater understanding of the biological impact of stress is needed to improve strategies to overcome weaning stress. The focus of this review paper is to briefly describe how the biological stress associated with weaning impacts intestinal morphology, structure, physiology, and intestinal immune responses that can impact subsequent production efficiencies such as growth, intake, morbidity, and mortality.
基金supported by the National Key R&D Program of China(2018YFC1200601)Applied Technology Research and Development Project of Heilongjiang Province(GA19B301)+1 种基金Key-Area Research and Development Program of Guangdong Province(2019B020211004)the grant from the State Key Laboratory of Veterinary Biotechnology Program(SKLVBP201801)。
文摘African swine fever(ASF)is a devastating infectious disease in swine that is severely threatening the global pig industry.An efficacious vaccine is urgently required.Here,we used the Chinese ASFV HLJ/18 as a backbone and generated a series of genedeleted viruses.The virulence,immunogenicity,safety,and protective efficacy evaluation in specific-pathogen-free pigs,commercial pigs,and pregnant sows indicated that one virus,namely HLJ/18-7GD,which has seven genes deleted,is fully attenuated in pigs,cannot convert to the virulent strain,and provides complete protection of pigs against lethal ASFV challenge.Our study shows that HLJ/-18-7GD is a safe and effective vaccine against ASFV,and as such is expected to play an important role in controlling the spread of ASFV.
基金part of the Sino-German cooperation project of the Recycling of Organic Residues from Agricultural and Municipal Residues in China (http://www.organicresidues.de) and the National Natural Science Foundation of China (No. 40971177)
文摘Gaseous emission （N2O, CH4 and NH3） from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon （TOC） was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N20 was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 （p = 0.0189）, CH4 （p = 0.0113） and N20 （p = 0.0493） emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N20 losses. C/N ratio could affect the NH3 （p = 0.0442） and CH4 （p = 0.0246） emissions significantly, but not the N20. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.
