RESUMO
PCV2 is one of the most economically important viral agents in swine worldwide. Recently, PCV3 has been frequently reported, and the co-infection of PCV2 and PCV3 is common in China. In order to explore the distribution, epidemiology and genetic diversity of PCV2 and PCV3, a total of 1,760 clinical tissue samples were randomly collected from 18 different regions in Henan province of China from October 2018 to September 2019 and screened for the presence of PCV2 and PCV3 by a duplex real-time PCR assay. The results showed that the positive rates of PCV2 and PCV3 were 72.90% and 5.17% respectively, and the co-infection rate of the two viruses was 3.64%. PCV2 and PCV3 are prevalent all year round. The prevalence of PCV2 in diseased pigs was 83.98%, higher than that in slaughterhouse pigs, while the prevalence of PCV3 in diseased pigs was 2.16%, slightly lower than that in slaughterhouse pigs. Furthermore, the complete genomes of 14 PCV2 and 3 PCV3 strains were obtained, among which 1 belonged to PCV2a, 5 belonged to PCV2b and 8 belonged to PCV2d. A new variant strain (XX2) might escape the host immune system. The phylogenetic analysis of PCV3 showed high nucleotide identity (>98%) between sequences obtained in this study and reference sequences. The results of this study might enrich the epidemiological data of PCV2 and PCV3 in Henan province and provide reference information for the comprehensive prevention and control of PCVAD.
Assuntos
Infecções por Circoviridae , Circovirus , Coinfecção , Doenças dos Suínos , Animais , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/veterinária , Circovirus/genética , Genótipo , Filogenia , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
The green production behavior of pig farmers is the basis for high-quality development in animal husbandry. In order to solve the problem of poor green production behaviors in small- and medium-sized pig farmers, it is necessary to analyze the influencing factors and how they interact with each other. The Rational Peasant Theory and Prospect Theory were used in this paper to analyze the occurrence motivation of the green production behaviors of small- and medium-sized pig farmers. The Logit model and the ISM analysis method were used to test the influencing factors and their mechanisms. This was conducted using data from a study of 747 small- and medium-sized pig farmers in Henan Province. The results show that the green production behaviors of small- and medium-sized pig farmers are motivated by internal expected return, affected by the monitoring pressure from external stakeholders and limited by their own resource capacity; the influencing factors of different green production behaviors are different, and there are more influencing factors of scientific disease control, standardized management and waste recycling than of rational feeding. The following shows how the influencing factors on pig farmers' green production behavior interact with one another: level of education â external pressure, farming conditions and operating characteristics â cognition of return â green production behavior (i.e., cognition of return is the direct factor; external pressure, farming conditions and operating characteristics are indirect factors; and level of education is the underlying factor). Some measures should be implemented to promote green production behaviors, such as the continuation of the support for green production, the strengthening of supervision and publicity, the increasing of investment in technology and equipment, and the improving of the green production literacy of farmers. In conclusion, this paper deepens the understanding of the mechanism of green production behaviors of small- and medium-sized pig farmers, and provides the theoretical basis and concrete measures for the government and for pig farmers.
Assuntos
Agricultura , Fazendeiros , Suínos , Animais , Humanos , Inquéritos e Questionários , Criação de Animais Domésticos/métodos , Fazendas , ChinaRESUMO
This paper analyzes the green production efficiency (GPE) and spatial divergence of the hog breeding industry, with the aim of providing a foundation for the rational layout of hog breeding and promoting the industry's high-quality development. The paper uses the SBM model to estimate GPE in 29 provinces, cities, and districts of China from 2006 to 2019. Furthermore, it analyzes the spatial divergence of GPE and its driving factors using divergence indexes and the Geodetector. The results show that China's GPE of the hog breeding industry increased from 0.409 to 0.496 between 2006 and 2019. The highest efficiency occurred during the I-period, while the lowest efficiency was observed during the II-period. The highest efficiency was in the key development region, and the lowest efficiency was in the potential growth region. The spatial divergence of GPE in the hog breeding industry expanded, with labor input, non-point source pollution, resource endowment, and environmental load bearing being the main driving factors for the expansion in each period. The potential growth region had the largest spatial divergence, mainly affected by resource endowment. In contrast, the constrained development region had the smallest spatial divergence, mainly affected by resource endowment and pollutant emissions. The spatial divergence of moderate and key development regions was considerable, mainly affected by environmental investment, environmental load bearing, and pollutant emissions. Therefore, the key to improving the GPE of the hog breeding industry is to promote the adoption of advanced technology, such as labor-saving, material-saving, and emission reduction technologies. Moreover, several actions should be taken to reduce the spatial divergence among different regions, such as integrated breeding, clean standards, large-scale breeding, and high-end boutique.
Assuntos
Poluentes Ambientais , Administração Financeira , Suínos , Animais , Indústrias , Investimentos em Saúde , Desenvolvimento Econômico , Eficiência , ChinaRESUMO
The pig industry is the pillar industry of animal husbandry in China, and epidemics can lead to drastic changes in pig supply, affecting the healthy development of the pig industry and residents' quality of life. This study analyzed the mechanism of the effect of swine epidemics on nonlinear shocks to pig supply, and monthly data on pig supply from January 2012 to June 2020 were applied to study the threshold effect of swine epidemics on pig stock and slaughter in China empirically, using the index of swine epidemics' width (ISEW) as the threshold variable. The results of this study were as follows: (1) The influence of the ISEW over 7 months on pig stock in China was divided into two ranges, and the pig stock did not change significantly when the ISEW was less than 0.25. Swine epidemics had a significantly negative impact on the pig stock when the ISEW was larger than 0.25. (2) The influence of the ISEW over 8 months on pig slaughter was also divided into two ranges. When the ISEW was less than 0.33, epidemics had a positive and significant effect on pig slaughter, while epidemics had a marked negative impact on pig slaughter when the ISEW was greater than 0.33. Based on these conclusions, this study proposed relevant measures for the prevention and control of swine epidemics.