Biochemical serum characteristics in fattening pigs infected with porcine circovirus type 2

Abstract

Circoviral infection is one of the most widespread disease among pig populations which cause significant economic losses. Plural complications, differences in biology of known strains, wide range of clinical and biochemical changes require the detail study of its pathogenesis. The aim of the study was to identify biochemical alterations in commercial pig herds caused by circoviral infection progress. The study was carried out with use spontaneously infected animals selected from the farming pig herd aged 17-21 weeks. Animals were previously vaccinated with various vaccines and protocols. Viremia was confirmed by RT-PCR method that serves as the main criterium to divide animals for control and experimental groups. The blood samples were collected to detect biochemical parameters with applying an automated biochemical analyzer, high-performance liquid chromatography and inductively coupled plasma emission spectrometry methods. The most higher circovirus concentration observed for 17 weeks of age with consequently reciprocal decrease at 18 weeks and an increase in PCV2 DNA concentration at 19-21 weeks, while it remained significantly consistent during 19-21 weeks. The progress in circoviral infection likely led to a notable increase in total protein content in blood serum at 17th (by 11.6%; P<0.05), 19th (by 12.7%; P<0.05), 20th (by 14.7%), and 21st (by 9.1%) weeks of age. These changes in animal blood from 17 to 20 weeks were attributed to globulins. The globulins content was observed in PCV2 infected pigs at 17, 18, 19, and 20 weeks exceeded control values by 34.4%, 17.7%, 18.4%, and 11.6%, respectively (P<0.05). At 21 weeks, pigs with PCV2 viremia showed a 20.9% higher (P<0.05) level of inorganic phosphorus and nearly twofold higher (P<0.05) alkaline phosphatase activity in blood serum. The selenium concentration in 17-week-old pigs in PCV2 infected group was higher by 17.8% (P<0.05) in respect with control. Contrary, decrease in vitamin E level by 23.2% (P<0.05) and 31.5% (P<0.05) was detected in pig groups for 19 and 21 weeks respectively. The primary biochemical changes in porcine circovirus infection include an increase in total protein content and globulin fractions that accompanied by a decrease in vitamin E level. These findings reflect the impact of PCV-2 infectious progress in swine homeostasis disturbance and can be applied to advance biochemical diagnostics and to construct new therapeutic and preventive measures.