Topic: PRRSV aerosol transmission
Table 1: Summary of air transmission literature in PRRSV pig herds and between pig houses
Table 2: Summary of air transmission literature in PRRSV area
Topic: Gasy ozone and ozone water kill microorganisms on different fecal contaminated surfaces
4ppm ozone water can reduce fecal contaminated microorganisms on smooth surfaces (plastics and metals) to a safe level (5log10) within 2 minutes; 9ppm gaseous ozone can kill fecal contaminated microorganisms on smooth surfaces (plastics and metals) 3.3log10 in 4 minutes; 9ppm ozone water can reduce fecal contaminated microorganisms on nylon and rubber surfaces to a safe level. On more complex surfaces (such as wood), up to 9ppm of ozone water and gaseous ozone cannot reduce fecal contaminated microorganisms to safe levels.
Question: Evaluate the detoxification status of sows after artificial infection with rotavirus (RV) and the impact of rotavirus (RV) on piglets
Experimental design: 1 group of sows were artificially infected 5 weeks, 4 weeks, and 3 weeks before birth; 2 group of sows were artificially infected 5 weeks and 3 weeks before birth; 3 group of sows were artificially infected 5 weeks before birth; the control group did not do any treatment.
Fecal samples were collected every two weeks from 5 weeks before birth to 2 weeks before birth, and then samples were taken once a week until weaning. When sows were given birth, five piglets produced by each sow were marked for the trial. The marked piglets were sampled four fecal swabs from piglet birth to weaning. The sow feces swabs were summarized in 3 groups, and the piglet feces swabs were summarized in vain.
Table 1: PCR test for sow rotavirus (PV)
Note: Before artificial infection, 2 sows were RVA positive and all sows were RVC negative. The first time there was an artificial infection of 35 sows, 26 of which showed detoxification, and 7 of them showed RVC. Four weeks before delivery, the number of RVA detox sows in the challenge group decreased, while the number of RVC detox sows increased. The peak of detoxification of sows in the first group of 1 occurred in 3.5 weeks before birth. All sows in this group showed RVA detoxification, and only one sow showed RVC detoxification. RVA detoxification was observed in all sows in the challenge group during delivery. RVA detoxification continues until weaning, while RVC detoxification occurs only at the second week after delivery.
Table 2: Piglet rotavirus (PV) PCR test
Note: At the 1st, 3rd and 15th postpartum, the piglet feces swabs RVA and RVC were positive. All piglets were negative for RVB during delivery. After weaning and conserving, except for one piglet, the other piglets were positive for RVA and RVC, and 28 of the 46 piglets were positive for RVB. For nursery sampling, the RVA CT values are about 12-14, while the RVB and RVC CT values are 20. In fattening house sampling, 100% of pigs were positive for RVA, RVB and RVC. The CT value is 20. The average weaning weights of 21-day-old-age-adjusted weaning were 14.7 pounds, 13.5 pounds, 13.7 pounds and 13.2 pounds, respectively. The difference between the 1st group of challenge and the control group was significant (P <>
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