Effects of water-cooled cover on physiological and production parameters of farrowing sows under hot and humid climates

The hot and humid climates,as encountered in the southern region of China with the open housing,can adversely impact the sows undergoing heat stress during the most vulnerable period at lactation.Hence,a water-cooled cover system(WCCs)for local cooling has essential practical value to improve productivity.The WCCs was developed for the sow crate of lactating sows separately,which performance was validated with the cooling efficiency in the sow occupied zone(SOZ)and physiological parameters.The results showed that the WCCs for the farrowing sows using aluminium plastic tubes connected in series could reach an appropriate cooling performance in adjacent units.The WCCs could decrease the SOZ air temperature by 3.0-4.5℃under the extremely hot climate when the indoor air temperature was 37℃,and maintain a suitable range(25-30℃)under the typical hot climate(<35℃).The respiration rate and skin temperature of farrowing sows had no significant difference between treatment group(WCC)and control group(sprinkle cooling)when the air temperature was below 30℃,but had a significant difference(p<0.05)when air temperature rose above 30℃.The control sows drank more during hot weather,and the feed intake was significantly lower than the sows with the WCCs(p<0.01).It was concluded that the WCCs could alleviate the heat stress of farrowing sows during typical hot climate.

Inactivation efficiency of slightly acidic electrolyzed water against microbes on facility surfaces in a disinfection channel

Slightly acidic electrolyzed water(SAEW,pH 6.0-6.5)is an ideal and environmentally-friendly disinfectant,which was used to prevent and control bacterial infections on farms.This work aims to investigate the inactivation effectiveness of SAEW in inactivating microbes in a disinfection channel.The bactericidal efficiency of SAEW on equipment surfaces was compared to two commercial disinfectants,Kuei A bromide solution(KAS,5:1000 v/v)and Glutaraldehyde solution(GS,5:1000 v/v).The disinfection effectiveness of SAEW in inactivating Salmonella enteritidis(S.enteritidis)on equipment surfaces in the disinfection channel was evaluated,and a model was developed using multiple linear regression analysis.Results indicated that SAEW was significantly(p<0.05)more efficient than KAS and GS on kits and clothing in the disinfection channel at 1 min.The SAEW did not contribute as aggressively to respiratory difficulty as KAS and GS.Maximum reductions of 2.362 log10 CFU/cm^(2),2.613 log10 CFU/cm^(2) and 2.359 log10 CFU/cm^(2) for Salmonella enteritidis were obtained from clothing surfaces,iron materials,and kits treated with SAEW for 2.5 min at a chlorine concentration of 220 mg/L.Moreover,the established model had a good fit-quantified by the determination coefficient R^(2)(0.939)and a lack of fit test(p>0.05).In addition,available chlorine concentration(ACC)was an important factor than other factors,and the inactivation efficiency of Salmonella enteritidis sprayed by SAEW treatment was different between iron materials,kits and clothing surfaces(iron>kit>clothing).