الفهرس 
cover englishOnly 14 pages are availabe for public view
 |  | from | 237 |  |  |
| | | from | 237 | | |
Abstract
Bad quality drinking water and faulty distribution system play a detrimental role on calf and adult cattle health, production and reproduction, giving chance for increasing rate of emerging health disorders and resulting in high rate of morbidity and mortalities in adult and calves. The present study aimed to evaluate rate of emerging health disorders, different health and reproductive indicators, production and growth performance, calf health in relation to drinking water quality and water distribution system in dairy and beef cattle farms. Also, to determine drinking water bacterial profile and evaluate commonly used disinfectants against isolated chlorine resistant strains. Structured questionnaire is used to survey a convenience sample of 132 Egyptian cattle farms suffering emerging health disorders to identify different risk factors and hygienic standards which may affect calf and adult cattle health, production and reproduction. One hundred and thirty-two, 132 water samples were collected for physicochemical and bacterial analysis, obtaining water bacterial profile, testing bacterial resistance to chlorine and detection of qacE resistance gene in the isolated chlorine-resistant E. coli strains. Statistical analysis was performed to identify the level of association between each water quality parameters along distribution system with number of emerging health disorders, adult cattle health and reproductive indicators, performance indicators and causes of calf mortality, also, finding the association between water bacterial profile and presence of chlorine resistant strains in each farm with the used disinfection, disinfectants types and rate of use. Results show moderate positive correlation (rho 0.3-0.7) between number of emerging health disorders and all farm indicators with all water parameters except pH in both winter and summer season. Moderate correlation was clear between both of beef FCR and dairy fed efficiency with all physicochemical parameters except pH. Also, water distribution system (from water source to tanks, calf house and adult house troughs) significantly affects water quality both in winter and summer season. All water parameters except pH in both winter and summer showed moderate positive correlation (rho 0.331-0.66) with causes of calves’ mortality rates. Bacterial profile strains count, and presence of chlorine-resistant strains showed weak to moderate correlation (rho 0.15-0.46) with different farm disinfection, disinfectants types and rate of use. In vitro, evaluation of the efficacy of commercially used disinfectants on the isolated bacteria revealed that Peroxymonosulfate killed the highest number of strains and QACs killed the lowest at different contact times. Conclusion, drinking water quality highly affects the rate of emerging health disorders, different farm health and reproductive indicators, beef and dairy performance, causes of calf’s mortality in investigated cattle farms, considering effects of other factors that affect water quality such as the effect of water faulty distribution system, the use of disinfectants in presence of resistant bacterial strains, management and hygiene standards inside cattle farms in Egypt.