***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective High NH3 emissions from poultry houses are reported to have negative impacts on health , welfare and safety of birds and humans , and on the environment . Objective of the present study was to determine the effects of two litter amendments on the NH3 levels in broiler closed houses under hot-humid conditions . Methods Giving a completely r and omize design , nine closed houses , each housed 32,500 birds on paddy husk litter  , were r and omly allocated into two treatment ( Mizuho ; a bacterial culture mix and Rydall OE ; an enzymatic biocatalyst ) and control groups .  NH3 levels were determined thrice a day ( 0600 , 1200 , and 1800 h ) , at three heights from the litter surface ( 30 , 90 , and 150 cm ) , at 20 predetermined locations of a house , from day 1 to 41 . Results Rydall significantly reduced the NH3 level compared to control and Mizuho . NH3 levels at 30 cm were significantly higher than that of 90 and 150 cm . The NH3 levels at 30 cm height were higher than 25 ppm level from day 9 , 11 , and 13 in Mizuho , control , and Rydall groups , respectively to day 41 . NH3 levels at 150 cm height were higher than maximum threshold limit of 50 ppm for human exposure from day 12 , 14 , and 15 in Mizuho , control , and Rydall groups , respectively to day 33 . Being significantly different among each other , the NH3 level was highest and lowest at 0600 and 1800 h. Litter amendments had no significant effects on growth performance . Rydall significantly increased the litter N content on day 24 . Conclusion It was concluded that the NH3 levels of closed house broiler production facilities under tropical condition are so high that both birds and workers are exposed to above recommended levels during many days of the growing period . Compared to microbial culture , the enzymatic biocatalyst was found to be more effective in reducing NH3 level Two commercially available litter treatments , aluminum sulfate and sodium bisulfate , were tested to determine their effect on Campylobacter and Salmonella levels associated with commercial broilers during a 6-wk grow-out period . A total of 20 broiler houses at 10 different locations were studied ; 5  aluminum sulfate-treated houses  , 5  sodium bisulfate-treated houses  , and 10 paired , untreated control houses . A single application rate was investigated for each treatment . Fecal sample s ( n=20 per house ) were analyzed at wk 2 , 4 , and 5 and 6 for Campylobacter and Salmonella . The results indicated that , at the application rates investigated , both acidifying litter treatments caused a slight delay in the onset of Campylobacter colonization in broiler chicks .  Salmonella levels remained unaffected , with no significant effect seen with either treatment ( P > 0.05 ) . Campylobacter population s and Salmonella incidence associated with unprocessed , whole-carcass rinse sample s ( n=10 per house ) analyzed at the end of production ( wk 5 and 6 ) were unaffected by treatment The  survival of Salmonella Typhimurium LT2 in r and omly packed beds of glass beads , microporous silica particles and Sephadex microspheres is examined . It is shown that the decrease in the percentage cell recovery in these porous material s at reduced water content is not correlated with the global water activity as determined by conventional vapour pressure measurements but rather with the osmotic shock induced by the sudden redistribution of water and air among the microscopic pores in the matrix surrounding the cells . For this reason the bacterial survival and growth data correlates best with physical measurements , such as NMR and electrical conductivity , which are sensitive to the microscopic air-water distribution . The implication s of this observation in food safety and preservation are discussed ABSTRACT The litter quality is an important factor affecting the performance , welfare and carcass quality of the broilers . Depending on the progress of the fattening duration , some material s may be added to the litter in order to keep the pH , moisture and ammonia levels in the litter under control . Sepiolite is a natural material and it has strong absorbing ability to the water . Therefore , the aim of this study was to determine the effects of sepiolite additions to different litter material s on performance and some welfare parameters of broilers and litter characteristics . A total of 288 1‐d‐old male broiler chicks ( ROSS‐308 ) were used . Birds were r and omly allocated to 2 litters ( wood shavings and rice hull ) and 3 sepiolite groups ( 0 , 25 , 50 % ) with 6 replication , and each pen contains 8 chicks . Fattening performance , IgG , tonic immobility period , feather score , skin injures , breast burns , and footpad burns of broilers were not affected significantly by sepiolite additions to the litter . However , sepiolite addition to the litter can improve litter quality . There was no significant difference between 2 litter material s because both have same color . There were no significant interactions in examined parameters . In conclusion , addition of sepiolite at 25 and 50 % levels to litter material s may be used as a litter material in the broiler production without adverse welfare and performance problem 
    Output:
    
Conclusion None of the litter treatments influenced the  feed intake of broilers .
Meta-analyses of the selected studies showed positive and significant effects of the litter treatments on broiler performance and litter quality when compared with controls .
Alkalizing was associated with worse feed conversion and high mortality of broilers