Comparison of number of Streptococcus uberis calculated on a volume or weight basis in sand and sawdust bedding.
OBJECTIVE
To determine a method for comparing counts of Streptococcus uberis in sand and sawdust and account for the influence of weight or volume of the bedding material.


METHODS
2 sources of kiln-dried sawdust and 2 sources of washed sand.


METHODS
Sterilized bedding material (100 ml) was weighed and uniformly distributed in an aluminum pan. Each sterilized bedding material was inoculated with a mean of 3.6 X 10(6) (experiment 1) or 2.4 X 10(7) (experiment 2) colony-forming units (CFU) of S uberis/ml of bedding material. Without allowing time for replication of S uberis, inoculated bedding materials were washed with sterile saline (0.9% NaCl) solution. A 200-ml aliquot of wash solution was serially diluted up to 2,500 times with additional saline solution and inoculated on plates containing tryptose agar with 5% sheep blood. After incubation for 48 hours, number of CFU of S uberis was counted. This procedure was replicated 19 and 16 times for each bedding material in experiments 1 and 2, respectively.


RESULTS
Evaluation of Bonferroni 95% confidence intervals revealed significant differences for counts of S uberis calculated on a weight basis between sand and sawdust.


CONCLUSIONS
Comparison of counts of S uberis determined on a volume basis for sand and sawdust accentuates to a lesser degree the weight difference of the bedding materials and ensures a more appropriate comparison of number of S uberis.
Gabler
M T
MT
Department of Animal Science, College of Agriculture, University of Minnesota, St Paul 55108, USA.
Reneau
J K
JK
Farnsworth
R J
RJ
D000818:Animals; D015169:Colony Count, Microbial / Q000662:veterinary; D004197:Disease Reservoirs / Q000662:veterinary*; D004391:Dust; D006799:Housing, Animal; D012822:Silicon Dioxide; D013291:Streptococcus / Q000254:growth & development* / Q000302:isolation & purification; D014934:Wood
D004391:Dust; D012822:Silicon Dioxide