the influence of bedding material and collecting period

excreta were recorded as well. The efficiency of performance was evaluated in terms
of production number (PN) as follows (Swain & Sundaram, 2000).
PN =
abw x % liv.
Days x fc/10
Where, abw = average body weight gain; liv. = percent livability; days = duration of
fattening in days; fc = food conversion.
2.3 Ammonia
Ammonia production was tested with a "Dräger Multi Gas Detector" (Dräger Saftey
AG Co. KgaA, 2001). On day 30 the samples were taken by stroking the pump ten
times at different places in each cage (approximate one minute/cage). The Dräger
tubes change from yellow to blue for a positive value for ammonia. The principle of
the reaction is:
NH? + pH indicator
blue reaction product
The atmospheric pressure was collected from the Bloemfontein weather bureau and
worked to a factor F.
1013
F =
Actual atmospheric pressure (hPa)
The measured value was then multiplied with the F – factor.
2.4 Moisture absorption and release
Moisture absorption and release were calculated according to the method described by
Pearson et al. (1999) as follows:
2.4.1 Absorption
Five 10 g samples of each type of bedding material were placed in bags measuring
150 x 80mm with a pore size of 53 ±10um. The weighed samples were submersed (in
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