3.4. Slurry characteristics and gaseous emissions
Water intake during the collection period was not affected by treatments, averaging 4.24 ± 1.48 (SD) kg/d. Slurry excretion
and initial slurry characteristics such as DM, OM, total Kjeldahl N (TKN) and pH were similar among treatments (Table 7).
However, total ammonia N (TAN) was significantly lower in the slurry from animals fed SB diet compared to that from
animals fed SFM (P < 0.05). Slurry from WDDGS treatment had intermediate values. Total volatile fatty acids concentration
was not different among treatments, although a contrast between slurry from treatment SB tended (P < 0.10) to give a higher
amount compared with thatfrom treatment WDDGS. This difference comes mainly from the differences observed for butyric
acid concentration, which was significantly higher in treatment SB compared to the others (P < 0.05).
In terms of gas emission, although the overall effect of treatments did not reach a significant level, the contrast between
the slurry from diet SB led to a lower NH3 emission per kg of slurry than diet SFM, with the slurry from diet WDDGS giving
intermediate values. When NH3 emission was expressed as the proportion of the initial TKN or on a daily basis, the trend
was similar to that observed for absolute emission, but the differences were not significant. In contrast, the biochemical CH4
potential (B0) from slurry was higher (P < 0.05) in treatment SB than in SFM, with the values of treatment WDDGS being