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close this bookBioconversion of Organic Residues for Rural Communities (UNU, 1979)
close this folderIndian experience with treated straw as feed
View the document(introduction...)
View the documentIntroduction
View the documentExperience with straw treatment
View the documentField testing and demonstration of straw treatment
View the documentGeneral considerations
View the documentSummary
View the documentAnnex 1. The energy efficiency of the two-stage, feed-fuel processing of straw in indian villages
View the documentAnnex 2. Method of calculating the value presented in table 2 for the efficiency of naoh energy usage
View the documentAnnex 3. Recommendations to farmers on the treatment of straw
View the documentAnnex 4. Calculated efficiency of milk production by straw-fed village buffaloes
View the documentReferences
View the documentDiscussion summary

Annex 2. Method of calculating the value presented in table 2 for the efficiency of naoh energy usage

The MJ of NaOH energy input per MJ additional energy stored as body-weight gain was calculated as follows.

1,000 kg untreated straw provided for



1,000 kg treated straw provided for



In 222 days a calf fed untreated straw also consumed

222 x 0.8 = 178 kg oilcake

In 167 days a calf fed treated straw also consumed

167 x 1.0 = 167 kg oilcake

In 222 days a calf fed untreated straw gained

222 x 0.25 = 55.5 kg

In 167 days a calf fed treated straw gained

167 x 0.42 = 70.0 kg

Therefore, the treatment of straw increased weight gain by 70.0 - 55.5 = 14.5 kg/1,000 kg straw. (This figure is conservative, because a calf fed treated straw consumed slightly less oilcake/1,000 kg straw than the one fed untreated straw.) The energy value of this bodyweight gain is taken as 9.6 MJ/kg (calves about 1-year-old gaining at a rate of 0.40 kg/day[19]), or 139.2 MJ for 14.5 kg. The manufacturing energy cost of NaOH is estimated to be 51 MJ/kg;

1,000 kg straw x 3.3 kg NaOH/100 kg x 51 = 1,683.