Effect of Heat Processing on Chemical Composition, Protein Fractions and Digestibility of Broiler litter

Document Type : Research Paper


1 Graduate Student, Animal Science Department, Faculty of Agriculture, Tarbiat Modarres

2 Faculty Member, Animal Science Department, Faculty of Agriculture, Tarbiat Modarres University, Tehran, Iran

3 Academic Staff, Animal Science Research Institute, Karaj, Iran

4 Postgraduate Student, Animal Science Department, Faculty of Agriculture, Tarbiat Modarres University, Tehran, Iran


Effect of heat processing on the nutritive value of broiler litter, as a potential ruminant feedstuff,
was studied in two pilot plans, processing through an assessment of chemical composition, protein
fractionation according to CNCPS as wells digestibility making use of Tilley and Terry method. In a
manufactory located in the city of Sabzevar. The average values of Dry Matter (DM), Crude Protein
(CP), Neutral Detergent Fiber (NDFom), Acid detergent fiber (ADFom), ash, Ca, P, Mg, K, Na, Fe,
Mn, Cu and Zn in the unprocessed broiler litter constituted 83.5% of the fresh matter, 26.4, 41.3, 14.2,
18.6, 1.85, 0.97, 0.8, 1.0, 0.065 % of DM, 910.75, 332.73, 58.14 and 384.4 mg/kg of DM,
respectively. These values for the processed litter, respectively, amounted to 92.9 % of fresh weight,
25.5, 46.2, 14.4, 18.6, 1.74, 0.95, 0.72, 0.94, 0.062 % of DM, 1029.3, 304.25, 54.74 and 379.75 mg/kg
of DM. As for the Semnan manufactory, the average values for the unprocessed litter were,
respectively,73.2 % of fresh weight, 28.8, 16.0, 17.2, 1.92, 1.13, 0.61, 1.1, 0.036 % of DM, 1328.6,
374.0, 52.69 and 345.0 mg/kg of DM. Fllowing the processing operations the mentioned values
changed to 82.3 % of fresh weight, 28.3, 49.1, 18.5, 17.8, 1.86, 0.94, 0.60, 0.87, 0.035 % of DM,
1598.2, 338.67, 51.15 and 302.6 mg/kg of DM, respectively. Protein fractions A, B1, B2, B3 and C in
the unprocessed litter at Sabzevar manufactory were, respectively 51.8, 18.5, 17.1, 7.13 and 5.01 % of
CP. The values for Semnan manufactory were recorded as 50.3, 11.1, 24.6, 9.51 and 5.4 % of CP,
respectively. After heat processing, accomplished and fot both manufactories, fractions A and B1 were
reduced, wtereas B2, B3 and C increased (P<0.05). The in vitro DM Digestibility (DMD), Organic
Matter Digestibility (OMD) and ME contents for the unprocessed litter, respectively, were 799, 798
g/kg and 9.63 MJ/kg DM for Sabzevar manufactory, and 780, 791 g/kg and 9.70 MJ/kg DM for
Semnan,s. Heating process had no significant effect on digestibility and ME (P>0.05), except for
DMD at Sabzevar manufactory, which had singificantly decreased. The Pressing method of processing
reduced (P<0.05) DMD, OMD (771 and 773 g/kg) and ME (9.31 MJ/kg of DM) as compared with
unprocessed litter. Overall, although application of indirect heat processing of broiler litter somehow
reduced CP, Mg and Cu contents, but by removal of the pathogenic organisms it can lead ot the
production of a protein supplement, enriched in mineral,s as a ruminant feedstuff and which can help
reduc the environmental pollution.