▁amount ▁of ▁feed , ▁depending ▁on ▁the ▁stage ▁of ▁the ▁f atten ing ▁process , ▁the ▁bird ' s ▁weight , ▁and ▁the ▁amount ▁of ▁feed ▁the ▁bird ▁last ▁ing ested . ▁At ▁the ▁start ▁of ▁production , ▁a ▁bird ▁might ▁be ▁fed ▁a ▁dry ▁weight ▁of ▁ ▁of ▁food ▁per ▁day ▁and ▁up ▁to ▁ ▁( in ▁dry ▁weight ) ▁by ▁the ▁end ▁of ▁the ▁process . ▁The ▁actual ▁amount ▁of ▁food ▁force - f ed ▁is ▁much ▁greater , ▁because ▁the ▁birds ▁are ▁fed ▁a ▁m ash ▁with ▁a ▁composition ▁of ▁about ▁ 5 3 % ▁dry ▁and ▁ 4 7 % ▁liquid ▁( by ▁weight ). ▁This ▁is ▁the ▁equivalent ▁to ▁around ▁ 1 , 9 0 0 ▁gr ams ▁per ▁day ▁in ▁total ▁mass . ▁ ▁The ▁feed ▁is ▁admin ister ed ▁using ▁a ▁fun nel ▁fitted ▁with ▁a ▁long ▁t ube ▁( 2 0 – 3 0   cm ▁long ), ▁which ▁forces ▁the ▁feed ▁into ▁the ▁bird ' s ▁es oph ag us . ▁If ▁an ▁aug er ▁is ▁used , ▁the ▁feed ing ▁takes ▁about ▁ 4 5 ▁to ▁ 6 0 ▁seconds , ▁however , ▁modern ▁systems ▁usually ▁use ▁a ▁t ube ▁fed ▁by ▁a ▁p neum atic ▁p ump ▁with ▁an ▁operation ▁time ▁of ▁ 2 ▁to ▁ 3 ▁seconds ▁per ▁du ck . ▁During ▁feed ing , ▁efforts ▁are ▁made ▁to ▁avoid ▁dam aging ▁the ▁bird ' s ▁es oph ag us , ▁which ▁could ▁cause ▁injury ▁or ▁death , ▁although ▁research ers