How to set right input to "while read line"?

Question

I my code I have while cycle which reads from file:

teams=()
status=()
novy=true
j=0
k=0
while read line; do
name=$( echo "$line" | cut -d ":" -f 1 - )
for i in "${teams[@]}"; do
    if [ "$i" = "$name" ]; then
      novy=false
  c=$( echo "$line" | cut -d ":" -f 3 - )
  status[$k]="${status[$k]}+$c"

  break
fi
k=$(( k+1 ))
novy=true

done
if "$novy"; then
    teams[$j]="$name"
    status[$j]=$( echo "$line" | cut -d ":" -f 3 - )
    j=$(( j + 1 )) 
    novy=false
  fi
k=0
done < ms.txt

But now I want to modify input ms.txt so I tried this:

input=$( cat ms.txt )
some modifiations of input (by echo "$input" I verified that the input is in right form)
echo "$input" | while read line; do
name=$( echo "$line" | cut -d ":" -f 1 - )
for i in "${teams[@]}"; do
    if [ "$i" = "$name" ]; then
      novy=false
  c=$( echo "$line" | cut -d ":" -f 3 - )
  status[$k]="${status[$k]}+$c"

  break
fi
k=$(( k+1 ))
novy=true

done
if "$novy"; then
    teams[$j]="$name"
    status[$j]=$( echo "$line" | cut -d ":" -f 3 - )
    j=$(( j + 1 )) 
    novy=false
  fi
k=0
done

But now the code doesn't work, I don't know why. The while cycle doesn't read the input same as before and it prints some errors.