Problem parsing line in file

I am VERY new to unix scripting. I am having trouble parsing a line into fields for further processing.

I have this script:

#bin/sh

cat ztest2.txt | while read line
do
zvar1=`echo $line | cut -f6`
echo "zvar1 is " $zvar1
done

********************
ztest2.txt looks like:

1 2 3 4 5 6 7 8
2 3 4 5 6 7 8 9
3 4 5 6 7 8 9 10
4 5 6 7 8 9 10 11

where the spaces in between the numbers are tabs.

the output of this script is:

zvar1 is 1 2 3 4 5 6 7 8
zvar1 is 2 3 4 5 6 7 8 9
zvar1 is 3 4 5 6 7 8 9 10
zvar1 is 4 5 6 7 8 9 10 11

if i just run from the command line:
cut -f6 ztest2.txt

i get
6
7
8
9

Can anyone help.

#bin/sh

cat ztest2.txt | while read line
do
zvar1=`echo $line | awk '{print $6}'`
echo "zvar1 is " $zvar1
done

Thank you. That works. Of course that's the simple part. My actual data is far more complicated than my example but at least I can move forward now.