avoiding jagged lines on mp2

I tried to get a mpeg2 file from a dv file from camera using:

ffmpeg -f dv -s 720x576 -i dvfile.avi -b 2500 -ab 128 -vcodec mpeg2video \ 
outfile.mpg

result is good if I have images without too much movements, but is the
people move too much i get a lod of annoying jagged lines due to
interlacing. Other times i resorted in the dirt way, encoding as a 384x288
images, so using only even fields , but losing a lot of details.
since post of the movie are maps and other drawing of course i want to
keep the most detail it is possible, and the problem can be seen only when
some one is gesturing. There is a way to avoid it ?