get first value of a dot separated string (Bash)

Hey so I have a string in bash named

chicken.fasta.count.sorted.topthree.txt It's a string delimited by dots and I want the value before the first dot.

I just want the substring 'chicken' and I want to store it in a variable.

Can someone show me the way?

s="$chicken.fasta.count.sorted.topthree.txt"
animal_name="${s%.*}

Maybe using cut command:

echo "chicken.fasta.count.sorted.topthree.txt | cut -d '.' -f 1

Use either of these Perl one-liners:

echo 'chicken.fasta.count.sorted.topthree.txt' | perl -lne 'print /([^.]*)/'

or

echo 'chicken.fasta.count.sorted.topthree.txt' | perl -F'[.]' -lane 'print $F[0]'

/([^.]*)/ : match the pattern that has any non-dot character ([^.]) repeated 0 or more times (*). The pattern is captured with parentheses and pass to print, which prints it.

The Perl one-liner uses these command line flags:
-e : Tells Perl to look for code in-line, instead of in a file.
-n : Loop over the input one line at a time, assigning it to $_ by default.
-l : Strip the input line separator ("\n" on *NIX by default) before executing the code in-line, and append it when printing.
-a : Split $_ into array @F on whitespace or on the regex specified in -F option.
-F'[.]' : Split into @F on a literal dot (.), rather than on whitespace.

SEE ALSO:
perldoc perlrun: how to execute the Perl interpreter: command line switches
perldoc perlre: Perl regular expressions (regexes)
perldoc perlre: Perl regular expressions (regexes): Quantifiers; Character Classes and other Special Escapes; Assertions; Capture groups
perldoc perlrequick: Perl regular expressions quick start