Yoreh Deah Siman 16 Seif 7

 

ז אֵין אִסוּר אוֹתוֹ וְאֶת בְּנוֹ אֶלָּא בִּבְהֵמָה טְהוֹרָה בִּלְבַד, שֶׁנֶּאֱמַר:   (וַיִּקְרָא כב, כח) וְשׁוֹר אוֹ שֶׂה אֹתוֹ וְאֶת בְּנוֹ לֹא תִשְׁחֲטוּ בְּיוֹם אֶחָד וְנוֹהֵג בְּכִלְאַיִם הַבָּא מִמִּין כֶּבֶשׂ וּמִמִּין עֵז.

 

Seif 7

It is not forbidden to slaughter a mother and her offspring only if its a kosher domesticated animal, as it is said:(in Vayikra 22:28) Do not slaughter an ox or a sheep and its offspring on one day.”

However it is prohibited to slaughter it if it were a hybrid with a sheep or a goat” or with a wild animal such as a mountain goat or a deer, etc.