Lewis & Short

1. partĭo, ōnis, f. [pario], a bearing, bringing forth young (ante-and post-class.): horresco misera, mentio quoties fit partionis, Plaut. Truc. 1, 2, 92; Afran. ap. Non. 217, 31: mulieris, Gell. 3, 16, 9; 12, 1, 20.
Of hens, a laying of eggs: hae (gallinae) ad partiones sunt aptiores, Varr. R. R. 3, 9, 4.