Definition of "breeding"

In analysing the ecological conditions of an animal population we have above all to focus our attention upon the most sensitive stages within the life cycle of the animal, that is, the period of breeding and larval development.

1950, Gunnar Thorson, “Reproductive and Larval Ecology of Marine Bottom Invertebrates”, in Biological Reviews, volume 25, number 1, pages 1–45

Plant breeding is always a numbers game. […] The wild species we use are rich in genetic variation, and individual plants are highly heterozygous and do not breed true.

2013 May-June, David Van Tassel, Lee DeHaan, “Wild Plants to the Rescue”, in American Scientist, volume 101, number 3, page 222

She had her breeding at my father's charge.

c. 1604–1605 (date written), William Shakespeare, “All’s Well, that Ends Well”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iii]

Honest gentlemen, I know not your breeding.

c. 1596–1599 (date written), William Shakespeare, “The Second Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act V, scene iii]