The phrase that is translated in English as “fattened calf” is translated in Fuyug as “the calf full of grease.” (Source: David Clark)
In some Hindi translations it is translated as mota pashu (मोटा पशु) or “fattened animal” to avoid the traditionally negative association with slaughtering cows. (In the case of पवित्र बाइबिल, the Common Language Hindi Bible, a footnote is added that says “In the original text: ‘calf.'”)
The now commonly-used English idiom “kill the fatted calf” (meaning having a celebration for someone who’s been away a long time) was first coined in 1526 in the English New Testament translation of William Tyndale. (Source: Crystal 2010, p. 277)
For other idioms in English that were coined by Bible translation, see here.
Many languages distinguish between inclusive and exclusive first-person plural pronouns (“we”). (Click or tap here to see more details)
The inclusive “we” specifically includes the addressee (“you and I and possibly others”), while the exclusive “we” specifically excludes the addressee (“he/she/they and I, but not you”). This grammatical distinction is called “clusivity.” While Semitic languages such as Hebrew or most Indo-European languages such as Greek or English do not make that distinction, translators of languages with that distinction have to make a choice every time they encounter “we” or a form thereof (in English: “we,” “our,” or “us”).
For this verse, translators typically select the inclusive form (including the slaves).
Source: Velma Pickett and Florence Cowan in Notes on Translation January 1962, p. 1ff.
kai phagontes euphranthōmen ‘and let us eat and enjoy ourselves, or, celebrate,’ both acts occurring together. For euphrainomai cf. on 12.19.
The fatted calf, or, ‘the fattest/best calf,’ “the prize calf” (Good News Translation); An American Translation has an active finite form, “the calf we are fattening” (and in vv. 27 and 30, “the calf he has, resp. you have, been fattening”). Calf, or, ‘young bull,’ cf. on “ox” in 13.15; the generic ‘beast’ is sometimes a sufficient designation, e.g. in East Nyanja, Lomwe, Yao. If the whole concept is foreign to the receptor culture one may say, ‘the very best food I, or, we (inclus.), keep in supply.’
Eat and make merry, or ‘let-us(inclus.)-eat having a feast’ (Tae’), or in a single verb, ‘let-us(inclus.)-be-feasting’ (Toraja-Sa’dan); and cf. 12.19.
Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.