2,452. All Living Things Are Significant

Maachalos Assuros 16:6

The same laws apply to meat cooked with milk and to a regular animal that was slaughtered in the Temple courtyard, i.e., it is prohibited to benefit from the latter under rabbinic law. This will be discussed IY”H in Hilchos Shechitah. Even the slightest volume of these things renders a mixture prohibited until they’re removed. Similarly, if a sciatic nerve was cooked with other cords or with meat and it can be identified, it should be removed and the rest is then permitted; this is because it doesn’t impart taste. If the sciatic nerve can’t be identified, then everything is prohibited. Since the sciatic nerve is considered an independent item, it is deemed significant. Therefore, it renders a mixture prohibited in even the smallest measure.

Maachalos Assuros 16:7

Similar to the previous halacha, all living creatures are considered significant and are never nullified. Therefore, if an ox condemned to stoning gets mixed with 1,000 other oxen, or a calf whose neck is to be broken gets mixed with 1,000 other calves, or a dove for the cleansing of a metzora (colloquially a “leper,” but not really) gets mixed with 1,000 other doves, or a firstborn donkey gets mixed with 1,000 donkeys, in all of these cases it is prohibited to benefit from any of them. Regarding other things, even when the practice is to sell them by count, they can be nullified in the usual ratios.