Animal Food During Shemitta
Shiur #15 addressed the issur of wasting shemitta fruits and the obligation (and possibly mitzva, according to the Ramban) to eat them. The first mishna in the eighth perek introduces differences between animal and human food which might reveal an important theme about kedushat shvi'it in general.
Though animal food also possesses kedushat shvi'it, a person may use this food for medical applications. The gemara in Sukka (40a) explicitly states that according to all opinions (even that of Rebbi Yossi, who allows the use of shemitta produce as cleansing agents – see shiur #13), shemitta produce may not be used medically. By employing the phrase "lakhem le-akhla," the Torah bans the use of shemitta food for medical purposes (which in no way can be compared to eating). Since, however, the modifier of 'le-akhla' appears after the term 'lakhem' (referring to human beings), food which isn't suitable for 'lakhem,' i.e. animal feed, may be used for medical purposes. What does this halakha indicate about these different levels of kedushat shvi'it and about kedushat shvi'it in general?
The simplest approach is to fully equate animal and human food in terms of their kedusha but to concede a technical and limited difference. Using animal food for human medical purposes is a legitimate use and maintains the kedusha restrictions which apply equally to animal food. The Yerushalmi (8:1), however, questions whether animal food may be used for dyeing for animals. The hava aminah implies that although animal food possesses kedusha (and cannot be indiscriminately wasted), it can be used for any constructive purpose. By allowing medical uses, the Torah actually redefines a completely separate category of kedushat shvi'it for animal food. The demands of this category are simply that items be used constructively, but without care as to how they are used.
An earlier Yerushalmi (7:1) ruled that animal feed may be used to cover crops and prevent them from drying. Ostensibly, human food cannot be used in this manner. This halakha indicates that although animal food must be used for kedusha-type purposes, they possess a very broad range of permissible uses. Unlike human food, which must be eaten (or used in a manner similar to eating), animal food simply may not be wasted or diverted to non-kedusha uses. The kedusha attendant upon human food is meant to facilitate use; hence, we find strict guidelines about which uses are permissible. The kedusha of animal food is more absolute, the primary consequence being the issur to waste. Using it for non-kedusha uses is wasteful; any constructive use, however, is permitted.
The continuation of the Yerushalmi (8:1) provides an important halakha regarding this question. The mishna had discussed items which are sometimes used for animal or human food and at other times for firewood. In these instances, the mishna rules that if one intended to use them (presumably at the point of harvest) for animal or human food, they 'acquire the chumrot (restrictions) of animal or human food,' while if he planned to use them for firewood, they possess no kedusha. The Yerushalmi then inquires as to the unique 'chumra' of animal food to which the mishna had referred. It responds that animal food may not be cooked, since animals generally eat their food raw. This halakha might suggest that animal food does indeed possess the restrictive. use-specific kedusha similar to human food and must be eaten in the conventional manner. Why else would a person be prohibited from cooking animal food, even though the animal will eat and enjoy it?
Upon second glance, however, we might explain the Yerushalmi (which is cited by the Rambam) in a different manner. We might claim that, in general, the prohibition of cooking shemitta food is not because of the irregular use to which the food is subjected. Rather there exists a blanket prohibition against changing or altering shemitta produce, unless of course, that change is part of the cooking process. In such a case, cooking is defined as facilitating eating, rather than changing. In fact, the Arukh Ha-shulchan derives an issur to dye human food or turn a liquid into a solid even though these processes do not lead to any significant waste. Unless the alteration can be seen as vital to the cooking process, they are forbidden, because alteration itself is forbidden.
If we concede that altering food is prohibited on its own terms, and cooking it is permitted only as a manner of preparing it for eating, we might easily understand the issur to cook animal food even if the animal will benefit more from the cooked version. The kedusha of human food is benefit-centric in that it obligates use – and specific use. As cooking allows this use, it is permissible. Animal food, however, possesses a more basic kedusha which simply prevents wasting. As part of this identity the food cannot be cooked since that is also considered wasting. In this case, the concept of cooking to facilitate eating doesn't apply, because the kedusha of animal food is realized in more objective and absolute terms.
The nature of the prohibition to alter shemitta produce can be discerned in a mishna in Terumot (11:1) which cites an argument between Rebbi Yehuda and the Chakhamim as to whether teruma wine may be cooked. The Tana Kama prohibits doing so since cooking changes the wine, while Rebbi Yehuda allows it, as cooking improves the wine. From a logical standpoint, Rebbi Yehuda's position makes sense; why should improvements be forbidden? The Yerushalmi cites the following explanation of the Tana Kama's position: by cooking the wine, one thereby reduces the amount of people who will drink (as presumably fewer people drink processed wine). This explanation seems to evoke our earlier definition of the prohibition to change shemitta and teruma food. Change is, in and of itself, forbidden, unless it is defined as part of the food's preparation process. According to Rebbi Yehuda, the fact that cooking improves wine renders cooking part of this process. The Tana Kama disagrees only because he feels that something that reduces the population of potential drinkers cannot be considered part of the preparation for the food's consumption. [Note: Neither the mishna nor the Rambam cite the prohibition of cooking shemitta wine. The Pe'at Ha-shulchan, though, extrapolates the issur (at least according to the Tana Kama) from the mishna in Terumot.]
It is quite possible that this question regarding the nature of kedushat shvi'it of animal food can be discerned from the actual source of this halakha. The Yerushalmi (Shvi'it 8:1) cites two different methods for deriving this halakha. According to the first, the juxtaposition of the word 'le-akhla' to the word 'lakhem' indicates that specifically human food must be eaten and not used for medical purposes. The second strategy recognizes that in fact the term to eat (which seems to limit medical uses) appears twice in the pasuk. This textual phenomenon, known as mi'ut achar mi'ut (the rough equivalent of a double negative), always suggests some inclusion. Though human food was EXCLUDED from medical applications, animal food was INCLUDED. Certainly, the first approach more powerfully suggests a categorically new definition for animal food. By juxtaposing human food to the word le-ekhol and not aligning animal food in that manner, the Torah might be suggesting two different models for kedushat shvi'it. Animal food possesses kedusha which prohibits wasting it; human food possesses kedusha which requires benefiting from it. Animal food may be used for medical purposes or to protect wheat but cannot be cooked, while human food must be directly benefited from but can be cooked to prepare it in a better form.