1) AGADAH: THE FOUR SIGNS OF A KOSHER BIRD
The Mishnah teaches that there are four signs of a Kosher bird. A bird is Kosher only if it is not "Dores" (see following Insight), it has an extra toe, it has a crop (Zefek), and the inner membrane of its gizzard (Kurkevan) can be peeled.
The Gemara later (139b) says that the Torah uses the word "Tzipor" (Devarim 22:6) specifically to denote a Kosher bird. The AVNEI NEZER points out that the second letters of the four signs of a Kosher bird spell the word "Tzipor": Etzba Yeseirah, Zefek, Dores, Kurkevano Niklaf.
Moreover, the word "Tzipor" there is written with the letter "Vav," but the "Vav" is not pronounced ("Kesiv v'Lo Kri"). The "Vav" corresponds to the sign of "Dores." That is the only sign that requires that something be absent from the bird in order for it to be Kosher; it must not be a bird that is Dores. Accordingly, since it is a sign that must be absent, rather than present, for the bird to be considered Kosher, it is written but is not read!
2) A BIRD THAT IS "DORES"
OPINIONS: The Mishnah teaches that there are four signs of a Kosher bird. A bird is Kosher only if it is not "Dores," it has an extra toe, it has a crop (Zefek), and the inner membrane of its gizzard (Kurkevan) can be peeled.
What does the Mishnah mean when it says that a Kosher bird must not be "Dores"?
(a) RASHI (DH ha'Dores) explains that this refers to a bird that holds its food in its claws and lifts what it eats to its mouth.
TOSFOS (61a, DH ha'Dores) argues with Rashi's explanation, because we find that even a chicken -- which certainly is Kosher -- eats in such a manner.
The BACH (YD 82) explains that Tosfos understands that Rashi means that the bird lifts up its food with its beak, and therefore Tosfos asks that chickens do the same. However, Rashi actually means that the bird lifts its food with its claws, which a chicken does not do.
(b) RASHI later (62a, DH v'Hani Mili) writes that the bird uses its claws to pin its prey to the ground in order that it not move while the bird eats it bit by bit.
(See RASHASH and ARUCH HA'SHULCHAN, who explains that the question of Tosfos is on Rashi's second explanation. This is also implied by the words of the ROSH and MORDECHAI, as the SICHAS CHULIN points out.)
(b) Tosfos cites RABEINU TAM who explains that "Dores" means that the bird eats its prey while it is still alive and does not wait for its prey to die. (See also RASHI to Bava Kama 16b, DH Daras, who explains that this is the meaning of "Dores" when used in reference to wild animals, such as the lion.)
(c) The RAMBAN explains that "Dores" refers to a bird that kills its prey by striking it with it claws (what we refer to as a bird of prey).
The RAMBAM (Hilchos Ma'achalos Asuros 1:20, based on the words of Rebbi Shimon ben Elazar on 65a) adds that a bird that catches its prey in flight and eats it while in flight is called "Dores." (Z. Wainstein, Y. SHAW)
3) A BIRD WITH AN EXTRA TOE
OPINIONS: The Mishnah teaches that there are four signs of a Kosher bird. A bird is Kosher only if it not "Dores" (see previous Insight), it has an extra toe ("Etzba Yeseirah"), it has a crop (Zefek), and the inner membrane of its gizzard (Kurkevan) can be peeled.
What does the Mishnah mean when it says that a Kosher bird must have "an extra toe"?
(a) RASHI (DH Etzba Yeseirah) explains that this refers to an additional toe that is located at the back of the foot, higher up on the leg than the other toes.
(b) The RAN points out Rashi's explanation is problematic, because the Gemara says that a Nesher -- which is not a Kosher bird -- has no Etzba Yeseirah, and yet it has an extra back toe. The Ran explains instead that "Etzba Yeseirah" means that one of its front toes is larger than the others.
(63a, DH Netz) quotes those who maintain that a Nesher is an eagle, but he argues and says that a Nesher must be some other bird, because the Gemara says that a Nesher has none
of the signs of a Kosher bird, while an eagle has an Etzba Yeseirah. (For a discussion of the identity of the Nesher, see Insights to Chulin 61:1
.) The PRI CHADASH
explains that TOSFOS
understands that "Etzba Yeseirah" means an extra toe at the back of the foot, as Rashi explains.) (Z. Wainstein)
4) ANIMALS THAT CHEW THEIR CUD BUT DO NOT HAVE SPLIT HOOVES
QUESTION: The Gemara infers from the verses in the Torah that list the animals that have only one sign of a Kosher animal (Vayikra 11:4-7) that these are the only animals that possess one sign.
However, empirical observation shows that the llama also possesses one sign, as it chews the cud but lacks true split hooves. Why does the Torah not mention the llama?
(a) Perhaps the llama may be classified as a type of camel, and the Torah includes it when it mentions the camel. This approach, however, is not satisfactory, because the llama and camel are considerably dissimilar. Furthermore, there are other animals -- such as kangaroos and capybaras -- that have only one characteristic but that cannot be subsumed into the Torah's categories.
(b) Perhaps the Gemara refers only to the animals in the region of Asia, where Eretz Yisrael, the area where the Torah was intended to be fulfilled in its entirety, is located. The llama, kangaroo, and capybara all live in South America and Australia, and not in Asia.
5) THE IDENTITY OF THE "SHAFAN" AND "ARNEVES"
QUESTION: The Beraisa says that any animal that brings up the cud surely has no upper teeth, and is Tahor. The Gemara asks that the Shafan and Arneves, which are Tamei (Vayikra 11:5-6) bring up their cud, and yet they have upper teeth.
(a) What is the "Shafan"?
(b) What is the "Arneves"?
(a) A number of defining characteristics for the Shafan are given in the Torah. The verse says, "The high hills are for the ibex, the rocks are a refuge for the Shefanim" (Tehilim 104:18). This clearly implies that the Shafan lives among rocks.
Another verse says, "The Shefanim are not a strong nation, and so they place their home in the rock" (Mishlei 30:26). This verse not only says that the Shafan lives among rocks, but that it is a relatively small and weak animal that is vulnerable to attack by larger or stronger animals.
The overwhelming majority of opinions explain that the Shafan is the hyrax (see Graphic #1:1a). Indeed, the "rock hyrax" is indigenous to Israel and always lives in rocky areas. (The members of Kollel Iyun Hadaf have observed and photographed hyraxes in the rocky crag on the coast as far north as Rosh Hanikrah, and as far south as Ein Gedi in the Dead Sea region; see Graphic #1:1b.) It has a multitude of tunnels and hiding places among the rocks, and can be seen to dart into hiding when it senses danger. It has large, upper incisor teeth, as the Gemara here says. Its feet have toes that look like stubby outgrowths. The thick nails on the toes do not encase the feet, and thus are not considered hooves by the Torah.
However, the Torah says that the Shafan brings up its cud. Does the hyrax indeed bring up its cud?
There are differing reports in the scientific and lay literature with regard to rumination in hyraxes. According to most modern zoological research, hyraxes do not ruminate according to the normal understanding of the term, "Ma'aleh Gerah." Because of the lack of this characteristic, some commentators suggest that the hyrax is not the proper identification of the Shafan, but rather the Shafan is some other animal that is unknown to us (see commentary of RAV SAMSON RAFAEL HIRSCH to Vayikra 11:5). According to this approach, determining whether there is or was another possible candidate for the Shafan would require extensive research into the zoological and archaeological record.
However, some suggest that the Torah's definition of rumination is not the same as the strict zoological definition. Although a hyrax does not regularly regurgitate its food in order to digest it as a cow does, some claim that it has been observed to regurgitate small quantities and reingest it. However, the claim that it regurgitates small quantities of food for further chewing is disputed. Perhaps the Torah's definition of rumination is even broader, and may include even acts that appear to the observer to be rumination, whether or not they involve the regurgitation of food, such as the hyrax's common habit of moving its jaws even when it is not grazing. (See THE CAMEL, THE HARE, AND THE HYRAX, chapter 6.)
(b) The Gemara in Megilah (9b) writes that the Chachamim who were forced to translate the Torah for Ptolemy wrote in place of the Arneves (which they did not write, because it was the name of Ptolemy's wife), "The animal with short feet." RASHI there writes, "Short feet, because its arms (front legs) are shorter and smaller than its legs (hind legs)." The Gemara in Shabbos (27a) mentions that it has soft fur. All authorities identify the Arneves as the hare.
With regard to the characteristic of "Ma'aleh Gerah," hares do not ruminate according to the normal understanding of the term. However, they do possess other biological peculiarities which can be described as "bringing up the cud." Hares excrete special pellets that they reingest for further nutrition. The hare, like the hyrax, has the habit of working its jaws even when it is not grazing, similar to a ruminant.
The SICHAS CHULIN writes that the fact that the hyrax and hare do not ruminate like normal ruminants may answer a question on the Gemara here. Why does the Gemara say that there is no animal that brings up the cud and lacks split hooves except for the camel, when the Torah itself says that the Shafan and Arneves possess these characteristics? (See RASHI and TOSFOS who answer that the Gemara's mention of the camel is a representative reference to all these animals. The TIFERES YAKOV answers that the Gemara refers only to animals that lack upper teeth, and the camel is the only such animal that brings up its cud and lacks split hooves.) The Sichas Chulin suggests that the Gemara is alluding to the fact that when the Torah says that the Shafan and Arneves are "Ma'aleh Gerah," it does not ruminate like a cow or camel in the normal sense of the word, but rather they possess other forms of digestive peculiarities that can be referred to as "Ma'aleh Gerah."
6) THE NEED FOR A "MESORAH" WITH REGARD TO A "CHAYAH" OR "BEHEMAH"
OPINIONS: The Gemara quotes a Beraisa that says, "These are the signs of a [Kosher] Chayah." The Gemara asks why the Beraisa needs to specify the signs of a Kosher Chayah, when those signs are identical to the signs of a Kosher Behemah, as the verse (Vayikra 11:2-3) explicitly mentions Chayah with regard to the signs of a Kosher animal. The Gemara explains that the Beraisa is teaching that there are signs that distinguish a Chayah from a Behemah, so that one knows that the animal is a Chayah and thus its Chelev is permitted. The Beraisa says that a Chayah has horns and hooves. The Gemara explains that the horns must have certain qualities in order to be a sign of a Chayah (see following Insights).
Does it suffice to identify a Chayah as a Kosher animal by its anatomical signs, or is it also necessary to have a tradition that this particular animal is a Kosher Chayah? The Gemara later (63b; see Insights there) teaches that it is necessary to have a tradition ("Mesorah") that a particular type of bird is Kosher in order for it to be permitted (in addition to having the signs of a Kosher bird enumerated in the Mishnah here). Does the requirement for a Mesorah apply only to fowl, or also to other animals?
(a) The SHULCHAN ARUCH (YD 82:2) mentions the requirement for a Mesorah only with regard to fowl and makes no mention of it with regard to the Halachos of a Chayah (YD 80). The REMA (YD 82:3) writes that one should not rely on the signs of a Kosher bird, and one may eat only a bird for which there is a clear Mesorah that it is permitted.
(b) The SHACH (YD 80:1) writes that he does not discuss at length the Simanim of a Chayah because "we must rely only on what we know [to be a Kosher Chayah] through Mesorah." The PRI MEGADIM and KAF HA'CHAYIM (YD 80:5) understand that the Shach means that we must have a Mesorah to differentiate a Chayah from a Behemah in order to permit its Chelev, but we may rely on the Simanim of a Kosher animal in order to eat the animal itself, without having a Mesorah that this animal is permitted.
(c) However, the CHOCHMAS ADAM (36:1) understands that the Shach means that there must be a Mesorah that the animal is a permitted Chayah even with regard to eating its meat, and not just with regard to permitting its Chelev, and that what the Rema writes with regard to fowl (see (a) above) applies to Chayos as well.
Moreover, the CHAZON ISH (end of YD 11) understands that the Shach's requirement for a Mesorah applies not only to fowl and to Chayos, but also to Behemos as well. Accordingly, the Chazon Ish writes that we should not permit a newly-discovered species of animal to be eaten (see below), even when it has the signs of a Kosher animal.
The dispute about whether a newly-discovered species of Chayah or Behemah is permitted to eat without a Mesorah is relevant in practice with regard to a number of species of cattle. The Poskim discuss at length the status of the buffalo, as well as other species. One famous discussion involves the "Indian ox," also known as the "zebu." (The zebu is known in America, into which it was imported in the middle of the nineteenth century, as "Brahman cattle.") The zebu (Bos indicus) is a domestic animal of the cattle family, which characteristically has a fatty hump on its back behind its neck (see Graphic #1:4). The zebu is used in Central and South America where it is interbred with domestic cattle to produce an animal that has greater resistance to heat and illness, and that has better meat (with less fat) than ordinary cows. The incidence of Sirchos in the lungs of such animals is also much less frequent (see Insights to Chulin 49:1
Over sixty years ago, the meat industry in Israel wanted to import zebu meat. The Chief Rabbi, Rav Yitzchak Herzog zt'l, saw no reason to prohibit it, as it is a Behemah with all of the signs of a Kosher animal, and a Mesorah is not needed for a Behemah. In practice, however, the rabbinate did not permit the meat to be imported, in deference to the view of the Chazon Ish as mentioned above. The Chazon Ish, in a letter to Rav Herzog (recorded in IGROS CHAZON ISH 2:83) wrote, "Even though the animal is certainly Tahor as evidenced by its Simanim (its hooves are split, it has no upper teeth, and it ruminates)... nevertheless according to our Hanhagah, that our sages established for us, we are careful not to accept a new species. This is clear from the Shach; the Pri Megadim's interpretation is not consistent with the words of the Shach, and the Chochmas Adam records the Shach's words in their straightforward sense. I now saw that the Aruch ha'Shulchan also rules in accordance with the simple meaning of the Shach's words.... This is the truth -- that since the days of the Shach and onwards, we have had an established Minhag not to accept any new species, to bring it upon the table of Yisrael, because of a safeguard against eating forbidden foods, which have breached the purity of Yisrael, and we should not breach this safeguard. I have no intention, Chas v'Shalom, to forbid that which is permitted, but my heart is pained with this Heter [of the newly-discovered species] because every breach causes more breaches. I am sure that [those who argue with me] will change their mind and agree that this cow should not be permitted -- not because there is a doubt about its status as a Kosher animal, but because of the Minhag that was established for us by great sages, the Shach, Chochmas Adam, Aruch ha'Shulchan.... The end of the matter is that in our times, when there is a strong urge to reform, it is not possible to do things that appear to be permitted when there has been a Minhag to prohibit them."
In most recent days this issue has resurfaced in Israel. As noted in the Jewish media (on 21 Adar 5764/March 14, 2004), it was discovered, reportedly, that most of the cows being slaughtered in the meat factories in South America (from which 90% of the meat in Israel is imported) are actually zebus, or crossbreeds with zebus. A committee was appointed by the Gedolim to research whether or not the very animal whose meat the Chazon Ish prohibited from being imported into Israel has been the primary source of meat for Israel for the past few decades, and whether or not the major Kashrus supervisory organizations have been aware of this. One of these Kashrus organizations (the one that follows the stringencies of the Chazon Ish) has stated publicly that all meat from South America should not be eaten, while the other Kashrus organizations permit the meat in accordance with the views that maintain that no Mesorah is necessary to permit a Behemah or Chayah.
7) THE IDENTITY OF THE "TZVI"
The Beraisa teaches that a sign that an animal is a Kosher Chayah (and its Chelev is permitted) is that it has horns and hooves. The Gemara explains that the horns must have certain qualities in order to be a sign of a Chayah. The Gemara says that the horns must be "Mefutzalos" (they branch out (RASHI
), or they are bent at the end (RABEINU TAM
); see below). The Gemara asks that a Tzvi does not have such horns and yet its Chelev is permitted. The Gemara concludes (see next Insight) that if the horns are "Mefutzalos," then the animal is certainly a Chayah. If its horns are not "Mefutzalos," then they must be "Keruchos" (grow in layers), they must be "Charukos" (grooved), and they must be "Chaduros" (pointed; see, however, SHULCHAN ARUCH
80:1, and see Background to the Daf
). The horns of a Tzvi have these three qualities.
What exactly is a Tzvi?
(a) RASHI (DH v'Harei Tzvi) writes that he does not know what animal the Gemara refers to as a Tzvi, because the animal that we commonly call a Tzvi does have branched horns. Rashi seems to refer to the deer, which has small, branched horns that split off from a central horn.
Rashi concludes that what we commonly call a Tzvi is different from what the Gemara calls a Tzvi. The Gemara refers to the "steinbuck" ("estainboc" in Old French, or "steenbok" in formal English), which has horns that do not split into branches. While this word today refers to a small antelope common to the plains of southern and eastern Africa, the ME'IRI and others seem to understand that Rashi is referring to the ibex (a type of wild goat that lives in mountain areas), which has two large horns that curl directly back from its head towards its back in a semi-circle shape. This seems apparent from Rashi himself in Rosh Hashanah (26b, DH Ya'el) who says that a Ya'el is a "steinbuck." Similarly, Rashi in Devarim (14:5) says that the "Ya'alei Sela," which apparently refers to a wild goat, is a "steinbuck."
TOSFOS (DH v'Harei Tzvi) quotes RABEINU TAM who asks that when the Gemara mentions a Tzvi, it must be talking about the deer, because the Gemara elsewhere mentions identifying features of a Tzvi that clearly refer to the features of a deer. The Gemara in Kesuvos (112a) says that a Tzvi's skin is very tight and would not be able to contain its body if not for the fact that its skin stretches so much. This is characteristic of a deer's skin. In addition, the Midrash (Shir ha'Shirim Rabah, end of chapter 8) says that the reason why the verse (Shir ha'Shirim 2:9) compares Hash-m to a Tzvi ("Domeh Dodi l'Tzvi") is because just as a Tzvi sleeps with one eye open, so does Hash-m constantly keep His eye on us, as it were, and protect us during our exile (when Hash-m's immediate providence seems to have been removed from us). We find that this, too, is characteristic of a deer, which sleeps with one eye open.
(b) RABEINU TAM therefore concludes that the text in the Gemara should read "Mevutzalos," which means that the horns of a Chayah are mostly straight, and at the top they are bent. The Gemara asks that the Chelev of a Tzvi, deer, is permitted, and yet it does not have such horns, but rather its horns branch out.
The SICHAS CHULIN answers Rabeinu Tam's questions on Rashi's explanation by proposing that Rashi is not referring to the ibex, but rather to an animal known in Hebrew as the "Tzvi Eretz-Yisraeli" -- the gazelle, which has two horns without branches that shift directions as they curl outward (away from the center of the head). It has all of the characteristics that Tosfos mentions with regard to a deer. It is also very swift, fitting the description of the Mishnah in Avos (5:20) that says that one should "be as swift as a Tzvi to do the will of Hash-m." He points out that the Midrash (Shir ha'Shirim Rabah 2:21) gives an additional description of a Tzvi: "It skips and jumps from mountain to mountain, from valley to valley, from tree to tree, from shelter to shelter, from fence to fence... it appears and hides, appears and hides." This description fits the gazelle. (The "Tzvi Eretz-Yisraeli" does not refer to the antelope, as some incorrectly suggest. Such an animal is not native to Eretz Yisrael and certainly is not found in Europe, and thus Rashi would not be referring to such an animal. See SICHAS CHULIN, pages 414-415.)
However, the gazelle was not indigenous to the region in which Rashi lived, and it is unlikely that he would be referring to it. Moreover, Rashi himself in other places describes the "steinbuck" as an ibex. The Sichas Chulin explains that perhaps Rashi means to say that the "steinbuck" is an animal whose horns are similar to the animal which the Gemara calls a Tzvi. Rashi himself was unsure of the exact identity of the animal which the Gemara calls a Tzvi, as this animal is primarily found in the area of Eretz Yisrael (hence the name "Tzvi Eretz-Yisraeli"), and he knew only of the "steinbuck" (ibex) whose horns have similar properties to the horns of the Tzvi mentioned by the Gemara.
We are left with an interesting question. According to Rashi, what is the proper Torah name for what we know as a deer? The Sichas Chulin suggests that Rashi must have understood that the term that the Torah and Gemara use to refer to a deer is "Ayal" (or "Ayalah"). This is consistent with the Gemara in Yoma (29a) that says that the horns of an Ayalah are "Maftzilos l'Kan ul'Kan" -- they branch off to the sides, which indeed is characteristic of the horns of a deer. (Y. MONTROSE)
(c) RAV SA'ADYAH GA'ON suggests that the Gemara refer to the gazelle. The gazelle has all of the characteristics that are used to describe the Tzvi, and it does not possess branched horns. This animal matches the Scriptural description of the Tzvi as an agile and beautiful animal. It also matches the Gemara's statement that a Tzvi does not possess branched horns. (See Graphic #1:2.)
Rabbi N. Slifkin suggests that the reason why Rashi and Tosfos did not identify the Tzvi as the gazelle is that they never saw a gazelle. There are no gazelles in Europe, where Rashi and Tosfos lived, and therefore in Europe the name Tzvi was transposed to its closest equivalent -- the deer.
8) THE IDENTITY OF THE "KERESH"
OPINIONS: The Beraisa teaches that a sign that an animal is a Kosher Chayah (and its Chelev is permitted) is that it has horns and hooves. Rebbi Dosa says that if it has horns, then one does not need to examine its hooves, but if it has hooves, one still needs to examine its horns. The Beraisa adds that the Chelev of the "Keresh" is permitted, even though it has only one horn.
The Gemara quotes Rav Yehudah who says that the Keresh is the deer of Bei Ila'i. Rav Yosef says that the length of the deer of Bei Ila'i is sixteen Amos. It is possible that Bei Ila'i refers to the upper worlds ("Bei Ila'i"), and the deer of Bei Ila'i is a spiritual creature, and not an animal that exists in this world. However, it seems that there still is some animal, the Keresh, that exists in this world, for which the Beraisa finds it necessary to state that its Chelev is permitted.
What is this one-horned "Keresh"?
(a) The ARUCH HA'CHADASH writes that this one-horned animal is the rhinoceros. However, the rhinoceros obviously is not a Kosher animal; it neither ruminates nor has split hooves. The PRI CHADASH also understands the "Keresh" to be the rhinoceros and, consequently, he rules against the opinion of Rebbi Dosa who says that the Keresh is a permitted animal.
However, the BECHOR SHOR asserts that Rebbi Dosa is discussing only animals that possess both signs of a Kosher animal, and he is not referring to the rhinoceros. (See "Sacred Monsters - Mysterious and Mythical Creatures of Scripture, Talmud, and Midrash," page 74.)
(b) RASHI in Bava Basra (16b, DH Karna d'Keresh) says that the Keresh "is a type of Chayah and its horns are black like dye." It is interesting to note that Rashi writes "its horns," when the Gemara here states that it has only one horn (see RASHASH there who changes the Girsa in Rashi to read "horn").
The MAHARAM SHIF asks a similar question on the Gemara later (60a). The Gemara there quotes Rav Yehudah who says that "the bull that Adam ha'Rishon offered as a Korban had one horn on its forehead." However, the Gemara shortly afterwards quotes Rav Yehudah as saying that "Adam offered a bull whose horns grew before its hooves," saying that the bull had "horns," in the plural!
The Maharam Shif suggests that perhaps the answer lies in the seemingly superfluous words, "on its forehead." Rav Yehudah says that the bull that Adam offered "had one horn on its forehead" to differentiate that horn from the other, normal horns that it had. That is, besides its normal horns, it had one additional horn on its forehead.
The same approach answers why Rashi refers to the "horns" of the Keresh. Rashi is referring to the two normal horns of the Keresh, while the Gemara here is referring to the single horn that grows on its forehead. Accordingly, the SICHAS CHULIN suggests that the Gemara's description of the Keresh as a very large animal (sixteen Amos) that lives in the wild (Chayah) and that has two horns on the top of its head and one horn on its forehead matches the description of one known animal: the giraffe. While most giraffes have only two horns, many have an additional bump on their foreheads (see Graphic #1:3). In some subspecies, this bump develops into a horn. The body of a giraffe certainly is long, and -- depending on the various opinions of the Amah -- the giraffe indeed can reach sixteen Amos in height. Moreover, giraffes live in the wild, and have split hooves and chew their cud.
9) THE HORNS OF A "CHAYAH"
QUESTION: The Beraisa teaches that a sign that a Chayah is Kosher (and its Chelev is permitted) is that it has horns and hooves. The Gemara explains that the horns must have certain qualities in order to be a sign of a Chayah. The Gemara concludes that if the horns are "Mefutzalos" (they branch out (RASHI); they are bent at the end (RABEINU TAM)), then the animal is certainly a Chayah. If its horns are not "Mefutzalos," then they must be "Keruchos" (grow in layers), they must be "Charukos" (grooved), and they must be "Chaduros" (pointed).
RASHI (DH Ba'inan) explains why an animal's horns must have all of the other three qualities when they are not "Mefutzalos." When its horns are "Charukos," we know that it is not a bull. When its horns are "Chaduros," we know that it is not a goat. When its horns are "Keruchos," we know that it is not a "Karkuz" goat (which has horns that are "Chaduros" but not "Keruchos").
TOSFOS (DH v'Harei Ez) asks an obvious question. Why do the horns of the animal need to be "Chaduros" as well in order to determine that it is a Chayah? There is no animal (other than a Chayah) whose horns have both qualities of "Keruchos" and "Charukos," and thus it should suffice for the horns of the animal to be only "Charukos" and "Keruchos" in order to know that it is a Chayah! (Even an Ez Karkuz does not have horns that are "Keruchos.")
(a) Perhaps Rashi maintains that these two qualities indeed would suffice to prove that the animal is a Chayah. He understands that the intention of the Gemara is that "Chaduros" and "Keruchos" do not suffice to prove that the animal is a Chayah, since a bull's horns have those qualities, and a combination of "Chaduros" and "Charukos" also does not suffice, since the horns of an Ez Karkuz have those qualities. The combination of "Charukos" and Keruchos," though, suffices.
(b) TOSFOS answers that there must be some other type of goat that has horns that indeed are both "Charukos" and "Keruchos," and therefore an animal must have all three qualities, including "Chaduros," in order to determine that it is a Chayah.