THE AMOUNT OF SHEARINGS THAT IS LIABLE
Version #1 (Rashi) Abaye: We can defend one of the opinions you cited.
Version #1A: R. Yochanan himself holds (like he said above) that the Kohen gets five (even if the Yisrael only keeps one). He said in R. Yanai's name that the Kohen gets only one part in 60 (even though this is less than five, even according to the Shi'ur of R. Dosa).
Question: Rav contradicts himself. Above, he said a Maneh and a half! (A 60th of this is less than a Sela.)
Answer: Rav discusses a Maneh of 40 Sela'im, so a Maneh and a half is 60 Sela'im. The Kohen gets a Sela.
Version #2 (our text) Abaye: We can solve one of the difficulties in your teaching.
We can resolve the contradiction in R. Yochanan. He himself holds (like he told Isi) that 60 are liable. He said in R. Yanai's name that six are liable.
(Versions #1B and 2) Question: Rav contradicts himself. Here he says that 60 are liable. Above, he said a Maneh and a half!
Answer: Rav discusses a Maneh of 40 Sela'im.
(All versions) Question: Would the Tana really call 40 Sela'im a Maneh?!
(Beraisa): An unfinished pouch is not Mekabel Tum'ah, even if pomegranates would not fall out;
If it was finished and then tore, it receives Tum'ah if pomegranates would not fall out;
R. Eliezer ben Yakov says, it receives Tum'ah if it can hold balls of woof threads, each a fourth of a Maneh of 40 Sela'im.
(Mishnah): (One must give shearings that will weigh five Sela'im after they are cleaned.)
(Beraisa): The Yisrael need not clean them, just he must give enough so that after the Kohen cleans them, he will have five Sela'im.
(Mishnah): In order that the Kohen can make a small garment.
Question: What is the source of this?
Answer (R. Yehoshua ben Levi): "La'amod Leshares" - it must suffice to make a garment a Kohen serves in, the Avnet (belt).
Question: Perhaps it must suffice to make the (Kohen Gadol's) Me'il (coat)!
Answer: You may assume only the smallest amount, but nothing more than this.
Suggestion: Perhaps it must suffice to make a wool cap!
(Beraisa): The Kohen Gadol wore a wool cap. The Tzitz rested on it, to fulfill "v'Samta Oso Al Pesil Techeles."
Rejection: "Hu u'Vanav" - it must suffice for a regular Kohen as well.
Question: Wool is not needed for the Avnet of a regular Kohen!
This is not difficult according to the opinion that a regular Kohen's Avnet is unlike the Kohen Gadol's Avnet on Yom Kipur (which is pure linen). Rather, a regular Kohen's Avnet includes wool;
However, according to the opinion that it is the same, how can we answer?
Answer: The wool suffices for the Avnet of the Kohen Gadol. Also regular Kohanim wear Avnetim, albeit theirs are not of wool.
DOES THE MITZVAH APPLY IF HE SOLD THE SHEEP?
(Mishnah): If he dyed the wool before giving it, he is exempt...
(Rav Chisda): If he sold each sheep after shearing it (before shearing the next), he must give Reishis ha'Gez;
(R. Noson bar Hoshaya): He is exempt, for when he has five shearings, he does not own the sheep (it is not "Tzoncha").
Question (Mishnah): If one buys wool from (Rambam; Rashi - attached to) a Nochri's sheep, he is exempt;
Inference: Had he bought the sheep themselves (to shear them), he would be liable (even though after shearing each, it reverts to the Nochri; when he shears the last sheep, he no longer owns the previous ones)!
Answer (Rav Chisda, on behalf of R. Noson): The case is, the Nochri sold the sheep to the Yisrael for a period of time (longer than needed to shear them all).
(Mishnah): If Shimon buys wool attached to Reuven's sheep (if Reuven retained for himself, he is liable. If not, Shimon is liable.)
Question: Who is our Tana, who holds that if the seller retains for himself, he is liable?
Answer #1 (Rav Chisda): It is R. Yehudah;
(Mishnah): If Levi buys trees in Yosef's (grain) field, he must leave Pe'ah on each tree.
R. Yehudah says, this is only if he bought all the trees;
If Yosef retained trees, he leaves Pe'ah (Rashi - from his grain) on behalf of all the trees.
Objection (Rava): You yourself explained that R. Yehudah's law is only if Yosef started harvesting before he sold (for then he was already obligated to leave Pe'ah)!
Suggestion: Perhaps here also, Reuven sold the sheep after he started shearing them.
Rejection: Regarding Pe'ah, it says "uv'Kutzrechem Es Ketzir Artzechem" - once he starts, he must leave Pe'ah on the whole field;
There is no obligation for Reishis ha'Gez until he shears all five sheep!
Answer #2 (Rava): Our Tana is the Tana of the following Mishnah.
(Mishnah): If Reuven bought the innards of a cow from a butcher, he gives the stomach to a Kohen, without deducting from the price;
If Reuven bought by weight, he gives the stomach to a Kohen, and does not pay for its weight.
Inference: We conclude that one does not sell (Rashi; Tosfos - buy) Matanos that must be given to a Kohen. The same applies to Reishis ha'Gez!
Therefore, if the seller retained sheep, he must give the full amount;
If he sold all the sheep, the buyer has the Kohen's portion.
WHEN THE MITZVAH APPLIES
(Mishnah): Shilu'ach ha'Kan (sending the mother bird) applies in Eretz Yisrael and in Chutz la'Aretz, whether or not the Mikdash stands. It applies to Chulin, but not to Kodshim.
Kisuy ha'Dam applies to Chayos and birds, whether or not they are Mezuman (owned by the Shochet). This is a stringency over Shilu'ach ha'Kan, which does not apply to Mezuman.
Question: What is considered not Mezuman?
Answer: Geese or chickens that nested in an orchard are not Mezuman;
One is exempt if they nested in his house, and from sending domestic doves.
One is exempt from sending a Tamei bird, even if it is on Tahor eggs, or a Tahor bird sitting on Tamei eggs.
R. Eliezer obligates sending a male Korei sitting on eggs;
(Gemara - R. Avin or R. Meisha): In all these Perakim (from the 10th onwards) it says that the Mitzvah applies in Eretz Yisrael and in Chutz la'Aretz. There was no need to teach this, except for Reishis ha'Gez (and Perek Ha'Zero'a, regarding Matanos);
There, it was necessary to say this, to exclude the opinion of R. Ila'i, who exempts in Chutz la'Aretz. (It was taught in the other Perakim for parallel structure.)
(The other of R. Avin and R. Meisha): In all these Perakim it says whether or not the Mikdash stands. This was needed only for Oso v'Es Beno;
Since it is written in the Parshah of Kodshim, one might have thought that it applies only when we can bring Kodshim. The Mishnah teaches that this is not so.
(R. Avin and R. Maisha): In all these Perakim, the words "in Chulin and in Kodshim" are neeeded, except for Gid ha'Nasheh;
Obviously, Gid ha'Nasheh applies also to Kodshim. Should the Isur vanish because he was Makdish the animal?!
Question: We established the Mishnah to teach about offspring of Kodshim! (It is a Chidush that the Isur of the Gid takes effect, since the fetus is forbidden before the Gid is formed.)
Answer: We established it like this only to explain the Mishnah's Chidush that it applies to Kodshim;
We can say that it was taught merely for parallel structure! (We can say that the Mishnah discusses Chulin that was made Hekdesh, and it is no Chidush.)
(Mishnah): It applies to Chulin, but not to Kodshim.
Question: Why are Kodshim exempt?
Answer: "Shale'ach Teshalach" discusses a bird that you are commanded to send away, but not Kodshim (which you should bring to the Gizbar).
(Ravina): Likewise, the Mitzvah does not apply to a bird that killed a person. Such a bird should not be sent. It should be taken to Beis Din to be stoned!
Question: What is the case?
If Beis Din sentenced it to die, they would have killed it. How was it found?!
Answer: Rather, Beis Din did not sentence it. The finder must bring it to Beis Din to fulfill "u'Vi'arta ha'Ra mi'Kirbecha."