According to Rabbi Yehoshua’s tradition of the opinion of the Rabbis, we do not say that an animal gives birth after incomplete months, and therefore if it gave birth within its first year it must have become pregnant within thirty days of the discharge, which means the discharge was not indicative of a fetus and does not exempt the next offspring from being counted a firstborn. According to Rabbi Yehoshua’s own reasoning, we say an animal gives birth after incomplete months, and consequently it is possible the animal became pregnant later than thirty days after the discharge and its term of pregnancy was shorter than normal. If so, the discharge does exempt the next offspring from firstborn status.

And if you wish, say that everyone accepts Ze’eiri’s statement and we do not say that an animal gives birth prematurely, and here, they disagree with regard to whether or not the halakhic status of part of the day is like an entire day: According to Rabbi Yehoshua’s reasoning we say part of the day is like an entire day, and therefore it is possible for the goat to have become pregnant on the thirtieth day after experiencing the discharge and to give birth precisely five months later, just before the year ends. According to his tradition of the opinion of the Rabbis, we do not say part of the day is like an entire day, which means that the earliest possible birth is on the first day of the second year.

The baraita taught that Rabbi Akiva says: I have not arrived at this method of determining firstborn status. Rather, in any case where it is known the animal had previously given birth, the priest has nothing here. And in any case where it is known the animal had not previously given birth, its firstborn is given to the priest. And if it is uncertain, it may be eaten in its blemished state by the owner. The Gemara asks: What difference is there in practice between the opinions of Rabbi Akiva and Rabbi Yehoshua?

Rabbi Ḥanina of Sura says: There is a difference between them in a case where the animal came into the Jew’s possession after it had already started to produce milk. They differ as to whether or not the production of milk is sufficient to exempt an animal from having its next offspring counted a firstborn. Rabbi Akiva holds: Milk exempts it, as we follow the majority of animals, and the majority of animals do not produce milk unless they have given birth. And Rabbi Yehoshua holds: Since there is a minority of animals that do produce milk even though they have not given birth, the animal that is born later is an uncertain firstborn.

The Gemara asks: And is Rabbi Yehoshua concerned for a minority? Didn’t we learn in a mishna (Yevamot 119a): If a woman’s husband passed away before she had given birth to any children and the husband had no known brothers who could perform levirate marriage, even though she has a mother-in-law who traveled overseas and may have conceivably given birth to a male who could later perform levirate marriage, she does not need to be concerned for that possibility and may marry another man without finding out if a male child had been born. But if the mother-in-law left while she was full, i.e., pregnant, the daughter-in-law must be concerned that a male might have been born. Rabbi Yehoshua says: She does not need to be concerned.

And we say: What is the reasoning of Rabbi Yehoshua? He holds the majority of pregnant women give birth to a child and a minority miscarry. And of all those who give birth, half bear males and half bear females. Combine the minority of those who miscarry with the half that give birth to females, and conclude that the males are in fact a minority, and we are not concerned for a minority. Evidently, Rabbi Yehoshua holds there is no need to be concerned for a minority.

Rather, reverse the two opinions in the mishna. And in fact it is taught in that manner in a baraita: The production of milk exempts an animal from having its offspring counted a firstborn; this is the statement of Rabbi Yehoshua. Rabbi Akiva says: The production of milk does not exempt an animal from having its offspring counted a firstborn.

§ The Sages taught in a baraita: In the case of a kid that gave birth to female triplets and all her offspring each gave birth to female triplets, all of them, i.e., the offspring and their offspring, enter the pen to be tithed. The animal tithe applies only if one owns at least ten or more animals born in the same year that are not male firstborns. Rabbi Shimon says: I saw a single kid that yielded enough offspring to be subject to the tithe within its first year of life. The Gemara asks: Why do I need the baraita to teach that each offspring gave birth to three other offspring? Let one of them give birth to three, and let the other two give birth to two each, so that there are a total of ten goats born within a single year, which are therefore subject to the tithe.

The Gemara answers: Since there is one goat in this case that would not produce a sufficient number of offspring without giving birth to three, the baraita taught a case where all three goats gave birth to three offspring each, for the sake of consistency. The Gemara asks: But why do I need to teach that any goat gave birth to three at once at all? Let all the second-generation goats give birth to two offspring, and let her, the mother of the three second-generation goats, give birth again to another goat together with them. The fact that the baraita did not teach this case indicates that a goat cannot give birth again within the same year.