In the last Mishnah, we had a Machloket (dispute) about when the new year for the Ma'aser (tithe) of animals starts. As we mentioned, you cannot give Ma'aser on animals born in one year together with Ma'aser on animals born in a different year. They have to go into different pens and go through their own Ma'aser process. But we had a question: When does the year start? Does it start on the first of Elul? Does it start on the first of Tishrei? Or is there a Safek (doubt)? Here we'll follow the idea in this Mishnah that the new year for Ma'aser Behemah (animal tithe) starts on the first of Tishrei.
The Mishnah says: All animals born from the first of Tishrei until the following 29th of Elul, which is almost a full 12 months, combine. Ma'aser can be given from all these animals together. From the first of Tishrei to the 29th of Elul, all animals born during that year could be tithed together. Animals born in different years would not be able to combine with these animals. Therefore, if someone had five animals born before Rosh Hashanah (Jewish New Year) and five animals born after Rosh Hashanah, they would not combine to be tithed together, since they were born in different years. If he has no other animals, these groups would not combine. There would be no Ma'aser obligation. As we mentioned, you need at least 10. Here he has five and five that were born in different years. He doesn't have the minimum of 10, and therefore there would be no Ma'aser.
If he has five animals born before the first or second goren date (tithing deadline) designated for separating Ma'aser, as we learned in the last Mishnah, and five animals born after the goren date, they would combine to be tithed together. All 10 were born in the same year, and the goren dates weren't meant to stop animals born before or after from being tithed together. But if you cannot give Ma'aser because you don't have enough animals by one goren, you could just wait till the next goren and give it together with the animals born after that first goren, to have a total of at least 10. As we'll explain. If so, and the dates aren't meant to stop animals born before and after from combining, then why do we have three goren dates for the Ma'aser of animals? What we say here is: until the goren date arrives, a person is permitted to sell or slaughter the newborn animals without giving Ma'aser. Once the goren date arrives, he's not allowed to sell or slaughter them until he gives the Ma'aser. But if a person did violate and transgress by slaughtering an animal after the goren date without giving Ma'aser, he would be exempt from punishment, and the animal is allowed to be eaten. The reason is the Isur, the prohibition of slaughtering an animal that Ma'aser wasn't given from. After the goren date, the goren date is only derabbanan (rabbinic), and the Rabbis did not add any penalty in this type of case once the prohibited act was already done.