What did Yaakov mean when he pointed out that the ewes and goats in Lavan's flocks did not lose their babies?
Seforno and Rashbam: He meant that, bearing in mind, his (Yaakov's) total dedication when tending to his sheep, Lavan's suspicion that he had stolen from him was completely unfounded, considering the lengths to which he went to make sure that none of his ewes or goats would miscarry.
Ohr ha'Chayim: Shepherds sometimes eat animals and claim that the mothers miscarried, so the owner will not know. Hashem caused that there were no miscarriages, to remove any possible suspicion of Yaakov!
Why did Yaakov add that he did not eat his Eilim (rams)?
Rashbam: He meant that he did follow the custom of the shepherds of that time, who would slaughter and eat male sheep. Malbim - it is permitted, based on the custom; I did not eat any. Ha'amek Davar - this is because they are not needed so much; they do not give birth [and a small number of males can impregnate the females - refer to 32:15:1:1 and the note there].
Moshav Zekenim (from Bava Kama 65b): Even a newborn lamb is called "Ayil." 1
Moshav Zekenim: Even though a Drashah includes a Palgas (a sheep in its 13th month, for less than 13 months is not called Ayil), that is for Kodshim. Here we discuss Chulin.
Why did Yaakov emphasize that he was with him for 20 years?
Rashi (to 37:34): I will be punished for this time. Yaakov mourned over Yosef the same amount of years that he was away from his parents and neglected Kibud Av v'Em. 1
Ohr ha'Chayim: A thief or swindler can refrain from evil for a short time, but not for a long time. I worked for you for 20 years - all equally good! And I was not with someone who does not understand deceit (who might not notice). I was with you!
Surely Yaakov did not know what his punishment would be. Perhaps he said this with Ru'ach ha'Kodesh, unaware of the Derashah that he will be punished for these years. (PF)
QUESTIONS ON RASHI
Rashi writes: "Based on this verse, [our Sages] said, even a one-day old ram is called a ram (Ayil)." But for the Halachos of Korbanos, is it called an Ayil only in its second year?
Gur Aryeh: Regarding Korbanos, the Torah specifies lambs and rams separately (e.g. Bamidbar 15:5-6). The word 'Ayil' means strength, 1 and a ram reaches its full strength only in its second year. But when the word Ayil is used generically, such as here, this distinction is not made; as it belongs to the strong category of animals.