What are Mekusharos and Atufim?
Rashi #1 (citing Targum Onkelos) and Targum Yonasan: ?Mekusharos? are those that become pregnant early (like a B?chor), 1 ?Atufim?, those that become pregnant late 2
Rashi #2 (citing Menachem ben S?ruk): ?Atufim? are totally covered in fleece, and sheep that are not interested in being heated through mating.
Ramban (in Pasuk 41) #1: ?Mekusharos? are males that constantly follow the females, and are inextricably bound to them - like "ve'Nafsho Keshurah be'Nafsho" - 44:30. The resulting babies are called ?Keshurim? after their fathers.
Ramban (in Pasuk 37) #2: Some say that ?Mekusharos? are strong; their limbs are tightly-knit, ?Atufim?, weak, which are therefore less lustful.
Rashbam: ?Mekusharos? are when most of the sheep became pregnant and gave birth at the eame time, and ?Atufim?, the stragglers that gave birth later. 3
Moshav Zekenim (in Pasuk 37): ?Mekusharos? are males that are tied [so they cannot mate], ?Atufim?, sheep that are totally wrapped [to protect their wool]. 4
Tosfos ha'Shalem (in Pasuk 40): ?Atufim? are fat animals that will give birth by themselves. ?Mekusharos? are barren animals.
Hadar Zekenim (in Pasuk 38): ?Mekusharos? are born in summer and have been shorn) and ?Atufim?, in winter (when the sheep are covered with wool.
Or Zaru'a: ?Atufim? are covered (with one color, white or black), ?Mekusharos?, with two colors.
Da'as Zekenim (in Pasuk 41): Just like people tie a string around B?choros (or Bikurim - Rosh in Pasuk 41), Ya?akov tied a string around the forelegs of the Mekusharim.
Sheep multiply rapidly (Chulin 84b), bearing offspring even within their first year. By taking the earlier yield for six years consecutively, Ya?akov's portion would grow exponentially in relation to Lavan's. (CS)
This is synonymous with answer #1, only the Rashbam explins the word ?Mekusharos? differently.
It is unclear however, why, in this answer and in the answer #6, the Mekusharos went to Ya?akov and the Atufos, to Lavan?
