The black/white (Pennsylvania) calf was born days before September 25, 2014 and the red heifer (Texas) was born on that date ; the Jewish New Year and the first day of Shemitah year. Both with the number "7" on their face.

Famine explained in 3 parts: The Bible, the news article linked, the video.

1. Genesis 41: 25-32
25 And Joseph said unto Pharaoh, The dream of Pharaoh is one: God hath shewed Pharaoh what he is about to do.

26 The seven good kine are seven years; and the seven good ears are seven years: the dream is one.

27 And the seven thin and ill favoured kine that came up after them are seven years; and the seven empty ears blasted with the east wind shall be seven years of famine.

28 This is the thing which I have spoken unto Pharaoh: What God is about to do he sheweth unto Pharaoh.

29 Behold, there come seven years of great plenty throughout all the land of Egypt:

30 And there shall arise after them seven years of famine; and all the plenty shall be forgotten in the land of Egypt; and the famine shall consume the land;

31 And the plenty shall not be known in the land by reason of that famine following; for it shall be very grievous.

32 And for that the dream was doubled unto Pharaoh twice; it is because the thing is established by God, and God will shortly bring it to pass.

2. Calf With ‘7’ On Its Head Named After Big Ben
By Dave Crawley
September 25, 2014 at 9:26 am
The calf dubbed “Little Ben” was born with a “7” on his forehead. It’s a fact which has not gone unnoticed by Facebook followers.
The little cow has gone viral, and that’s no bull. Some fans think it’s a harbinger of a seventh Super Bowl victory. And the players are “udderly” amazed.
Maurkice Pouncey: “That’s not Photoshopped, is it?”
KDKA’s Dave Crawley: “No, not Photoshopped.”
pittsburgh.cbslocal.com/2014/09/25/calf-with-7-on-its-head-named-after-big-ben/

3. In this video, Jonathan Cahn: 2 times 7 Cows appeared in America like in Pharaoh's Egypt. "Rabbi Jonathan Cahn reveals how he learned about the two cows with the number 7 on their heads having appeared in America. The news about the first one was spread on the 1st day of the Shemitah Year (7th year), the 2nd one was born on that same day on the beginning of the Shemitah Year, on September 25th, 2014. What do they stand for? This video section had been published at the Jim Bakker Show on March 25 and 26, 2015."