Playing 0.8.2a. I have 3 barns. Two were 10/10 cows and 1 was empty all tier 1. I started the upgrade of my 1st barn to tier 2 when it finished i would adjust my max cows up by 1 per year . I also started the upgrade of the 2nd barn after the 1st one completed and then raised the max cows by 1 each year also. when my first barn reached 17 cows and my second was at 15 the trader finally came with cows and I was able to buy 2 (all he had) and put them in barn 3. I then waited until my 1st barn was at 20 cows and moved 1 to the 2nd barn giving both 19 cows. I had 6 cows in barn 3 due to buying 3 and having 1 birth that same year.I upgraded barn3 at that time. The next year I put one each from barns 1&2 in 3 giving it 9 with it’s birth 1. The next year barn 1 Had 3/0, 2 had 21/20 and 3 had 11/13. The births message said 6 births. Sorry as it was late and it frustrated me I just shut down the computer and went to bed so no save to send.
I tried to replicate this from my save game and could not. I will note that when the issue happened that the trader icon was staying over the trading post even with no traders present and the fishermen were showing no fish present when they were fishing and catching fish. I read threads on both of these and so restarted my computer and both were fixed when I started from my save game. Maybe this is related to that.