Cowbell

Cowbell is a special item that is absolutely necessary to upgrade your Cowshed. You can find one at the Train Attack daily event. 

It is also important to mention:

• Cowshed can be upgraded up to level 3.
  Raising cows is a high-level activity, so you’ll need Tier 3 resources to build a Cowshed. Therefore, upgrading it to level 2 and level 3 will require Tier 4 and Tier 5 resources correspondingly. 
• Upgrading the Cowshed is beneficial in 3 different ways:
  — Store more cows in it (Level 1 — 6 cows; Level 2 — 12 cows; Level 3 — 18 cows);
  — Increased cow growth rate (Level 1 — 2 cows; Level 2 — 4 cows; Level 3 — 6 cows);
  — Increased feeder capacity (Level 1 — 3300; Level 2 — 6600; Level 3 — 9900).