No, I would not worry. Lots of thing can affect it. Stress is a big one. For some birds just looking at them is stressful. If they are panting excessively, wheezing, coughing, obviously in distress, then I would worry. I've never actually measured the respiration rate of a bird in all my years of chicken keeping!
https://thisnzlife.co.nz/understanding-how-a-chicken-breathes/
https://www.hobbyfarms.com/chicken-stats/
https://thisnzlife.co.nz/understanding-how-a-chicken-breathes/
https://www.hobbyfarms.com/chicken-stats/