for those who those who are not familiar thumping these is a condition on which the animal is breathing heavily and it is manifested by constriction of its abdominal area every time it is inspiring.
HOw to control or avoid : By means of vaccination. thumping is a clinical sign that the animal is suffering from a respiratory problem. The list could go on in terms of respiratory problem, andyan ang Mycoplasma, pastuerella, influeza etc...
By giving vaccination for the most common respiratory problem in your area you are lessening the probability that the animal could have this problem.
Disinfection of the farm could also help.
ALso, kung mamaintain nyo ang temperature ng inyong kulungan to be not too fluctuating dapat hindi extreme ang temperature. yun tipong sobrang init sa tanghali tpos pagdating sa hapon or gabi ang lamig naman.
IF you have thumping then give antibiotic like oxytetra or tylosin. Vitamins supplementation would also help.