PENGARUH PERBEDAAN SISTEM VENTILASI KANDANG TERHADAP KADAR AMONIA DAN PERTUMBUHAN DOMBA PENGGEMUKAN

The productivity of fattening sheep is strongly influenced by housing environmental management, particularly the ventilation system, which plays an important role in maintaining air quality and thermal comfort. This study aimed to examine the effect of different housing ventilation systems (exhaust fan and non-exhaust fan) on ammonia (NH₃) concentration and Average Daily Gain (ADG) of sheep. The research employed an observational (survey) method, with measurements of ammonia concentration, temperature, and humidity conducted over a 7-day period at three observation times per day in two housing systems, each containing 15 sheep. The collected data were analyzed using the Independent Samples T-Test. The results showed that the average ammonia concentrations in both housing systems were within a safe range and did not differ significantly (P > 0.05), with values of 9.49 ppm in the non-exhaust fan housing and 9.92 ppm in the exhaust fan housing. Although ammonia levels were relatively similar and well below the threshold of 20–25 ppm, a highly significant difference in growth performance was observed (P < 0.01). Sheep housed in the exhaust fan system exhibited a higher ADG of 0.239 kg/day compared to 0.105 kg/day in the non-exhaust fan system. These findings indicate that improvements in sheep performance were not driven by ammonia toxicity, but rather by enhanced thermal comfort provided by mechanical ventilation, which reduced heat stress and improved growth efficiency.