Minimum ventilation requirement and associated energy cost for aerial ammonia control in broiler houses
1996
Xin, H. | Berry, I.L. | Tabler, G.T.
Minimum ventilation rate (MVR) and bird performance of four commercial-scale broiler houses were monitored for 16 consecutive growouts. A complete house clean-out was conducted after the 7th growout and again after the 13th growout. Between the clean-outs, only caked litter was removed, and new bedding was added to the old litter. The MVR needed to control indoor aerial ammonia to within 25 to 30 ppm (MVRa), for growouts raised on old litter, largely exceeded the normal MVR (MVRn) needed for moisture control during the first week of brooding. In particular, MVRa averaged nine times MVRn on day one, and declined exponentially with bird age. Elevated MVRa during a two week brooding period requires additional propane fuel use of 136 L (36 gal) and 57 L (15 gal) per 1,000 birds, at an outside temperature of -17.8 degrees C (0 degrees F) and 10 degrees C (50 degrees F), respectively. This extra fuel or heat requirement should be considered in designing supplemental heating capacity for broiler houses using old litter. Moreover, the results obtained from this study suggest that broilers raised on old litter are more likely to have higher carcass condemnation rate than those raised on new litter. Heating broiler houses at 35 degrees C (95 degrees F) for two days before chick placement seems helpful in extracting ammonia from old litter, but may not be cost-effective. Thus, whenever possible, house cleaning after each growout is desirable to improve energy use efficiency and indoor air quality. In particular, partial cleaning of the brooding end only would be cost-effective and is recommended.
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