The influence of litter age, litter temperature and ventilation rate on ammonia emissions from a broiler rearing facility

Abstract

Broiler production is a prime example of high density animal production. Broilers are often grown in production houses containing 20 000 birds or more at densities of 0.06 m 2 per bird. Broiler litter typically contains 4 to 6 % nitrogen, much of which is in the NH 3 or NH 4 + form. The mixture of litter and manure is effectively a nitrogen storehouse. Under the proper conditions, a considerable quantity of this nitrogen will be released as ammonia (Carr et al., 1990). Many factors, such as season of the year, ambient temperature and humidity, bird health, and management practices can influence ammonia volatilization from broiler rearing facilities (Coufal, 2005). Ammonia is formed from the breakdown of nitrogenous waste products in poultry manure (undigested proteins and uric acid) by exogenous enzymes produced by microorganisms. Factors that exhibit direct control over these processes have been identified as pH, temperature, and moisture (Elliot and Collins, 1982). Ammonia release is depressed at pH < 7 but is very high at pH > 8 (Parker et al., 2005). Therefore, in a commercial broiler grow-out facility, pH would seldom be a factor determining NH 3 volatilization since the pH of broiler litter is Supported by Slovak-Norwegian Project No. 2032051 "Reducing Environmental Impact from Large-Scale Animal Production in Slovak Republic". ABSTRACT:The research reported in this article attempts to address the ammonia problem by quantifying the effect of several variables on ammonia concentrations and emissions. These variables include litter temperature, litter age and ventilation rate. Data was collected in a commercial tunnel-ventilated grow-out facility with deep litter, designed for 25 000 broilers, during 6 consecutive flocks. Birds were housed from hatching to approximately 40 days of age. Litter temperature and litter age were positively correlated (P < 0.0001) with the production of ammonia gas. The amount of ammonia emissions increased with the litter age (P < 0.0001) as a consequence of both the increased ammonia concentration and the ventilation rate (P < 0.0001). The lowest concentrations of NH 3 were observed in a "summer" period, although ammonia emissions tended to be higher just in summer months because of a higher ventilation rate. The elevated levels of ammonia in winter were attributed to the lower ventilation rate during cold weather. After the evaluation of ammonia emissions it can be concluded that during the grow-out period of broilers kept on renewed litter there is an average loss of 6.18 g ammonia per bird and/or 0.043 kg of ammonia per bird yearly. The increase in litter temperature during grow-out periods is a process which could be controlled to prevent excessive ammonia volatilization from housing facilities.

Emission of Harmful Gases from Poultry Farms and Possibilities of Their Reduction

“…The elevated levels of ammonia in winter were attributed to the lower ventilation rate during cold weather. During the fattening period of broilers kept on renewed litter there is an average loss of 6.2 g ammonia per bird and/or 0.04 kg of ammonia per bird yearly (Knížatová et al, 2010c). Dolan et al (2013) found that at the average temperature and relative humidity 23.9 °C and 57.96%, respectively, in the hall and by the average 1.92 kg live body weight of birds (in 33rd day of fattening cycle) NH 3 production of 7.437 mg.kg…”

Effect of the age and season of fattening period on carbon dioxide emissions from broiler housing

“…The influence of season on the Effect of the age and season of fattening period on carbon dioxide emissions from broiler housing M. Knížatová 1 , Š. Mihina 1,2 , J. Brouček 1 , I. Karandušovská 2 , G.J. Sauter 3 , J. Mačuhová amount of produced emissions is in fact the influence of ventilation rate, depending on the need to cool the temperature in the interior environment (Knížatová et al, 2010).…”

Nitrous Oxide Release from Poultry and Pig Housing

“…Most poultry are grown on dirt floors with different bedding materials, which generally need to be very absorbent (to limit the production of ammonia and harmful pathogens) and must have a reasonable drying time [39][40][41].…”

“…Another type of house used in layer production is a single-story stair-step house. The cleaning frequency of both types of systems may be based on several factors: the quality of the manure or manure litter in the pit or in the house, the storage space remaining, or the integrator specified clean-out cycle [40][41][42][43][44][45][46][47][48][49][50]. Concentrations of harmful gases are commonly high in aviaries and floor housing systems in which manure is not regularly removed [51].…”

“…Other factors can be expected to have an influence, such as litter amount (initial amount or regular inputs), flocking density, mortality, temperature, and moisture of outside air [60][61][62]. Also, additional authors have highlighted the quality of litter and quality of air related to the intensity of ventilation [41,63].…”