Aerial Ammonia Concentrations Research Articles

Environmental Characteristics and Bacterial Counts in Bedding and Milk Bulk Tank of Low Profile Cross-Ventilated, Naturally Ventilated, and Compost Bedded Pack Dairy Barns

Low profile cross-ventilated freestall (CV) and compost bedded pack barns (CB) are two newer housing options for dairy producers in the Upper Midwest. The CV barns are fully enclosed facilities that rely on mechanical ventilation and typically use evaporative cooling for heat abatement during the warmer months. The CB barns are a loose housing system that is generally bedded with dry wood sawdust and tilled twice daily. The objectives of this study were to describe the housing system and assess air quality (aerial ammonia and hydrogen sulfide), air velocity, light intensity, temperature, and relative humidity in CV, CB, and naturally ventilated freestall barns (NV). This cohort study was conducted on 18 commercial dairy farms, 6 of each housing type, in Minnesota and eastern South Dakota. Farms were visited four times, once each season between January and November 2008. Ammonia, hydrogen sulfide, light intensity, and air velocity measurements were taken twice each visit with 10 measurements per sampling time. Aerial ammonia concentrations were significantly higher in CV barns than CB and NV barns (5.2, 3.9, and 3.3 ppm, respectively). Hydrogen sulfide concentrations were 18, 33, and 19 ppb in CB, CV, and NV barns, respectively. There was a trend for higher hydrogen sulfide concentrations in CV barns. Light intensity was significantly lower in CV barns than CB and NV barns (111, 480, and 392 lux, respectively). There were no differences in air velocity among the housing systems. The mechanically ventilated CV barns were warmer in the fall and winter than the CB and NV barns. When outside temperature was above 27C, CV barns were 2.9C and 3.0C cooler than CB and NV barns, respectively. No differences were seen in bedding or bulk tank bacterial counts among the housing systems. Although CV barns had significantly higher aerial ammonia and a trend for higher hydrogen sulfide concentrations than NV and CB barns, ammonia and hydrogen sulfide concentrations were below the threshold that would affect cow performance or human health. In conclusion, the three housing systems assessed had adequate air quality and ventilation to provide a safe environment for workers and animals.

Time Delay for Aerial Ammonia Concentration Measurements in Livestock Buildings

Correct measurements of ammonia concentration in air still present considerable challenges. The high water solubility and polarity can cause it to adsorb on surfaces in the entire sampling system, including sampling lines, filters, valves, pumps and instruments, causing substantial measuring errors and time delays. To estimate time delay characteristics of a Photo Acoustic Multi Gas Monitor 1312 and a Multi Point Sampler continuous measurement of aerial ammonia concentrations at different levels was performed. In order to obtain reproducible data, a wind tunnel was used to generate selected concentrations inside and a background concentration representing the air inlet of the tunnel. Four different concentration levels (0.8 ppm, 6.2 ppm, 9.7 ppm and 13.7 ppm) were used in the experiments, with an additional outdoor concentration level as background. The results indicated a substantial time delay when switching between the measuring positions with high and low concentration and vice versa. These properties may course serious errors for estimation of e.g. gas emissions whenever more than one measuring channel is applied. To reduce the measurement errors, some suggestions regarding design of the measurement setup and measuring strategies were presented.

The impact of chronic environmental stressors on the social behaviour of growing pigs, Sus scrofa

Introduction The effects of common and current environmental stressors on the social behaviour of farm animals are poorly understood and have never before been tested in controlled conditions. Here, we report the results of a longitudinal, multi-factorial experiment designed specifically to examine the individual, additive or interactive effects of elevated ammonia, noise and dim light levels on the social behaviour of growing pigs under strictly controlled environmental conditions. Material and methods Two batches of 126 4-week-old hybrid gilts (50% Pietrain, 25% white Duroc, 12.5% Large White, 12.5% Landrace) were obtained at weaning. Eight rooms were allocated to eight experimental treatments in a 23 multifactorial design. Each treatment comprised elevated or low levels of light intensity (nominally 200 vs. 40 lux), atmospheric ammonia concentration (nominally 20 ppm) and dim light intensities (<40 lux) can affect aggression in pigs. Aggression in pigs is signalled with odour and visual cues. Group-mate recognition can be olfactory, and odour cues may be masked by the ammonia, affecting perception and modulating the formation of stability in the group. The findings reported here may have implications for the welfare of farmed pigs in the UK. Ventilation systems should be designed further to minimise the aerial ammonia concentrations to avoid potential exacerbation of aggressive acts early in the development of the pigs. In addition, it seems that dim lighting may increase aggressive acts, again, early in the development of the pigs, and the industry should take account of this when designing facilities in the future

Interactive Effects of Ammonia and Light Intensity on Hematochemical Variables in Broiler Chickens

This study examined the influence of early atmospheric ammonia exposure, light intensity throughout rearing, and their interaction on blood gases, electrolytes, and acid-base balance in broiler chickens under environmentally controlled conditions. The experiment consisted of a 3 × 3 factorial arranged in a randomized complete block design, with trials being replicated over time. The 9 treatments consisted of 3 levels (0, 25, and 50 ppm) of ammonia concentrations for 14 d and levels (0.2, 2.0, and 20 lx) of light intensities from 8 to 36 d of age. Venous blood samples were collected on d 6, 11, 14, and 35. On d 6, partial pressure of CO2 and Na+ increased significantly (P ≤ 0.05), whereas partial pressure of O2, pH, and K+ decreased with increasing ammonia concentration. As light intensity increased, pO2 and K+ were significantly (P ≤ 0.05) reduced. Ammonia × light intensity interactions were observed for hemoglobin, hematocrit, K+, and BW. The interaction of ammonia and light intensity for 7 d further exacerbated physiological variables. The main effect of ammonia was more pronounced than that of light intensity. These conditions worsened as the duration of ammonia concentration exposure and light intensity increased from d 7 to 14 of exposure. However, all affected variables returned to near normal at later time points in the exposed chickens so that the apparent effects were lost. Plasma corticosterone and glucose concentrations were not significantly altered by exposure to differing levels of ammonia or light intensity, suggesting an absence of stress related to ammonia, light intensity, or their interaction. It was concluded that exposure of broiler chickens to aerial ammonia concentrations of 0 to 50 ppm from d 1 to 14 posthatch in the presence of light intensities ranging from 0.2 to 20 lx had no direct effect on some physiological blood variables and did not induce stress in broilers.

Measuring Ammonia Concentrations and Emissions from Agricultural Land and Liquid Surfaces: A Review

Aerial ammonia concentrations (C g) are measured using acid scrubbers, filter packs, denuders, or optical methods. Using C g and wind speed or airflow rate, ammonia emission rate or flux can be directly estimated using enclosures or micrometeorological methods. Using nitrogen (N) recovery is not recommended, mainly because the different gaseous N components cannot be separated. Although low cost and replicable, chambers modify environmental conditions and are suitable only for comparing treatments. Wind tunnels do not modify environmental conditions as much as chambers, but they may not be appropriate for determining ammonia fluxes; however, they can be used to compare emissions and test models. Larger wind tunnels that also simulate natural wind profiles may be more useful for comparing treatments than micrometeorological methods because the latter require larger plots and are, thus, difficult to replicate. For determining absolute ammonia flux, the micrometeorological methods are the most suitable because they are nonintrusive. For use with micrometeorological methods, both the passive denuders and optical methods give comparable accuracies, although the latter give real-time C g but at a higher cost. The passive denuder is wind weighted and also costs less than forced-air C g measurement methods, but it requires calibration. When ammonia contamination during sample preparation and handling is a concern and separating the gas-phase ammonia and aerosol ammonium is not required, the scrubber is preferred over the passive denuder. The photothermal interferometer, because of its low detection limit and robustness, may hold potential for use in agriculture, but it requires evaluation. With its simpler theoretical basis and fewer restrictions, the integrated horizontal flux (IHF) method is preferable over other micrometeorological methods, particularly for lagoons, where berms and land-lagoon boundaries modify wind flow and flux gradients. With uniform wind flow, the ZINST method requiring measurement at one predetermined height may perform comparably to the IHF method but at a lower cost.

A preliminary investigation into the effects of forage type on ammonia levels in stables for horses

Ammonia is generally present within all livestock buildings; it is a by-product of protein digestion. Chronic obstructive pulmonary disease (COPD) is probably the most common cause of chronic coughing in horses in the UK. This has resulted in horse owners offering haylage, which is a low–dust alternative to hay (Moore–Colyer and Longland, 2000). However, Moore–Colyer and Longland (2000) reported that haylage usually contains more protein than hay (70 vs. 44 g CP/kg). When protein supplied in the diet exceeds the requirements of the horse, urea production will increase and consequently ammonia output will increase. Aerial ammonia concentrations can be regarded as a predisposing factor of COPD (Pratt, 2000). The aim of this experiment was to investigate the effects of offering horses different basal forages (hay vs. haylage) on the aerial ammonia concentrations within stables at different times during the day.

Effect of husbandry and housing of pigs on the organoleptic properties of bacon

A study of 23 farms in the north east of Scotland was undertaken to test for differences in the eating quality of bacon. Data were collected on management practices, genotype, feed and housing characteristics. Dust concentrations were measured photometrically, aerial ammonia concentrations chemically, and pig cleanliness on a five-point scale. Bacon samples from four animals (two male, two female) from each farm were subjected to a sensory profile analysis by a trained panel. Sixteen attributes were assessed describing appearance, texture, taste and aroma. Significant differences ( P<0.05) were found between farms for all attributes. Step-wise regression analysis showed that the main differences were due to breed type, floor type and housing conditions, with straw courts giving rise to bacon of superior eating quality compared to other housing systems.

Dietary manipulation to reduce aerial ammonia concentrations in nursery pig facilities.

Two 4-wk trials (preliminary study) and three 5-wk trials (major study) were conducted to determine the effects of adding Yucca schidigera extract or anhydrous calcium chloride to nursery diets on the growth performance of nursery pigs and aerial ammonia concentration. The pigs were weaned between 13 and 15 d of age and had an initial BW of 3 to 6 kg. In each trial, pigs were allotted to three identical pig nursery rooms that were environmentally regulated. There were three diets (one diet per room): 1) control, containing 23% CP; 2) control plus 125 ppm of Yucca schidigera extract; and 3) control plus 1.95% anhydrous calcium chloride. Growth performance was recorded weekly. Aerial ammonia concentration was measured daily using aspiration detector tubes and during the last week of each trial using diffusion tubes. Manure samples were collected twice a week during the experimental period to determine ammonia and N concentrations and pH. Plasma urea concentration was determined in blood samples collected from the pigs at the end of each trial. Data were analyzed using split-plot and Latin square designs for the preliminary and major studies, respectively. Feed intake was similar among pigs fed all three diets. There were no differences in ADG and ADG/ADFI (G/F) between pigs fed the control diet and pigs fed the yucca extract diet (P > or = 0.41). In all trials, pigs fed the calcium chloride diet had lower ADG and G/F than pigs fed the other two diets (P < 0.05). In the preliminary study, aerial ammonia tended to be greater in the rooms in which pigs were fed the control diet than in the rooms with pigs fed the yucca extract diet (P = 0.08) and the calcium chloride diet (P = 0.11). In the major study, aerial ammonia increased weekly (diet x week; P < 0.001) in all rooms. In the 4th wk, ammonia concentrations were greater (P < 0.001) in the rooms in which pigs were fed the control diet than in the rooms in which the other two diets were fed. Dietary treatment had no effect on plasma urea concentration (P > or = 0.10), manure ammonia and N concentrations (P > or = 0.50), and manure pH (P > or = 0.78). Although aerial ammonia concentrations were relatively low, the addition of Yucca schidigera extract or calcium chloride to the diet of nursery pigs reduced ammonia concentrations in the nursery rooms.

A LABORATORY STUDY ON METAL CORROSION BY AMMONIA GAS

The effects of aerial ammonia on metal corrosion was examined in this study. Tests were conducted using threeenvironmentally controlled chambers at three different ammonia levels (0 ppm, 100 ppm, and 200 ppm). Four types ofmetal products (uncoated 1010 carbon steel, galvanized steel, Galvalume, and pure zinc) were evaluated for weight lossesand corrosion rates over a two-month test period. The test results showed that aerial ammonia, instead of acceleratingmetal corrosion, reduced the corrosion rates for steel. Weight losses for uncoated 1010 carbon steel samples in thechamber without ammonia were three and six times higher than those in chambers with ammonia levels of 100 ppm and200 ppm, respectively. The corrosion rates were greatly reduced from 7.3 m/year to 1.2 m/year over the two-monthperiod when ammonia level increased from 0 ppm to 200 ppm. For galvanized steel and pure zinc samples, the influenceof ammonia on the corrosion processes was not apparent; however, there was a slight increase in corrosion rate forGalvalume samples with the increase of aerial ammonia concentrations.

Effects of Atmospheric Ammonia on Pulmonary Hemodynamics and Vascular Permeability in Pigs: Interaction with Endotoxins

The influence of atmospheric ammonia on the somatic growth, the plasma cortisol and ammonia concentrations, and cell blood counts was investigated in pigs exposed to four concentrations (0, 25, 50, and 100 ppm) for 6 days in a specifically designed air-pollutants exposure chamber. The effects of this gas on pulmonary vascular hemodynamics and permeability and on the endotoxin-induced vascular response were also assessed using an isolated perfused lung preparation. The total pulmonary blood flow resistance (Rt) was partitioned into four components: arterial (Ra), pre-(Ra′) and post-(Rv′) capillary and venous (Rv). The capillary filtration coefficient (Kf,c) was evaluated by using a gravimetric technique. None of the concentrations of ammonia significantly modified the plasma cortisol and ammonia concentrations or the differential leukocyte percentages and total white blood cell count, suggesting an absence of stress related to ammonia. In exposed animals, lethargy and a concentration-related depression of the somatic growth were observed. The equation of the regression line plotted relating the mean values of the changes in body weight gain recorded over the exposure period expressed as percentages of the initial body weight (y) and ammonia concentrations (x) was: y = 3.204 − 0.177x + 0.001x2(r = 0.99; p≤0.013). Endotoxin infused in the perfusion liquid of lungs from unexposed animals for 180 min induced a significant 208% increase in Rt (p < 0.001) which can be ascribed to a 338 and 180% increase in Ra′ and Rv′, respectively. Endotoxin infusion also induced a 62% (p ≤ 0.001) increase in the Kf,c. Exposure of pigs to ammonia at any concentration did not modify the baseline values of any hemodynamic or permeability parameters. However, the hemodynamic response to endotoxins in lungs from pigs exposed to 100 ppm was significantly altered. The increase in Rt, Ra′, and Rv′ observed in unexposed pigs was completely abolished as shown by the limited changes in Rt (+34.9%). An intermediate reaction (+131.7%) was obtained in pigs exposed to 50 ppm. This inhibiting effect of ammonia was closely correlated with gas concentration by a linear regression (r = 0.99; p ≤ 0.037). The changes in the Kf,c recorded in the control group were not modified by exposure to ammonia. It was concluded that exposure of pigs to aerial ammonia concentrations from 0 to 100 ppm for 6 days has no direct effect on the pulmonary microvascular hemodynamics and permeability and induces no stress response. A marked depressive effect on the somatic growth is observed at concentrations greater than 25 ppm. Concentrations greater than 50 ppm can modulate the pulmonary vascular response to endotoxins.

Use of Dietary Fat to Reduce Dust, Aerial Ammonia and Bacterial Colony Forming Particle Concentrations in Swine Confinement Buildings

ABSTRACT AN experiment was conducted to determine the effect of dietary fat on pigs and air quality of swine confinement buildings. Addition of tallow to the diet improved pig performance, and reduced aerial and settled dust concentrations. Aerial ammonia concentrations and the numbers of BCFP were lower (60 and 75%, respectively) in the building in which the diet containing 7.5% tallow was fed.