Ammonia Emissions from Twelve U.S. Broiler Chicken Houses

Twelve commercial broiler houses in the U.S. were each monitored for at least thirteen 48 h periods over the course of one year to obtain ammonia emission data. Paired repetition of houses on four farms represents current construction with variety in litter management (built-up or new litter each flock) and climate conditions (cold or mixed-humid). Ammonia concentration was determined using portable electrochemical sensors incorporating a fresh air purge cycle. Ventilation rate was determined via in-situ measurement of fan capacity, fan on-off times, and house static pressure difference. There were seasonal trends in exhaust ammonia concentration (highest in cold weather) and ventilation rates (highest in warm weather) but not for emission rate. Flocks with at least three monitoring periods (13 of 22 flocks) demonstrated similar emission rates at a given bird age among the four study farms and across the seasons. An analysis of emissions from all houses on the three farms using built-up litter resulted in predicted regression slopes of 0.028, 0.034, and 0.038 g NH3 bird-1 d-1 per day of age; the fourth farm, managed with new litter, had the lowest emission rate at 0.024 g NH3 bird-1 d-1. The intercept of these composite relationships was influenced by litter conditions, with flocks on new litter having essentially no emissions for about six days while built-up litter flocks had emissions starting at flock placement. Data from all four farms and all flocks provided a regression slope of 0.031(±0.001 std error) g NH3 bird-1 d-1 per day of age. Emission rate per animal unit for built-up litter flocks indicated very high emissions for the youngest birds (under 14 days of age), after which time the emissions decreased exponentially and were then relatively steady for the balance of the flock cycle

Comparison of Direct vs. Indirect Ventilation Rate Determination for Manure Belt Laying Hen Houses

Direct measurement of ventilation rate in livestock housing can be a formidable task due to uncontrollable variations in fan and system performance as caused by factors such as operation static pressure, fan belt condition, and dust accumulation on shutters and blades. Indirect, CO2-balance method offers a potentially viable, more flexible alternative to estimating ventilation rate. The reliability of CO2 balance method depends on the validity of relationship between CO2 production and metabolic rate of the animals and the knowledge of CO2 generation by the housing environment. Metabolic rates of modern laying hens have recently been quantified in intensive large-scale laboratory measurements. However, performance of the indirect method remains to be evaluated under field production conditions. This paper compares ventilation rates of a commercial laying hen house with manure belt (manure removed daily) obtained from direct measurement based on in-situ fan performance and runtime vs. indirect determination based on CO2 balance. The results indicate that indirect determination based on CO2 balance was well in agreement with that of direct measurement. Application of the CO2-balance method to evaluate building ventilation rate can improve the affordability and versatility of poultry emission studies

Comparison of Direct vs. Indirect Ventilation Rate Determinations in Layer Barns using Manure Belts

Direct measurement of building ventilation rate in livestock housing is a formidable task due to uncontrollable variations in fan and system performance that are caused by factors such as building static pressure, fan belt slippage, and dust accumulation on shutters and blades. Estimating building ventilation rate by an indirect method based on a CO2 balance offers a potentially viable alternative to direct measurement. The validity of the CO2 balance method depends on the validity of relationship between CO2 production inside the building and metabolic rate of the animals and the knowledge of CO2 generation by the housing environment. Metabolic rates of modern laying hens have recently been quantified in intensive large-scale laboratory measurements. However, performance of the indirect method remains to be evaluated under field conditions. This article compares building ventilation rates obtained by direct measurement and by a CO2 balance. The test was conducted at a commercial laying hen house that used manure belts with daily manure removal. The results indicate that ventilation rates estimated by the indirect method were not significantly different (P \u3e 0.2) from those as determined by the direct measurement when the averaging or integration time interval was 2 h or longer. Careful application of the indirect method could greatly improve the affordability and versatility of endeavors toward quantifying air emissions from confined animal housing

Ammonia Emissions from USA Broiler Chicken Barns Managed with New Bedding, Built-up Litter, or Acid-Treated Litter

Poultry producers in the United States have attempted to maintain barn aerial ammonia (NH3) levels below 25 ppm to improve air quality, and more recently to decrease aerial emissions to the atmosphere. Our objective was to investigate the influence of litter management strategies on NH3 emissions from commercial broiler barns employing new bedding, acid-treated built-up litter (sodium bisulphate), or untreated built-up litter (normal practice). Nearly 400 barn-days of NH3 emissions data were collected from 12 broiler barns on four farms monitored in 48-hour episodes over one year. On each study farm, the barns were paired for repetition of conditions. Emission was calculated as the product of gas concentration of the exhaust air and barn ventilation rate. Use of new bedding for every flock led to consistently lower NH3 emission (averaging 0.35 g NH3/(bird d)) at day 21 of the 42-day flock grow-outs, followed by flocks raised on the annual cleanout with new bedding (0.52 g NH3/(bird d)). Built-up litter without any treatment had the highest emission (0.73 g NH3/(bird d)), followed by the built-up litter with acid treatment (0.63 g NH3/(bird d)). One study site was managed with two barns using litter treatment and two identical barns with untreated, built-up litter for a side-by-side comparison of results under field conditions. Ammonia emissions from treated built-up litter barns were similar to those from untreated built-up litter barns, however, the temporal pattern of emissions provided evidence that ammonia held in the acid-treated litter at the beginning of the flock was released during the latter period of the flock cycle

Odor Evaluation and Gas Emission from Manure of Dairy Heifers Fed High/Low - Forage Quality and High/Low-Concentrate Diets

A heifer feeding trial evaluated the impact of high/low forage quality and high/low concentrate level nutrient-balanced diets on simultaneous odor and gas emissions from the manure. Gas concentration was determined using an infrared photoacoustic analyzer over a 24-hour period using a steady-state flux chamber setup containing urine:feces as-excreted from eight individual heifers. Odorous air samples were collected from chamber headspace and evaluated by six human assessors for pleasantness, intensity and detection threshold using a forced-choice dynamic olfactometer. Ammonia emission ranged from 0.64 to 3.94 mg NH3 cm-2 d-1 across diets. Average ammonia emission from the low concentrate (80% forage) diets (2.11 mg NH3 cm-2 d-1) was larger than the high concentrate (20% forage) diets (1.69 mg NH3 cm-2 d-1), but not significantly different. Carbon dioxide emission was significantly higher (p= 0.0143) in the low concentrate diets. There was a linear increase of methane emission as reduced quality forage (corn stover) was increased in the low-concentrate diet (p = 0.030). Nitrous oxide emissions were similar and low in all diets. Highest average odor emission (8.58 OU m-2 sec-1) was from the low concentrate, high forage quality (80% corn silage) diet while lowest emission (5.01 OU m-2 sec-1) was measured when forage quality was reduced (32% silage; 48% stover). Odor emission tended to be reduced with lower quality forage diets, but with no significant difference. The volume of feces produced from the high concentrate diet was about half that from the low concentrate diet heifers. But total manure produced by the high concentrate diet heifers was 23% higher due to increased urine production

Pharmacogenetic Discovery in CALGB (Alliance) 90401 and Mechanistic Validation of a VAC14 Polymorphism That Increases Risk of Docetaxel-Induced Neuropathy

Purpose Discovery of single nucleotide polymorphisms (SNPs) that predict a patient\u27s risk of docetaxel-induced neuropathy would enable treatment individualization to maximize efficacy and avoid unnecessary toxicity. The objectives of this analysis were to discover SNPs associated with docetaxel-induced neuropathy and mechanistically validate these associations in preclinical models of drug-induced neuropathy. Experimental Design A genome-wide association study was conducted in metastatic castrate-resistant prostate cancer patients treated with docetaxel, prednisone and randomized to bevacizumab or placebo on CALGB 90401. SNPs were genotyped on the Illumina HumanHap610-Quad platform followed by rigorous quality control. The inference was conducted on the cumulative dose at occurrence of grade 3+ sensory neuropathy using a cause-specific hazard model that accounted for early treatment discontinuation. Genes with SNPs significantly associated with neuropathy were knocked down in cellular and mouse models of drug-induced neuropathy. Results 498,081 SNPs were analyzed in 623 Caucasian patients, 50 (8%) of whom experienced grade 3+ neuropathy. The 1000 SNPs most associated with neuropathy clustered in relevant pathways including neuropathic pain and axonal guidance. A SNP in VAC14 (rs875858) surpassed genome-wide significance (p=2.12×10-8 adjusted p=5.88×10-7). siRNA knockdown of VAC14 in stem cell derived peripheral neuronal cells increased docetaxel sensitivity as measured by decreased neurite processes (p=0.0015) and branches (p\u3c0.0001). Prior to docetaxel treatment VAC14 heterozygous mice had greater nociceptive sensitivity than wild-type litter mate controls (p=0.001). Conclusions VAC14 should be prioritized for further validation of its potential role as a predictor of docetaxel-induced neuropathy and biomarker for treatment individualization

Functional Analysis of Alleged NOGGIN Mutation G92E Disproves Its Pathogenic Relevance

We identified an amino acid change (p.G92E) in the Bone Morphogenetic Protein antagonist NOGGIN in a 22-month-old boy who presented with a unilateral brachydactyly type B phenotype. Brachydactyly type B is a skeletal malformation that has been associated with increased Bone Morphogenetic Protein pathway activation in other patients. Previously, the amino acid change p.G92E in NOGGIN was described as causing fibrodysplasia ossificans progressiva, a rare genetic disorder characterized by limb malformations and progressive heterotopic bone formation in soft tissues that, like Brachydactyly type B, is caused by increased activation of Bone Morphogenetic Protein signaling. To determine whether G92E-NOGGIN shows impaired antagonism that could lead to increased Bone Morphogenetic Protein signaling, we performed functional assays to evaluate inhibition of BMP signaling. Interestingly, wt-NOGGIN shows different inhibition efficacies towards various Bone Morphogenetic Proteins that are known to be essential in limb development. However, comparing the biological activity of G92E-NOGGIN with wt-NOGGIN, we observed that G92E-NOGGIN inhibits activation of bone morphogenetic protein signaling with equal efficiency as wt-NOGGIN, supporting that G92E-NOGGIN does not cause pathological effects. Genetic testing of the child's parents revealed the same amino acid change in the healthy father, further supporting that p.G92E is a neutral amino acid substitution in NOGGIN. We conclude that p.G92E represents a rare polymorphism of the NOGGIN gene - causing neither brachydactyly nor fibrodysplasia ossificans progressiva. This study highlights that a given genetic variation should not be considered pathogenic unless supported by functional analyses