US Broiler Research Articles

236 Assessment of Early-Stage Thermal Manipulation on Broiler Chicken Muscle Satellite Cell Populations at Transfer and Hatch

Abstract Multi-stage hatching egg incubators are challenging to manage but still common throughout the US broiler industry. It is difficult to satisfy all embryonic temperature requirements in systems where late-stage embryos must be kept from overheating while ensuring early-stage embryos are not at sub-optimal temperatures. Our previous work showed improvements in performance and meat yield when incubation temperature was increased to 38.6 °C from embryonic day (ED) 4 to 11 as opposed to lowering it to 36.4 °C compared with a 37.5 °C control. The objective of this work was to assess the effect of thermal variation (TV) during early-stage incubation (ESI) on muscle satellite cell (SC) heterogeneity in broiler chicks at transfer and hatch to explore the mechanism responsible for increased meat yield in our previous study. Broiler breeder eggs (n = 2,160) were incubated at 37.5 °C from embryonic day (ED) 0 to 3. On ED 4, COLD incubator set points decreased to 36.4 °C, HOT incubator set points increased to 38.6 °C, and control incubators remained 37.5 °C (n = 2 incubators per treatment). On ED 11, all incubators were set to 37.5 °C until ED 18 when eggs were transferred to hatchers. At transfer (ED 18) and hatch (ED 21), pectoralis major (PM) and biceps femoris (BF) muscle samples were collected from 6 chicks per treatment. Samples were immunofluorescence stained to facilitate taxonomy of SC populations expressing the myogenic regulatory factors and SC markers, MyoD, MRF4, and Myf5, by fluorescence microscopy. Data were analyzed as a 1-way ANOVA with the GLIMMIX procedure of SAS. Means were separated at P ≤ 0.05 with the PDIFF option. Tendencies were declared when 0.0501 ≤ P ≤ 0.10. Chicks from COLD incubators had the greatest density of MyoD+:Myf5+ SC in their BF (P = 0.0261) and tended to have a greater density of MyoD+:MRF4+ SC in their PM muscle (P = 0.0562) compared with chicks from HOT incubators. On ED 21, chicks from HOT incubators had the greatest density of MyoD+:MRF4+:Myf5+ SC in their PM muscle (P = 0.0406). Temperature gradients as small as 1.1 °C during ESI altered BF SC populations in chicks at transfer and PM SC populations at both transfer and hatch. Overall, these results indicate that TV during ESI can influence SC population kinetics in both PM and BF muscles of modern, fast-growing, high-yielding broiler chicks at ED 18 and 21. Further investigation is needed to understand the longer-term effects on SC populations and the cell signaling pathways involved over time during the post-hatch grow out period to explain the meat yield responses observed in our previous work.

319 Reflections at the Halfway Point of a Multi-Institutional Comprehensive Usda Sustainable Agriculture Systems Project: Empowering the US Broiler Industry for Transformation and Sustainability

Abstract We received funding for a USDA SAS project that began in September (2019) that involves 7 institutions and approximately 30 faculty. Overarching goals of the project are to improve the system wide efficiency of nutrient and water use in broiler production through a) a better understanding and manipulation of the host physiology and microbial influence on water and nutrient efficiency, b) implementation of novel algal-based technology, and c) effecting educational-behavioral changes through enhanced education and extension programs. To date: a) We have had group progress report meetings 6-8 times per year, and b) we have supported or involved 19 undergraduate students, 22 grad students, and 6 post-docs on the project. The group collectively has published 15 book chapters, 74 refereed publications, 7 theses/dissertations, and filed 2 patents. We also had a symposium at a national meeting. Despite restrictions due to Covid, we have been able to have students take part in internships at U of A and Cornell. A minor in Sustainable Agriculture Systems has been established at Cornell. A class offered by Cornell (The global food, energy, and water nexus – engaging students from the US, China, and India to Chart a Sustainable Future) enables students to participate in the class and receive credit from their home institution. This class incorporates faculty involved in the SAS grant as well as many international guest speakers who are experts in their field. An area we hope to improve upon is getting our message out to our clientele and general public via several different methods.

The 'sustainability gap' of US broiler chicken production: trade-offs between welfare, land use and consumption.

In 2018, over nine billion chickens were slaughtered in the United States. As the demand for chickens increases, so too have concerns regarding the welfare of the chickens in these systems and the damage such practices cause to the surrounding ecosystems. To address welfare concerns, there is large-scale interest in raising chickens on pasture and switching to slower-growing, higher-welfare breeds as soon as 2024. We created a box model of US chicken demographics to characterize aggregate broiler chicken welfare and land-use consequences at the country scale for US shifts to slower-growing chickens, housing with outdoor access, and pasture management. The US produces roughly 20 million metric tons of chicken meat annually. Maintaining this level of consumption entirely with a slower-growing breed would require a 44.6%–86.8% larger population of chickens and a 19.2%–27.2% higher annual slaughter rate, relative to the current demographics of primarily ‘Ross 308’ chickens that are slaughtered at a rate of 9.25 billion per year. Generating this quantity of slower-growing breeds in conventional concentrated animal feeding operations (CAFO) would require 90 582–98 687 km2, an increase of 19.9–30.6% over the 75 577 km2 of land used for current production of Ross 308. Housing slower-growing breeds on pasture, the more individually welfare-friendly option, would require 108 642–121 019 km2, a 43.8–60.1% increase over current land use. Allowing slower-growing breeds occasional outdoor access is an intermediate approach that would require 90 691–98 811 km2, an increase of 20–30.7% of the current land use, a very minor increase of land relative to managing slower-growing breeds in CAFOs. In sum, without a drastic reduction in consumption, switching to alternative breeds will lead to a substantial increase in the number of individuals killed each year, an untenable increase in land use, and a possible decrease in aggregate chicken welfare at the country-level scale. Pasture-based management requires substantial additional land use. These results demonstrate constraints and trade-offs in animal welfare, environmental conservation and food animal consumption, while highlighting opportunities for policies to mitigate impacts in an integrated manner using a One Health approach.

Estimates of on-farm antimicrobial usage in broiler chicken production in the United States, 2013-2017.

Antimicrobial use is a key selective force behind the emergence of resistant bacteria. Therefore, optimizing strategies for more efficacious and targeted antimicrobial use is an essential component of efforts to combat antimicrobial resistance. To bolster stewardship programmes in animal agriculture, processes are needed for the systematic collection of on-farm antimicrobial use data. The objective of this study was to develop a system for collecting on-farm antimicrobial use data from the US broiler industry and to have it be representative of the largest commercial broiler producers in the United States that comprise the vast majority of national broiler production. Participation was voluntary. Data were collected for the period 2013 through 2017 and are reported on a calendar year basis. Using statistics from USDA:NASS as a denominator, the data supplied by participating companies accounted for approximately 81.7% of broiler production in the United States in 2013 and increased to approximately 87.2% in 2017. The data that were submitted for 2017 are based on approximately 7,897,339,357 chicks placed, 7,541,449,430 chickens slaughtered and 48,225,124,865 pounds liveweight produced. The use of antimicrobials in the hatchery decreased substantially between 2013 and 2017; the approximate percentage of broiler chicks placed that received hatchery antimicrobials decreased from 93% in 2013 to 17% in 2017. Medically important in-feed antimicrobial use decreased substantially. For example, in-feed tetracycline use decreased approximately 95% between 2013 and 2017. Medically important water-soluble antimicrobial use decreased substantially for most antimicrobials. Between 2013 and 2017, water-soluble penicillin use decreased approximately 21%, water-soluble tetracycline use decreased approximately 47%, and water-soluble lincomycin use decreased approximately 28%. While a reduction in antimicrobial amounts used may be an important indicator of improved stewardship, reducing the need for antimicrobials through improved disease prevention should be considered a more important objective and a better indicator of overall flock health and optimal antimicrobial use.

Joint Oligopsony‐Oligopoly Power in Food Processing Industries: Application to the us Broiler Industry

Food manufacturers and retailers mediate transactions between farm product markets and finished product markets for a large number of agricultural products. In such settings, producers at the intermediary stages of the supply chain have the potential to exercise market power jointly over agricultural producers in the upstream farm product market and over consumers in the downstream market for finished goods. In this paper, we examine settings in which food processors jointly exercise oligopsony power over farmers in the upstream market and oligopoly power over consumers in the downstream market. We demonstrate how forward contracts in the procurement market affect equilibrium prices in the downstream consumer market, allowing food processors to raise margins by leveraging oligopsony power. We apply our model to the US broiler industry and show that tournament contracts for live chicken procurement can be employed as an instrument to extend spatial oligopsony power in the upstream procurement market to soften price competition in the downstream processed goods market.

China–Broiler Products (Article 21.5 – United States) – can the sum of the parts be less than the whole?

AbstractThis article explores economic and legal issues in the WTO dispute China–Broiler Products (Article 21.5–United States). In 2011, the US initiated a dispute against the conduct and results of China's 2009 trade remedy investigation into US broiler products (chickens). The Panel Report found that China had acted inconsistently with its WTO obligations. On the basis of a redetermination, China continued to impose duties and the United States initiated WTO compliance proceedings. The compliance Panel Report, circulated in 2018, concluded that China had failed to comply with its WTO obligations when allocating costs to construct US domestic prices for broiler products. However, China was found to have acted consistently with its WTO obligations with respect to two claims which raise some interesting legal questions. Ultimately, after almost a decade of litigation, China removed the antidumping and countervailing duties on US broiler products in 2018.

Comprehensive Broiler Supply Chain Model with Vertical and Horizontal Linkages: Impact of US–China Trade War and USMCA

AbstractThis paper builds a comprehensive supply chain model of the US broiler industry that accounts for corn and soybean meal, feed mills, breeders, hatcheries, grow-out farms, broiler processing, value-added processing, and international trade. The model is calibrated and simulated to analyze the effects of (1) corn and soybeans tariffs imposed by China and (2) change in the Canadian tariff-rate quota proposed under US–Mexico–Canada–Agreement. The first scenario indicates that feed price falls while supply increases, which decreases the production costs of breeders and grow-out farms. The second scenario shows that exports to Canada rise at the expense of exports to Mexico.

“All along the curves”: Bridging the gap between comparative statics and simultaneous econometric models

A simultaneous econometric model of supply and demand provides estimates of own-price effects and the effect of exogenous variables on supply or demand. Most of the time economists use elasticities derived from econometric analysis in a ceteris paribus context, more seldom in a total elasticity setting (Buse in J Farm Econ 40:881–891, 1958). Perhaps even more seldom net effects of exogenous changes on prices and quantities are determined in a Muth (Oxf Econ Pap 16:221–234, 1964) type model. In this paper, we replicate the econometric model by Epple and McCallum (Econ Inq 44:374–384, 2006) and use it to specify a comparative static model that quantifies the period-to-period net effects on price and quantity from observed changes in the exogenous variables. Furthermore, we extend (Braekkan et al. in Eur Rev Agric Econ 45:531–552, 2018) approach for computing unexplained demand shifts by also calculating unexplained shifts in supply. This bridges the gap between comparative statics and simultaneous econometric models. Unexplained supply and demand shifts account for the unexplained variation in the endogenous variables. The data used in this application are from the US broiler chicken market.

External Societal Costs of Antimicrobial Resistance in Humans Attributable to Antimicrobial Use in Livestock.

Antimicrobial use (AMU) in animal agriculture contributes to antimicrobial resistance (AMR) in humans, which imposes significant health and economic costs on society. Economists call these costs negative externalities, societal costs that are not properly reflected in market prices. We review the relevant literature and develop a model to quantify the external costs of AMU in animal agriculture on AMR in humans. Parameters required for this estimate include (a) the health and economic burden of AMR in humans,(b) the impact of AMU in animal agriculture on AMR in animals, (c) the fraction of AMR in humans attributable to animal agriculture, and (d) AMU in animals. We use a well-documented historic case to estimate an externality cost of about US$1,500 per kilogram of fluoroquinolones administered in US broiler chicken production. Enhanced data collection, particularly on the third and fourth parameters, is urgently needed to quantify more fully the externalities of AMU in animal agriculture.

MinION sequencing to genotype US strains of infectious laryngotracheitis virus

ABSTRACTOver the last decade the US broiler industry has fought long-lasting outbreaks of infectious laryngotracheitis (ILTV). Previously, nine genotypes (I-IX) of ILTVs have been recognized using the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) method with three viral alleles (gB, gM and UL47/gG). In this study, the genotyping system was simplified to six genotypes by amplicon sequencing and examining discriminating single nucleotide polymorphisms (SNPs) within these open reading frames. Using phylogenomic analysis of 27 full genomes of ILTV, a single allele (ORF A/ORF B) was identified containing SNPs that could differentiate ILTVs into genotypes congruent with the phylogenetic partitioning. The allelic variations allowed for the cataloging of the 27 strains into 5 genotypes: vaccinal TCO, vaccinal CEO, virulent CEO-like, virulent US and virulent US backyard flocks from 1980 to 1990, correlating with the PCR-RFLP genotypes I/ II/ III (TCO), IV (CEO), V (virulent CEO-like), VI (virulent US) and VII/VIII/IX (virulent US backyard flock isolates). With the unique capabilities of third generation sequencing, we investigated the application of Oxford Nanopore MinION technology for rapid sequencing of the amplicons generated in the single-allele assay. This technology was an improvement over Sanger-based sequencing of the single allele amplicons due to a booster amplification step in the MinION sequencing protocol. Overall, there was a 90% correlation between the genotyping results of the single-allele assay and the multi-allele assay. Surveillance of emerging ILTV strains could greatly benefit from real-time amplicon sequencing using the single-allele assay and MinION sequencing.RESEARCH HIGHLIGHTSA multi-allelic assay identified nine ILTV genotypes circulating in the USSingle-allele genotyping is congruent with whole genome phylogenetic partitioningUS ILTV strains can be grouped into five genotypes using the single-allele assayThe single-allele assay can be done using MinION sequencing of barcoded amplicons

China – Broiler Products (Article 21.5 – United States) (DS427) – Can the Sum of the Parts Be Less Than the Whole?

This article explores economic and legal issues in the WTO dispute China – Broiler Products (Article 21.5 – United States) (DS427). In 2011, the US initiated a dispute against the conduct and results of China’s 2009 trade remedy investigation into US broiler products (chickens). The Panel Report found that China had acted inconsistently with its WTO obligations. On the basis of a redetermination, China continued to impose duties and the United States initiated WTO compliance proceedings. The compliance Panel Report, circulated in 2018, concluded that China had failed to comply with its WTO obligations when allocating costs to construct US domestic prices for broiler products. However, China was found to have acted consistently with its WTO obligations with respect to two claims which raise some interesting legal questions. Ultimately, after almost a decade of litigation, China removed the antidumping and countervailing duties on US broiler products in 2018.

Impacts of poultry house environment on poultry litter bacterial community composition.

Viral and bacterial pathogens are a significant economic concern to the US broiler industry and the ecological epicenter for poultry pathogens is the mixture of bedding material, chicken excrement and feathers that comprises the litter of a poultry house. This study used high-throughput sequencing to assess the richness and diversity of poultry litter bacterial communities, and to look for connections between these communities and the environmental characteristics of a poultry house including its history of gangrenous dermatitis (GD). Cluster analysis of 16S rRNA gene sequences revealed differences in the distribution of bacterial phylotypes between Wet and Dry litter samples and between houses. Wet litter contained greater diversity with 90% of total bacterial abundance occurring within the top 214 OTU clusters. In contrast, only 50 clusters accounted for 90% of Dry litter bacterial abundance. The sixth largest OTU cluster across all samples classified as an Arcobacter sp., an emerging human pathogen, occurring in only the Wet litter samples of a house with a modern evaporative cooling system. Ironically, the primary pathogenic clostridial and staphylococcal species associated with GD were not found in any house; however, there were thirteen 16S rRNA gene phylotypes of mostly Gram-positive phyla that were unique to GD-affected houses and primarily occurred in Wet litter samples. Overall, the poultry house environment appeared to substantially impact the composition of litter bacterial communities and may play a key role in the emergence of food-borne pathogens.

Ammonia emissions from broiler production in the San Joaquin Valley

Ammonia is the primary basic gas in the atmosphere and has the most important role in the neutralization of atmospheric acids generated by fossil fuel combustion. The reaction product forms a NH(4)(+) aerosol, which is a major component of atmospheric particulates. These NH(4)(+) particulates are part of atmospheric haze and may be transported long distances from the production site before returning to the surface by dry deposition or scavenged by precipitation. Animal production produces a significant component of anthropogenic NH(3) emissions and the National Academy of Sciences concluded that NH(3) emissions estimates from animal feeding operations have not been characterized sufficiently, leading the US Environmental Protection Agency to institute studies in the United States to obtain NH(3) emissions from animal feeding operations under the US Environmental Protection Agency Air Consent Agreement. The objective of this study is to obtain additional broiler NH(3) emissions estimates using a backward Lagrangian stochastic technique. This technique uses NH(3) concentrations measured upwind and downwind of the farm, wind observations, and atmospheric dispersion model calculations to obtain whole-farm emissions. Ammonia emissions were low at bird placement and increased steadily after about the third week of growth. At the end of the flock (47 d, ~297,000 birds), cumulative emissions for the flock cycle period were 0.016 kg of NH(3).bird(-1).flock(-1). Between-flock emissions, including bird harvest, cleanout, temporary storage of litter outside of the buildings, and downtime (buildings closed), added another 0.003 kg of NH(3).bird(-1).flock(-1). Emissions from this broiler farm were less than from some eastern US broiler farms but were comparable to broiler farms in Europe. Based on the results of this study and a similar winter study at this same farm, total flock wintertime and summertime (flock cycle plus between-flock) NH(3) emissions from this farm represented 7.8 and 8.3% of feed N as NH(3)-N, respectively, or an annual average of 8.1%.

Development and application of an RT-PCR test for detecting avian nephritis virus

The development of a reverse transcriptase-polymerase chain reaction (RT-PCR) test for detecting avian nephritis virus (ANV) is described. Primers, which amplified a fragment of 182 base pairs (bp), were located in the conserved 3′ untranslated region (UTR) of the genome. The limit of detection of the test was estimated to be approximately 18 viral copies using a 10-fold dilution series of in vitro transcribed RNA. Positive signals were produced with representative ANV samples, some of which were not detected by previously described RT-PCR tests for detecting ANV, but other avian astroviruses including chicken astrovirus isolates and duck hepatitis virus types 2 and 3 tested negative. When applied to gut content samples from UK, German and US broiler flocks with enteritis/growth problems, ANVs were detected by RT-PCR in 82/82 (100%) samples. ANVs were also detected in 80/96 (83%) pooled gut content samples from longitudinal surveys of four broiler flocks displaying below-average performance. Whereas all samples collected on day 0 from the surveys were negative for ANV, all samples collected at days 4/5, 7, 10, 14, 21 and 28 tested positive. Sequence determinations performed with amplicons produced with 14 field samples confirmed the ANV specificity of the test, while comparative and phylogenetic analyses based on 109-nucleotide 3′-UTR sequences demonstrated that the majority of ANVs investigated were more closely related to the serotype 2 ANV (accession number AB 046864) than to the serotype 1 ANV (accession number NC 003790).

Comparative field evaluations of in ovo applied technology

Mass vaccination of poultry has advanced in recent years with field application of in ovo vaccination technologies in hatcheries worldwide. Working from a laboratory concept to a commercially available system within a matter of a decade, with subsequent full application to 90% of US broiler production a few years later, the commercial systems continue to be an area for study and continued understanding. Within the production setting, 2 methods to evaluate the types of equipment available for this technology were evaluated in this research. Utilizing a whole hatchery approach and paired testing in a field setting allowed for direct comparison of the 2 US-manufactured in ovo systems (Embrex Inovoject System and Intelliject). The results of the whole hatchery study showed an advantage for 1 system at d 18 and 19 transfer, with the Embrex Inovoject System showing as much as a 2.32% advantage in percentage of hatch. Paired testing showed a statistical difference in percentage of hatchability at d 18 of transfer favoring the Embrex Inovoject System but no difference at d 19 transfer. Differences in the 2 systems were additionally evaluated in terms of day of transfer and flock age.

Effects of tertiary microsieving on the composition of poultry processing wastewater

SUMMARY Experiments were conducted to establish baseline values and processing plant variability in the reduction in concentrations of 5 wastewater parameters and 15 minerals after bench-scale tertiary microsieving of poultry processing wastewater (PPW) to 53 µm. Most US poultry processing plants currently use a 2-stage series of primary and secondary mechanical screens in the Fine (1,500 to 6,000 µm) and Very Fine (250 to 1,500 µm) micron range to remove gross offal before the wastewater enters advanced treatment systems. Poultry processors could receive substantial economic and environmental benefits by reducing the amount of fine particulate matter in PPW entering advanced wastewater treatment systems through the use of tertiary microscreening, which is the physical screening of PPW below 250 µm. This would increase the volume of offal recovered while decreasing associated wastewater treatment costs. Composite samples of PPW from 3 US broiler slaughter plants were collected after secondary rotary screening and analyzed for mean concentrations (mg/L) of chemical oxygen demand (2,733 mg/L), total solids (2,304 mg/L), total volatile solids (1,822 mg/L), total suspended solids (1129 mg/L), and total Kjeldahl nitrogen (161 mg/L). Tertiary microsieving reduced total suspended solids by 27 to 37%, total volatile solids by 16 to 22%, total solids by 16%, total Kjeldahl nitrogen by 8%, and chemical oxygen demand by 7%. The PPW samples were also analyzed for mean concentrations (mg/L) of sodium (119.9), potassium (61.0), phosphorus (33.5), calcium (26.2), silicon (13.9), magnesium (8.9), iron (1.8), aluminum (0.6), zinc (0.3), copper (0.16), manganese (0.102), boron (0.036), molybdenum (0.019), nickel (0.016), and chromium (0.013). Four of the 7 elements with mean concentrations >1 mg/L (sodium, potassium, phosphorus, and magnesium) were generally unaffected by microsieving.

Fate of antimicrobial-resistant enterococci and staphylococci and resistance determinants in stored poultry litter

The use of antimicrobials in commercial broiler poultry production results in the presence of drug-resistant bacteria shed in the excreta of these birds. Because these wastes are largely land-disposed these pathogens can affect the surrounding environment and population. In this analysis, we characterized the survival of antimicrobial-resistant enterococci and staphylococci and resistance genes in poultry litter. Temperature, moisture, and pH were measured in the litter over a 120-day period from storage sheds at three conventional US broiler chicken farms, as well as colony-forming units of Enterococcus spp. and Staphylococcus spp. Selected isolates from each sampling event were tested for resistance to eight antimicrobials used in poultry feeds as well as the presence of resistance genes and mobile genetic elements. Temperatures greater than 60 degrees C were only intermittently observed in the core of the litter piles. Both antimicrobial-resistant enterococci and staphylococci, as well as resistance genes persisted throughout the 120-day study period. Resistance genes identified in the study include: erm(A), erm(B), erm (C), msr(A/B), msr(C), and vat(E). This study indicates that typical storage practices of poultry litter are insufficient for eliminating drug-resistant enterococci and staphylococci, which may then be released into the environment through land disposal.

Effects of vibratory microscreening on proximate composition and recovery of poultry processing wastewater particulate matter

Experiments were conducted to compare the effects of tertiary microscreen gap size on the proximate composition and rate of recovery of particulate matter from poultry processing wastewater (PPW). A high-speed vibratory screen was installed within the wastewater treatment area of a southeast US broiler slaughter plant after the existing primary and secondary mechanical rotary screens. Microscreen panels with nominal gap size openings of 212, 106 and 45 μm were investigated. The particulate matter samples recovered were subjected to proximate analysis to determine percent moisture, fat, protein, crude fiber and ash. The average percent wet weight moisture (%WW) content for all samples was 79.1. The average percent dry matter (%DM) fat, protein, crude fiber and ash were 63.5, 17.5, 4.8 and 1.5, respectively. The mean concentration of total solids (TS) recovered from all microscreen runs was 668 mg/L, which represents a potential additional daily offal recovery rate of 12.1 metric tons (MT) per 3.78 million L (1.0 million gallons US) of PPW. There was no significant difference in the performance of the three microscreen gap sizes with regard to proximate composition or mass of particulate matter recovered.

Environmental performance in the US broiler poultry sector: Life cycle energy use and greenhouse gas, ozone depleting, acidifying and eutrophying emissions

Most published research concerning the environmental impacts of broiler poultry production is limited to assessments of on-farm gaseous and nutrient emissions. Here, ISO-compliant Life Cycle Assessment was used to predict the broader, macroscale environmental impacts of the material and energy inputs and emissions along the US broiler supply chain. It was found that feed provision accounts for 80% of supply chain energy use, 82% of greenhouse gas emissions, 98% of ozone depleting emissions, 96% of acidifying emissions and 97% of eutrophying emissions associated with the cradle-to-farm gate production of broiler poultry. On-farm inputs and emissions, largely related to heating and ventilation contribute on average only 9% of these impacts. These results underscore the fallacy of “landless farming” and the importance of full supply-chain environmental management for improving sustainability in the US poultry industry.

Assessment of Dietary Rovabio Excel in Practical United States Broiler Diets

The focus of this study was to evaluate a feed enzyme (Rovabio Excel) in diets fed to commercial broilers reared in environments typical to that observed in the US broiler industry and destined to be marketed at BW at or near 2.5 kg. The feed enzyme was tested in diets differing in amino acid and energy composition. The main effect of altered nutrient levels, mainly reduced amino acids, was higher abdominal fat at processing. The formulation addition of the exogenous feed enzyme to diets differing in nutrient contents and energy did not affect broiler live performance or carcass traits. However, the exogenous feed enzyme decreased 14-d mortality in experiment 1 and 41-d mortality in experiment 2 but was without effect on mortality in experiment 3. Future research elucidating any benefits on mortality from the exogenous feed enzyme may aid commercial poultry producers. Further, reducing dietary nutrient levels beyond that considered in this study may allow for exogenous enzyme benefits in broiler live production and carcass traits to be observed as mediated through nutrient liberation.