Animal Production Systems Research Articles

Producing pasture-like milk from goats in confinement

We have previously shown that grazing in East-Mediterranean brushlands is associated with improved milk quality. However, grazing exposes animals to predation, heat stress, and parasites, and imposes labor constraint. In order to verify the hypothesis that feeding the tannin-rich browse species lentisk (Pistacia lentiscus L.) to confined dairy goats could serve as proxy to grazing in improving milk composition, 30 Damascus goats were assigned to 3 treatments for 3 weeks: goats were grazing for 4 h daily in Mediterranean brushland (treatment P) or were fed indoors with vetch hay without (H), or with (HPIS) lentisk foliage. Milk yield and dry matter intake were not affected by treatment. HPIS milk was richer in protein and milk-fat content than H milk. H milk had highest urea concentration, smallest milk-fat globules and highest phospholipid content (milk-fat basis). Curd firmness was 39 and 50% higher in the HPIS group, compared with P and H, respectively. HPIS milk had 39 and 90% higher n-3 fatty acids concentration than P and H, respectively. This study suggests that access to P. lentiscus intensifies the effect of grazing in Mediterranean woodland on milk composition. Thus, we present a nutritional strategy that not only retains the exceptional nutritional values and productivity of pasture feeding, but also participates in a profitable and sustainable agriculture with an emphasis on intensive ruminant animal-production systems.

Drivers of Consumer Liking for Beef, Pork, and Lamb: A Review.

Tenderness, juiciness, and flavor have been associated with consumer acceptance of beef, lamb, and pork. Drivers of consumer liking are interrelated across these species, but there are differences in consumer preferences. Animal age, animal diet, and subsequent marbling impact consumer liking across species. For beef, consumer research prior to the 1990s showed that tenderness was the main driver of liking. Consumer tenderness and juiciness liking are highly correlated. More recent research has shown that as overall tenderness improved and tenderness variation decreased, flavor has become a more important driver of beef consumer liking. Flavor is affected by consumer preparation methods, familiarity with different flavor presentations, and animal production systems. Animal diet impacts consumer perception of beef tenderness and flavor, especially when comparing forage-fed versus grain-fed beef. Flavor preferences vary across countries more so than preferences for beef based on consumer tenderness preferences and are most likely influenced by the consumption of locally produced beef and the flavor-derived type of beef traditionally consumed. Drivers of pork consumer liking have been shown to be affected by pH, color, water holding capacity, animal diet, and the presence of boar taint compounds. While tenderness and juiciness continue to be drivers of consumer liking for pork, flavor, as impacted by animal diet and the presence of boar taint compounds, continues to be a driver for consumer liking. For lamb, the flavor, as affected by diet, and animal age continue to be the main drivers of consumer liking. Lamb consumers vary across countries based on the level of consumption and preferences for flavor based on cultural effects and production practices.

The Potential Effect of Dietary Tannins on Enteric Methane Emission and Ruminant Production, as an Alternative to Antibiotic Feed Additives – A Review

Abstract Antibiotic growth promoters in livestock nutrition cause microbial resistance which produces threats to human health. Therefore, tannins have been considered as natural alternative antibiotic feed additives which possess various biological properties including antimicrobial, anti-inflammatory, antioxidant and immunomodulatory. Additionally, these plants also have antiparasitic and anti-bloat characteristics which contribute to inhibit the enteric methane emission in order to improve nutrient digestibility, milk and meat quality, fatty acids composition and ruminant production. Antibiotic growth promoters have been practiced in animals feeding to increase feed intake, growth rate, weight gain as well as reduce metabolic disorders and energy losses in the rumen. In 2006, the European Union banned the usage of antibiotic growth promoters in the feeding of livestock. This antibiotic resistance issue has increased demand to explore the natural feed additives that might be useful for animal production system. Consequently, natural forages have been categorized as potential feed additives in animal production since it improves nutritive value, protein digestibility, increase amino acid absorption and growth rate. But, some plant materials are usually rich in tannins known as anti-nutritional factors. Therefore, the application of tannin-rich plants in ruminant nutrition needs great precaution due to its possible injurious effects (dose dependent) on animal health such as metabolic disorders. Hence, there is need to give attention to the usage of tannins in ruminant nutrition as an alternative to antibiotics feed additives to investigate its effects on enteric methane emissions and ruminants production. In addition, safety and risk associated with tannins feeding have also been briefly discussed.

Effects of heat stress on the gut health of poultry.

Stress is a biological adaptive response to restore homeostasis, and occurs in every animal production system, due to the multitude of stressors present in every farm. Heat stress is one of the most common environmental challenges to poultry worldwide. It has been extensively demonstrated that heat stress negatively impacts the health, welfare, and productivity of broilers and laying hens. However, basic mechanisms associated with the reported effects of heat stress are still not fully understood. The adaptive response of poultry to a heat stress situation is complex and intricate in nature, and it includes effects on the intestinal tract. This review offers an objective overview of the scientific evidence available on the effects of the heat stress response on different facets of the intestinal tract of poultry, including its physiology, integrity, immunology, and microbiota. Although a lot of knowledge has been generated, many gaps persist. The development of standardized models is crucial to be able to better compare and extrapolate results. By better understanding how the intestinal tract is affected in birds subjected to heat stress conditions, more targeted interventions can be developed and applied.

Automation Applications in Integrated Animal Production System

In livestock enterprises, with the developing technology, the use of automation instead of control with manpower has become widespread. With the use of automation, it provides easy and reliable production, healthy product, decrease of labor force, prevention of economic losses, periodic and systematic operation and keeping data record regularly. In this way, it is possible to evaluate all records of animal production in digital environment. Control element (PC, PLC, PIC, Microprocessor, Electronic Cards), Activation Element (Motors, Cylinders, motion elements, etc.), Process (Production, temperature, control, chemical, events, etc.), Adjustment in automation used in animal husbandry Element (Acceleration, Angle, Speed, Flow, Encoders, Force, Load, Price, Pressure, Temperature, Slope, Torsion, Vibration Measurement Elements). Thanks to the intelligent sensors and controllers of these elements, feed and water of animals are recorded from central computers in automation control. In the studies, S7-300 PLC was used to carry out the general operation and collect the data. In addition, SCADA is used for central system supervision and control, data collection and storage, irrigation and feeding, warning and warning for security. In this study, it is aimed to give information about the use of automation in industrial animal husbandry enterprises.

Mineral profiling of muscle and hepatic tissues of Australian Merino, Damara and Dorper lambs: Effect of weight loss.

Seasonal weight loss (SWL) is a major constraint to extensive animal production systems. The Australian sheep production is based on merino sheep, a European breed not tolerant to SWL. Tolerant alternative breeds such as the fat-tailed Damara and the Dorper have been increasingly used in Australia and elsewhere, due to their robustness. The aim of this study was to understand the mineral profile of muscle and liver tissues of Australian Merino, Damara and Dorper, when subjected to SWL in order to understand SWL-tolerance physiology. Twenty-four lambs were divided randomly between growing (control) and nutritionally restricted groups for each breed. The trial lasted 42days. Animals were weighed bi-weekly and at the end of the trial, lambs were slaughtered. Liver and muscle samples were taken immediately after slaughter. Mineral assessment was carried out using inductively coupled plasma-optical emission spectrometry. Analysis of variance showed mineral concentrations were generally increased in the muscle of restricted animals, mainly because of fat tissue mobilization. An increase in Zn and Fe concentrations indicates an increase of enzymatic activity in the liver of restricted sheep as well as differential abundance of Fe-containing proteins. High concentrations of Cu in the liver of Dorper indicate higher ability to accumulate this element, even under SWL.

Le phosphore dans les systèmes d'élevage

Le phosphore en agriculture constitue à la fois une ressource limitée et une source potentielle de pollution lorsqu'il est utilisé en excès comme fertilisant. Les systèmes d'élevages jouent un rôle particulièrement important dans les flux de phosphore, les déjections animales contribuant à l'échelle nationale à près de la moitié des apports sur les sols, avec une forte variabilité selon les régions. Les produits animaux contribuent aussi largement à la couverture des besoins pour l'alimentation humaine en apportant près de 60 % du phosphore total de la ration moyenne des Français. L'efficacité de rétention du phosphore par les animaux est très variable selon les espèces. La plus élevée est obtenue chez le poulet standard, suivi du porc, du poulet label rouge et de la vache laitière, les poules pondeuses et les vaches allaitantes présentant des efficacités plus faibles. Toutefois, à l'échelle du système de production, les pressions en phosphore organique sont plus faibles pour les élevages de ruminants qui disposent de plus de surface d'épandage. Ces dernières années l'amélioration des connaissances des besoins et de l'utilisation digestive du phosphore ont permis de réduire fortement les apports en phosphore et les rejets, avec pour les animaux monogastriques l'effet additionnel de l'utilisation de phytases. Les pertes de phosphore vers l'environnement étant limitées, comparativement aux pertes d'azote, il est théoriquement possible d'atteindre des valeurs très élevées d'efficacité d'utilisation du phosphore dans les systèmes agricoles, mais ceci nécessite un parfait recyclage du phosphore des déjections animales et de celui des coproduits animaux.

Protected Blend of Organic Acids and Essential Oils Improves Growth Performance, Nutrient Digestibility, and Intestinal Health of Broiler Chickens Undergoing an Intestinal Challenge.

The growing restriction of antibiotic growth promoters (AGP) use in farming animals has raised a concern regarding the viability of the animal production system. In this new context, feed additives with proven positive impact on intestinal health may be used as strategy to avoid losses on performance. The aim of this study was to evaluate the effects of a protected blend of organic acids and essential oils [P(OA+EO)] on growth performance, nutrient digestibility, and intestinal health of broiler chickens. A total of 1,080 Cobb × Cobb 500 male broilers were randomly distributed in four treatments with 10 replicates (27 birds/each). Treatments were as follow: non-challenged control; challenged control; AGP (enramycin at 10 g/t); and P(OA+EO) at 300 g/t. All birds on challenged groups were challenged with Eimeria spp. at 1 day and with Clostridium perfringens at 11, 12, and 13 days. Body weight gain (BWG), feed intake and feed conversion ratio (FCR) were evaluated until 42 days. At 17 days, one bird per pen was orally gavaged with fluorescein isothiocyanate-dextran (FITC-d) and blood samples were collected for FITC-d detection to assess intestinal permeability. At 21 days, apparent ileal nutrient and energy (IDE) digestibility, intestinal macroscopic and histologic alterations (ISI) and, expression of mucin2 (MUC2), claudin1 (CLDN1), and occludin (OCLN) genes in the jejunum were evaluated. From 1 to 42 days, birds from the non-challenged and P(OA+EO) groups had greater (P < 0.001) BWG compared to challenged control and AGP groups. The challenged control group presented the worst FCR (P < 0.001). IDE was 106 kcal/kg greater when broilers were fed P(OA+EO) compared to the challenged control group. Broilers supplemented with P(OA+EO) had improved intestinal integrity with lower blood FITC-d concentration and ISI scores, and greater expression of MUC2, CLDN1, and OCLN genes compared to the challenged control group (P < 0.05). In conclusion, the P(OA+EO) and the AGP led to increased growth performance, nutrient digestibility and intestinal health of challenged broilers. A marked difference occurred in favor of the P(OA+EO), suggesting that this blend may be used to improve intestinal health and broiler growth performance in AGP free programs.

Moral dilemmas of animal production systems.

An ethics of animal production “systems” consists of a Moral Operating System. A Moral Operating System consists of an “internal” professional “care” ethics, an “external animal” ethics, and an “emergent” ethics in life sciences enabling change by responsible innovation. It is important to broaden the existing ethical frameworks on agriculture to new scientific methods and technologies. A Moral Operating System will help scientists, stakeholders, and policymakers to understand, evaluate, and monitor the integration of ethical aspects of agricultural systems.

Prevalence and Molecular Characteristics of Extended-Spectrum and AmpC β-Lactamase Producing Escherichia coli in Grazing Beef Cattle.

The emergence of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producing Escherichia coli represent a contemporary public health threat. ESBL and AmpC β-lactamase genes translocate between chromosomes and plasmids, facilitating rapid spread throughout the environment. In this study, ESBL/AmpC producing bacteria were isolated from beef cattle farms with seldom antibiotic use. Eleven farms out of 17 tested, had ESBL/AmpC producing E. coli in animals, soil, and forage samples. Fifty-nine CTX-M or CMY-2 positive E. coli isolates were further characterized with whole-genome sequencing. The isolates commonly carried CMY-2, TEM, or CTX-M genes, and over half encoded both CTX-M and TEM genes. Using comparative genomics, antimicrobial resistance genes from 12 classes of antimicrobial were identified and confirmed by antibiotic susceptibility test, revealing multidrug resistance against multiple classes of antibiotics. Virulence factors related to adherence, invasion, iron uptake, and bacterial secretion systems were shared by all isolates; some of which were identified as enteropathogenic E. coli. Phylogenetic analyses revealed a pattern of close genetic relatedness, suggesting that ESBL/AmpC producing E. coli were transmitted among farms as well as independent evolution within farms. Our results indicate that ESBL and AmpC β-lactamases prevail in food animal production system regardless antibiotic use and have the characteristics for zoonotic transmission.

Chlortetracycline inhibits seed germination and seedling growth in Brassica campestris by disrupting H2O2 signaling

Antibiotics have been identified as a new type of environmental contaminant because of their increased use in farm animal production systems. Those drugs that animals are not absorbed mostly are excreted in the feces and urine and contaminates soils. However, the effects of antibiotics on crop plants are still largely unknown. In this study, we determined the effects of chlortetracycline (CTC), a veterinary drug released into the agricultural field by grazing animals or through manure application, on the growth and physiology of Brassica campestris seedlings. Differently from animals, Brassica campestris seedlings have accumulated 5–10-fold higher CTC during cultivation rather than excretion. Morphologically, CTC delays seed germination and inhibits seedling growth such as shortening primary root length and decreasing chlorophyll level. At the molecular level, CTC accumulation in plants downregulated the expression of superoxide dismutase (SOD) genes and decreased the production of hydrogen peroxide (H2O2). Since H2O2 is one of the signaling components involved in the regulation of root growth, exogenous application of H2O2 partially restored the growth and physiology of CTC-treated seedlings. These results suggest that application of CTC-containing manure or compost to soil delays seed germination and inhibits plant growth.

Genetic parameters for feed efficiency in Romane rams and responses to single-generation selection

Feeding costs represent one of the highest expenditures in animal production systems. Breeding efficient animals that express their growth potential while eating less is therefore a major objective for breeders. We estimated the genetic parameters for feed intake, feed efficiency traits (residual feed intake (RFI) and feed conversion ratio (FCR)), growth and body composition traits in the Romane meat sheep breed. In these traits, selection responses to single-generation divergent selection on RFI were evaluated. From 2009 to 2016, a total of 951 male lambs were tested for 8 weeks starting from 3 months of age. They were weighed at the beginning and at the end of the testing period. Backfat thickness and muscle depth were recorded at the end of the testing period through ultrasound measurements. Feed intake was continuously recorded over the testing period using the automatic concentrate feeders. The heritability of RFI was estimated at 0.45 ± 0.08, which was higher than the heritability of FCR (0.30 ± 0.08). No significant genetic correlations were observed between RFI and growth traits. A favourable low negative genetic correlation was estimated between RFI and muscle depth (−0.30 ± 0.15), though additional data are needed to confirm these results. The selection of low RFI sires based on their breeding values led to the production of lambs eating significantly less concentrate (3% decrease in the average daily feed intake), but with the same growth as lambs from sires selected based on high RFI breeding values. We concluded that in meat sheep, RFI is a heritable trait that is genetically independent of post-weaning growth and body composition traits. A one-generation divergent selection based on RFI breeding values highlighted that substantial gains in feeding costs can be expected in selection schemes for meat sheep breeds.

Erasing gametes to write blastocysts: metabolism as the new player in epigenetic reprogramming.

Understanding preimplantation embryonic development is crucial for the improvement of assisted reproductive technologies and animal production. To achieve this goal, it is important to consider that gametes and embryos are highly susceptible to environmental changes. Beyond the metabolic adaptation, the dynamic status imposed during follicular growth and early embryogenesis may create marks that will guide the molecular regulation during prenatal development, and consequently impact the offspring phenotype. In this context, metaboloepigenetics has gained attention, as it investigates the crosstalk between metabolism and molecular control, i.e., how substrates generated by metabolic pathways may also act as players of epigenetic modifications. In this review, we present the main metabolic and epigenetic events of pre-implantation development, and how these systems connect to open possibilities for targeted manipulation of reproductive technologies and animal production systems.

Assessment of yield gaps on global grazed‐only permanent pasture using climate binning

To meet rising demands for agricultural products, existing agricultural lands must either produce more or expand in area. Yield gaps (YGs)-the difference between current and potential yield of agricultural systems-indicate the ability to increase output while holding land area constant. Here, we assess YGs in global grazed-only permanent pasture lands using a climate binning approach. We create a snapshot of circa 2000 empirical yields for meat and milk production from cattle, sheep, and goats by sorting pastures into climate bins defined by total annual precipitation and growing degree-days. We then estimate YGs from intra-bin yield comparisons. We evaluate YG patterns across three FAO definitions of grazed livestock agroecosystems (arid, humid, and temperate), and groups of animal production systems that vary in animal types and animal products. For all subcategories of grazed-only permanent pasture assessed, we find potential to increase productivity several-fold over current levels. However, because productivity of grazed pasture systems is generally low, even large relative increases in yield translated to small absolute gains in global protein production. In our dataset, milk-focused production systems were found to be seven times as productive as meat-focused production systems regardless of animal type, while cattle were four times as productive as sheep and goats regardless of animal output type. Sustainable intensification of pasture is most promising for local development, where large relative increases in production can substantially increase incomes or "spare" large amounts of land for other uses. Our results motivate the need for further studies to target agroecological and economic limitations on productivity to improve YG estimates and identify sustainable pathways toward intensification.

Chemical treatment of poultry litter affects the conjugation of plasmid-mediated extended-spectrum beta-lactamase resistance genes in E. coli

There is a general consensus among healthcare leaders that animal production industries should improve practices aiming to mitigate antimicrobial resistance, a significant global threat to public health. However, the epidemiology of antimicrobial resistance in animal production systems is very complex as a result of innumerous sources and dissemination routes of resistant bacteria. Furthermore, antimicrobial resistance can be transferred among bacteria by mobile elements, such as plasmids, which play a major role in the dissemination of antimicrobial resistance. In broiler production, litter contaminated by feces during the production cycle can serve as a potential reservoir for bacteria harboring antimicrobial resistance genes that can then be disseminated to susceptible bacteria. This study reports the effect of 1) different materials used as litter and 2) different litter recycling protocols on the conjugation frequencies of IncIII plasmids harboring extended-spectrum beta-lactamase–resistant genes among Escherichia coli isolates . Results found that, compared with cane bagasse litter, the use of wood shavings as litter decreased the conjugation frequency among E. coli isolates ( P < 0.001). In regard to the recycling protocols, the presence of chemical residues in both types of litter materials was associated with a decreased conjugation frequency, with lowest frequencies observed for quicklime and superphosphate. Our findings suggest that the type of material used as poultry litter as well as litter recycling procedures, distinguished by means of chemical compounds, may affect plasmid conjugation among E. coli isolates.

PSXII-42 The lactational response in dairy cows to supplementation of calcium gluconate embedded in a fat matrix

Abstract Functional nutrients that facilitate gastrointestinal health may serve as an alternative to the use of antimicrobials in animal production systems. Gluconic acid has been used as a prebiotic health promoter in non-ruminant applications. It is poorly absorbed in the small intestine and is fermented to butyrate in the lower gastrointestinal tract. The gut health benefits of butyrate have been demonstrated in both non-ruminant and ruminant models, but effects of post-ruminal gluconic acid supplementation are not well described. The objective of this study was to determine the effects of calcium gluconate embedded in a fat matrix (CGFM; 40% CaGlu) on dry matter intake, blood metabolites, milk production and fecal short chain fatty acid (SCFA) production in early lactation dairy cows (21 ± 2 DIM) fed to 100% of energy and protein requirements. The experiment was a 3 x 3 replicated Latin square with 13 replicates (3 cows/replicate), 3 experimental periods (each 28 d) and 3 dietary treatments of control (0 g/d), 16 g/d and 25 g/d of CGFM. There was no treatment effect on DMI and milk yield. The relationship between dose of CGFM (i.e. 0, 16, 26 g/d) and milk fat and protein yield, energy corrected milk was significantly quadratic (P &amp;lt; 0.05) while feed efficiency tended to be quadratic (P = 0.08). The greatest response was in milk fat yield, which increased 90 g/d over control at 16 g/d of CGFM. No significant changes in blood metabolite concentrations or fecal SCFA concentrations were observed between treatments, although there was a numerical increase in non-esterified fatty acid concentration in response to the 16 g/d CGFM dose (P = 0.16). The response to supplementation of fat-embedded calcium gluconate appears to alter energy partitioning in the lactating dairy cow, as demonstrated with subtle changes in circulating lipid and increased fat yield.

PSII-6 Deep Learning image segmentation for extraction of body measurements and prediction of body weight in Nile tilapia

Abstract Individual measurement of traits of interest is of great importance for breeding and management decisions in animal production systems. However, measurements are often taken manually, which is laborious and also stressful for the animals. Therefore, the development of fast, precise and indirect measurement methods is paramount. An appealing way for such a task is through computer vision systems (CVS). Hence, the objectives of the current work were: 1) Devise a CVS for autonomous measurement of Nile tilapia body area, length, height, and eccentricity; and 2) Evaluation of linear models for prediction of body weight (BW). The pixels of 822 RGB images of live fish were labeled into background, fish fins or body using the “MTurk” crowdsourcing service. This dataset was then split into training (60% of data) and testing sets for the development of Deep Learning Networks for image segmentation into the three pixel categories. The networks differed in input image size (10 to 40% of original size) and number of encoder/decoder layer stacks (1 to 5). An independent dataset with 831 images was used for validation of the linear predictive models. The results for intersection over union (IoU) show that a network with input of 20% of the original size and 4 encoder/decoder stacks achieved the best results, with IoU on the test dataset of 99, 90 and 64% for background, fish body and fin, respectively (Figure 1). Predicted segmentation from this network on randomly selected images is shown in Figure 2. From the linear models evaluated, the one considering only area as input showed predicted R2 of 0.92 for fish BW (Table 1). In conclusion, the devised CVS was able to correctly separate fish body from background and fins, and a linear model using fish body area as input provided good predictive quality of Nile tilapia BW.

5 Precision animal welfare for pigs

Abstract Precision animal management (PAM), was a term created by engineers to describe technologies that improve the sustainability of intensive animal production systems. Focused efforts include improving product-efficiency and environmental impact (e.g. robotics in milk production). These PAM technologies have been incorporated in intensive swine production systems (e.g. feeding systems, waste-management). There is a perception that animal welfare efforts reduce efficiency, thus reducing sustainability. This perception is challenged with the development and application of precision animal welfare (PAW) technologies. Examples include: 1) a response system to stimulate sows to stand when they are crushing piglets (Swineguard, Swine Tech, Cedar Rapids, IA); 2) a visual-based automatic tracking system to detect sickness and agonistic interactions at an per-animal level (Schmidt et al., University of Nebraska at Lincoln, NE), and; 3) environmental enrichment (EE) that simultaneously provides mental-stimulation to pigs and automatically collects data (Hulbert et al., K-State, Manhattan, KS). The first two technologies may be applied for improved efficiency, which may not motivate animal caretakers to adopt new housing strategies. Restricted space-allowance limits behavior-expression, and consequently, limits the amount and type of data that can be gained from the technologies. Therefore, more work is needed to apply these technologies on pigs in alternative housing systems (e.g. pens instead of farrowing stalls). Animal welfare improves with EE, but pigs can extinguish EE-use (i.e. boredom) or destroy EE-devices. Non-destructible, stimulating EE were tested on mini-boars. The automated data served a behavioral-biomarker for detecting subclinical injury biomedical research projects. This EE can be scaled-up for commercial pigs and has great potential for improving welfare of pigs in intensive systems while simultaneous providing semi real-time information to animal caretakers at an per-animal level. For swine production, early-adopters and investors are needed to help animal welfare researchers and engineers to transform technologies from PAM into PAW.

204 Discriminating intrauterine growth-restricted piglets through near-infrared spectroscopy of amniotic fluids

The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production systems, leading to substantial economic losses. The multifactorial causes of IUGR make their prediction before or during pregnancy a challenging task. The amniotic fluid, containing chemical secretions of both the developing fetus and the amnion-allantois membrane, may offer a unique opportunity to investigate the causes of IUGR in piglets. Here we applied near-infrared spectroscopy (NIRS) as a rapid tool to discriminate the chemical composition of the amniotic fluid from IUGR fetuses at different gestational ages. The uteri of gravid sows were dissected at 60% (n=6 sows) and 90% (n=6 sows) of gestational age. Amniotic fluids were collected with a sterile 10-mL syringe connected to an 18-G needle under visual guidance, and samples without blood contamination were kept at 4°C while the fetus was measured. Samples were selected according to fetal weight and were classified as small (mean − 2 SD), medium (mean), and large (mean + 2 SD) sizes in each litter. Selected samples were kept at −80°C until NIRS transmittance spectra collection (350-2500nm). At 60% of gestational age, male fetuses weighed 96±1.2, 133±1.7, and 159±1.9g and female fetuses weighed 117±1.1, 137±1.8, and 152±1.8g for small, medium, and large groups, respectively. The fetal weights at 90% of gestational age averaged 517±0.6, 757±0.6, and 912±0.7g for males and 532±0.6, 718±0.9, and 911±0.6g for females for small, medium, and large sizes, respectively. Chemometric analysis of the amniotic fluid spectra was applied to the wavelength range 1300-1600nm using a balanced data set (n=425) with an 80/20 calibration/validation distribution for linear discriminant analysis (LDA-PCA). Overall, we were able to discriminate samples according to fetal size and gestational age; LDA-PCA showed the highest size classification occurring with spectra derived from the small fetuses with an accuracy of 94.5-100% and 100% and 70.6% for the calibration and validation processes from 60% and 90% of gestational age, respectively. By contrast, when the analysis considered each sex at 60% of gestational age, the medium and small fetuses presented the highest size classification for females and males correspondingly. At 90% of gestational age, the large fetuses presented the best discrimination for both sexes. In conclusion, we were able to detect and discriminate chemical changes of the amniotic fluid from different fetuses using NIRS, indicating that this fluid contains molecules that may characterise IUGR in piglets. These observations will permit future investigations to identify specific molecules associated with IUGR that would lead to possible real-time corrective actions before birth. This work was supported by USDA-ARS grant no. 58-6402-3-018.

Review of Antibiotic Resistance, Ecology, Dissemination, and Mitigation in U.S. Broiler Poultry Systems

Since the onset of land application of poultry litter, transportation of microorganisms, antibiotics, and disinfectants to new locations has occurred. While some studies provide evidence that antimicrobial resistance (AMR), an evolutionary phenomenon, could be influenced by animal production systems, other research suggests AMR originates in the environment from non-anthropogenic sources. In addition, AMR impacts the effective prevention and treatment of poultry illnesses and is increasingly a threat to global public health. Therefore, there is a need to understand the dissemination of AMR genes to the environment, particularly those directly relevant to animal health using the One Health Approach. This review focuses on the potential movement of resistance genes to the soil via land application of poultry litter. Additionally, we highlight impacts of AMR on microbial ecology and explore hypotheses explaining gene movement pathways from U.S. broiler operations to the environment. Current approaches for decreasing antibiotic use in U.S. poultry operations are also described in this review.