Swine Feed Research Articles

Application of Genetic, Genomic and Biological Pathways in Improvement of Swine Feed Efficiency.

Despite the significant improvement of feed efficiency (FE) in pigs over the past decades, feed costs remain a major challenge for producers profitability. Improving FE is a top priority for the global swine industry. A deeper understanding of the biology underlying FE is crucial for making progress in genetic improvement of FE traits. This review comprehensively discusses the topics related to the FE in pigs including: measurements, genetics, genomics, biological pathways and the advanced technologies and methods involved in FE improvement. We first provide an update of heritability for different FE indicators and then characterize the correlations of FE traits with other economically important traits. Moreover, we present the quantitative trait loci (QTL) and possible candidate genes associated with FE in pigs and outline the most important biological pathways related to the FE traits in pigs. Finally, we present possible ways to improve FE in swine including the implementation of genomic selection, new technologies for measuring the FE traits, and the potential use of genome editing and omics technologies.

P36. Effect of probiotics yeast and bacillus on the in-vivo digestibility and in-vitro fermentation of high fibre swine feed ingredients

P36. Effect of probiotics yeast and bacillus on the in-vivo digestibility and in-vitro fermentation of high fibre swine feed ingredients

Versatility of a Salmonella Loop-Mediated Isothermal Amplification Assay Using Multiple Platforms and Master Mixes in Animal Food Matrices.

Improvement in Salmonella detection methods greatly enhances the efficiency of various food testing programs. A Salmonella loop-mediated isothermal amplification (LAMP) assay has been validated in animal food through multi-laboratory validation. The study aimed to demonstrate the versatility of this molecular assay while expanding it to multiple platforms and various reagent choices for use in animal food testing. Following the U.S. Food and Drug Administration (FDA)'s Guidelines for the Validation of Analytical Methods for the Detection of Microbial Pathogens in Foods and Feeds, we examined the inclusivity, exclusivity, and LOD of the assay using two platforms (7500 Fast and Genie II) and three LAMP master mixes (GspSSD, GspSSD2.0, and WarmStart) in seven animal food matrixes (dry cat food, dry dog food, cattle feed, dairy feed, horse feed, poultry feed, and swine feed). The FDA's Bacteriological Analytical Manual (BAM) Salmonella culture method was the reference method. Inclusivity and exclusivity data were consistent among all six platform and master mix combinations with a few exceptions. Comparable LODs were observed down to the single-cell level (WarmStart was 10-fold less sensitive). Performance was similar to the BAM method for detecting fractional positive results in seven animal food matrixes. Nonetheless, LAMP time to positive results and annealing/melting temperature differed among master mixes and platforms. The Salmonella LAMP assay was successfully validated in two platforms and three master mixes, making it a flexible tool for use by the FDA's field laboratories in regulatory testing of animal food and for adoption by other food testing programs. We demonstrated the LAMP assay's versatility on two platforms and three master mixes for the rapid and reliable screening of Salmonella in seven animal food matrixes. GspSSD2.0 was the fastest master mix (time to positive results as early as 3.5 min) while Genie II had several attractive features from a user perspective.

Effects of Pelleting and Long-Term High-Temperature Stabilization on Vitamin Retention in Swine Feed.

Simple SummaryPelleting of animal feeds has been practiced for decades, to denature protein, increase starch gelatinization, decrease anti-nutrient factor content, and improve the nutritional value of feed ingredients. Long-term high-temperature stabilization after pelleting has been employed by feed manufacturers to control the spread of pathogenic microorganisms, especially African swine fever through feed. However, pelleting is an aggressive process against vitamins, and prolonged high temperatures may further damage the vitamins’ structure. Our results showed that the recovery of vitamin A, vitamin E, vitamin B2, and vitamin B6 significantly decreased after pelleting and long-term high-temperature stabilization, and the high-temperature stabilization process has the most significant influence.The objective of this study was to study the effect of pelleting and long-term high-temperature stabilization on the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in swine feed. Piglet diets (diet 1 and 3) were pelleted after conditioning at 83 °C for 120 s, and were high-temperature stabilized at 90 °C for 8.5 min after pelleting; the finishing pig diets (diet 2, 4, and 5) were pelleted after conditioning at 82 °C for 90 s, and were high-temperature stabilized at 85 °C for 9 min after pelleting; the samples were obtained before condition, after condition, after pelleting, and after cooling. The contents of vitamin A and vitamin E in diets 1–5 and vitamin B2, and vitamin B6 in diets 3–5 were detected. The results showed that: (1) the conditioning process had no significant effect on the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in all experimental diets (p > 0.05); (2) the pelleting process and high-temperature stabilization process after pelleting had different degrees of influence on vitamins, among which the stabilization process had a more significant effect on the retention of vitamins. After pelleting and long-term high-temperature stabilization, the retention of vitamin A, vitamin E, and B2, and vitamin B6 were 68.8–77.3%, 56.9–90.1%, 63.8–70.3%, and 60.1–67.0%, respectively. In the process of pelleting and long-term high-temperature stabilization, the retention of vitamin A, vitamin E, vitamin B2, and vitamin B6 in the feed were significantly reduced (p < 0.05). Therefore, vitamin loss during high temperature and over a long period of time is worth considering, and vitamins must be over-supplemented.

SISTEMA PRODUTIVO SUINÍCOLA: ABORDAGENS BIOLÓGICA, DE PROCESSOS, SISTÊMICA E LOGÍSTICA

O conhecimento das atividades, processos, bem como do fluxo de insumos, produtos e informações podem basear o gerenciamento de um sistema produtivo, ocasionando assim vantagens competitivas, redução de custos e previsões de ações futuras. Neste contexto, o presente trabalho tem como objetivo apresentar - fundamentado na literatura e através de enfoques biológico, produtivo, sistêmico e logístico - os processos, entradas, saídas, atividades e fluxos que fazem parte da produção suinícola, a fim de contribuir para o seu desenvolvimento econômico, social e ambiental. Através de uma visão sistêmica da produção suinícola, verificou-se que a distância entre as granjas e a região fornecedora de ração influencia fortemente aspectos econômicos e ambientais. Assim, granjas localizadas próximas às plantações de grãos apresentam vantagens competitivas. Baseado neste argumento verificou-se uma tendência migratória da suinocultura brasileira, da região sul para a nova fronteira agrícola MAPITOBA. A fim de mitigar os efeitos negativos ocasionados por esta migração, medidas tecnológicas, administrativas e políticas devem ser tomadas.

61 Persistence and Distribution of African Swine Fever Virus in Feed and Feed Mill Environment Over Time After Manufacture of Experimentally Inoculated Feed and Subsequent Manufactured Batches of Feed

Abstract To reduce the risk of feed-based pathogens causing disease, some feed manufacturers quarantine high-risk ingredients before their inclusion in feed. Data exists that confirms this practice is effective, but there is no information about swine pathogen survival in mill environments. This objective of the study was to determine survival of African swine fever virus (ASFV) in swine feed and mill surfaces. A pilot-scale feed mill manufactured a batch of ASFV-free feed (Batch 1), followed by a batch inoculated with ASFV (5.6×104 TCID50/gram; Batch 2). Then 4 subsequent ASFV-free batches were manufactured (Batch 3-6). After each batch,10 feed samples were aseptically collected in a double ‘X’ pattern. During feed manufacturing, 24 steel coupons were placed on the floor of the manufacturing area and feed dust settled on them during the milling process and overnight. Feed samples and steel coupons were stored at room temperature. Three of each were randomly selected and analyzed for ASFV DNA on d 1, 3, 7, 14, 28, 60, 90, and 180. The interaction of batch and day impacted (P = 0.023) the number of genomic copies detected per gram of feed. There were no differences of genomic copies/g in early batches; but the quantity of detectable ASFV decreased with increasing storage time after collection. In Batches 4-6, the greatest quantity of ASFV was detected on d 1, but the lowest quantity was detected on d 7, 60, and 28 or 180 for Batches 5, 6, and 7, respectively. There was no evidence (P = 0.433) of ASFV degradation on environmental coupons over the 180-d storage period. This study found that quarantine time can help reduce, but not eliminate ASFV in feed over time. However, ASFV survives on feed manufacturing surfaces for at least 180 d. Additional research is necessary to evaluate the viability of detected virus to cause illness.

264 Awardee Talk: A Systems Approach for Evaluating Productivity, Nutritional Efficiency, and Environmental Impacts of Feeding Programs for Growing-Finishing Pigs

Abstract Traditional evaluation of swine feeding programs have generally focused only on economically important performance and carcass measures but achieving sustainable pork production also requires formulating diets to reduce negative environmental impacts. Therefore, a systems approach is needed to evaluate swine feeding programs from multiple perspectives. The objectives of this study were to compare productivity, nutritional efficiency, and environmental outcomes of four different growing-finishing feeding programs consisting of diets containing corn and soybean meal (CSBM), low protein CSBM supplemented with crystalline amino acids (LP), CSBM with 30% distillers dried grains with solubles (DDGS), and DDGS supplemented with crystalline Ile, Val, and Trp (DDGS+IVT). In experiment 1, growth performance and carcass characteristics of pigs (n=288; initial BW=36.9±4.2 kg) were measured in a 12-wk feeding trial. There were no differences in ADG, ADFI, carcass yield, and carcass fat-free lean percentage observed among feeding programs but gain:feed was greater (P &amp;lt;0.05) in pigs fed CSBM and DDGS+IVT than pigs fed LP. In experiment 2, nitrogen and phosphorus balance of pigs (n=32; initial BW=59.9±5.1 kg) were determined in a metabolism study. Pigs fed CSBM had greater N retained (P &amp;lt;0.05) than those fed other diets, but pigs fed LP had greater (P &amp;lt;0.05) protein efficiency ratio but lower (P &amp;lt;0.05) P intake than pigs fed CSBM and DDGS. In experiment 3, data collected from the previous 2 experiments were used to calculate environmental impacts of the four feeding programs through life-cycle assessments using Opteinics™ (BASF, Lampertheim, Germany). Feeding CSBM had the least impact per 1,000 kg carcass weight on climate change and fossil resource use, while LP had the least impact on acidification, water use, and total environmental footprint. These results indicate that each feeding program has comparative advantages depending on the metrics, which requires using a holistic systems approach for decision-making to improve the sustainability of pork production.

PSVI-19 Yeast-Based High Protein DDGS Has Similar Energy Digestibility in Comparison to Commonly Used Feed Ingredients in Swine Diets

Abstract Alternative ingredients and co-products from the ethanol and biofuel industries represent an opportunity for utilization in swine diets. In this context, understanding nutritional value to practical swine feeding begins with product characterization and determination of nutrient digestibility. The objective of this study was to determine metabolizable energy (ME) of Yeast-based high protein DDGS (HP-GDDY) fed to growing pigs in comparison with common feed ingredients in swine diets. A total of 28 barrows were adapted to individual metabolic crates and fed with 7 diets, a corn-based basal diet and 6 corn–based diets containing spray dried HP-GDDY, ring dried HP-GDDY, conventional DDGS, soybean meal (SBM), enzymatically-treated soybean meal (HP300), and fish meal (FM). Pigs were fed at 4% of BW and assigned to a crossover design with 2 collection periods, which provided 8 observations for each treatment. Fecal and urine samples were collected for 5 d after 7 d of adaptation to determine gross energy content and calculate ME (Table 1). Energy digestibility in spray GDDY and ring GDDY diets was greater than conventional DDGS diet and similar to SBM, HP300, and FM diets. The ME content in ring GDDY (3,926.7 Kcal/Kg) was similar to spray GDDY (4,480.5 Kcal/Kg). The ME in SBM (3824.5 Kcal/Kg), HP300 (3,883.8 Kcal/Kg), and FM (3,823 Kcal/Kg) was similar to spray and ring GDDY. Energy values for spray (4480.48 Kcal/Kg) and ring (3926.70 Kcal/Kg) GDDY are higher when compared with previous reported values for HP DDGS (3732 Kcal/Kg, NRC, 2012). Data from this study support that HP-GDDY products have comparable or greater energy value to commonly used ingredients in swine diets and that drying method had minor influence on energy digestibility. These novel feed ingredients can be used in practical pig diet formulation.

PSV-5 Effects of Benzoic Acid and an Essential Oils Blend on Detection of Swine Viruses in Inoculated Swine Feed and Premix

Abstract Feed has been shown to harbor viable viruses over an extended period. This study investigated the use of benzoic acid (BA) and an essential oils blend (EO) to mitigate the presence of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and Senecavirus A (SVA) in a complete diet (Exp. 1) and a vitamin premix (Exp. 2). Experiment 1 consisted of a control with no additive, 0.5% BA, 0.5% BA and 200 ppm EO, 0.3% BA and 120 ppm EO, and 0.25% BA and 100 ppm EO. Feed samples were inoculated with PEDV, PRRSV, and SVA. For Exp. 2, the control contained no additive, and treatment had 2.68% EO included to mitigate PEDV. Inoculated feed or premix was stored at room temperature with sampling points at 2, 5, and 15 d post-inoculation (dpi). Samples were analyzed using triplex qRT-PCR to detect changes in RNA quantities for all viruses. Detectible PRRSV in the feed demonstrated a quadratic decrease over time (P = 0.038). A significant treatment × day interaction was observed in the feed for both PEDV (P = 0.008) and SVA (P &amp;lt; 0.001). The 0.5% BA treatment had greater (P &amp;lt; 0.05) amounts of detectible PEDV on d 2 and 5 and decreased detectible PEDV on d 15 compared with control. The 0.5% BA treated feed demonstrated decreased (P &amp;lt; 0.05) detectable SVA at 2 dpi but greater detectible SVA at 15 dpi compared with control. Both PEDV and SVA demonstrated viral degradation over time. The use of the EO in the vitamin premix had no evidence of main or interactive effects. In conclusion, 0.5% BA decreased PEDV at 15 dpi, but BA and EO mitigation in this model did not provide consistent evidence for increased viral degradation. However, time decreased detectability of all three viruses.

Optimization of Extrusion Process for Pentosanase-Supplemented Swine Feed: Evaluation of Physical Properties and Enzyme Stability

Extrusion of pentosanase supplemented swine feed to improve digestibility was optimized and the extrudates’ physical properties, and enzyme stability were investigated. The effects of feed moisture content, die end temperature, and screw speed on product responses, including expansion ratio, bulk density, and hardness were evaluated using the response surface methodology. Following conditions yielded the swine feed with physical properties comparable to the commercial products, feed moisture content at 18–21% (w/w), die end temperature of 95–120 °C, and screw speed at 100–150 rpm. Crude pentosanase was added to the ingredients at 0.5 g/kg and extruded with 2 levels of die end temperature at 95 and 110 °C. Residual activity of pentosanase in extruded swine feed indicated that an increase in die end temperature reduced the activity by 34–35%. Higher activity and stability of pentosanase were observed at pH 3.0 compared to pH 6.8. A significant decrease in the enzyme activity was observed during a 4 week storage period at room temperature. Optimal conditions for the extrusion of pentosanase-supplemented swine feed were obtained. However, the enzyme stabilization in extruded swine feed during the long storage requires further study.

Fiber digestibility in growing pigs fed common fiber-rich ingredients – A systematic review

Abstract The application of high-fiber ingredients in the swine feed industry has some limitations considering that high amounts of fiber are resistant to endogenous enzymatic degradation in the pig’s gut. However, there is growing interest in fiber fermentation in the intestine of pigs due to their functional properties and potential health benefits. Many strategies have been applied in feed formulations to improve utilization efficiency of fiber-rich ingredients and stimulate their prebiotic effects in pigs. This manuscript reviews chemical compositions, physical properties, and digestibility of fiber-rich diets formulated with fibrous ingredients for growing pigs. Evidences presented in this review indicate there is a great variation in chemical compositions and physical properties of fibrous ingredients, resulting in the discrepancy of energy and fiber digestibility in pig intestine. In practice, fermentation capacity of fiber components in the pig’s intestine can be improved using strategies, such as biological enzymes supplementation and feed processing technologies. Soluble dietary fiber (SDF) and insoluble dietary fiber (IDF), rather than neutral detergent fiber (NDF) and acid detergent fiber (ADF), are recommended in application of pig production to achieve precise feeding. Limitations of current scientific research on determining fiber digestibility and short chain fatty acids (SCFA) production are discussed. Endogenous losses of fiber components from non-dietary materials that result in underestimation of fiber digestibility and SCFA production are discussed in this review. Overall, the purpose of our review is to provide a reference for feeding the pig by choosing the diets formulated with different high-fiber ingredients.

Ideating A Sustainable Swine Feed Prototype: A Qualitative Approach in Farmers’ Pain Point Identification and Product Development

There is a growing interest and trend in new product development (NPD) from food waste. However, most qualitative approaches rarely use the lean entrepreneur concept in the context of new product development (NPD), which allows for understanding customer insight rather than the traditional qualitative approach. Therefore, this study aims to (1) explore the swine farmer behaviors, desired outcomes, and pain points in using swine feedstuffs, (2) select three representative segments and identify high-value customers of swine feeds, and (3) develop a sustainable swine feed prototype from the fermented fish industrial residues. The target users, 24 pig farmers from 11 provinces across the Northeastern Region of Thailand, were recruited to participate in this research. Qualitative in-depth semi-structured interviews and thematic analysis were conducted to analyze their behaviors, desired outcomes, and pain points towards pig feed usages. The framework was combined with in-depth qualitative interviews and the customer, problem, and solution zoom tools. The results revealed that household farmers were the target customer segment of swine feed made from fermented fish industrial wastes. In addition, the findings showed that the household farmers typically fed their pigs with instant feeds and alternative feeds. Moreover, their desired outcomes were the pellet feed with nutrients. Furthermore, the pain points of the household farmers were the expensive cost of feeds and mold in feeds. Therefore, this segment needs to minimize the cost of feeds by using other sustainable alternatives.

Efficacy of biosynthesizing folate, riboflavin and typical probiotic traits reveal the potential use of \(\textit{Lactobacillus plantarum}\) LCN13 as a feed additive for swine farming

Lactic acid bacteria have been advocated as probiotics to replace antibiotic growth promoters, improve growth performance, and reduce cost production in swine farming. The aim of this study is to identify and evaluate the probiotic traits of strain LCN13 isolated from traditionally fermented feed for swine. Thirty-five bacterial isolates with different morphological characteristics were isolated, among which 9 isolates showed the ability to produce lactic acid and antibacterial activity against pathogenic bacteria. Among them, isolate LCN13 exhibited a strong capacity to produce lactic acid (18.5 ± 0.31 g/L), inhibited gastrointestinal pathogens such as Salmonella typhimurium ATCC 14028 (18.3 ± 1.52 mm), Escherichia coli ATCC 11105 (24.7 ± 2.14 mm), and Staphylococcus epidermidis ATCC 35984 (31.6 ± 2.93 mm), and produced 182 ng/mL folate and 233 ng/mL riboflavin as measured by LC-MS/MS after 24 hours of incubation. Based on morphological, biochemical, and 16S rRNA gene analysis, the isolate LCN13 was identified as Lactobacillus plantarum. Phenotypic analysis revealed that L. plantarum LCN13 showed remarkable resistance to 1.2% ox-bile salt, 2.0 mM H2O2, and pH 3.0. In addition, the ability to produce high levels of folate (253.6 ± 10.7 ng/mL) and riboflavin (312.0 ± 12.2 ng/mL) after 48 hours was exploited for the first time in the L. plantarum. Taken together, L. plantarum LCN13 might serve as a potential probiotic candidate for animal farming.

Applications of Smart Technology as a Sustainable Strategy in Modern Swine Farming

The size of the pork market is increasing globally to meet the demand for animal protein, resulting in greater farm size for swine and creating a great challenge to swine farmers and industry owners in monitoring the farm activities and the health and behavior of the herd of swine. In addition, the growth of swine production is resulting in a changing climate pattern along with the environment, animal welfare, and human health issues, such as antimicrobial resistance, zoonosis, etc. The profit of swine farms depends on the optimum growth and good health of swine, while modern farming practices can ensure healthy swine production. To solve these issues, a future strategy should be considered with information and communication technology (ICT)-based smart swine farming, considering auto-identification, remote monitoring, feeding behavior, animal rights/welfare, zoonotic diseases, nutrition and food quality, labor management, farm operations, etc., with a view to improving meat production from the swine industry. Presently, swine farming is not only focused on the development of infrastructure but is also occupied with the application of technological knowledge for designing feeding programs, monitoring health and welfare, and the reproduction of the herd. ICT-based smart technologies, including smart ear tags, smart sensors, the Internet of Things (IoT), deep learning, big data, and robotics systems, can take part directly in the operation of farm activities, and have been proven to be effective tools for collecting, processing, and analyzing data from farms. In this review, which considers the beneficial role of smart technologies in swine farming, we suggest that smart technologies should be applied in the swine industry. Thus, the future swine industry should be automated, considering sustainability and productivity.

Effect of Grain Moisture Content and Roller Mill Gap Size on Various Physical Properties of Yellow Dent Corn Flour

Corn has six main varieties grown globally for animal feed, human consumption, and commercial/industrial purposes. Flour is an end-product of corn dry-milling. Products that are derived from corn flour often show differences in physical, chemical, and pasting properties due to corn varietal differences, milling methods, differences in flour particle sizes, and drying temperatures. The study aimed to determine the effect of different moisture contents of yellow dent corn and roller gap sizes, on the physical properties of the resulting corn flour. The possibility to use the flour in the manufacturing of animal feed and ethanol production was also considered. Yellow dent corn grain with moisture contents (MC) of 8%, 14.0%, and 18%, and roller gap sizes (GAP) of 0.1016 mm, 0.2032 mm, and 0.3048 mm were used. The Witt corrugated roller mill equipment with rollers of 1/32 inches corrugations was used to produce fine grits and flours. The particle sizes obtained were between 0.54 mm and 0.75 mm which increased with an increase in MC and GAP. Grain with 8% MC and GAP of 0.1016 mm and 0.2032 mm, and grain with 14.0% MC and GAP of 0.1016 mm can produce flour of particle sizes good for swine feed. Grain with 8% MC and GAP of 0.3048 mm and grain with 14.0.0% MC and GAP of 0.1016 mm and 0.2032 mm can produce flour of particle sizes good for ruminant feed. Grain with 18% MC and GAP of 0.1016 mm, and grain with 14.0% MC and GAP of 0.2032 mm can produce flour of particle sizes good for poultry feed. GAP of 0.1016 mm and 8% MC can produce flour of particle sizes suitable for the ethanol production industry. Flour preparation should purposely be done based on grain MC and GAP. The geometric mean diameter of particle sizes ranged from 0.54 mm-0.75 mm, and the geometric mean diameter of particle sizes increased with increasing MC and GAP. Also, grains with 8% MC had the highest loss in flour, and the higher moisture of 18% significantly affected the red color of flour.

Development of a highly sensitive monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay for the detection of avilamycin in feed

ABSTRACT An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed using a highly sensitive and specific monoclonal antibody against avilamycin. The immunising antigen synthesised through the carbonyldiimidazole (CDI) method was used to prepare antibodies. The established ic-ELISA, after optimisation of conditions, possessed a half maximum inhibitory concentration (IC50) value of 7.44 ng mL−1 and the detection limit of 0.21 ng mL−1 in the standard curve. The spiked experiments indicated that the limits of detection were 1.86 µg kg−1 and 2.31 µg kg−1 in swine feed and chicken feed, respectively. In addition, the average recoveries ranged from 74.7 to 105.4% with the coefficient of variation less than 11%. The good correlation (R2 = 0.9818) between the result of ic-ELISA and HPLC demonstrated the reliability of the developed ic-ELISA, which showed that the ic-ELISA developed here achieves the aim of strengthening the monitoring of avilamycin residues and the inspection of import and export related products.

Interspecific variation in wildlife responses to cattle, swine and chicken feed in the forests surrounding poultry farms.

To strengthen farm biosecurity, wildlife behaviors around livestock environments require significant attention. Livestock feed is considered one of essential factors that attract wildlife to the livestock environment. We experimentally studied wildlife response to cattle, swine, and chicken concentrated feeds in the forests surrounding poultry farms. In 14 feeding sites, four feed conditions were established: without feed (control); cattle feed; chicken feed; and swine feed. Wildlife behaviors at each feed point were monitored using infrared cameras. In 3,175 videos, 10 mammals were photographed on 10 or more occasions. Wildlife more frequently appeared at the points with feed than without feed. In addition, the number of videos that captured foraging or interest behaviors was largest for swine feed, followed by chicken feed, then cattle feed. There was a large difference among wildlife in their response to livestock feeds, although each species did not have a strong preference for a specific feed. Livestock feeds invite frequent visits by high and moderate response groups, especially omnivores and carnivores with omnivorous tendencies. Therefore, to protect against such wildlife intrusion, leftover feed and feed storage must be properly managed. This study also suggests that livestock feeds may not cause intrusions by rare response group species; hence, if their intrusions occur, they may be due to factors other than livestock feed. The study situation can partly reflect actual feed-stealing situations. The results will contribute to consider the properly management to protect livestock environments from wildlife intrusions.

Effect of Percent Fines in Pelleted Diets on Growth Performance of Grow-Finish Pigs During Three Phases of Production

Swine feed is commonly pelleted to improve F/G, feed handling characteristics, and bulk density. However, the degree of improvement in F/G of pigs depends on pellet quality or the percent fines at the feeder. The objective of this study was to determine if the response to pellet quality was dependent on the BW range of grow-finish pigs. Therefore, a total of 350 pigs (initially 80 lb; line 600 × 241, DNA) were randomly placed in 35 pens with 10 pigs per pen (5 barrows and 5 gilts per pen). All pigs were fed a common diet until the onset of the first experiment. At this time, pens of pigs were weighed to determine average pig weight per pen and split into 7 blocks based on average pen weight. Treatments were randomly assigned to pens within block. There was a total of 5 treatments with 7 replications per treatment. For Exp. 1, 2, and 3, pigs were fed treatments for 20 days from 96 to 150 lb, 21 days from 179 to 234 lb, and 20 days from 260 to 317 lb, respectively. Between each experiment, a 10-day washout period was utilized to mitigate any residual effects from the previous experiment and pens were rerandomized to treatment before the start of each experiment. Treatments consisted of 10% fines (screened pellets), pellets with increasing fines inclusions (45, 65, and 85% fines), and mashed feed. Experiment 1 (96 to 150 lb) treatments contained 90.4, 67.6, 46.4, and 12.5% fines at the feeder. There was no evidence of differences in ADG or ADFI in pigs fed the mash diet compared to those fed any of the pelleted treatments. However, pigs fed pellets with 12.5% fines had improved (P < 0.05) F/G compared to those fed mash diets. Pig ADFI and total feed cost increased (linear, P > 0.006) in those fed pelleted diets with an increasing percentage of fines. Pigs fed pelleted diets with increasing percentage of fines (linear, P = 0.002) had poorer F/G. Experiment 2 (179 to 235 lb) treatments consisted of 86.0, 60.5, 43.6, and 15.5% fines at the feeder. There was no evidence of differences in ADG. Pigs fed 86.0% fines had a tendency for increased (P < 0.1) ADFI and poorer F/G when compared to the mash diet. Therefore, total feed cost increased (P < 0.05) for pigs fed pellets with 86.0% fines when compared to pigs fed the

Persistence of African Swine Fever Virus in Feed and Feed Mill Environment over Time after Manufacture of Experimentally Inoculated Feed

To reduce the risk of disease from harmful feed-based pathogens, some feed manufacturers quarantine high-risk ingredients prior to their inclusion in feed. Data exist that confirms this practice is effective, but to our knowledge there is no information about porcine pathogen survival in mill environments. The objective of this study was to determine survival of African swine fever virus (ASFV) in swine feed and on mill surfaces after manufacture of experimentally inoculated swine feed. A pilot-scale feed mill was placed within a biosecurity level (BSL) 3 facility to manufacture batches of feed. The priming batch, Batch 1, was ASFV-free feed and was followed with Batch 2 which was experimentally inoculated with ASFV (5.6 × 104 TCID50/gram). Four subsequent ASFV-free batches were then manufactured (Batch 3-6). After each batch of feed, 10 feed samples were aseptically collected in a double ‘X’ pattern. During feed manufacturing, 24 steel coupons were placed on the floor of the manufacturing area and feed dust was allowed to settle onto them overnight. Once feed manufacturing was completed, feed samples and steel coupons were stored at room temperature. On the day of (day 0) and d 3, 7, 14, 28, 60, 90, and 180 after feed manufacturing, feed samples and 3 steel coupons were randomly selected, taken out of storage, and analyzed for ASFV DNA. For feed samples there was a statistically significant (P = 0.023) batch × day interaction for log10 genomic copies per gram of feed, and a marginal statistical significance (P = 0.072) for batch × day interaction for cycle threshold (Ct) values. This indicates that the batch of feed and days held at room temperature impacted the amount of the detectable ASFV DNA in feed samples. There was no evidence (P = 0.433) of ASFV degradation on environmental coupons over the 180-d storage period. This study found that quarantine time can help reduce, but not eliminate ASFV DNA in feed over time. Surprisingly, ASFV DNA is detectable on feed manufacturing surfaces for at least 180 days.

Effect of Percent Fines in Pelleted Diets on Growth Performance of Grow-Finish Pigs During Three Phases of Production

Swine feed is commonly pelleted to improve F/G, feed handling characteristics, and bulk density. However, the degree of improvement in F/G of pigs depends on pellet quality or the percent fines at the feeder. The objective of this study was to determine if the response to pellet quality was dependent on the BW range of grow-finish pigs. Therefore, a total of 350 pigs (initially 80 lb; line 600 × 241, DNA) were randomly placed in 35 pens with 10 pigs per pen (5 barrows and 5 gilts per pen). All pigs were fed a common diet until the onset of the first experiment. At this time, pens of pigs were weighed to determine average pig weight per pen and split into 7 blocks based on average pen weight. Treatments were randomly assigned to pens within block. There was a total of 5 treatments with 7 replications per treatment. For Exp. 1, 2, and 3, pigs were fed treatments for 20 days from 96 to 150 lb, 21 days from 179 to 234 lb, and 20 days from 260 to 317 lb, respectively. Between each experiment, a 10-day washout period was utilized to mitigate any residual effects from the previous experiment and pens were rerandomized to treatment before the start of each experiment. Treatments consisted of 10% fines (screened pellets), pellets with increasing fines inclusions (45, 65, and 85% fines), and mashed feed. Experiment 1 (96 to 150 lb) treatments contained 90.4, 67.6, 46.4, and 12.5% fines at the feeder. There was no evidence of differences in ADG or ADFI in pigs fed the mash diet compared to those fed any of the pelleted treatments. However, pigs fed pellets with 12.5% fines had improved (P < 0.05) F/G compared to those fed mash diets. Pig ADFI and total feed cost increased (linear, P > 0.006) in those fed pelleted diets with an increasing percentage of fines. Pigs fed pelleted diets with increasing percentage of fines (linear, P = 0.002) had poorer F/G. Experiment 2 (179 to 235 lb) treatments consisted of 86.0, 60.5, 43.6, and 15.5% fines at the feeder. There was no evidence of differences in ADG. Pigs fed 86.0% fines had a tendency for increased (P < 0.1) ADFI and poorer F/G when compared to the mash diet. Therefore, total feed cost increased (P < 0.05) for pigs fed pellets with 86.0% fines when compared to pigs fed the