C. K. Jones

Evaluating lysine requirements of nursery pigs fed low protein diets with different sources of nonessential amino acids

The Lys requirement of nursery pigs may be dependent on the source of nonessential AA (NEAA) nitrogen or the source of Lys itself. However, little peer-reviewed data examines these phenomena. The objectives of these experiments were to determine if the Lys requirement of pigs is altered when 1) low protein diets are supplemented with different sources of NEAA nitrogen or 2) Lys is supplied as a crystalline source instead of intact protein such as soybean meal (SBM). Two 14-d experiments were conducted using 450 (Exp. 1) and 540 (Exp. 2) pigs (PIC C22/C29 × 337). There were 10 treatments in each experiment, each aligned as a 2 × 5 factorial. In Exp. 1, there were 2 sources of NEAA (l-Gln + l-Gly or l-Gly + l-Ala + l-Pro + l-His) and 5 levels of Lys (1.2, 1.3, 1.4, 1.5, and 1.6%). In Exp. 2, there were 2 sources of proteins providing additional Lys (l-Lys HCl or SBM) and the same 5 levels of Lys. Following weaning at 18 to 22 d of age, pigs were fed a common starter diet for 5 d postweaning followed by a 14-d treatment period. Pigs were weighed and feed disappearance determined on d 0, 7, and 14 of the experiment. Data were analyzed using the MIXED and NLIN procedures of SAS (SAS Inst., Cary, NC). In Exp. 1, increasing CP and Lys resulted in a quadratic increase (P < 0.05) in ADG and a linear improvement (P < 0.05) in G:F during the 14-d treatment period. Breakpoint regression analyses revealed that optimum ADG was obtained at 1.36% Lys, while optimum G:F was obtained at 1.45% Lys. The source of NEAA did not affect (P > 0.10) growth performance during the treatment period. In Exp. 2, both ADG and G:F increased linearly (P < 0.05) with increasing Lys. Optimal ADG was obtained at 1.47% Lys, but the breakpoint for optimum G:F was above tested levels. Source of Lys did not affect (P > 0.10) ADG, but pigs fed additional Lys from crystalline sources had improved (P < 0.05) G:F than those fed additional Lys from intact protein at 1.50% Lys; however, the analyzed Lys values at this level differ. Overall, these data show that the standardized ileal digestibility Lys requirement of pigs is not altered when low protein diets are supplemented with different sources of NEAA nitrogen. Feed efficiency appears to be maximized when additional Lys is supplied by l-Lys HCl instead of SBM, but more research is needed to confirm this phenomenon.

Effects of drought-affected corn and nonstarch polysaccharide enzyme inclusion on nursery pig growth performance

The effectiveness of carbohydrase enzymes has been inconsistent in corn-based swine diets; however, the increased substrate of nonstarch polysaccharides in drought-affected corn may provide an economic model for enzyme inclusion, but this has not been evaluated. A total of 360 barrows (PIC 1050 × 337, initially 5.85 kg BW) were used to determine the effects of drought-affected corn inclusion with or without supplementation of commercial carbohydrases on growth performance and nutrient digestibility of nursery pigs. Initially, 34 corn samples were collected to find representatives of normal and drought-affected corn. The lot selected to represent the normal corn had a test weight of 719.4 kg/m3, 15.0% moisture, and 4.2% xylan. The lot selected to represent drought-affected corn had a test weight of 698.8 kg/m3, 14.3% moisture, and 4.7% xylan. After a 10-d acclimation period postweaning, nursery pigs were randomly allotted to 1 of 8 dietary treatments in a completely randomized design. Treatments were arranged in a 2 × 4 factorial with main effects of corn (normal vs. drought affected) and enzyme inclusion (none vs. 100 mg/kg Enzyme A vs. 250 mg/kg Enzyme B vs. 100 mg/kg Enzyme A + 250 mg/kg Enzyme B). Both enzymes were included blends of β-glucanase, cellulose, and xylanase (Enzyme A) or hemicellulase and pectinases (Enzyme B). Pigs were fed treatment diets from d 10 to 35 postweaning in 2 phases. Feed and fecal samples were collected on d 30 postweaning to determine apparent total tract digestibility of nutrients. The nutrient concentrations of normal and drought-affected corn were similar, which resulted in few treatment or main effects differences of corn type or enzyme inclusion. No interactions were observed (P > 0.10) between corn source and enzyme inclusion. Overall (d 10 to 35), treatments had no effect on ADG or ADFI, but enzyme A inclusion tended to improve (P < 0.10; 0.74 vs. 0.69) G:F, which was primarily driven by the improved feed efficiency (0.76 vs. 0.72; P < 0.05) of pigs fed Enzyme A in Phase 2 (d 10 to 25 postweaning) and was likely a result of improved xylan utilization. In conclusion, drought stress did not alter the nonstarch polysaccharide concentration of corn beyond xylan concentration, so it was not surprising that enzyme inclusion showed little benefit to nursery pig growth performance. However, improved feed efficiency of pigs fed diets containing Enzyme A from d 10 to 25 postweaning warrants further investigation

Evaluating Chemical Mitigation of Porcine Epidemic Diarrhea Virus (PEDV) in Swine Feed and Ingredients

Porcine Epidemic Diarrhea Virus (PEDV) is primarily transmitted by fecal-oral contamination. Research has confirmed swine feed or ingredients as potential vectors of transmission, so strategies are needed to mitigate PEDV in feed. The objective of this experiment was to evaluate the effectiveness of various chemical additives to prevent or mitigate post-processing PEDV contamination in swine feed and ingredients. Treatments were arranged in a 7 × 4 factorial with seven chemical treatments and four feed matrices. The chemical treatments included: negative control with no chemical addition, 0.3% commercial formaldehyde product, 1% sodium bisulfate, 1% sodium chlorate, 3% custom organic acid blend (OA), 2% custom essential oil blend (EO), and 2% custom medium chain fatty acid blend (MCFA). The four matrices included a complete swine diet, blood meal, meat and bone meal, and spray-dried animal plasma. Matrices were first chemically treated, then inoculated with PEDV, stored at room temperature, and analyzed by RT-PCR on d 0, 1, 3, 7, 14, 21, and 42 post inoculation. Formaldehyde, MCFA, EO, and OA addition each decreased RNA concentration of PEDV compared to the control (P < 0.05), with formaldehyde being the most effective on d 0. Feed matrix appears important in PEDV retention, as RNA concentrations were lower in the swine diet and blood meal than meat and bone meal or spray-dried animal plasma on d 0 (P < 0.05). Additionally, PEDV stability over time was influenced by matrix as RNA concentrations were greater by d 42 for spray-dried animal plasma and meat and bone meal than the complete swine diet and blood meal. In summary, time, formaldehyde, MCFA, EO, and OA all enhance the RNA degradation of PEDV in swine feed and ingredients as measured by RT-PCR, but their effectiveness varies within matrix. Notably, the MCFA was equally as successful at mitigating PEDV as a commercially-available formaldehyde product.

Evaluation of the Effects of Flushing Feed Manufacturing Equipment with Chemically- Treated Rice Hulls on Porcine Epidemic Diarrhea Virus Cross Contamination During Feed Manufacturing

Various strategies have been proposed to mitigate potential risk of porcine epidemic diarrhea virus (PEDV) transmission via feed and feed ingredients. Wet disinfection has been found to be the most effective decontamination of feed mill surfaces; however, this is not practical on a commercial feed production scale. Another potential mitigation strategy would be using chemically treated rice hulls flushed through the feed manufacturing equipment. Therefore, the objective of this study was to determine the effects of medium-chain fatty acids (MCFA) or formaldehyde-treated rice hull flush batches as potential chemical mitigation strategies for PEDV during feed manufacturing. Feed without evidence of PEDV RNA contamination was inoculated with PEDV. Based on polymerase chain reaction analysis, this feed had a cycle threshold (Ct) = 30.2 and was confirmed infective in bioassay. After manufacturing the PEDV-positive feed, untreated rice hulls, formaldehyde-treated rice hulls, 2% MCFA(a 1:1:1 blend of hexanoic, octanoic, and decanoic acid) treated rice hulls, or 10% MCFA-treated rice hulls were flushed through laboratory scale mixers. For the untreated rice hulls, 3 of 6 samples had detectable PEDV RNA, whereas 1 of 6 formaldehyde-treated rice hull flush samples and 2 of 6 of the 2% MCFA rice hull flush samples had detectable PEDV RNA. However, PEDV RNA was not detected in any of the 10% MCFA rice hull flush samples. Then, rice hulls treated with 10% MCFA were mixed and discharged through a production scale mixer and bucket elevator following PEDV-positive feed. No rice hull flush or feed samples from the mixer following chemically treated rice hull flush had detectible PEDV RNA. However, one 10% MCFA rice hull sample collected from the bucket elevator discharge spout had detectible PEDV RNA. Dust collected following mixing of PEDV contaminated feed had detectable PEDV RNA (Ct = 29.4) and was infectious. However, dust collected immediately after the 10% MCFA rice hull flush batch had a reduced quantity of PEDV RNA (Ct = 33.7) and did not cause infection. Overall, the use of rice hull flushes effectively reduced the quantity of detectible RNA present after mixing a batch of PEDV-positive feed. Chemical treatment of rice hulls with formaldehyde or 10% MCFA provided additional reduction in detectible RNA. Finally, dust collected after manufacturing PEDV-inoculated feed has the potential to serve as a vector for PEDV transmission.

Evaluating the Effect of Manufacturing Porcine Epidemic Diarrhea Virus (PEDV)-Contaminated Feed on Subsequent Feed Mill Environmental Surface Contamination

This study aimed to utilize the only known pilot feed mill facility approved for pathogenic feed agent use in the United States to evaluate the effect of manufacturing Porcine Epidemic Diarrhea Virus (PEDV)contaminated feed on subsequent feed mill environmental surface contamination. In this study, PEDV inoculated feed was manufactured and conveyed on equipment along with four subsequent batches of PEDV-free feed. Equipment and environmental surfaces were sampled using swabs and analyzed for the presence of PEDV RNA by PCR. The experiment was replicated three times with decontamination of the feed mill and all equipment between replications. Overall, environmental swabs indicated widespread surface contamination of the equipment and work area after a PEDV contaminated batch of feed was processed. There was little difference in environmental sample cycle threshold (Ct) values after manufacturing each of the subsequent PEDV-negative feed batches. In summary, introduction of PEDVinfected feed into a feed mill will likely result in widespread contamination of equipment and surfaces, even after several batches of PEDV-free feed are produced. Eliminating the PEDV RNA from the feed mill environment was challenging and required procedures that are not practical to apply on a regular basis in a feed mill. This data suggests that it is extremely important to prevent the introduction of PEDVcontaminated feed, ingredients, or other vectors of transmission to minimize PEDV-risk. More research should be conducted to determine if contaminated surfaces can lead to PEDV infectivity and to determine the best feed mill PEDV-decontamination strategies.

Stability of Four Commercial Phytase Products under Increasing Conditioning Temperature

A study was conducted to determine the stability of four commercial phytase products exposed to increasing conditioning temperatures. The four commercial products used were: Quantum Blue G (AB Vista, Plantation, FL); Ronozyme Hi Phos GT (DSM Nutritional Products, Parsippany, NJ); Axtra Phy TPT (Dupont, Wilmington, DE); and Microtech 5000 Plus (Guangdong Vtr Bio-Tech Co., Ltd., Guangdong, China). The phytase products were mixed as part of corn-soybean meal-based swine diet at a concentration recommended to provide a 0.12% aP release. All four diets were analyzed for phytase activity to establish baseline phytase activity for each product. Diets were then conditioned at four temperatures (149, 167, 185, and 203 F). The entire process was repeated on four consecutive days to create four replicates. Samples were taken while feed exited the conditioner and before entering the pellet die. Phytase stability was expressed as the residual phytase activity (% of baseline) at each conditioning temperature. No product × temperature interactions were observed for actual conditioning temperature, conditioner throughput, or residual phytase activity. As the target temperature increased the conditioning temperature increased (linear; P < 0.001) and conditioner throughput decreased (linear; P < 0.001). No evidence was observed for effects of phytase product on conditioning temperature or conditioner throughput. As target temperature increased, phytase activity decreased (linear; P < 0.001). Residual phytase activity decreased 1.07% for every 1 F increase in conditioning temperature between the target temperatures of 149 to 203 F. The product main effect was significant (P < 0.001). The Microtech 5000 Plus had decreased (P < 0.05) phytase activity when compared to all other products. There was no evidence for residual phytase differences between the Quantum Blue G, Ronozyme Hi Phos GT, or Axtra Phy TPT products. In the current experiment, target conditioning temperatures had a significant effect on phytase stability regardless of product, resulting in linear decreases in residual phytase activity as temperature was increased. However, Microtech 5000 Plus had decreased residual phytase activity (% of initial) when compared to all other products.

Effects of dietary supplementation of formaldehyde and crystalline amino acids on gut microbial composition of nursery pigs

Formaldehyde-based feed additives are approved in the US for Salmonella control and reducing bacterial contamination in animal feed. However, we hypothesize formaldehyde inclusion in swine diets may influence gut microbial composition due to its antimicrobial properties which might negatively influence microbial populations and pig growth performance. Also, formaldehyde inclusion in diets is known to reduce the dietary availability of amino acids. Therefore, our study was conducted to characterize if the effects of feed formaldehyde-treatment are due to influences on microbial population or diet amino acid (AA) sources. Dietary treatments were arranged in a (2u2009×u20092)u2009+u20091 factorial with formaldehyde treatment (none vs. 1000 ppm formaldehyde) and crystalline AA inclusion (low vs. high) with deficient AA content plus a positive control diet to contain adequate AA content without dietary formaldehyde. Treating diets with formaldehyde reduced growth rate (Pu2009=u20090.001) while the AA inclusion had no evidence of impact. Formaldehyde reduced feed bacterial content and altered fecal microbial communities (Pu2009<u20090.05). Therefore, we conclude that the negative influence on growth was due to the impact on the fecal microbial community. Implications are that strategies for feed pathogen control need to take into account potential negative impacts on the gut microbial community.

The amino acid composition and protein quality of various egg, poultry meal by-products, and vegetable proteins used in the production of dog and cat diets

ABSTRACT New protein ingredients are used to support pet food market growth and the development of new products while maintaining animal dietary needs. However, novel protein sources (e.g., spray‐dried chicken, and (or) rice, pea, and potato protein concentrates) have limited data available regarding their protein quality. The objective of this study was to evaluate protein ingredients used in the pet food industry by laboratory analysis and a chick growth assay as a model. Following analysis for proximate and amino acid composition, chicks (six birds per pen with four pens per treatment) were fed experimental diets for 10 d. Diets contained 10% crude protein from each of the experimental protein sources (spray‐dried egg—SDEG; spray‐dried egg white—SDEW, spray‐dried inedible whole egg—SDIE, chicken by‐product meal—CBPM, chicken meal—CKML, low‐temperature fluid bed air‐dried chicken—LTCK, low‐temperature and pressure fluid bed dried chicken—LTPC, spray‐dried chicken—SDCK, whey protein concentrate—WPCT, corn gluten meal—CGML, corn protein concentrate—CPCT, potato protein isolate—PPIS, rice protein concentrate—RPCT, pea protein isolate—PEPI, soy protein isolate—SPIS, and soybean meal—SBML) along with an N‐free diet (negative control). Chicks fed SDEG, SDIE, and LTPC had the highest protein efficiency ratio (PER; P < 0.0001; 5.18, 5.37, and 5.33, respectively), LTCK and SDCK were intermediate (4.54 and 4.79), and the CBPM and CKML were the lowest among the poultry proteins for EAA:NEAA, PER, and Lys availability. Among the vegetable proteins, PPIS and SBML had the highest PER values (3.60 and 3.48, P < 0.0001). In general, the chick PER method ranked the quality of animal protein sources higher than vegetable proteins, and these results were consistent with the EAA:NEAA ratio and Lys availability.

Animal Feed Mill Biosecurity: Prevention of Biological Hazards

Abstract To maintain the sustainable production of animal agriculture to feed the growing human population, animal feed manufacturers must use a variety of feed ingredients. These ingredients can be derived from plant- and animal-based sources, and both can present challenges regarding contamination with biological hazards. Biological hazards in animal feed can be categorized as transmissible spongiform encephalopathies and microbiological contaminants, with a more comprehensive draft list published by the FDA in 2006. More recently, feed has been identified as a vector for the transmission of viral particles, specifically porcine epidemic diarrhea virus. With the majority of animal feed being produced at commercial feed mills, these facilities play an important role in preventing the introduction of biological hazards from contaminating finished feeds. Although the complete elimination of biological hazards in finished animal feeds is not obtainable, multiple interventions can be implemented to reduce the risk. The following is a brief overview of animal feed ingredients and how they are derived and processed into finished feeds, associated biological hazards with various animal feed ingredients, recent regulatory guidelines regarding biological hazards, and an outline of the steps required to implement a biosecurity plan at a feed mill.

105 Young Scholar Presentation: A Review of Medium Chain Fatty Acids and Their Recent Role in Feed Safety.

Medium chain fatty acids (MCFA), have been researched extensively to reduce the likelihood of animal feed being contaminated by biological pathogens, including bacteria and viruses. Medium chain fatty acids have shown to be bactericidal and bacteriostatic by incorporating themselves into the lipid membrane of bacteria, which alters the cell membrane permeability leading to cell death. However, the effectiveness can be dependent upon the MCFA chain length and species of bacteria. Most research completed prior to 2013 focused on the antimicrobial properties of MCFA. However, with the emergence of Porcine Epidemic Diarrhea Virus (PEDV), MCFA began to gain more attention for their potential uses in feed safety and swine nutrition as a potential antiviral additive. Medium chain fatty acids have shown repeated success against PEDV in vivo and in vitro. Notably, 2% MCFA [1:1:1 blend of caproic, caprylic, and capric] was equally successful at mitigating PEDV as commercially-available formaldehyde products in complete swine feed (P>0.05). However, the effectiveness varies within feed matrix, as MCFA was not as effective as formaldehyde at mitigation in spray dried animal plasma and meat and bone meal (P<0.05). A lower concentration of the MCFA blend (1%), as well as the individual addition of 0.66% caproic, 0.66% caprylic, or 0.66% capric acids also enhanced the RNA degradation of PEDV in complete swine feed (P<0.05). Other research has evaluated the same 2% MCFA blend in a transboundary based study, replicating the time and environmental condition that feed ingredients undertake during a trip from China to the United States. Again, the MCFA treated ingredients were deemed to be negative throughout the simulated transboundary trip (P<0.05). Medium chain fatty acids have also been evaluated as a surface decontaminate and as a potential feed mill flush step. However, the overall effectiveness was not as substantial as the results observed in the feed ingredient studies. Currently, it is not known what the exact mode of action of the MCFA is against PEDV, but it is hypothesize that the MCFA are interacting with the lipid bilayer envelope of the virus and altering the envelope in a way in which it cannot bind with the host receptors. This mode of action would be similar to that of the bacteria as both outer membranes consist of a lipid bilayer. Future research is now focused on the use of MCFA against other enveloped and non-enveloped swine viruses as well as an antibiotic alternative in swine production.