Dietary pectin at 0.2% in milk replacer did not inhibit growth, feed intake, or nutrient digestibility in a 3-week neonatal pig study.

Pectin is a fermentable soluble fiber that can be used as a thickener in formulas for infants and young children. The Joint FAO/WHO Expert Committee on Food Additives concluded that pectin is not of concern for inclusion in infant formula at up to 0.2%. As part of the safety assessment of the suitability of pectin for young infants (≤12 weeks of age), we conducted a 3-week dietary study in a neonatal pig model to 1) investigate the impact of pectin at different doses on neonatal pigs' growth and 2) explore the potential explanation for the dose response. Male and female neonatal pigs were fed milk replacer containing 0, 0.2%, or 1% pectin beginning on postnatal day 2 for 21 days. Body weight, feed intake, and apparent ileal digestibility of dry matter, crude protein, and energy were reduced in pigs fed diets containing 1% pectin (P < 0.01) but not in pigs fed with 0.2% pectin. These data indicate that inclusion of pectin in the diet at 0.2%, equivalent to 704 mg/kg BW/day is safe, well tolerated, and did not result in any adverse health effects in this neonatal pig study.

Effects of dietary clays on performance and intestinal mucus barrier of broiler chicks challenged with Salmonella enterica serovar Typhimurium and on goblet cell function in vitro.

In vivo and in vitro experiments were conducted to test for beneficial effects of dietary clays on broiler chicks challenged with Salmonella enterica serovar Typhimurium and to explore potential mechanisms. First, two hundred forty 1-d-old male broilers (initial BW: 41.6 ± 0.4 g) were allotted in a 2 × 4 factorial arrangement in a randomized complete block design. There were 2 infection treatments (with or without Salmonella) and 4 diets: basal (BAS), 0.3% smectite A (SMA), 0.3% smectite B, and 0.3% zeolite. The Salmonella reduced (P < 0.05) the growth rate of chicks fed the BAS, and feeding clay largely restored it (challenge × diet interaction, P < 0.05). Goblet cell number and size were increased (P < 0.05) by Salmonella in chicks fed the BAS and were reduced (P < 0.05) in Salmonella-challenged chicks by feeding SMA. Villus height was reduced by the Salmonella challenge in the chicks fed dietary clays (P < 0.01) but not in chicks fed the BAS (interaction P < 0.05). A human adenocarcinoma cell line (LS174T) was cultured in vitro in 3 separate experiments in the absence or presence of 3 concentrations (0.05, 0.10, and 0.50%) of SMA. Expression of mucin 2 (MUC2), resistin-like molecule ß (RELMß), and trefoil factor 3 (TFF3) were determined by real-time reverse-transcription PCR. The expression of RELMß was increased and expression of MUC2 was reduced (P < 0.05) by 0.10% SMA. Also, LS174T cells were cultured without or with SMA (0.05 and 0.10%) and the medium and cell lysate were analyzed for RELMß using an immunoblot assay. Protein expression of RELMß in the cell lysate was reduced (P < 0.05) by SMA addition but increased in the medium, indicating that SMA increased secretion of RELMß, thus depleting the cell and concentrating this protein in the medium. In conclusion, the dietary clays restored the growth depression caused by Salmonella, and changes in goblet cell function may contribute to the benefits of one of the clays, specifically SMA.

Standardization of a silver stain to reveal mesoscale myelin in histological preparations of the mammalian brain.

BACKGROUND: The brain is built of neurons supported by myelin, a fatty substance that improves cellular communication. Noninvasive magnetic resonance imaging (MRI) is now able to measure brain structure like myelin and requires histological validation. NEW METHOD: Here we present work in small and large biomedical model mammals to standardize a silver impregnation method as a high-throughput histological myelin visualization procedure. Specifically, we built a new staining well plate to increase batch size, and then systematically varied the staining and clearing cycles to describe the staining response curve across taxa and conditions. We compared tissues fixed by immersion or perfusion, mounted versus free-floating, and cut as thicker or thinner slices, with two-weeks of post-fixation. RESULTS: The staining response curves show optimal staining with a single exposure across taxa when incubation and clearing epochs are held to within 3-9 min. We show that clearing was slower in mounted vs free-floating tissue, and that staining was faster and caused fracturing earlier in thinner sliced and smaller volumes of tissue. COMPARISON WITH EXISTING METHODS: We developed a batch processing approach to increase throughput while ensuring reproducibility and demonstrate the optimal conditions for fine myelinated fiber morphology visualization with short cycles (<9 minutes). CONCLUSIONS: We present our optimized protocol to reveal mesoscale neuroanatomical myelin content in histology across mammals. This standard staining procedure will facilitate multiscale analyses of myelin content across development as well as in the presence of injury or disease.

Effects of maternal inflammation on growth performance, carcass characteristics, and meat quality of offspring pigs.

The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; n=7) or saline (CON, n=7) from d 70-84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning does of 10 µg LPS/kg BW and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at d 66 of age a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on d 0, 35, 70, and 105 of the finishing trial to determine ADG, ADFI, and G:F. On d 106, pigs were slaughtered under supervision of the United States department of Agriculture Food Safety Inspection Service (USDA-FSIS). Ending live weight (ELW), hot carcass weight (HCW), and dressing percentage were determined. Left side of carcasses were weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force (WBSF) and proximate analysis. No differences (P ≥ 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (d 0-105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (P = 0.03). There was a tendency for carcass yield to be reduced (P = 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area (LMA) tended to be reduced (P = 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (P ≥ 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (P ≥ 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except for LPS pigs tended to have a reduction (P ≥ 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (P ≥ 0.25) in muscle fiber composition or size, however LPS pigs tended (P = 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring.

Effects of a coccidiosis challenge on dietary methionine recommendations in broilers.

Broilers are commonly exposed to coccidiosis infections, and the use of dietary strategies to reduce losses in growth performance has practical implications for the poultry industry. Methionine (Met) is typically the first limiting amino acid for broilers and is involved in metabolic and immunological pathways; however, literature is conflicting on how dietary Met requirements are affected by environmental stressors. Our objective was to assess how the Met requirement changes during coccidiosis based on results of growth performance, carcass traits, and health outcomes. Two trials were conducted using 780 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 12 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35, Trial 2 only) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2.61 to 6.21 g/kg digestible Met. Trial 2 experimental grower diets were formulated to contain 15% below, at, or 15% above the Met requirement determined in Trial 1. Birds were exposed to a coccidiosis challenge on d 11, with blood and tissue collection (1 bird/pen) on d 18 and carcass processing on d 35 (2 birds/pen) in Trial 2. Data were analyzed using a 1- or 2-way ANOVA. A non-linear regression analysis was conducted in Trial 1 to determine the Met requirement of 4.32 g of digestible Met/kg of diet using BW gain. Coccidiosis infection reduced (P < 0.05) growth performance during the experimental grower and overall study periods in Trial 2. Increasing dietary Met from below requirement to meeting requirement during the grower period improved (P < 0.001) BW gain and feed conversion ratio (FCR), but this effect was only significant between treatments below and above the requirement for the overall study period. There was an interactive effect (P = 0.038) on FCR for the overall study period. These findings provide evidence that the Met requirement is likely increased during coccidiosis based on growth performance outcomes.

Defining optimal dietary starch, oil, and amino acid inclusion levels for broilers experiencing a coccidiosis challenge.

Alternative methods to alleviate coccidiosis in broilers are of interest to producers, including dietary strategies to minimize disruptions in growth rate and efficiency when faced with health challenges. Our objective was to determine optimal combinations of dietary starch, amino acids (AA), and oil to benefit productivity of broilers experiencing Eimeria-induced immune activation. Two trials were conducted using 1,536 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 17 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2,700 to 3,300 kcal/kg AME. Trial 2 included 10 experimental grower diets following a simplex lattice design consisting of 3 basal lots formulated to have the highest starch (45.4%), oil (10.2%), or AA density (120, 1.33% digestible Lys) and mixed in 4 equally spaced levels for each component (0, 0.33, 0.67, 1). These mixtures enabled varying densities of AA (80-120% of recommendation), starch:oil (4:1-20:1), and AME (2,940-3,450 kcal/kg). Bird and feeder weights were collected on d 0, 10, 24, and 35, and birds were exposed to an Eimeria challenge on d 11 or 12. In trial 2, excreta samples were collected for AME determination and carcasses were processed on d 36. Data were analyzed using ANOVA, t test, or regression. In Trial 1, BW gain and feed conversion were improved (P < 0.05) by increasing dietary AME. In Trial 2, birds receiving diets containing AA at 93 to 107% of recommendations and higher oil exhibited improved (P < 0.05) performance, but increased starch at the expense of oil reduced performance (P < 0.05). Relative breast and fat pad weights were not influenced by diet in Trial 2. We determined that broilers mildly challenged with Eimeria would exhibit highest BW gain when receiving diets containing 35.8% starch, 8.9% oil, and 101.3% of AA recommendations, which can be utilized by producers to maintain productivity under health-challenged conditions.

Combined dietary effects of supplemental threonine and purified fiber on growth performance and intestinal health of young chicks.

Characterization of intestinal health in poultry has become imperative as specialized ingredients become more common in poultry diets. We tested whether purified fiber affects dietary Thr requirements and intestinal morphology of young chicks. In experiment 1, three diets containing 7% added silica sand (control), cellulose, or high-methoxy pectin were used. Six replicate pens of 6 chicks received dietary treatments through d 14 posthatch, at which time growth performance and nutrient digestibility were determined. In experiment 2, the effect of purified fiber on dietary Thr requirements was determined using a Thr-deficient basal diet (3.2 g of Thr/kg of diet) and 7 graded levels of supplemental Thr (0 to 9.6 g/kg of diet). Six replicate pens of 5 chicks were tested from d 8 to 21 posthatch, and ileal tissue was collected at the conclusion of the study for histological evaluation. In experiment 1, pectin reduced (P < 0.05) weight gain, feed efficiency, DM digestibility, and AME(n) compared with the control diet. In experiment 2, supplemental Thr requirements were estimated by fitting growth performance data to a 1-slope, broken-line (i.e., piece-wise) regression model. For the control and cellulose- and pectin-containing diets, supplemental Thr requirements were estimated at 3.64, 2.60, and 2.38 g of Thr/kg of diet, and at 778, 737, and 576 mg of supplemental Thr intake over the 21-d study, respectively, based on BW gain. For histological measures, crypts were deepest (P < 0.03) in the cellulose treatment; total goblet cell count and density were highest (P < 0.03) in the pectin-fed birds, and mixed goblet cell counts were highest (P < 0.03) in the control treatment. The serosa was thickest in the cellulose treatment with adequate supplemental Thr, and acidic and neutral goblet cell counts were highest in the control treatment with adequate Thr supplementation (fiber × Thr, P < 0.05). These findings suggest both dietary Thr concentration and fiber source affect growth performance, intestinal morphology, and mucin secretion in young chicks, which may directly affect poultry feeding strategies.

Modulation of the intestinal environment, innate immune response, and barrier function by dietary threonine and purified fiber during a coccidiosis challenge in broiler chicks.

Coccidiosis is a major contributor to economic losses in the poultry industry due to its detrimental effects on growth performance and nutrient utilization. We hypothesized that the combined effects of supplemental dietary Thr and purified fiber may modulate the intestinal environment and positively affect intestinal immune responses and barrier function in broiler chicks infected with Eimeria maxima. A Thr-deficient basal diet (3.1 g of Thr/kg of diet) was supplemented with 70 g/kg of silica sand (control) or high-methoxy pectin and 1 of 2 concentrations of Thr (1.8 or 5.3 g/kg of diet; 4 diets total), and fed to chicks from hatch to d 16 posthatch. On d 10 posthatch, chicks received 0.5 mL of distilled water or an acute dose of Eimeria maxima (1.5 × 10(3) sporulated oocytes) with 6 replicate pens of 6 chicks per each of 8 treatment combinations (4 diets and 2 inoculation states). Body weight gain, feed intake, and G:F increased (P < 0.01) with addition of 5.3 g of Thr/kg of diet. Eimeria maxima schizonts were present only in intestinal tissue sampled from infected birds (P < 0.01). Weights of cecal digesta were highest (P < 0.01) in pectin-fed birds, and ceca with the heaviest weights also had the highest concentrations of total short-chain fatty acids. Expression of interleukin-12 in ileal mucosa was highest (P < 0.01) in infected birds receiving the control diet with 5.3 g of supplemental Thr/kg. In cecal tonsils, interferon-γ expression was highest in infected birds receiving the control diet (fiber × infection, P < 0.05); interferon-γ expression was lowest in infected birds fed the high Thr diet (Thr × infection, P < 0.05). There were no differences due to infection or Thr supplementation for cytokine expression in birds fed pectin-containing treatments. Overall, we conclude that although pectin has some protective function against coccidiosis, Thr supplementation had the greatest effect on intestinal immune response and maintenance of near normal growth in young broiler chicks infected with E. maxima.

Dietary guanidino acetic acid is an efficacious replacement for arginine for young chicks.

Guanidino acetic acid (GAA) is synthesized in the liver and kidney from Arg and Gly and subsequently methylated by S-adenosylmethionine to form creatine. Four bioassays were carried out to determine the capacity of GAA to serve as a dietary replacement for Arg for growing chicks. Broiler chicks were fed Arg-deficient dextrose-casein (0.88% Arg) or corn-corn coproduct-soybean meal (1.0% Arg) basal diets during 9-d battery feeding trials involving 5 pens of 4 chicks per treatment. The dextrose-casein diet was shown to be markedly deficient in Arg as both weight gain and G:F increased (P < 0.01) due to addition of Arg, GAA, or creatine. The optimal level of added GAA was 0.12% of the diet, but this level of GAA or 1.0% creatine-H(2)O did not improve growth performance when added to an Arg-adequate diet. A second assay confirmed this level of optimal Arg in a 2 × 2 factorial arrangement of l-Arg and GAA supplementation. Using a practical-type diet based on corn, corn gluten meal, distillers dried grains with solubles, and soybean meal, similar improvements (P < 0.05) in G:F resulted from addition of 0.25% Arg, 0.12% GAA, or 0.15% creatine·H(2)O. These results demonstrate that 0.12% supplemental GAA, like creatine, produces consistent growth responses in young chicks fed Arg-deficient diets. To provide further evidence of the capacity for GAA to serve as a dietary Arg replacement, the dextrose-casein diet was supplemented with 7 graded doses of Arg in the absence or presence of 0.12% GAA (14 total diets). Quadratic (P < 0.01) responses in weight gain and G:F responses to supplemental Arg were observed. Similar supplemental Arg requirements were estimated in the absence and presence of 0.12% GAA, but GAA elicited a greater improvement (P < 0.05) in G:F when added to Arg-deficient, compared with Arg-adequate, diets. Collectively, these data indicate that GAA can be used as an efficacious replacement for dietary Arg for young chicks.

Effects of oligosaccharides in a soybean meal-based diet on fermentative and immune responses in broiler chicks challenged with Eimeria acervulina.

Fermentable oligosaccharides, particularly those found in soybean meal (SBM), may modulate fermentation in the ceca, thus affecting intestinal immune responses to intestinal pathogens. We hypothesized that fermentable oligosaccharides found in SBM would positively affect cecal fermentation and intestinal immune status in chicks challenged with an acute coccidiosis (Eimeria acervulina) infection and fed either a SBM-based diet or a semi-purified soy protein isolate- (SPI) based diet. Using a completely randomized design, 1-d-old broiler chicks (n = 200; 5 replications/treatment; 5 chicks/replication) were assigned to 1 of 4 SBM- or SPI-based diets containing either dietary cellulose (4%) or a fermentable carbohydrate, galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex (4%). On d 9 posthatch, an equal number of chicks on each diet were inoculated with either distilled water (sham control) or E. acervulina (1 × 10(6) oocysts) and then euthanized on d 7 postinoculation. Overall, body weight gain and feed intake were greater (P < 0.01) for SBM-fed chicks, regardless of infection status. Gain:feed ratio was greater (P ≤ 0.05) for SPI-fed chicks except during d 3-7 postinoculation. Infection status, but not fiber source, affected propionate, isobutyrate, isovalerate, and total branched-chain fatty acid concentrations (P ≤ 0.02). Soybean meal-based diets resulted in greater (P ≤ 0.04) short-chain fatty acid and branched-chain fatty acid concentrations than SPI-based diets. Messenger RNA fold changes relative to uninfected SBM-cellulose-fed chicks of all duodenal cytokines were greater (P ≤ 0.01) for infected chicks, and SBM-fed chicks had greater (P < 0.01) interferon-γ and interleukin-12ß expression compared with SPI-fed chicks. Cecal tonsil cytokine expression was also affected (P ≤ 0.02) by infection; however, protein source only affected (P < 0.01) interleukin-1ß expression in this tissue. Overall, a SBM-based diet, compared with a semi-purified SPI-based diet with a different ingredient composition, resulted in greater weight gain, feed intake, and short-chain fatty acid production regardless of infection status, and also greater duodenal cytokine expression in E. acervulina- infected chicks, which is hypothesized to be related to the nutrients and oligosaccharides found in SBM.

The effects of a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex in broiler chicks challenged with Eimeria acervulina.

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against pathogenic infection. We hypothesized that a mannose-rich, galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent weight loss resulting from acute coccidiosis (Eimeria acervulina) infection of chicks. Using a completely randomized design, 1-d-old commercial broiler chicks (n = 160; 4 replications/treatment; 5 chicks/replication) were assigned to one of 4 corn-soybean meal-based diets containing supplemental GGMO-AX (0, 1, 2, or 4%) that replaced dietary cellulose. On d 9 posthatch, an equal number of chicks on each diet were inoculated with either distilled water (sham control) or E. acervulina (1 × 10(6) oocysts). All birds were euthanized on d 7 postinoculation (PI) for collection of cecal contents and duodenal tissue. Overall, BW gain of chicks was not affected by diet PI, whereas infection decreased (P < 0.01) weight gain on d 0 to 7 PI. Feed intake was not affected by dietary treatment, but infection decreased (P < 0.01) feed intake on d 0 to 7 PI. Overall, infection, but not diet, decreased (P < 0.01) G:F on d 0 to 7 PI. Cecal propionate concentrations were independently affected by infection and diet, while butyrate concentrations were affected only by infection (P = 0.02). Cecal Bifidobacterium spp. populations were affected (P < 0.01) by diet, with the 2% GGMO-AX resulting in the highest cfu/g of cecal contents (on a DM basis). Messenger RNA expression of all duodenal cytokines evaluated was affected by infection status (P ≤ 0.02) but not by dietary treatment alone. Supplementing 4% GGMO-AX consistently resulted in the greatest fold change in proinflammatory cytokine expression, while inhibiting antiinflammatory cytokine expression, which indicates a more robust innate immune response. Despite decreasing performance, 4% dietary GGMO-AX improved select fermentation indices and the innate intestinal immune response to an acute E. acervulina infection.

Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium.

Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively affect immune status and prevent colonization and shedding in Salmonella typhimurium-infected chicks. Using a completely randomized design, 1-d-old commercial broiler chicks (n = 240 chicks; 4 replications/treatment; 5 chicks/replication) were assigned to 1 of 6 dietary treatments differing in concentration of GGMO-AX (0, 1, 2, or 4%) or containing 2% Safmannan or 2% short-chain fructooligosaccharides. Cellulose was used to make diets iso-total dietary fiber. On d 10 posthatch, an equal number of chicks on each diet were inoculated with either phosphate-buffered saline (sham control) or Salmonella typhimurium (1 × 10(8) cfu). All birds were euthanized on d 10 postinoculation (PI) for collection of intestinal contents and select tissues. Body weight gain and feed intake of chicks were greater (P < 0.05) in infected chicks PI for all time periods, except for weight gain on d 0 to 3 PI. Gain:feed was affected (P < 0.05) by diet, with Safmannan-fed chicks having the highest G:F and 1% GGMO-AX-fed chicks having the lowest. The GGMO-AX substrate demonstrated effects similar to a prebiotic substrate as indicated by increased cecal short-chain fatty acid concentrations, decreased cecal pH, and increased populations of Lactobacillus spp. and Bifidobacteria spp. as dietary GGMO-AX concentration increased. Excreta Salmonella typhimurium populations on d 5 and 10 PI, and ileal and cecal Salmonella typhimurium populations, tended to be affected (P < 0.10) by the main effect of diet. Messenger RNA expression of IFN-γ in the cecal tonsils was the only cytokine independently affected by infection and diet (P < 0.01). Chicks fed 2 and 4% GGMO-AX had similar expressions of IFN-γ and IL-1ß, regardless of infection, suggesting that Salmonella typhimurium virulence was suppressed. Dietary supplementation with GGMO-AX resulted in prebiotic-like effects but did not limit Salmonella typhimurium intestinal colonization or shedding, but possibly decreased the virulence of Salmonella typhimurium within the digestive tract.

Effects of phytase supplementation and increased nutrient density on growth performance, carcass characteristics, and hypothalamic appetitive hormone expression and catecholamine concentrations in broilers from 1 to 43 days of age.

Two experiments were conducted to evaluate extra-phosphoric effects of phytase and nutrient density on growth performance, meat yield, and hypothalamic appetitive hormone expression and catecholamine concentrations of broilers. Experiment 1 determined differences of digestible amino acid concentrations and AMEn using 256 Yield Plus × Ross 708 broilers (32 cages, 8 birds/cage) fed diets without or with 4,500 phytase units (FTU)/kg inclusion (16 reps/treatment). In Experiment 2, 832 Yield Plus × Ross 708 broilers (32 pens; 26 birds/pen) were provided diets in a 2 × 2 factorial arrangement consisting of 2 nutrient contents (without or with increased density) and 2 phytase inclusions (0 or 4,500 FTU/kg). Increased nutrient density was formulated to contain 0.007, 0.015, 0.013, 0.021, 0.024%, and 61 kcal/kg higher digestible SAA, Lys, Thr, Val, Ile, and AMEn (from Experiment 1) respectively, compared with the control diet. Growth performance was determined at 14, 28, and 40 d of age and carcass characteristics at 41 d of age. At 43 d of age, plasma inositol, hypothalamic appetitive hormone expression, and catecholamine concentrations were determined from 4 birds/pen. Additive effects of phytase inclusion and increased nutrient density resulted in the lowest (P < 0.05) feed conversion from 1 to 40 d of age and the heaviest (P < 0.01) breast meat weights among dietary treatments. Phytase addition numerically increased feed intake (P = 0.06) and BW gain (P = 0.051) compared with birds fed diets without phytase from 1 to 40 d of age. Plasma inositol and dopamine concentrations were 2.3- and 1.2-fold higher (P < 0.01), respectively, in broilers fed phytase-added diets than birds fed diets without phytase inclusion. However, mRNA expression of neuropeptide Y, agouti-related peptide, proopiomelanocortin, cholecystokinin A receptor, ghrelin, and serotonin concentration were not different (P > 0.05) among treatments. These data indicated additive effects of phytase supplementation and increased nutrient density on growth performance and meat accretion of broilers. However, the influence of phytase on feed intake warrants future research.

Sodium buffered formic acid concentration and feed pH is stable over a 3-month period.

Promoting feed hygiene with organic acids is an effective method to prevent foodborne illnesses from bacterial infection. The stability and acidification of mash and pelleted feed with sodium buffered formic acid was investigated. The acid product was incorporated to reach total formate inclusion levels of 0, 6, or 12 g/kg for swine nursery feed; 0, 4, or 9 g/kg for swine finishing feed; and 0, 3, or 6 g/kg for broiler grower feed. Samples were analyzed for total formate and pH on d 4, 32, 60, or 88 post-manufacturing. The concentration of formate remained stable across an 88-d period (P < 0.01). Treatment with the formic acid product decreased feed pH with increasing inclusion levels (all P < 0.01). Within each inclusion level of acid and across time, pH tended to increase in pelleted feed and decrease in mash feeds (all P < 0.01); however, these changes were small (0.1 units pH). These data suggest that sodium buffered formic acid can be applied to both mash and pelleted feed to provide continuous acidification over a 3-month period.

Effects of methylsulfonylmethane and neutralizing anti-IL-10 antibody supplementation during a mild Eimeria challenge infection in broiler chickens.

A 28-day experiment was conducted in broilers to study the effects of feeding methylsulfonylmethane (MSM) and IL-10-neutralizing antibody from dried egg product (DEP) on the growth performance, immune responsivity, oxidative stress parameters, and gut health outcomes during a mild infection with mixed species of Eimeria. A total of 500 male Ross 308 chicks were allocated to five treatments: sham-inoculated (uninfected) chickens fed control diet (UCON), Eimeria-infected chickens fed control diet (ICON), and Eimeria-infected chickens fed control diet supplemented with 287 U/tonne of DEP (I-DEP), 0.4% MSM, or their combination (I-DEP-MSM), with 10 replicate cages of 10 birds per treatment. All infected groups received 1 mL of an oral inoculum containing Eimeria acervulina (10,000 oocysts), Eimeria maxima (5,000 oocysts), and Eimeria tenella (5,000 oocysts) on study days 7 and 14. Data were analyzed as a two-way ANOVA for all treatments including Eimeria-infected groups, in addition to a single degree of freedom contrast to compare uninfected and infected groups receiving the control diet. Mild Eimeria infection did not influence the growth performance in ICON compared with UCON at any time points. Overall (day 0-28) growth performance parameters were not influenced by either infection or dietary supplementation of MSM or DEP. However, birds in I-DEP-MSM showed improved ADG during study day 7 to 14 (i.e., 7 d after primary inoculation) indicating a beneficial effect immediately after Eimeria infection. Although MSM supplementation reduced thiobarbituric acid reactive substances (day 21 and 28), both MSM and DEP improved the total antioxidant capacity (day 21) in the plasma of infected birds. Histopathological outcomes were not influenced by treatments, and fecal oocyst output was higher in MSM- and DEP-supplemented groups than with ICON, indicating no beneficial effects. Similarly, expression of cecal inflammatory cytokines (IL-10, IL-1ß, and interferon-γ) was not affected by MSM, DEP, or their combination. Overall, the current results suggest that both MSM and DEP supplementation may benefit birds during a mild Eimeria infection as indicated by improvements in ADG and oxidative stress outcomes.

Dietary methylsulfonylmethane supplementation and oxidative stress in broiler chickens.

Methylsulfonylmethane (MSM) is an organic, sulfur-containing compound widely used as a dietary supplement to improve joint health and treat arthritic pain. An experiment was conducted to study the effects of feeding 0.05% MSM to broilers exposed to diet-induced oxidative stress on tissue MSM distribution, growth performance, oxidative stress biomarkers, and immune responsivity. A total of 528 birds were allocated to 4 dietary treatments (fresh oil-no MSM, fresh oil-MSM, oxidized oil-no MSM, oxidized oil-MSM) as provided ad libitum to 11 replicate cages of 12 birds per treatment. Blood and tissue samples were collected to analyze MSM concentrations, and oxidative stress biomarkers including concentrations of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), total glutathione, and glutathione peroxidase (GPx) and reductase (GR) activities. Additionally, blood samples collected at day 25 were used to quantify T-cell (TC) populations using flow cytometry. Overall, MSM was quantified in all tissues and plasma samples of MSM-treated groups at all time points. Oxidized oil reduced (P = 0.006) feed intake over the 21-d feeding period, but MSM did not affect growth equally across time points. No effects (P > 0.2) of MSM or oil type were observed on TC populations. In the presence of oxidized oil, MSM reduced (P = 0.013) plasma TBARS and increased (P = 0.02) liver GPx at day 21, and increased (P = 0.06) liver GR at day 7. Irrespective of dietary oil type, groups supplemented with MSM showed higher plasma TAC at day 7 (P = 0.023), liver GPx activity at day 21 (P = 0.003), and liver GR activity at day 7 (P = 0.004) compared with groups not receiving MSM. In conclusion, 0.05% dietary MSM supplementation partially protected birds from oxidative stress but did not affect immune cell profiles.

Dietary supplementation with anti-IL-10 antibody during a severe Eimeria challenge in broiler chickens.

Attenuation of host IL-10 activity during Eimeria infection may elicit a robust Th1 response to eliminate the parasite from the gut epithelium. An experiment was conducted to study the effects of feeding IL-10 neutralizing antibody delivered via a dried egg product (DEP) on growth performance, immune responsivity, and gut health outcomes during a severe challenge with either Eimeria acervulina (study 1) or Eimeria tenella (study 2) following FDA CVM #217 protocol to test anticoccidial products. A total of 720 male Ross 308 chicks were used in each study, with 15 replicate cages of 12 birds and the following 4 treatments: sham-inoculated (uninfected) control diet (UCON), Eimeria-infected control diet (ICON), and Eimeria-infected control diet supplemented with DEP at 2 levels (165 [I-165] or 287 [I-287] U/tonne in study 1 and 143 [I-143] or 287 [I-287] U/tonne in study 2). Individual birds assigned to infected treatment groups received a single oral dose of either 200,000 E. acervulina (study 1) or 80,000 E. tenella (study 2) oocysts at 12 d of age (i.e., d post inoculation [DPI] 0), whereas uninfected birds were sham-inoculated with tap water. A one-way ANOVA was performed on outcomes including growth performance, hematology, serum chemistry profiles, immunophenotyping profiles, and intestinal lesion scores. In both studies, DPI 0 to 7 weight gain, feed intake, and feed conversion ratio were worse (P < 0.05) in all infected groups compared with the UCON group. Compared with ICON, DEP supplementation elicited no differences on overall growth performance. Histopathology and lesion scores revealed severe damage to the gut epithelium owing to the Eimeria challenge, yet DEP supplementation did not improve these outcomes or oocyst shedding, hematological measurements, or serum chemistry. However, DEP supplementation improved (P < 0.05) the percentage of circulating CD3+ cells at 6 DPI in study 2. These results indicate that DEP does not appear to elicit a coccidiostatic effect during a severe infection with E. acervulina or E. tenella.

Guanidinoacetic acid is efficacious in improving growth performance and muscle energy homeostasis in broiler chicks fed arginine-deficient or arginine-adequate diets.

Two studies were conducted to test the efficacy of guanidinoacetic acid (GAA) to spare Arg and serve as a precursor of creatine (Cr) by evaluating growth performance and muscle cellular energy homeostasis in broiler chicks. In both studies, 12 replicate pens of 6 chicks received dietary treatments beginning at day 2 post-hatch. At conclusion of each study, muscle biopsy samples were collected within 60 s of euthanasia for analysis of Cr-related energy metabolites. In study 1, Arg-deficient starter and grower basal diets were supplemented with 0 (negative control, NC), 0.06, 0.12, or 0.18% GAA, or supplemental Arg (positive control, PC; 0.37 and 0.32% L-Arg in starter and grower phases, respectively). Dietary GAA elicited graded improvements, with final BW, overall BW gain, and overall G:F being increased (P < 0.05) by 0.12% GAA compared with the NC diet with no difference to PC diet. Increases (P < 0.001) of phosphocreatine (PCr), total Cr (tCr), and glycogen concentrations, as well as the PCr-to-adenosine triphosphate (ATP) and glycogen:ATP ratios, were observed with supplementation of 0.12% GAA compared with the NC diet, even exceeding responses to the PC diet. In study 2, Arg-adequate starter and grower basal diets were supplemented with 0 (negative control, NC), 0.06, or 0.12% GAA, 0.12% Cr monohydrate (PC1), or salmon protein (PC2; containing total Arg concentrations equal to those of the NC diet in each phase and containing similar Cr as in PC1). Overall G:F was increased (P < 0.05) by PC1, but not by PC2, compared with the NC, while GAA supplementation elicited a response intermediate to NC and PC1 diets. However, GAA supplementation increased (P < 0.01) concentrations of tCr and glycogen, as well as the PCr:ATP and glycogen:ATP ratios, when compared with the NC (Arg-adequate) diet. Collectively, these data indicate that GAA can be used to replace Arg in practical, Arg-deficient diets and improve muscle energy homeostasis in broiler chicks receiving either Arg-deficient or Arg-adequate practical diets.

Effects of Yucca schidigera-derived saponin supplementation during a mixed Eimeria challenge in broilers.

An experiment was conducted to determine if dietary Yucca-derived saponin supplementation could ameliorate the immune and growth responses of broilers during a mixed coccidian challenge. A total of 576 two-day-old male Ross 308 broiler chicks were housed in galvanized starter batteries and randomly assigned to 1 of 4 dietary treatment groups (12 replicate cages of 12 birds). Dietary treatments were corn-soybean meal-based and included 1) control diet + sham-inoculated (Ucon), 2) control diet + Eimeria oocyst challenge (Icon), 3) control diet with 250 mg/kg Yucca-derived saponin product + Eimeria oocyst challenge (ISap250), and 4) control diet with 500 mg/kg of Yucca-derived saponin product + Eimeria oocyst challenge (ISap500). On study day 14, birds were orally inoculated with 1.5 mL of tap water containing Eimeria acervulina, E. maxima, and E. tenella (100,000, 40,000, and 30,000 oocysts/dose, respectively), or sham-inoculated with 1.5 mL of tap water. Eimeria-challenged birds exhibited a reduction in growth compared with uninfected birds (P < 0.001); however, there were no detectable differences due to dietary treatment among Eimeria-challenged groups. Mucosal thickness in the jejunum was increased (P < 0.042) in all infected groups and there were no differences among infected groups; however, saponin supplementation included at 250 mg/kg was not significantly different from the uninfected birds. Lymphocytes as a percentage of total white blood cells were increased (P < 0.014) in all Eimeria-challenged groups at 7 D post-inoculation compared with uninfected birds, but birds supplemented at 250 mg/kg were not different from uninfected birds. Cecal and duodenal IFN-γ expression increased with infection when compared with sham-inoculated birds. Cecal and duodenal IL-1ß expression increased (P < 0.008 and P < 0.039) due to infection, and ISap250 and ISap500 treatments ameliorated IL-1ß expression to levels not different from sham-inoculated birds. These results suggest that saponin supplementation may provide some immunomodulatory effects during a mixed coccidian challenge as evidenced by lymphocyte responses, changes in intestinal structure, and alterations in cecal and duodenal inflammatory cytokine mRNA expression.

Toxicity and tissue distribution of methylsulfonylmethane following oral gavage in broilers.

An experiment was conducted to investigate the toxicity and tissue distribution of methylsulfonylmethane (MSM) following oral gavage in broilers. A total of four hundred and thirty-two 15-day-old Ross 308 male broilers were allotted to 6 treatments with 6 replicates of 12 birds per replicate and administered a single oral dose of MSM at 0, 50, 100, 300, 1,000, or 2,000 mg/kg BW (Study 1). Another one hundred and sixty-eight 3-day-old chicks were allotted to either control or test group (Study 2) and administered a daily oral gavage of either 0 or 1, 500 mg/kg BW of MSM for 21 D consecutively. Blood and tissue samples were collected over a 48 h (Study 1) or 21 D (Study 2) period and analyzed for MSM concentrations. Toxicity was assessed through changes in hematology and clinical blood chemistry. In Study 1, plasma MSM concentrations were below 167 µg/mL at all time-points in birds receiving up to 300 mg/kg BW, and were significantly higher (P < 0.05) in birds receiving 1,000 or 2,000 mg/kg BW. Similarly, only the highest 2 MSM dosages elicited increased lymphocyte and decreased heterophil counts at 8 h (P < 0.003) and decreased hematocrit at 48 h (P = 0.015). Growth performance variables were unaffected by MSM in Study 2, and plasma and tissue MSM concentrations were highest on study day 21, with MSM-dosed birds always exhibiting higher (P < 0.03) concentrations compared with the control. Birds in Study 2 that were dosed with MSM had decreased liver enzyme concentrations at day 7 and 21 and decreased glucose and phosphorus at day 7. Importantly, MSM was detected in plasma and all tissues of control groups, confirming that MSM is synthesized de novo in chickens. In conclusion, oral MSM at either acute (single dose at 1,000 to 2,000 mg/kg BW) or sub-chronic (1,500 mg/kg BW daily for 21 D) concentrations did not cause any adverse effects on growth or clinical outcomes and appeared to be absorbed and distributed throughout the body.