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Novelty preference paradigms have been widely used to study recognition memory and its neural substrates. The piglet model continues to advance the study of neurodevelopment, and as such, tasks that use novelty preference will serve especially useful due to their translatable nature to humans. However, there has been little use of this behavioral paradigm in the pig, and previous studies using the novel object recognition paradigm in piglets have yielded inconsistent results. The current study was conducted to determine if piglets were capable of displaying a novelty preference. Herein a series of experiments were conducted using novel object recognition or location in 3- and 4-week-old piglets. In the novel object recognition task, piglets were able to discriminate between novel and sample objects after delays of 2 min, 1 h, 1 day, and 2 days (all P < 0.039) at both ages. Performance was sex-dependent, as females could perform both 1- and 2-day delays ( P < 0.036) and males could perform the 2-day delay ( P = 0.008) but not the 1-day delay ( P = 0.347). Furthermore, 4-week-old piglets and females tended to exhibit greater exploratory behavior compared with males. Such performance did not extend to novel location recognition tasks, as piglets were only able to discriminate between novel and sample locations after a short delay ( P > 0.046). In conclusion, this study determined that piglets are able to perform the novel object and location recognition tasks at 3-to-4 weeks of age, however performance was dependent on sex, age, and delay. [ABSTRACT FROM AUTHOR]

Background: Choline is essential for synthesis of phospholipids, neurodevelopment, and DNA methylation. It is unknown whether dietary perinatal choline deficiency affects maternal milk composition.Objective: We examined whether perinatal maternal dietary choline deficiency influences porcine-milk composition.Methods: Yorkshire sows were fed choline-deficient (CD) or choline-sufficient (CS) gestation diets [544 or 1887 mg choline/kg dry matter (DM), respectively] from 65 d before to 48 h after parturition and then fed lactation diets (517 or 1591 mg choline/kg DM, respectively) through day 19 of lactation. Milk was collected from 7 sows fed each diet at days 0 (colostrum), 7-9 (mature milk), and 17-19 (preweaning) of lactation. Sow plasma was collected 65 d before and 19 d after parturition. Milk was analyzed for choline metabolite, fatty acid (FA), and amino acid composition. All outcomes were analyzed to assess main and interactive effects of choline intake and time.Results: Plasma choline metabolites did not differ before treatment, but free choline, betaine, and dimethylglycine concentrations were lower in CD-fed than in CS-fed sows at day 19 of lactation (interaction; P < 0.05). Milk betaine concentrations responded similarly, with no differences due to choline intake at day 0 of lactation, but lower concentrations in CD-fed than in CS-fed sows at day 18 of lactation (interaction; P < 0.001). Certain milk long-chain FAs also exhibited no differences at day 0 of lactation but higher concentrations in CD-fed than in CS-fed sows at day 18 of lactation (P < 0.05).Conclusions: These data indicate that, in pigs, dietary choline deficiency induces alterations in plasma choline metabolites that are evident at the end of lactation. Betaine and select FAs in milk are sensitive to maternal dietary choline deficiency and day of lactation. Alterations in concentrations of these nutrients may affect early-life neonatal development. [ABSTRACT FROM AUTHOR]

Background: Dietary fiber intake leading to short-chain fatty acid (SCFA) production could be a strategy to combat intermittent bouts of inflammation during ulcerative colitis.Objective: Our objective was to evaluate dietary potato fiber (PF) in attenuating inflammation using a dextran sodium sulfate (DSS)-induced colitis mouse model. We hypothesized that PF would show anti-inflammatory effects compared with cellulose due in part to SCFA production.Methods: Male C57Bl/6J mice were fed diets containing either 8% cellulose or 14.5% PF for a 22-d feeding study. Starting on study day 14, mice were provided either distilled water (control) or 2% (wt:vol) DSS in drinking water for 5 d (cellulose+control, n = 17; PF+control, n = 16; cellulose+DSS, n = 17; and PF+DSS, n = 16). Body weights and food and water intakes were collected daily from day 14 through day 22. Distal colon tissue was analyzed for histologic outcomes and changes in gene expression, and cecal contents were analyzed for SCFA concentrations. Data were analyzed by ANOVA, with repeated measures applied where necessary.Results: At day 5 post-DSS induction, cellulose+DSS mice exhibited a 2% reduction (P < 0.05) in body weight compared with PF+DSS and PF+ and cellulose+control mice. PF+DSS mice had greater (P < 0.05) cecal butyrate concentrations [24.5 μmol/g dry matter (DM)] than did cellulose+DSS mice (4.93 μmol/g DM). Mice fed PF+DSS had lower (P < 0.05) infiltration of leukocytes in the distal colon than did mice fed cellulose+DSS (mean histology scores of 1.22 and 2.30, respectively). Furthermore, mice fed cellulose+DSS exhibited 1.42, 11.5, 8.48, and 35.5 times greater (P < 0.05) colon mRNA expression of tumor necrosis factor α (Tnfa) and interleukin (Il) 1b, Il6, and Il17a, respectively, and 7.10 times greater (P < 0.05) expression of C-X-C motif ligand 1 (Cxc1) compared with mice fed PF+DSS.Conclusions: These results suggest that PF fed to mice before and during DSS colitis attenuates inflammation, potentially through SCFA production; however, future studies are needed to understand the role of dietary fiber intake and immune activation. [ABSTRACT FROM AUTHOR]

Background: Because human breast milk is a rich source of phospholipids and gangliosides and breastfed infants have improved learning compared with formula-fed infants, the importance of dietary phospholipids and gangliosides for brain development is of interest. Objective: We sought to determine the effects of phospholipids and gangliosides on brain and cognitive development. Methods: Male and female piglets from multiple litters were artificially reared and fed formula containing 0% (control), 0.8%, or 2.5% Lacprodan PL-20 (PL-20; Arla Foods Ingredients), a phospholipid/ganglioside supplement, from postnatal day (PD) 2 to PD28. Beginning on PD14, performance in a spatial T-maze task was assessed. At PD28, brain MRI data were acquired and piglets were killed to obtain hippocampal tissue for metabolic profiling. Results: Diet affected maze performance, with piglets that were fed 0.8% and 2.5% PL-20 making fewer errors than control piglets (80% vs. 75% correct on average; P < 0.05) and taking less time to make a choice (3 vs. 5 s/trial; P < 0.01). Mean brain weight was 5% higher for piglets fed 0.8% and 2.5% PL-20 (P < 0.05) than control piglets, and voxel-based morphometry revealed multiple brain areas with greater volumes and more gray and white matter in piglets fed 0.8% and 2.5% PL-20 than in control piglets. Metabolic profiling of hippocampal tissue revealed that multiple phosphatidylcholine-related metabolites were altered by diet. Conclusion: In summary, dietary phospholipids and gangliosides improved spatial learning and affected brain growth and composition in neonatal piglets. [ABSTRACT FROM AUTHOR]

Iron deficiency is common throughout the world and has been linked to cognitive impairments. Using neonatal piglets to model human infants, we assessed the impact of iron deficiency on spatial learning and memory. Artificially reared piglets were fed 1 of 3 liquid diets with varying concentrations of iron: control (CON), mildly deficient (MID), or severely deficient (SID; 100, 25.0, or 10.0 mg iron/kg milk solids, respectively) for 4 wk. Relative to CON, SID and MID piglets had reduced hemoglobin (P < 0.05) as well as magenta skin color (P < 0.001), which correlated with hematocrit (R² = 0.76; P < 0.001). SID and MID hemoglobin differed at wk 3 and 4 (P< 0.05). In a hippocampal-dependent, spatial, T-maze task, SID piglets were unable to acquire the task (post hoc contrast: first vs. last day of acquisition), while MID piglets demonstrated deficits in reversal learning (P= 0.032). Iron concentrations in the liver (P< 0.001), serum (P = 0.003), and hippocampus (P = 0.004), but not prefrontal cortex, were lower in MID and SID compared with CON piglets. The level of the transferrin receptor mRNA (TFfl) was greater in the prefrontal cortex of CON piglets than in MID and SID piglets (P= 0.001) but not the hippocampus. Gene expression of several neurotrophic factors and proinflammatory cytokines, as well as whole-brain and hippocampal volume, were not affected by dietary treatment. In conclusion, neonatal iron deficiency leads to cognitive impairment, which may be due in part to a reduced iron concentration in the hippocampus. [ABSTRACT FROM AUTHOR]

A dysregulated overexpression of inflammatory mediators by microglia may facilitate cognitive aging and neuro-degeneration. Considerable evidence suggests the flavonoid luteolin has antiinflammatory effects, but its ability to inhibit microglia, reduce inflammatory mediators, and improve hippocampal-dependent learning and memory in aged mice is unknown. In initial studies, pretreatment of BV-2 microglia with luteolin inhibited the induction of inflammatory genes and the release of inflammatory mediators after lipopolysaccharide (LPS) stimulation. Supernatants from LPS-stimulated microglia caused discernible death in Neuro.2a cells. However, treating microglia with luteolin prior to LPS reduced neuronal cell death caused by conditioned supernatants, indicating luteolin was neuroprotective. In subsequent studies, adult (3-6 mo) and aged (22-24 mo) mice were fed control or luteolin (20 mg/d)-supplemented diet for 4 wk and spatial working memory was assessed as were several inflammatory markers in the hippocampus. Aged mice fed control diet exhibited deficits in spatial working memory and expression of inflammatory markers in the hippocampus indicative of increased microglial cell activity. Luteolin consumption improved spatial working memory and restored expression of inflammatory markers in the hippocampus compared with that of young adults. Luteolin did not affect either spatial working memory or inflammatory markers in young adults. Taken together, the current findings suggest dietary luteolin enhanced spatial working memory by mitigating microglial-associated inflammation in the hippocampus. Therefore, luteolin consumption may be beneficial in preventing or treating conditions involving increased microglial cell activity and inflammation. [ABSTRACT FROM AUTHOR]

Four chick bioassays were conducted to evaluate the threonine (Thr) replacement value of L-homoserine (HS). Growth rate was increased (P < 0.05) by dietary addition of 800 mg L-HS/kg diet to a purified diet severely deficient in Thr or by the addition of 800 or 1000mg of L-HS/kg diet to a corn-peanut meal diet distinctly deficient in Thr. The addition of an isomolar level of α-ketobutyrate, a catabolic product of both Thr and HS, did not elicit a response. Standard-curve methodology predicted a Thr replacement value of 38 ± 9% for HS. Interactions (P < 0.01) were observed in assays 2 and 4 between dietary Thr adequacy and 800 or 1000 mg L-HS/kg supplementation. Thus, HS improved growth performance when added to a Thr-deficient diet (0.46 g Thr/100 g diet), but it decreased growth performance when added to the same diet containing surfeit Thr 10.80 g Thr/100 g diet). The results indicate that low levels of HS elicit a growth response in young chicks fed Thr-deficient diets. [ABSTRACT FROM AUTHOR]

A 72-h time-course study was conducted to elucidate the physiological mechanism underlying cysteine (Cys) toxicity in chicks beginning at 8-d posthatch. Biochemical markers quantified in plasma and liver samples collected from chicks receiving 30 g/kg excess dietary Cys were compared with baseline measurements from chicks receiving an unsupplemented corn-soybean meal diet over a 72-h feeding period. Concomitant with chick mortality were indices of acute metabolic acidosis, including a rapid increase (P < 0.001) in anion gap that resulted from a reduction (P < 0.001) in plasma HCO3- of ~40% and a 2.8-fold increase (P < 0.001) in plasma sulfate in chicks receiving excess Cys. Additionally, provision of 30 g/kg excess Cys resulted in a 1.5-fold increase (P< 0.05) in hepatic oxidized glutathione compared with the 0-h control time-point. Excess dietary Cys did not affect plasma free Met, but plasma free Cys increased (P< 0.05) from 89 to 107 µmol/L at 12 hand remained elevated through 36 h. Strikingly, ingestion of 30 g/kg excess Cys caused more than a doubling (P < 0.001) of plasma free cystine, the oxidized form of Cys, beginning 12 h after initiating the study, and it remained elevated throughout the 72-h feeding period. Taken together, these data suggest that ingestion of 30 g/kg excess L-Cys causes both acute metabolic acidosis and oxidative stress in young chicks when fed a nutritionally adequate, corn-soybean meal diet. [ABSTRACT FROM AUTHOR]

The ability of betaine to serve as a methyl donor in chicks was assessed in 3 bioassays using a choline-free purified diet that contained adequate methionine (Met). In assay 1, choline and betaine were each supplemented at 300 mg/kg in a 2 x 2 factorial arrangement of diets. Supplemental choline improved (P < 0.05) growth performance over the 9-d growth period, whereas betaine alone had no effect. In assay 2, graded supplements of choline produced a linear increase (P < 0.05) in growth performance criteria over a 9-d growth period. Additionally, hepatic betaine-homocysteine (Hcy) methyltransferase (BHMT) activity decreased linearly (P < 0.05), whereas plasma total Hcy remained unchanged. Addition of 260 or 600 mg/kg betaine to the choline-free basal diet did not affect growth performance or BHMT activity, but 600 mg/kg betaine reduced (P < 0.05) plasma total Hcy. Assay 3 was designed to quantify the ability of betaine to spare choline. Minimal supplemental choline requirements of 20.8 +/- 1.50 mg/d (722 mg/kg diet) and 10.5 +/- 1.03 mg/d (412 mg/kg diet) were estimated in the absence and presence of 1000 mg/kg supplemental betaine, respectively. Based on these estimates, 50% of the dietary choline requirement must be supplied as choline per se, but the remaining 50% can be replaced by betaine. Collectively, these data suggest betaine and Met have minimal choline-sparing activity in chicks fed purified diets devoid of preformed choline. However, addition of betaine to diets containing minimal choline allows a marked reduction in the total dietary choline requirement. [ABSTRACT FROM AUTHOR]

Relative bioefficacy and toxicity of Met precursor compounds were investigated in young chicks. The effectiveness of DL-Met and 2-keto-4-(methylthio)butyric acid (Keto-Met) to serve as L-Met precursors was quantified using Met-deficient diets of differing composition. Efficacy was based on slope-ratio and standard-curve methodology. Using L-Met as a standard Met source added to a purified diet, DL-Met and Keto-Met were assigned relative bioefficacy values of 98.5 and 92.5%, respectively, based on weight gain. Relative bioefficacy values of 98.5 and 89.3% were assigned to DL-Met and Keto-Met, respectively, when chicks were fed a Met-deficient, corn-soybean meal-peanut meal diet. Thus, both DL-Met and Keto-Met are effective Met precursor compounds in chicks. Additionally, growth-depressing effects of L-Met, DL-Met, and Keto-Met were compared using a nutritionally adequate corn-soybean meal diet supplemented with 15 or 30 g/kg of each compound. Similar reductions in weight gain, food intake, and gain:food ratio were observed for each compound. Subjective spleen color scores, indicative of splenic hemosiderosis, increased linearly (P < 0.01) with increasing intakes of each compound, suggesting a similarity in overall toxicity among these compounds. Because conversion of Keto-Met to L-Met in vivo merely requires transamination, Keto-Met may prove to be a useful supplement not only in food animal production, but also as a component of enteral and parenteral formulas for humans suffering from renal insufficiency. [ABSTRACT FROM AUTHOR]

A comparative species investigation of the relative pharmacologic effects of sulfur amino acids was conducted using young chicks, rats, and pigs. Ingestion of excess Met, Cys, or Cys-Cys supplemented at 2.5-, 5.0-, 7.5-, or 10 times the dietary requirement in a corn-soybean meal diet depressed chick growth to varying degrees. Strikingly, ingestion of excess Cys at 30 g/kg Cys (7.5-times the dietary requirement) caused a chick mortality rate of 50% after only 5 d of feeding. Growth was restored and chick mortality was reduced by supplementing diets containing 25 g/kg excess Cys with KHCO3 at log/kg. Additionally, mortality was prevented by supplementing the drinking water of chicks receiving 25 g/kg supplemental Cys with H2O2 (0.05% final concentration). After young rats and pigs consumed excess Cys or Cys-Cys up to 40 g/kg for 14 d, weight gain was severely depressed, but we observed no mortality. An excess of dietary Cys-Cys ≥=48 g/kg caused some mortality in rats. Pigs exhibited rapid recovery from growth-depressing excesses of Cys or Cys-Cys. These results lend credence to the acute toxic effects associated with the ingestion of excess sulfur amino acids and highlight the potential for excess dietary cyst(e)ine to be more pernicious than Met in certain species. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Manganese Neurotoxicity May Underlie the Association Between Early Life Iron Deficiency and Impaired Spatial Cognition in Neonatal Piglets," by N. L. Maitre, J. L. Aschner and M. Aschner within the same issue.

This study sought to determine the relationship among broiler performance, organ development, and indicators of microbiota colonization. A total of 1,200 two-day-old male Ross 308 broiler chicks, divided among 3 cohorts of equal size, were housed in battery cages, and allotted based on body weight. On study d 11, birds were weighed, and birds with BW gain within the 10th and 90th percentiles were assigned to the Slow and Fast groups, respectively. Birds (n = 30 for each group) selected on d 11 were provided water and a corn-soybean meal-based diet ad libitum while maintained individually through study d 25 (i.e., a 14-d growth period). Parameters regarding growth performance, organ and intestine weights and lengths, and intestinal volatile fatty acid concentrations were measured. All data were analyzed by one-way ANOVA using the Mixed procedure of SAS. Fast birds exhibited greater (P < 0.001) BW gain and feed intake than slow birds, but feed conversion ratio (FCR) did not differ (P = 0.19). Additionally, Slow birds had higher (P < 0.05) relative weights (% of BW) for nearly all organs on d 11 and 25, most notably the gizzard, proventriculus, pancreas, and liver. Conversely, intestinal sections were longer (P < 0.05) in the Fast birds. Measurement of gut histomorphology did not show any notable differences between growth rate groups in terms of villi height, crypt depth, or their ratio for either time-point (P > 0.05). In terms of volatile fatty acid concentrations of luminal contents, acetate concentrations were 10.2% higher (P < 0.001) in the ileum of the Slow birds compared with Fast birds on d 25. Overall, the findings suggest that total BW gain is influenced by the development of metabolically active organs, as supported by lower weight gain in Slow birds with relatively larger organ weights and shorter intestinal lengths than their Fast counterparts. The general lack of differences in fermentation end-product concentrations in luminal contents does not rule out influence of the microbiota on growth rate of broilers, which warrants further investigation. [ABSTRACT FROM AUTHOR]

Despite its importance in poultry research, there is lack of standardized and practical techniques to measure intestinal permeability in a noninvasive manner. Therefore, this research sought to standardize a procedure using lactulose (Lac) and mannitol (Man) to measure intestinal barrier function in broilers. Twenty-one-day-old male and female Ross 308 birds were orally gavaged (either 2 mL/kg BW or fixed 3 mL per bird) with a solution containing 5 to 25 g Lac and 1 to 5 g Man dissolved in pure water to reach 100 mL of final solution. Feed withdrawal (FW ; 2–24-h duration) prior to dosing with Lac and Man (LacMan) was mainly used to induce graded intestinal permeability. Blood samples were collected at 60-, 90-, or 120-min after LacMan dosing using serum or plasma (K 2 EDTA and/or Na-Heparin) blood tubes. Lac and Man concentrations were quantified by HPLC. Plasma samples collected 90-min after LacMan dosing elicited the least variable response (22.4% vs. 22.8% or 23.4% CV when compared with 60- and 120-min sampling time-points, respectively), and both markers were detectable after administering a solution containing the lowest concentration of Lac and Man. However, analytical problems arose when using Na-Heparin anticoagulant as high glucose levels interfered with Lac quantification. Upon improving the chromatographic technique, it became evident that a 24-h FW increased (P < 0.01) Lac concentrations. In the last trial, a more severe glucose interference was observed, resulting in no Lac detection within an entire treatment group. Twelve hours of FW increased (P < 0.01) Man concentration in the plasma of birds receiving the solution containing 3 g Man, but had no effect on the birds receiving the solution containing 5 g Man. A 24-h FW did not affect the Man concentrations in birds receiving the solution containing either 3 or 5 g Man. With inconsistency of Lac detection throughout our trials, it was concluded that the combination of Lac and Man is an unreliable marker to predict intestinal barrier function in broilers. [ABSTRACT FROM AUTHOR]

Accurate quantitative non-invasive assessments of arterial cerebral blood volume (aCBV) can greatly benefit the study of cerebral vascular health in both humans and in animal models. In recent years, progress has been made in the techniques available to quantify CBV with magnetic resonance imaging (MRI). Here, we compared a non-invasive technique, measuring inflowing vascular space occupancy with dynamic subtraction (iVASO-ds) with a contrast-based vascular space occupancy measurement in piglets. In addition, we measured how the iVASO-ds derived aCBV changed with piglet development from 4 weeks to 8 weeks. Our results indicate that there is a significant correlation between the non-invasive iVASO-ds derived aCBV and CBV quantified using a gadolinium contrast agent, despite the contrast-based method providing significantly higher estimates of CBV resulting from challenges inherent to using the contrast-based technique. In addition, it was possible to see significant increases in blood volume across 4 weeks to 8 weeks in pig development with the non-invasive technique. Our results suggest that the non-invasive technique, iVASO-ds can assess aCBV in the developing piglet, both cross-sectionally and longitudinally, and has significant advantages over the contrast-based quantification method. [ABSTRACT FROM AUTHOR]

This study was designed to test graded supplementation of a thermostable xylanase in pelleted, wheat-based diets fed to broiler chickens over a 28-d period. A total of 600 Ross 708 male broilers were allotted to 1 of 5 dietary treatments: positive control (PC), negative control (NC ; 125 kcal of AME/kg diet reduction relative to PC), and NC supplemented with 10, 15, or 30 g/ton of xylanase. Wheat-soybean meal-based diets were pelleted and fed in 2 feeding phases (14-d each). Study outcomes included growth performance, AME, and ileal digesta viscosity with 20 battery cages of 6 birds per treatment. Data were analyzed by 1-way ANOVA along with estimation of Pearson correlation coefficients. Whereas no difference between NC and PC was observed for BW gain, NC birds exhibited increased (P < 0.05) feed intake during each feeding phase and overall, which caused improvements (P < 0.05) in feed conversion ratio (FCR) for PC vs. NC birds. The analyzed AME of PC birds was 112 kcal/kg of diet greater (P < 0.05) than for NC birds, though no differences in digesta viscosity were observed. Xylanase supplementation of the NC diet at 15 or 30 g/ton elicited overall improvements (P < 0.05) in BW gain beyond the PC, while the 30 g/ton level equalized feed intake with the PC. Regardless of level, xylanase supplementation improved (P < 0.05) the FCR relative to the NC, thereby equalizing the response with the PC. Similarly, supplementation with any xylanase level increased (P < 0.05) AME over the NC, making all treatments synonymous with the PC. Digesta viscosity of all xylanase-supplemented treatments was decreased relative to both the NC and PC treatments. Overall, this study provided clear evidence that addition of a thermostable xylanase to pelleted wheat-based diets elicited improvements in growth performance of broilers concomitant with a reduction in digesta viscosity and elevation of analyzed dietary AME content. [ABSTRACT FROM AUTHOR]

• Two brain atlases for the pig at two time points were created. • Twenty-six regions of interest were identified. • A template for tract-based spatial statistics was developed for the pig. • Normative data for brain measures for the young and adolescent pig are provided. Neurodevelopmental studies utilize the pig as a translational animal model due to anatomical and morphological similarities between the pig and human brain. However, neuroimaging resources are not as well developed for the pig as they are for humans and other animal models. We established a magnetic resonance imaging-based brain atlas at two different ages for biomedical studies utilizing the pig as a preclinical model. Twenty artificially-reared domesticated male pigs (Sus scrofa) and thirteen sow-reared adolescent domesticated male pigs (Sus scrofa) underwent a series of scans measuring brain macrostructure, microstructure, and arterial cerebral blood volume. An atlas for the 4-week-old and 12-week-old pig were created along with twenty-six regions of interest. Normative data for brain measures were obtained and detailed descriptions of the data processing pipelines were provided. Atlases at the two different ages were created for the pig utilizing newer imaging technology and software. This facilitates the performance of longitudinal studies and enables more precise volume measurements in pigs of various ages by appropriately representing the neuroanatomical features of younger and older pigs and accommodating the proportion differences of the brain over time. Two high-resolution MRI brain atlases specific to the domesticated young and adolescent pig were created using defined image acquisition and data processing methods to facilitate the generation of high-quality normative data for neurodevelopmental research. [ABSTRACT FROM AUTHOR]

Production of crystalline amino acids (AA) through microbial fermentation concomitantly provides an AA-enriched biomass that may serve as a cost-effective supplement for broiler chickens. We investigated the effects of feeding a fermentation biomass product containing approximately 62% Lys on growth performance, organ growth, and clinical outcomes of broilers. Beginning at 2 d post-hatch, a total of 360 Ross 308 chicks were randomly assigned to 1 of 5 treatments provided to 12 replicate cages of 6 birds. Practical corn-soybean meal-based dietary treatments included: negative control (NC ; no supplementation of L-Lys, 1.01 and 0.86% standardized ileal digestible Lys in starter and grower phases, respectively), NC + 0.23% L-Lys HCl (positive control; PC), and NC supplemented with 0.30, 0.90, or 1.50% Lys biomass (LB) in both phases. Feed and water were provided ad libitum throughout the study. Individual bird and feeder weights were recorded on study day 0, 10, 21, and 35. At study conclusion, birds from each treatment were randomly selected to collect blood and tissue samples. The PC and 0.30% LB diets elicited similar overall (day 0–35) body weight gain and birds were heavier (P < 0.001) than the NC and other LB treatments. The PC, 0.30% LB, and 0.90% LB groups had better (P < 0.001) overall feed conversion ratio than NC. Some LB-supplemented treatments elicited increased (P < 0.001) relative spleen and ileum weight compared with NC and PC. Heterophils were increased (P < 0.001) in LB treatments compared with PC and NC. Lymphocytes were decreased (P < 0.001) in LB treatments compared with NC, and 1.50% LB was similar to PC. This resulted in an increased (P < 0.001) heterophil-to-lymphocyte ratio in some LB treatments, which may have resulted from general AA supplementation or the LB product. Collectively, these results suggest that addition of up to 0.30% LB restored growth performance when added to a Lys-deficient practical diet and elicited results identical to the Lys-adequate PC diet with no negative clinical effects. [ABSTRACT FROM AUTHOR]