Effects of Iron Oxide Nanoparticle Supplementation on the Growth Performance, Serum Metabolites, Meat Quality, and Jejunal Basal Morphology in Broilers.

The current research aimed to evaluate the supplemental effects of iron oxide nanoparticles (IONPs) on production performance, viscera development, blood metabolites, redox status, meat quality, and jejunal histology in broilers. A total of 300 day-old broilers were randomly divided into six groups with five replicates per group. Birds were fed on a corn soybean-based diet supplemented with 0, 20, 40, 60, or 80 mg/kg IONPs or 80 mg/kg of FeSO4 for 35 days. The feed conversion ratio (FCR) was improved in birds supplemented with 60 mg/kg IONPs. The pH24h was lower in birds supplemented with 40 mg/kg IONPs compared to that of the bulk group. Pectoral muscle fascicle diameter and fiber density were significantly increased in 20 mg/kg IONP-supplemented birds compared to those of the bulk group, respectively. The muscle fiber diameter was higher in 40 mg/kg IONP-supplemented birds compared with the bulk group. The jejunal villus height, crypt depth, and villus surface area were significantly increased with 60 mg/kg IONP supplementation, whereas villus width was decreased in birds supplemented with 40 mg/kg IONPs. The villus-height-to-crypt-depth ratio was lower in IONP-supplemented birds compared to the bulk group. IONP supplementation improved the FCR, jejunal, and pectoral muscle morphology without affecting the carcass characteristics and redox status of broilers.

Professional Identity of Pakistani Veterinary Students: Conceptualization and Negotiation.

Most work on the professional identity of veterinary and medical professionals has been conceptualized in the USA and Europe. It reports professional identity formation to be highly individualized, triggered by experiences of identity distress, and identity negotiation strategies to be generally focused around personal reflection. However, within Asia, important sociocultural differences exist that might influence professional identity and its development. Societal values may take precedence over individual ones, and some cultures consider the veterinary profession as stigmatized. With this background, we seek to understand professional identity and its construction in Pakistani veterinary students. We selected five students through purposive sampling and invited them for narrative interviews. Social identity theory and Maslow's theory of hierarchy of needs predominantly contributed to the theoretical framework, which together with principles of social phenomenology and narrative analysis informed qualitative analysis of the transcribed interviews using an in-depth approach. We found that students' professional identity was predominantly socially constructed, though their sense of their identity was not very well developed. Role models, social stigma, professional socialization in clinical settings, gender, and to some extent, cultural interpretations of religious messages seemed to mediate professional identity development. Students responded differently to their understanding of professional stigma, making sense of stigma through strategies such as denial or internalization. Since Pakistani veterinary students experience social and personal values differently compared to those from predominantly individualistic cultures, identity formation through reflecting on personal values may be less effective than strategies that emphasize social learning and beliefs.

Effect of Selenium Nanoparticles and Mannan Oligosaccharide Supplementation on Growth Performance, Stress Indicators, and Intestinal Microarchitecture of Broilers Reared under High Stocking Density.

The current study investigated the potential of selenium nanoparticles (SeNPs) and mannan-oligosaccharide (MOS) supplementation in ameliorating high stocking density (HSD) stress in broilers. A total of 392 day-old male chicks were divided into seven groups with eight replicates (n = 7): NSD [basal diet (BD) + normal stocking density: 10 bird/m2], HSD [BD + high stocking density: 16 bird/m2], Se−HSD [BD + Selenium (Se) 0.15 mg/kg], MOS−HSD (BD + MOS 5 gm/kg), Se−MOS−HSD (BD + Se 0.15 mg/kg and MOS 5 gm/kg), SeNPs−HSD (BD + SeNPs 0.15 mg/kg) and SeNPs−MOS−HSD (BD + SeNPs 0.15 mg/kg and MOS-5 gm/kg). HSD stress decreased (p < 0.05) weekly body weight and body weight gain and increased (p < 0.05) FCR compared to the NSD group. Supplementation with SeNPs and the SeNPs−MOS combination improved (p < 0.05) the weekly body weight and FCR in HSD-stressed broilers during the 5th and 6th weeks. On day 21, HSD stress decreased (p < 0.05) duodenal villus height (VH) and villus surface area (VSA) and increased (p < 0.05) serum corticosterone and cholesterol compared to the NSD group. Supplementation with the SeNPs−MOS combination increased (p < 0.05) duodenal VH and VH:CD, and jejunal total goblet cell (TGC) density and decreased (p < 0.05) serum corticosterone and cholesterol and ileal intra-epithelial lymphocyte (IEL) density in HSD-stressed broilers. On day 42, HSD stress decreased (p < 0.05) duodenal and jejunal VH, VSA, VH:CD, PCNA positive cell density and TGC density, Ileal VSA and TGC density, and increased (p < 0.05) serum cholesterol and ileal IEL density compared to the NSD group. Supplementation with the SeNPs−MOS combination increased (p < 0.05) spleen and bursa absolute weights, duodenal VH, VSA, VH:CD, PCNA positive cell density and jejunal VH, VH:CD, and decreased (p < 0.05) serum cholesterol and ileal IEL density in HSD-stressed broilers. Our findings signify that HSD is stressful for broilers particularly during the finishing phase. Supplementation with the SeNPs−MOS combination mitigated HSD stress by partially improving the gut microarchitecture, gut barrier function and performance indicators.

Supplementation of Selenium Nanoparticles-Loaded Chitosan Improves Production Performance, Intestinal Morphology, and Gut Microflora in Broiler Chickens.

The current study aimed to evaluate the efficacy of selenium nanoparticles (SeNPs), combined or loaded with chitosan (COS), in broiler chickens reared under standard management protocols. The parameters under investigation were production performance, organ development, components of the intestinal barrier, and ileal microbial count. Two hundred and forty day-old chicks were raised in five groups, with each group containing eight replicates (n=6/replicate). The control group received a basal diet whereas the other four groups received basal diets supplemented with SeNPs (0.5 mg/kg), COS (200 mg/kg), SeNPs+COS (0.5 mg/kg SeNPs + 200 mg/kg COS), and SeNPs-loaded COS (SeNPs-L-COS) (200 mg/kg) respectively. On day 35, two birds/replicate were sampled to collect the viscera under investigation. The results revealed that dietary inclusion of SeNPs-L-COS increased (p<0.05) the body weight gain and improved (p<0.05) feed conversion ratio. Similarly, SeNPs-L-COS supplementation increased (p<0.05) the small intestinal villus surface area as well as the count of acidic goblet cells and intraepithelial lymphocytes when compared with the control group. Whereas the total goblet cell count was higher (p<0.05) in the small intestines of both the SeNPs+COS and SeNPs-L-COS groups. Microbial analysis of ileal contents also revealed an increase (p<0.05) in Lactobacilli species count with a concurrent decrease (p<0.05) in Escherichia coli count in the SeNPs-L-COS group when compared with the COS and control groups. Based on the results of the current trial, we can conclude that supplementation with SeNPs-L-COS is a superior combination for promoting the gut health and performance of broilers.

Effectiveness of Mild to Moderate Hypothermic Cardiopulmonary Bypass on Early Clinical Outcomes.

BACKGROUND: Intraoperative hypothermia is an integral part of cardiopulmonary bypass (CPB), and a precise degree of hypothermia may improve the early clinical outcomes of cardiac surgery. Presently, there is no agreement on an accurate, advantageous temperature range for routine use in CPB. To address this issue, we conducted a retrospective observational study to compare the effects of different hypothermic temperature ranges on primary (inotropic support, blood loss, and platelet count) and secondary (ventilation support and in-hospital stay) outcomes in patients undergoing elective cardiac surgery. METHODS: Data were retrieved from the medical database of the Cardiovascular Surgery Department, King Edward Medical University, Lahore-Pakistan (a tertiary care hospital), dating from February 2015 to December 2017. Patients were divided into mild (34 °C to 36 °C), intermediate (31 °C to 33 °C), or moderate (28 °C to 30 °C) hypothermic groups. RESULTS: Out of 275 patients, 245 (89.09%) fit the inclusion criteria. The cohort with mild hypothermic CPB temperatures presented better clinical outcomes in terms of requiring less inotropic support, less blood loss, fewer blood transfusions, improved platelet counts, shorter in-hospital stays, and required less ventilation support, when compared with other hypothermic groups. CONCLUSIONS: Mild hypothermic CPB (34 °C to 36 °C) may produce better clinical outcomes for cardiac surgery and improve the quality of health of cardiac patients.

Season influence on serum kisspeptin level and its association with hormonal levels and semen kinematics of buffalo bulls (Bubalus bubalis).

Kisspeptin has an important role in the stimulation of hypothalamic-pituitary-gonadal axis in term of pubertal development, release of reproductive and metabolic hormones and ultimately affecting the fertility. The aim of the present study was to evaluate the serum kisspeptin level and its correlation with semen quality and selected hormones in buffalo bulls during the summer and spring seasons. Semen and blood samples from eight Nili-Ravi buffalo bulls (age: 9.21 ± 1.02 years) were collected. Semen was analysed using computer-assisted semen analysis. Serum concentrations of kisspeptin, gonadotropin releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, cortisol, triiodothyronine (T3), thyroxin (T4) and insulin like growth factor (IGF-1) were estimated using enzyme-linked immunosorbent assay kits. Kisspeptin was neither affected by seasons and nor correlated with semen parameters and hormones. Higher levels of GnRH, LH, cortisol, IGF-1, total motility (TM), average path velocity (VAP), straight-line velocity (VSL), curvilinear velocity (VCL) and linearity (LIN) were recorded in summer compared to spring. Correlations of GnRH versusIGF-1 and LH, LH versus IGF-1 and cortisol, FSH versus T4 and testosterone, testosterone versus T3 and T4 and T3 versus T4 were observed. The GnRH and IGF-1 were positively associated with TM, VAP, VSL, VCL and LIN. The LH was correlated with VSL, straightness and LIN. In conclusion, GnRH, LH, and IGF-1 correlations with semen parameters can be used to indicate semen quality. The buffalo bulls are well-adapted and can give quality semen in the summer season.

Efficacy of Whole-Blood Del Nido Cardioplegia Compared with Diluted Del Nido Cardioplegia in Coronary Artery Bypass Grafting: A Retrospective Monocentric Analysis of Pakistan.

Background and Objectives: Cardioplegia is one of the most significant components used to protect the myocardium during cardiac surgery. There is a paucity of evidence regarding the utilization of whole-blood Del Nido cardioplegia (WB-DNC) on clinical outcomes in coronary artery bypass grafting (CABG). The purpose of this retrospective cross-sectional study is to compare the effectiveness of diluted (blood to crystalloid; 1:4) Del Nido cardioplegia (DNC) with WB-DNC in patients who underwent elective CABG in a tertiary care hospital in Lahore-Pakistan. Materials and Methods: This was a retrospective descriptive study conducted at the Department of Cardiovascular Surgery, King Edward Medical University, Lahore. The medical database of all consecutive patients admitted from January 2018 to March 2020 and who fulfilled the inclusion criteria were reviewed. Results: Out of 471 patients admitted during the study period, 450 underwent various elective cardiac surgeries. Out of 450, 321 patients (71.33%) were operated on for CABG. Only 234/321 (72.89%) CABG patients fulfilled our inclusion criteria; 120 (51.28%) patients received WB-DNC, while 114 (48.71%) patients were administered with DNC. The former group presented with better clinical outcomes compared with the latter in terms of lesser requirements of inotropic support, low degree of hemodilution, shorter in-hospital stay, improved renal function, and cost-effectiveness. Peak values of serum Troponin-T (Trop-T), creatine kinase-myocardial band (CK-MB) release, and activated clotting time (ACT) were also lower in the WB-DNC group compared with the DNC group. Conclusions: The WB-DNC conferred better myocardial protection, improved early clinical outcomes, and also proved to be economical for patients undergoing elective CABG compared with classical crystalloid cardioplegia solution.

Effect of Bacillus cereus and Phytase on the Expression of Musculoskeletal Strength and Gut Health in Japanese Quail (Coturnix japonica).

We conducted a 28-day trial to evaluate the influence of Bacillus cereus and phytase supplementation on the expression of musculoskeletal strength and intestinal histological features in Japanese quail. Two-hundred day-old quail chicks were divided into four groups with five replicates (n=10): the first group served as a control and was fed only a basal diet (BD); the second group was fed BD + 0.1% B. cereus; the third group was fed BD + 0.01% microbial phytase; and the fourth group was fed BD + 0.01% microbial phytase + 0.1% B. cereus. Compared to the control, individual and combined supplementation of probiotic and phytase increased (P<0.05) the tibial weight, length, outside diameter, and weight of bone ash, but decreased (P<0.05) the weight-to-length index. The water-holding capacity, fiber diameter, fiber cross-sectional area, number of fibers per unit area, fascicle diameter, and fascicle cross-sectional area increased significantly (P<0.05) in birds fed on the combination of phytase and B. cereus. The villus height, width, depth, height-to-crypt depth, and surface area increased significantly (P<0.05) in the B. cereus and phytase groups on an individual basis. The strength of the musculoskeletal system was fully expressed when B. cereus and phytase were given synergistically. However, the histological features of the intestines improved in birds fed on an individual basis.

Single or Combined Applications of Zinc and Multi-strain Probiotic on Intestinal Histomorphology of Broilers Under Cyclic Heat Stress.

Two-hundred-eighty-day-old broiler chicks were divided into seven groups. The groups were designated as T1, thermoneutral zone; T2, heat stressed (HS); T3, HS + zinc (Zn) supplementation (30 mg/kg); T4, HS + Zn (60 mg/kg); T5, HS + probiotic (0.1 g/kg); T6, HS + probiotic (0.1 g/kg) + Zn (30 mg/kg); and T7, HS + Zn (60 mg/kg) + probiotic (0.1 g/kg). Significant decrease (p < 0.05) was observed in villus height (VH), VH to crypt depth ratio, and villus surface area of all intestinal segments in the T2 group when compared with the T1 group. The same parameters had significantly higher (p < 0.05) values in the jejunum and ileum of the Zn- and probiotic-supplemented groups (alone + combination) when compared with the T2 group. The birds exposed to HS showed fewer (p < 0.05) intraepithelial lymphocytes (IELs) in the jejunum and ileum than the T1 group, while their count increased in the jejunum and ileum with dietary treatments. In conclusion, Zn and probiotic positively modulated the intestinal microstructures of broilers kept under high environmental temperature.

Effects of Chromium-Loaded Chitosan Nanoparticles on the Intestinal Electrophysiological Indices and Glucose Transporters in Broilers.

The present study aimed to evaluate the effect of chromium-loaded chitosan nanoparticles (Cr-CNPs) on the electrophysiological indices, gene expression of glucose transporters, and tissue glycogen in broilers. A total of 200 one-day-old broilers were randomly divided into five groups, with each having five replicates (n = 8). Group A was fed a corn-soybean meal diet, while the diets of groups B, C, D, and E were supplemented with 200, 400, 800, and 1200 µg/kg of Cr as Cr-CNPs, respectively. On day 35, the jejunum was collected for electrophysiological study, gene expression of glucose transporters, and tissues glycogen determination. The basal short-circuit current and tissue conductance before the addition of glucose was the same in all groups. Following the addition of glucose, the change in short-circuit current decreased (p < 0.05) in the jejunal tissues of birds supplemented with 400 and 1200 µg Cr-CNPs compared with the control group. Gene expression of SGLT-1 and GLUT-2 remained unaffected with supplementation. The serum glucose and liver glycogen concentration decreased (p < 0.05) linearly with supplementation, while no effect was observed on muscle glycogen. In conclusion, Cr-CNPs supplementation decreases the glucose absorption and liver glycogen content, without affecting the gene expression of glucose transporters.

Correlation between Testicular Hemodynamic and Semen Quality Indices in Clinical Varicocele Patients in Pakistan.

Varicocele, a vascular event, is associated with infertility due to testicular damage that causes abnormal spermatogenesis in males. The goal of this study is to ascertain the diagnostic significance of scrotal color Doppler ultrasonography (CDUS) by measuring peak systolic value (PSV) and resistive index (RI) of the arteries supplying blood to the testis and their association with semen quality attributes. Sixty prospective patients (age: 20-50 years) undergoing microsurgical varicocelectomy at a teaching hospital were included in the study. Semen parameters and CDUS were recorded and testicular blood flow was determined as PSV and RI of subcapsular artery and intraparenchymal artery of the testes. Nonparametric statistics was applied to test the correlation/association of the semen quality with the PSV, RI, and other variables. Results revealed a significant negative correlation (r = -0.28; p < 0.05) between progressive motility of spermatozoa and resistive index of the intraparenchymal arterial blood flow. Furthermore, it was noticed that the progressive motility of spermatozoa was tended to be negatively correlated (r = -0.236) with resistive index of subcapsular arterial blood flow. In conclusion, this study has revealed that progressive motility of sperms has correlation with the intraparenchymal blood flow of testes. The progressive motility of sperms could be correlated with RI of testicular blood flow. The apparent lack of association between diameter of varicocele vein and semen quality signifies the need of investigating some other factors that may be involved in pathogenicity of varicocele. The diagnostic value of CDUS may be carefully interpreted and clinically correlated in assessment of severity of varicocele.

Effect of Dietary Supplementation of Zinc and Multi-Microbe Probiotic on Growth Traits and Alteration of Intestinal Architecture in Broiler.

This experiment aimed to investigate the effect of different levels of zinc (Zn) and a probiotic on the growth and intestinal health of broiler chickens. One hundred ninety-two-day-old broiler chicks were randomly assigned to 6 groups. The birds were supplemented with Zn (30 and 60 mg/kg) and a probiotic mixture alone or in combination with Zn. The results revealed that the broilers receiving a probiotic mixture alone or in combination with Zn (30 and 60 mg) increased (P < 0.05) final body weight, feed conversion ratio (FCR), and total goblet cell count in duodenum compared with the control group. Morphometry of the duodenum also revealed an increase (P < 0.05) in villus height (VH) and the ratio of VH and crypt depth in all the supplemented groups, whereas ileal VH increased (P < 0.05) only in Zn60 group when compared with control. Based on our results, we concluded that compared to the individual supplementation, the combined effect of Zn and probiotic mixture was superior in improving the growth performance and histomorphology of the intestine; however, the effect of two levels of Zn did not vary when combined with probiotic.

Pattern of varicocele vein blood gases in patients undergoing microsurgical Varicocelectomy.

BACKGROUND: Varicocele is known to be associated with infertility and sperm disorders. The exact cause of this ailment is not fully understood. There are limited numbers of studies where venous blood gases (VBGs) of varicocele veins were determined with conflicting results. Therefore, we have investigated the pattern of VBGs in both internal spermatic and external spermatic varicocele veins and correlation with semen quality parameters in infertile individuals who underwent left microsurgical varicocelectomy. METHODS: Patients (n = 27) undergoing left microsurgical varicocelectomy at a tertiary care hospital, were included in the study. Before surgery, semen parameters and scrotal color Doppler ultrasonography was performed. During surgery, blood sample was drawn from varicocele veins (internal spermatic and external spermatic veins) and a peripheral arm vein of the same patient as a control. The VBGs of all veins under study were estimated and compared with each other. The VBGs were also correlated with various semen quality parameters. Data, expressed as Mean ± SD, regarding VBGs in three veins were analyzed using one-way ANOVA. The correlation between VBGs and semen quality parameters was determined using Pearson's correlation. Differences were considered significant at p < 0.05. RESULTS: The pH was found to be higher (p < 0.01) in the internal spermatic vein compared with the external spermatic and the peripheral veins. Partial pressure of oxygen (pO2) and oxygen saturation (sO2) were higher (p < 0.01) in the internal spermatic vein compared with the peripheral vein. However, concentration of bicarbonate (HCO3) was lower (p < 0.01) in both veins compared with the peripheral vein. Partial pressure of carbon dioxide (pCO2) was also lower (p < 0.01) in the varicocele veins compared with the control vein. CONCLUSION: The internal spermatic veins had higher pH and oxygen tension, but lower HCO3 and pCO2 levels compared with the control peripheral veins. External spermatic veins had lower pCO2 and HCO3 but other VBGs were similar to the peripheral veins. The shift of VBGs of internal spermatic vein toward arterial blood pattern may be a missing link to understand the pathophysiology of varicocele.

Erratum to: Sub-chronic exposure to low concentration of dibutyl phthalate affects anthropometric parameters and markers of obesity in rats.

The correct name of the 1st and corresponding Author is Khalid Abdul Majeed.

Sub-chronic exposure to low concentration of dibutyl phthalate affects anthropometric parameters and markers of obesity in rats.

Dibutyl phthalate is an important phthalate ester extensively used in various products like plastics, adhesives, inks, pharmaceuticals, lacquers, varnishes, paper coatings, safety glasses, and cosmetics. The exposure of DBP to "one's health" is therefore inevitable. The present study focuses on elucidating the effect of low doses of DBP on anthropometric parameters and markers of obesity in rats in a 13-week study. A total of 48 rats were divided into three treatment groups as mg DBP/kg body weight per day: (a) 0 mg/kg (control), (b) 10 mg/kg (DBP-10), and (c) 50 mg/kg (DBP-50). The rats in each treatment (n = 16) were further equally divided into male and female rats for studying treatment and gender interaction. Anthropometric parameters, nutritional determinants, and markers of obesity in rats were studied. Two-way ANOVA was used to analyze the data (p < 0.05). Tukey's post hoc test was used for pairwise comparisons. DBP increased body weight gain, feed efficiency, abdominal to thoracic circumference ratio, and body mass index in rats. Serum cholesterol and alkaline phosphatase concentrations decreased with DBP treatment. Serum albumin, glucose, creatinine, and alanine transaminase increased with DBP treatments. Serum lactate dehydrogenase increased in DBP-10 but was not affected by DBP-50. Further low-dose investigations are needed to assess non-monotonic dose responses.

Effect of sodium butyrate on performance, immune status, microarchitecture of small intestinal mucosa and lymphoid organs in broiler chickens.

OBJECTIVE: This study aimed to examine the effect of sodium butyrate (SB) on growth performance, immune status, organs weights, and microarchitecture of lymphoid organs and small intestine. METHODS: A total of 120, 1-d-old broiler chicks were distributed into the following four treatment groups: corn-soy based basal diet (BD) without supplement (control), or the same BD supplemented with 0.1 g/kg zinc bacitracin (ZnB), 0.5 g/kg SB (SB-0.5), or 1.0 g/kg SB (SB-1), respectively. Six birds/group were killed on d-21 and d-35, and samples were collected. RESULTS: Cell-mediated immune response at 48 h post-Phytohemagglutinin-P injection, and antibody titer against Newcastle disease vaccine and sheep red blood cells on d-35 was noted higher (p<0.05) in SB-1 compared to ZnB and control. Lower (p<0.05) feed conversion ratio (FCR) was attained by the supplemented groups. Thymus and spleen weighed more (p<0.05) in SB-1, and bursa registered more (p<0.05) weight in both SB groups compared to control. On d-21, areas of thymus medulla and spleen germinal centers were noted higher (p<0.05) in SB-1 group. The villus height and villus surface area increased (p<0.05) in duodenum and jejunum in both SB groups on d-21, and in SB-1 on d-35, respectively compared to ZnB and control. On d-21, number of goblet cells containing mucins of acidic nature increased (p<0.05) in all the segments of small intestines in SB-1 group compared to control, and on d-35 in ileum compared to other groups. CONCLUSION: In conclusion, SB improved growth performance and immunity as well as modulated morphology of lymphoid organs and gut mucosa in broiler chickens.

WITHDRAWN: Venous Blood Gases of Varicocele Veins: Correlation With Testicular Blood Flow and Semen Quality in Varicocele Patients.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Quantitative differences in activities of back and pelvic limb muscles during walking and trotting between chronically lame and nonlame horses.

OBJECTIVE: To assess differences in activities of back and pelvic limb muscles by use of surface electromyography (SEMG) in chronically lame and nonlame horses during walking and trotting. ANIMALS: 12 nonlame horses and 12 horses with unilateral chronic mild to moderate pelvic limb lameness. PROCEDURES: On each horse, bipolar electrodes were attached to the skin over the midpoints of the right and left longissimus thoracis (Lot), semitendinosus (Set), biceps femoris (Bif), gluteus medius (Glm), and extensor digitorum longus (Edl) muscles. For each muscle, synchronous kinematic and SEMG recordings were made during walking and trotting on a treadmill; mean, maximum, and minimum muscle activities and maximum-to-mean and minimum-to-mean activity ratios were determined. For each lame or nonlame horse, data from both pelvic limbs were averaged; in lame horses, data from the nonlame and lame pelvic limbs were also examined separately (NL-L and L-L values, respectively). Comparisons were made among the 4 data sets and between gaits. RESULTS: During walking, the NL-L maximum-to-mean ratios for Bif and Glm muscles were significantly greater and in lame horses, L-L and NL-L minimum-to-mean ratios for Set, Bif, Glm, and Lot muscles were significantly less than those for nonlame horses. During trotting, minimum-to-mean ratios for Set, Glm, and Lot muscles in lame horses were significantly lower than those for nonlame horses. Activity of the Edl muscle was not affected by lameness. CONCLUSIONS AND CLINICAL RELEVANCE: In lame horses, variation in muscle use was detectable via SEMG. In chronically lame horses, back and pelvic limb muscle activities were affected differently during walking and trotting.