Veterinaria México OA

Evaluation of salinomycin for an extended period in laying replacement hens

Lilia Gutiérrez — 2026-01-22

The clinical efficacy of salinomycin premix (Pisacox®) administered in feed to replacement pullets to control coccidiosis was evaluated by dosing during 4 or 14 weeks. The productive performance, signs, and lesions associated with coccidiosis and direct oocyst counts were analyzed in 3 000 Bovans White pullets distributed in 3 groups of 1 000 birds having the same diet: control group (Ctrl) without coccidiostat; Sal₄group with the administration of salinomycin for 4 weeks; and Sal₁₄group that received salinomycin for 14 weeks. Predictably, in both Sal₄ and Sal₁₄treatments, lower oocyst counts than in the control were observed. However, it was more evident with Sal₁₄towards the end of the trial, whose oocyst count was < 5 000 g of feces. This response can be associated with better productivity variables. The coccidial-type intestinal lesions detected in control were classified as severe (2.55), while Sal₄ and Sal₁₄presented values of 1.0 and 0 (mild lesions and normal appearance, respectively). The accumulated mortality associated with coccidiosis was statistically higher in the Ctontrol group (9.8 %) (P < 0.001), 1.33 % for Sal₄, and 0.2 % for Sal₁₄(P < 0.05, between these two groups). In conclusion, using salinomycin for 4 weeks successfully controls clinical coccidiosis. However, the lower rate of coccidiosis, the improvement in productive variables, and the lower accumulated mortality in Sal₁₄allow for the proposal of including the treatment with salinomycin for 14 weeks in replacement pullets.

Soluble and membrane associated adenylate cyclases participate in capacitation with hyaluronic acid in bovine spermatozoa

Silvina Fernandez — 2026-03-26

Hyaluronic acid (HA), a glycosaminoglycan present in the female reproductive tract, mediates sperm motility, maturation and capacitation. Two adenylate cyclases, soluble (sAC) and membrane-associated (mAC), isoenzymes are present in spermatozoa, participating in different signaling mechanisms. The aim of this study was to determine the effect of adenylate cyclase isoenzymes inhibition on bovine sperm processes, such as capacitation, motility, viability, mitochondrial activity and fertilizing capacity, during sperm capacitation with HA. HA was used as a capacitation inducer, while LRE-1 (a specific sAC inhibitor) and 2,5-dideoxyadenosine (2,5-D) were used as sAC and mAC inhibitors, respectively. We evaluated sperm capacitation (chlortetracycline [CTC] technique), viability (trypan blue stain and differential interference contrast), mitochondrial activity (fluorochrome 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide [JC-1]) and motility (computer-assisted sperm analysis). We carried out in vitro fertilization (IVF) in IVF- modified synthetic oviductal fluid (mSOF) with frozen-thawed semen. We then cultured presumptive zygotes for 48 hours and analysed the cleavage rate. The addition of sAC or mAC inhibitors, alone or combined, produced a significant decrease in capacitation, mitochondrial activity and motility with respect to sperm samples incubated only with HA and controls (P < 0.05). Cleavage rates decreased with the addition of adeylate cyclase (AC) inhibitors compared to HA alone. We observed a greater decrease in cleavage rate with the addition of LRE-1 than with 2,5-D (P < 0.05). The combination of both inhibitors decreased the cleavage rate with respect to each inhibitor alone (P < 0.05). In bovine spermatozoa, both soluble and membrane-associated adenylate cyclase isoenzymes could participate in the intracellular signaling mechanism and mitochondrial function, which modulate HA capacitation and sperm fertilizing ability.

Body weight increases with body condition score in Katahdin ewes in Tabasco, Mexico

Ricardo Cordero-Morales — 2026-05-29

The objective of this study was to determine the relationship between body weight (BW) and body condition score (BCS) in non-pregnant, non-lactating Katahdin ewes under tropical conditions. Body weight and BCS were measured in 110 Katahdin ewes aged 2.5 years with mean BW of 43.18 ±6.73 kg and mean BCS of 2.38 ±0.82. Relationships were analyzed using correlation and linear regression. Body weight and BCS showed a strong positive correlation (r = 0.90; P < 0.001). The linear regression equation was BW = 25.66 (±0.84) + 7.34 (±0.33) × BCS (R² = 0.81, MSE = 8.39, RSD = 2.89, n = 110). These results indicate that 7.34 ±0.33 kg of BW are required for each unit change in BCS in Katahdin ewes managed under humid tropical conditions.

Evaluation of the degradability of pelagic sargassum under in vitro and in situ conditions for use in ruminant diets

Luis Alberto Canul-Ku — 2026-05-29

Pelagic sargassum is a mixture of several species of brown macroalgae rich in minerals, polysaccharides, and bioactive compounds; it reaches the Caribbean coasts in large quantities. The objective of this study was to evaluate its potential as an ingredient in ruminant feed based on its in situ degradability and in vitro gas production. 0 %, 10 %, 20 %, and 30 % percentages of sargassum were added to a substrate (Pennisetum purpureum VC CT-115 hay). Two cows with ruminal cannulas were used for the in situ trial, while in vitro gas production was evaluated following the Menke and Steingass methodology. The inoculum was an aliquot of ruminal fluid obtained through an esophageal probe from five grazing hair sheep. In situ degradability of dry matter (DM) decreased linearly (P < 0.0001) as the concentration of sargassum in the substrate increased from 0 % to 30 % (48 h: from 684.91 to 607.75 g/kg DM; 72 h: from 722.10 to 634.68 g/kg DM); organic matter (OM) showed a comparable trend. While the in vitro gas production curve was among the control group, 10 % and 20 % levels of inclusion, degradability of DM and OM, as well as the protozoa population, were did not differ significantly (P > 0.0001) across all treatments. We conclude that pelagic sargassum may be included at levels of 20 % and 30 % in situ and in vitro; however, its use under in vivo conditions requires further evaluation.

Codon usage bias and evolutionary dynamics of porcine Sapelovirus: insights into host adaptation

V. Mouna — 2026-01-22

Porcine sapelovirus (PSV), a member of the Sapelovirus genus within the Picornaviridae family, is a swine pathogen causing respiratory diseases, polioencephalomyelitis, and gastroenteritis. The infection results in economic loss in the swine industry and often co-occurs with bacterial, viral, or fungal infections. Despite its impact, the evolutionary dynamics and adaptation mechanisms of PSV remain poorly understood. This study investigates the evolutionary forces shaping adaptation of the PSV polyprotein gene through codon usage bias and nucleotide composition analysis. A total of 34 polyprotein coding sequences of PSV were retrieved from the NCBI database and analyzed using bioinformatics tools. The nucleotide composition analysis revealed adenine as the most abundant nucleotide, with thymine predominating at the third codon positions. The Guanine-Cytocine (GC) content was balanced overall, with variations in GC content at the third codon position values suggesting mutational pressure. Relative synonymous codon usage analysis identified overrepresented and underrepresented codons, highlighting host-specific selection pressures. The Effective number of codons and neutrality plots indicated that natural selection predominantly influences codon usage bias in PSV, while mutational pressure contributes less. Chargaff's second parity rule analysis confirmed deviations influenced by these forces, while dinucleotide abundance analysis provided insights into codon usage trends. The codon adaptation index (CAI = 0.584) suggested moderate adaptation of PSV to its natural host, Sus scrofa domesticus, reflecting evolutionary constraints on translational efficiency. Correspondence analysis highlighted factors driving viral evolution. These findings contribute to our understanding of PSV molecular evolution, supporting the development of antiviral strategies, vaccines, and diagnostic for disease control.

Effects of different doses of Foeniculum vulgare Mill. seeds on growth performance, intestinal and liver histology and gene expression levels in quail

Tülay Çimrin — 2026-03-27

This study aimed to determine the effects of ground fennel seed (FS) supplementation to quail feed on growth performance, some slaughter and carcass characteristics, histopathological changes in liver and ileum, and gene expression levels. A single factorial experimental design was used. In total, 160 seven-day-old mixed-sex Japanese quails (Coturnix coturnix japonica) were randomly assigned to four groups of four replicates each. Groups were fed with 0, 1, 2, and 4% FS-supplemented basal diet (control, FS1, FS2, FS4), respectively. Study results showed that FS supplementation did not affect growth performance. Intestinal villus height and villus width decreased significantly in female quails with FS supplementation. Crypt depth increased significantly in FS2 and FS4 males, while it decreased in FS2 females. FS supplementation significantly reduced fatty liver grades in females. The peroxisome proliferator-activated receptor alpha (PPARα) gene level was significantly increased in FS4 females compared to control group, FS1 and FS2 females and males, and FS4 males only. As a result, FS, a phytoestrogenic plant, has shown different effects depending on sex. The increase in PPARα gene level in FS4 females suggests that FS supplementation affects lipid metabolism in a sex-dependent manner and that the hepatoprotective effect of PPARα may increase as the amount of FS supplementation increases. Considering its positive effect on the grade of fatty liver and PPARα gene level, it was determined that FS supplementation at 4% can be used in female quail feeds to protect animal health and support functional food production.

High multidrug resistant Staphylococcus aureus and Escherichia coli in companion animals, southern Chile

Natalia Francisca Urzúa Pizarro — 2026-04-30

This study investigated phenotypic antimicrobial resistance in bacterial isolates from clinical samples of dogs and cats in southern Chile between 2021 and 2022. A total of 140 samples (109 from dogs, 31 from cats) were analyzed. Bacterial identification and antimicrobial susceptibility testing were performed using standard biochemical methods and Kirby-Bauer disk diffusion, interpreted according to The Clinical & Laboratory Standards Institute guidelines. The most frequent sample types were skin in dogs (50.5 %) and urine in cats (38.7 %). Coagulase-negative staphylococci (29.3 %), Escherichia coli (20.7 %), and Staphylococcus aureus (17.9 %) were the most commonly isolated bacteria. Multidrug resistance (MDR) was observed in 52 % of S. aureus and 51.7 % of E. coli isolates. Two isolates showed profiles suggestive of extended-spectrum β-lactamase (ESBL) production. E. coli exhibited resistance to all tested antimicrobials except imipenem. These findings reveal worrisome resistance patterns in companion animals in southern Chile and underscore the urgent need to integrate these species into regional antimicrobial resistance surveillance efforts.

Zoometría neonatal como predictor del desempeño productivo en lechones criollos Ts'üdi Xirgo

Julio Cesar Rodríguez-Montoya — 2026-02-19

La conservación de los recursos genéticos animales se considera un pilar para la seguridad alimentaria y el desarrollo rural mexicano; sin embargo, algunas poblaciones están en riesgo de desaparecer, como la de los cerdos criollos, que se concentran en un núcleo productivo rural muy pequeño, donde la alta mortalidad y la productividad de los lactantes reflejan las limitaciones. Primero, cuando los lechones nacieron, se pesaron (PN) y se tomaron sus medidas zoométricas: circunferencia cefálica (CC), circunferencia abdominal (CA), circunferencia torácica (CT), longitud corporal (LC), e índices zoométricos: índice de masa corporal (IMC) e índice ponderal (IP) de neonatos criollos ts´üdi xirgo. Mediante la construcción de modelos de regresión multivariable, se buscó la agrupación de variables, que permitan identificar lechones con mejores valores en las características productivas durante la lactancia: peso el día 21 (P21), peso al destete (PD) y ganancia de peso diaria (GPD). Se consideró que las agrupaciones incluyeran una variable zoométrica y un índice zoométrico al nacer como variable fija, y los días de lactancia (DL) como bloque. Algunas de las variables que influyen en la productividad de los lechones criollos son las características físicas. Hallamos que el conjunto de variables PN, CT, IP y DL brinda una mejor predicción para el P21 (P = 0.001) y el PD (P = 0.003), mientras que, para la GPD, las variables que se ajustan a los datos son PN, LC, IP y DL (P = 0.01). El uso de herramientas y protocolos para la identificación temprana de lechones en riesgo permite brindar las condiciones óptimas para una lactancia y un desarrollo eficaces, disminuyendo la mortalidad predestete, favoreciendo el incremento nacional de estos animales y sirviendo como impulso y apoyo económico para las familias productoras de cerdo criollo.

Evaluating the carbon footprint and sequestration potential of tropical cattle systems: a comparative life cycle approach

Adriana Rivera-Huerta — 2026-06-18

Advancing sustainable beef systems requires understanding the carbon footprint of livestock production. Mexico is responsible for high greenhouse gas (GHG) emissions from the livestock sector, an activity that extends across large areas of land in its tropical region. This study aimed to assess the contributions of two cattle grazing systems to climate change and to their carbon (C) sequestration potential, as well as to estimate their GHG balance. The analysis was conducted in accordance with the ISO 14067 standard based on the Life Cycle Assessment methodology. The “cradle-to-farm gate” approach was applied to evaluate the carbon footprint of 1 kg of live weight of calf, including C sequestration in two beef cow-calf grazing systems in the Mexican tropics: monoculture (MC) and silvopastoral (SP). Data collected from six cattle ranches (three monoculture and three silvopastoral), in the State of Yucatán, Mexico, were used. The system boundaries included pasture, feed supplements, agrochemicals, fossil fuels, electricity, and pesticides. The potential soil C equestration was estimated from the Ex-Ante Carbon-balance Tool version 9 of the Food and Agriculture Organization of the United Nations. The results revealed that MC systems exhibited lower GHG emissions than the SP, while soil C equestration was higher in the SP. The carbon balance shows a lower carbon footprint for the SP than the MC system, and the uncertainty analysis demonstrates that the SP system had lower variability than the MC. The outcomes of this study could be used to direct policies aimed at reducing the contribution of tropical grazing systems to climate change.

Sex-related variations in Bovine LH isoforms revealed by chromatofocusing

Jose Gerardo Perera-Marin — 2026-03-24

Luteinizing hormone (LH) is a gonadotropin found in both blood and pituitary tissue, and it plays a critical role in reproductive regulation in ruminants and other species. Distinct isoforms produced by post-translational modifications have been previously reported in the pituitary gland of ovariectomized cows and castrated bulls, treated with progesterone and estradiol, respectively. However, it remains unclear whether variations exist in the molecular forms of this hormone in intact prepubertal cattle. Anterior pituitary extracts of steers and heifers underwent chromatofocusing across a pH gradient (10–3.5), allowing classification of the eluted hormone forms into basic (pH ≥ 7.5), neutral (pH 7.4–6.5), and acidic fractions (pH ≤ 6.4) and on the basis of distinct isoforms (12 peaks of A–K). Radioimmunoassay was used to establish the immunological activity of LH isoforms. Overall, basic LH isoforms were present at higher concentrations than neutral or acidic forms in both steers and heifers. However, in steers the analysis by distinct isoforms of LH exhibited a slightly greater proportion of acidic isoforms J (pH 3.4–5.4) and neutral isoform G (pH 6–6.9) compared to heifers. In contrast, heifers showed slightly higher proportions of basic isoforms B (pH 9.2–9.9) and E (pH 7.8–8.7), neutral isoform F (pH 7.1–7.7), and acidic isoforms I (pH 5.7–6.4) and K (pH 3.3–4.9) than steers. Notably, the overall pituitary LH patterns observed in both groups were consistent with previously reported profiles, suggesting that these patterns are relatively stable despite physiological variation. Nevertheless, the subtle differences identified between sexes suggest that sex may influence the synthesis of LH isoforms at the pituitary level.

Evaluación de la producción de leche en ovejas sin pelo: estudio comparativo de dos métodos de estimación

Maritza Zaragoza-Vera — 2026-04-30

This study compared two methods for estimating milk yield (MY) in multiparous Pelibuey and Katahdin ewes accounting for litter size and week of lactation under tropical conditions. MY was assessed using the weight-suckle-weight (WSW) technique and hand milking (HM). Exploratory analysis was performed using box plots, followed by a repeated-measures ANOVA based on a mixed linear model including method, breed, litter size, and week as fixed effects, and ewe as a random effect. Method agreement was evaluated using Bland–Altman analysis. MY increased during the first three weeks of lactation, then stabilized or slightly declined. HM consistently produced higher average values than WSW. Katahdin ewes and those rearing twin litters yielded more milk than Pelibuey and single-litter counterparts. The mixed model showed that estimation method and litter size were the main sources of variation, followed by breed and week. The intraclass correlation coefficient (ICC = 28.11 %) indicated that slightly more than one-quarter of total variability was attributable to individual differences. The means ± SE plot suggested an interaction, with the largest HM–WSW discrepancy observed in Katahdin twin-litter ewes, the highest-producing group. The Bland–Altman plot revealed a systematic bias (-0.78 kg; HM > WSW) and poor agreement (limits of agreement -2.26 to 0.66 kg), indicating potential individual-level discrepancies. HM tends to overestimate MY relative to WSW, particularly in highly productive ewes. The two methods are not interchangeable without adjustment; their selection should consider ewe characteristics and study objectives, and correction for systematic bias is recommended when comparing results.

Serum lipopolysaccharide as a diagnostic and prognostic biomarker in Canis familiaris pyometra

Nayana Devarajan — 2026-01-22

Specific sensitive diagnostic markers for early diagnosis of canine pyometra have been widely attempted, but none have proven to be a perfect diagnostic marker for clinical practice. Lipopolysaccharide (LPS) or endotoxin is a cell wall component of gram-negative bacteria, released during bacterial death. The early release, inherent stability, and serotype-specificity of endotoxin suggest its potential as a good candidate for early diagnosis of pyometra. The present study focused on understanding the potential of LPS as a diagnostic and prognostic marker in canine pyometra. The study also tried to establish the correlation between bacterial isolates cultured from the vaginal discharge and endotoxin levels. A total of 12 animals presented to University Veterinary Hospitals with open and closed-cervix pyometra were selected and divided into two groups of six dogs each. Serum LPS concentration (ng/mL) was estimated on various days of observation using ELISA. Mean serum LPS concentration was higher in both groups on the day of presentation, and significantly higher levels were observed in animals with closed-cervix pyometra. Bacteriological examination revealed a predominance of gram-negative organisms in both groups. Hence, it establishes LPS as a better diagnostic marker of canine pyometra. Conversely, a reduction in the levels of LPS on subsequent days of observation confirms its efficacy as a prognostic marker.

Fermentation of tomato and apple pomaces with Aspergillus niger improves organic acid profile and broiler chicken performance

Ramazan Tosun — 2026-04-24

This study aimed to produce two functional feed additives via solid-state fermentation and evaluate their effects on performance, meat quality, and cecal microbiota in broiler chickens. A total of 288 mixed-sex Ross 308 broiler chicks were randomly assigned to nine dietary treatments (four replicates of eight chicks each). The control group received a basal diet, while treatment groups received the basal diet supplemented with increasing doses (300–2 400 mg/kg) of either fermented tomato pomace plus oat or fermented apple pomace plus rye. The trial lasted 49 days. Supplementation with the lowest and highest doses of fermented apple pomace plus rye significantly increased body weight and body weight gain (P < 0.05). The fermented tomato pomace plus oat increased breast meat lightness and yellowness at higher doses, whereas the fermented apple pomace plus rye decreased both color parameters (P < 0.05). The cecal lactic acid bacteria population increased with both additives at 300 mg/kg (P < 0.05). Both fermentation products yielded functional additives that improved body weight and weight gain during the starter period. The fermented apple pomace plus rye at 300 mg/kg showed the most consistent positive effects and can be recommended as a potential alternative feed additive for broiler chickens.

Eprinomectin and levamisole action on gastrointestinal nematodes in a Mexican dairy goat production system

Laura González-Reyes — 2026-04-23

The effectiveness of eprinomectin and levamisole was evaluated in a dairy goat herd in El Bajío with a history of multi-resistance to fenbendazole (0 %) and ivermectin (70 %) using the Fecal Egg Count Reduction Test. Larval cultures were used to assess the epidemiology of the disease. Thirty goats with ≥ 150 eggs per gram (EPG) and no anthelmintic treatment for ≥ 60 days were selected. The modified McMaster technique (sensitivity: 50 EPG) was used to quantify the parasite burden. Three groups (n = 10) were weighed and treated: eprinomectin (0.5 mg/kg, topical), levamisole (12 mg/kg, subcutaneous), and an untreated control. The effectiveness of eprinomectin was 65 %, while that of levamisole was 100 %. Trichostrongylus spp. (90–100 %) and Oesophagostomum sp. (10 %) were identified. The reduced effectiveness of eprinomectin may be linked to ivermectin resistance. Multidrug resistance in small ruminants highlights the urgent need for targeted selective treatments and integrated parasite management to preserve effective anthelmintics.

Phylogenetic analysis and nonsynonymous mutations in a Feline immunodeficiency virus env gene genotype A in Colombian cats

Cristina Úsuga-Monroy — 2026-05-29

El virus de la inmunodeficiencia felina es un retrovirus que infecta a los gatos domésticos. La variabilidad genética del virus, particularmente en la región V4–V5 del gen de la envoltura, puede contribuir a cambios específicos en los aminoácidos que afectan la patogenicidad viral y el desarrollo de siete subtipos distintos. El objetivo de este estudio fue determinar el genotipo circulante e identificar mutaciones no sinónimas mediante el análisis de un fragmento del gen env en una muestra de gatos domésticos de Colombia. Se recolectaron muestras de sangre de 151 felinos domésticos, se extrajo el ADN total y se amplificó un fragmento de 859 pb del gen env. La historia evolutiva fue reconstruida utilizando tanto métodos de máxima verosimilitud y metodos bayesianos. Adicionalmente, se analizaron las mutaciones no sinónimas dentro del fragmento de aminoácidos traducido del gen env mediante una herramienta predictiva. Se observó una prevalencia molecular de 5.29% (8/151) en la población muestreada. El genotipo A fue identificado como el genotipo circulante; sin embargo, las secuencias se agruparon en diferentes clados dentro de este genotipo. Este hallazgo se reflejó en la presencia de 12 sustituciones aminoacídicas no sinónimas, entre las cuales H86R (p<0.857), N88K (p<0.777), E41V (p<0.773) y K91D (p<0.743) presentaron una alta probabilidad de tener un impacto deletéreo. Estos resultados destacan la diversidad genética dentro del genotipo A del FIV y muestran el impacto potencial de mutaciones no sinónimas específicas sobre la patogenicidad viral.

A comprehensive analysis of lactation traits in the Arbia goat breed (Capra hircus) from Algeria

Djalel Eddine Gherissi — 2026-02-12

This study aimed to analyze the milk performance of Arbia does, the predominant goat breed in Algeria. A total of 389 quantitative and qualitative milk control records were collected from sixty-six dairy Arbia does monitored throughout their complete lactation period. The animals, managed under similar livestock practices, were located in two different agroecological regions: arid (Ar) and semiarid (SAr). The average lactation length (DIM) and interval between kidding (IKI) were 195.82 ±60.42 and 250.55 ±69.55 days, respectively, with milk production peaking at 89.22 ±10.76 days postkidding. The study recorded an average Total Milk Yield (TMY) of 207.18 ±76.86 kg, Daily Milk Yield (DMY) of 1.05 ±0.2 kg, and Persistency Coefficient (PC) of 72.91 ±4.13 %. The average Total Fat Yield (TFY), Total Protein Yield (TPY), Milk Fat Rate (MFR), and Milk Protein Rate (MPR) were 219.72 ±95.05 g, 745.28 ±88.68 g, 1.94 ±1.13 %, and 4.11 ±1.67%, respectively. Does from SAr produced more TFY and comparable TPY compared to those from Ar, despite having lower TMY and shorter DIM, reflecting significantly higher MFR and MPR in SAr. While lactation length showed potential influence on TMY (P = 0.07) and significant effects on TPY (P < 0.05), other factors, such as age, lactation number, and animals' origin, did not significantly affect TMY. Analysis revealed one production profile in Ar and two distinct lactation production profiles in SAr, suggesting the need for tailored optimization strategies based on this diversity in milk production characteristics.

Productive and reproductive indicators of bovine in the Guayzimi parish, Nangaritza canton, Zamora-Chinchipe, Ecuador

Orestes La O León — 2026-02-26

The evaluation of the cattle production system allows the diagnosis and suggestions of alternatives to improve production conditions. This study aimed to evaluate productivity and reproductive indicators and their relationship with the production systems in the parish of Guayzimi, canton of Nangaritza, in the province of Zamora-Chinchipe. A survey was conducted among bovine farmers in the study area, including questions related to social, productive, and reproductive aspects. A sample of 35 producers was analyzed using multivariate principal component analysis, descriptive statistics, correspondence analysis, and multiple correlation matrices Spearman's criterion. The results identified three main components: “Technical-Productive”, “Reproductive Efficiency”, and “Marketing,” which accounted for 35.1 %, 28.7 %, and 13.3 % of the total variance, respectively. Together, these components explained 77.7 % of the variance. The main issues identified were related to herd structure, showing a surplus of cows and bulls at 17.4 % and 78.6 %, respectively, and a deficit of heifers, calves, and young bulls at 21.3 %, 3.3 %, and 39.4 %, respectively. Additionally, a notable stagnation of females in the pre-reproductive stage suggesting they are not a significant variable in the production process. This study shows that achieving productive efficiency requires consideration of the relationship between 'herd organization + production organization + marketing” and the fact that stagnation in the flow of replacement female cattle is due to deficiencies in production strategies. Future studies could build on this research to strengthen the foundation of bovine production in the Guaizimi, Nangaritza, Zamora-Chinchipe.

Erysipelothrix rhusiopathiae infection in companion birds in selected regions of Iran

Parisa Khodakhah — 2026-06-19

Erysipelothrix rhusiopathiae is known to cause infections in humans following exposure to decaying organic matter or animals colonized with the organism, such as swine and fish. The aim of this study was to investigate the occurrence of this bacterium in companion birds in Iran. A total of 116 stool and tissue samples were collected from pigeons, cockatiels (n = 14), Grey Parrot (Psittacus erithacus), Red-and-green Macaw (Ara chloropterus) and Singing Parrot (Geoffroyus heteroclitus) admitted to veterinary clinics in Tabriz, Yazd, and Ahvaz. To investigate the presence of E. rhusiopathiae at the molecular level, DNA was extracted from all samples followed by PCR testing. After euthanasia, tissue samples were taken from the sick birds for histopathological examination. PCR analysis of tissue samples (trachea and brain) from two immature female pigeons yielded positive results for E. rhusiopathiae, representing a detection rate of 2.02 % (2/99) among birds from which tissue samples were collected. Histopathological examinations revealed necrotizing hepatitis, nephritis, myocarditis, rhabdomyolysis, pneumonia, and mild tracheitis with severe hyperemia, focal hemorrhages and varying degrees of inflammation in the examined tissues. From these results, it could be assumed that E. rhusiopathiae is present in the trachea and brain of Iranian companion birds, especially pigeons, as an important infectious agent that can have serious effects on the health and stability of these avian populations.

Determinación de la presencia de anticuerpos hacia diversos agentes patógenos en cerdos de granjas a pequeña escala en el centro de México

Rosalba Carreon Napoles — 2026-05-29

La presencia de patógenos que afectan al tracto respiratorio del cerdo es frecuente en poblaciones porcinas de todo el mundo y su importancia radica en el impacto económico que ocasionan, debido a su alta morbilidad, posible mortalidad y pérdidas productivas. Las granjas porcinas de pequeña escala (GPE), al operar con limitadas condiciones de bioseguridad, podrían favorecer la circulación y diseminación de patógenos respiratorios, afectando su productividad. El objetivo de este estudio fue determinar la presencia de anticuerpos contra Actinobacillus pleuropneumoniae (App), Mycoplasma hyopneumoniae (Mhyo), el virus del Síndrome Reproductivo y Respiratorio Porcino (PRRS) y el virus de Influenza porcina (IP [H1N1 y H3N2]) en cerdos de GPE ubicadas en el centro de México. Se recolectaron 66 muestras sanguíneas de cerdos en distintas etapas productivas en seis granjas con producción de ciclo completo, y se analizaron mediante pruebas serológicas. Las frecuencias de seropositividad fueron IP H1N1 (92.4%), App (43.9%), IP H3N2 (40.9%), Mhyo (39.4%) y PRRS (13.6%). Se observó una asociación significativa entre la seropositividad a App y la etapa productiva (P<0.01), con mayor frecuencia en cerdas reproductoras y de reemplazo. También se identificaron asociaciones serológicas entre Mhyo e IP H3N2 (P=0.02), y entre IP H3N2 y PRRS (P<0.01). Estos hallazgos evidencian una alta exposición a patógenos respiratorios en GPE, atribuible a la falta de medidas sanitarias y de manejo adecuadas. Se destaca la necesidad de fortalecer la vigilancia epidemiológica y la extensión veterinaria para mitigar los riesgos sanitarios y productivos en estas unidades.

Bovine mastitis in a small-scale dairy herd: microbiological diagnosis, antimicrobial susceptibility, and strategic analysis

Valeria Alejandra Morales-Murillo — 2026-03-25

Mastitis is an inflammatory condition of the mammary gland and a major cause of economic loss in dairy herds, affecting milk yield, quality, and animal welfare. This study was conducted in a Holstein herd in Aguascalientes, Mexico, to identify key bacterial pathogens, assess antimicrobial susceptibility, and evaluate milking practices using a Strengths, Weaknesses, Opportunities, and Threats and Analytic Hierarchy Process (SWOT–AHP) framework. Seasonal sampling was performed during the dry and rainy periods, with 129 milk samples and 66 equipment swabs collected. A higher proportion of bacteriologically positive milk samples was recorded in the rainy season (44 %) compared to the dry season (16 %). Coagulase-negative staphylococcus was the most frequently isolated microorganism, identified in both milk and surfaces. Mixed infections and environmental contamination were more prevalent during the rainy season. Antimicrobial susceptibility testing revealed a significant decline in sensitivity to penicillin, ampicillin, erythromycin, and tetracycline during the rainy season, while resistance to oxacillin remained consistently high. The SWOT-AHP analysis identified twelve strategic factors, with the highest global priorities assigned to the owner’s technical training (0.101), seasonal mastitis risk (0.101), and the potential for genetic improvement (0.101). Additional relevant factors included staff workload and hygiene challenges. The integration of microbiological data with strategic analysis provided a practical decision-making framework tailored to small-scale dairy operations. These findings underscore the value of continuous monitoring, rational antimicrobial use, and context-specific hygiene strategies. The combined application of qualitative diagnostics and semiquantitative scoring offers a replicable model for improving udder health and sustainability in tropical dairy production systems.

Etiological and histomorphological studies on enteritis in broiler chickens in Kashmir, India

Amir Bashir Kouchey — 2026-02-25

Enteric disorders comprise the most important groups of diseases affecting poultry birds and continue to be a major cause of high economic losses in many areas throughout the world, causing increased mortality rates, decreased weight gain, and increased feed conversion rates. This study was conducted to determine the prevalence and pathological investigations of various diseases affecting the intestines of poultry in the central part of the Kashmir Valley. 3 024 broiler chickens from 100 outbreaks of enteritis were necropsied and examined for the presence of lesions corresponding to different disease conditions. Various diseases were diagnosed based on history, clinical signs, gross pathology, and isolation of specific pathogens from the affected birds’ organs. The study revealed 45.69 % of enteritis associated with various specific and nonspecific disease conditions. The highest prevalence was associated with mixed infections (12.4 %), followed by colibacillosis (10.78 %), coccidiosis (8.23 %), salmonellosis (7.8 %), New Castle disease (3.34 %), nonspecific causes (1.92 %), and necrotic enteritis (1.22 %). The intestines showed gross changes including congestion, thickened walls, mucosal hemorrhages, ballooning, and a velvety appearance of the mucosa. Microscopically the intestines showed mucosal sloughing and necrosis, mononuclear cell infiltration, tunica muscularis thickening, and goblet cell hyperplasia.

Calidad fisicoquímica y microbiológica según los sistemas de producción de la leche y el queso fresco (cuajada) de bovino, en el Istmo de Tehuantepec, México

Lorena Guadalupe Ramón-Canul — 2026-01-22

El objetivo de esta investigación fue caracterizar la calidad fisicoquímica y microbiológica de la leche y el queso fresco (“cuajada”) de ganado bovino elaborado en el Istmo de Tehuantepec, Oaxaca, México, así como analizar los sistemas de producción pecuarios asociados a su elaboración. De cada sistema de producción se evaluaron 10 L de leche cruda bovina y 10 muestras de queso fresco (500 g cada una), y se determinaron parámetros microbiológicos y fisicoquímicos. Los productores en los sistemas de producción tienen entre 43 y 72 años y estudios de nivel superior concluidos. Los hatos bovinos oscilaron entre 64–187 cabezas con razas dominantes de Cebú (Bos indicus), Suizo e Indubrasil (Bos taurus × Bos indicus) con una producción de 100–168 litros de leche diarios. Los resultados mostraron que la leche y la cuajada no cumplen con los estándares microbiológicos de la normativa mexicana. En cuanto a las propiedades fisicoquímicas, la humedad del queso fue alta (50–61 %) y la proteína varió entre 17–35 %) y la grasa, 8–22 %. El análisis de color reveló alta luminosidad (L* 87–93) y tonalidad amarilla (b* 15–20), mientras que el perfil de textura indicó diferencias significativas en dureza (5–50 N) y cohesividad. Los hallazgos resaltan la importancia de capacitaciones técnicas para mejorar la calidad y seguridad de estos productos, preservando al mismo tiempo su valor cultural y tradicional.

Efecto de los taninos dietéticos sobre los parámetros productivos y la toxicidad del diésel en tilapia del Nilo juvenil (Oreochromis niloticus)

Julio César Cruz-Valdez — 2026-02-26

Nile tilapia is a highly nutritious source of protein, and its production through aquaculture practices leads to a lower carbon footprint when compared to the production of terrestrial species. However, environmental contamination poses a significant risk in aquaculture, necessitating strategies to mitigate its impacts on fish. This study evaluated the effects of experimental diets supplemented with tannins on performance parameters of Oreochromis niloticus over a 60-day feeding trial. At the end of the experiment, their potential hepatoprotective role was assessed in fish exposed to diesel-induced toxicity. The fish were fed a control diet (T1) or a diet supplemented with either 2 % (T2) or 4 % tannins (T3). Fourteen fish per tank were allocated across three tanks per treatment. After 60 days, seven fish from each treatment group were exposed to an acute diesel exposure to either an acute dose of diesel (50 µg/g) or fish oil (control). Performance parameters were then compared, and liver samples were obtained and used to determine alkaline phosphatase (ALP), carboxylesterase (CaE), and glutathione S-transferase (GST) enzymatic activity. Diesel exposure led to increased ALP activity, decreased CaE, and GST activities. However, no significant alterations in enzyme activities were observed in fish maintained under dietary treatments T2 and T3 following diesel exposure compared to the control group. Moreover, performance parameters remained unaffected by the inclusion of tannins in diets. These findings suggest that dietary tannins may provide a protective effect against diesel-induced physiological disturbances.

Schmallenberg virus: seroprevalence, risk and protective factors in aborted dairy cows in Algeria

Nadia Djellata — 2026-03-19

The Schmallenberg virus (SBV), an orthobunyavirus, recently emerged in Germany in 2011. It spreads rapidly via the Culicoides vector, causing a decline in milk production, abortions and malformations in cattle, sheep and goats. These significant economic losses for farmers, as well as the difficulty in diagnosing the disease due to its similarity to other abortive diseases such as bluetongue, epizootic haemorrhagic disease, bovine viral diarrhea and infectious bovine rhinotracheitis, make it an important subject of study in Algeria. The aim of this study was to detect the presence of antibodies against the Schmallenberg virus in dairy cows that had aborted in Algeria. 458 serum samples from cows that had aborted, belonging to 159 farms, were tested for the presence of anti-SBV antibodies using an indirect ELISA kit, supplemented by a survey questionnaire designed to identify risk factors associated with exposure to the Schmallenberg virus. The individual seroprevalence obtained was 46.3 % (212/458), with the year of visit in 2016 (odds ratio [OR] = 9.84; P = 0.007) and 2019 (OR = 14.39; P = 0.004) and the winter season (OR = 2.05; P = 0.037) being factors associated with an increased risk of individual exposure. Another factor identified as being associated with a reduced risk of exposure was the 4th month of gestation (OR = 0.41; P = 0.038). The seroprevalence of the herd was 73.6 % (117/159). At the herd level, herd size was the only factor associated with an increased risk of exposure to SBV (OR = 1.04; P = 0.01). The factors were associated with a reduced risk of exposure (implementation of a rodent and pest control plan, and presence of moulds in animal feed). The implementation of surveillance and prevention protocols for this disease is essential to protect animal health and the economy of cattle farms.