Objectives: The aim of this study was to isolate feline dental pulp stem cells (fDPSCs) and characterize their clonogenic and proliferative abilities, as well as their multipotency, immunophenotype and cytogenetic stability. Methods: Dental pulp was isolated by explant culture from two cats <1 year old at post mortem. Their clonogenicity was characterized using a colony-forming unit fibroblast assay, and their proliferative ability was quantified with a doubling time assay in passages 2, 4 and 6 (P₂, P₄ and P₆, respectively). Multipotency was characterized with an in vitro trilineage differentiation assay in P₂, and cells were immunophenotyped in P₄ by flow cytometry. Chromosomic stability was evaluated by cytogenetic analysis in P₂, P₄ and P₆. Results: The fDPSCs displayed spindle and epithelial-like morphologies. Isolated cells showed a marked clonogenic capacity and doubling time was maintained from P₂ to P₆. Trilineage differentiation was obtained in one sample, while the other showed osteogenic and chondrogenic differentiation. Immunophenotypic analysis showed fDPSCs were CD45⁻, CD90⁺ and CD44⁺. Structural and numerical cytogenetic aberrations were observed in P₂–P₄. Conclusions and relevance: In this study, fDPSCs from two cats were isolated by explant culture and immunophenotyped. Cells displayed clonogenic and proliferative ability, and multipotency in vitro, and signs of chromosomic instability were observed. Although a larger study is needed to confirm these results, this is the first report of fDPSC isolation and in vitro characterization.

Stem cell therapy in cat patients needs a high quantity of mesenchymal stromal/stem cells (MSCs) requiring in vitro propagation under culture conditions which may potentially impact cellular characteristics and genetic stability. This study aimed to assess the in vitro characteristics and cytogenetic stability of cat adipose tissue-derived MSCs (cAT-MSCs). For this purpose, morphological features, clonogenic potential, and proliferative capacity of cAT-MSCs were assessed at passages 2 (P₂), P₄, and P₆. Multipotency and immunophenotype were evaluated. Cytogenetic analyses were conducted up to P₆. The cAT-MSCs exhibited a spindle-shaped morphology in early passages. The doubling time increased from 2.5 days at P₂ to 9.4 at P₄ and 10.5 at P₆, accompanied by the observation of nuclear abnormalities such as cluster formation, karyorrhexis, karyolysis, and a decline in the mitotic index at P₄. Cells demonstrated multipotency capacity and were CD45−, CD90+, and CD44+. Metaphase analysis at P₂ and P₄ revealed some indications of structural instability such as gaps, breaks, deletions, duplications, and early chromatid segregation, but these alterations did not show an increase across passages. In conclusion, cAT-MSCs decreased their proliferative capacity after P₄, accompanied by morphological alterations and signs of structural instability.

La reserva de bovinos Criollos del Uruguay (BCU) cuenta con aproximadamente 600 individuos. Estos animales han demostrado una elevada rusticidad y capacidad de adaptación a medios poco favorables. En este trabajo se evaluó el crecimiento y la capacidad de producción de carne de 30 novillos Criollos en comparación con 10 novillos Hereford. Todos los animales recibieron el mismo manejo sanitario y de alimentación (pastoreo a campo natural, sin suplementación), desde los 6-8 meses de edad. A los 43 meses se seleccionó para faena una muestra de 6 novillos Criollos y 6 Hereford. La evolución del peso corporal fue similar, con una tendencia a favor de Hereford (p < 0,05 sólo al inicio y al final del experimento). Se detectaron diferencias significativas en área de ojo de bife (p < 0,05) y de espesor de grasa dorsal (p << 0,05) a favor de los Criollos. No se observaron diferencias significativas para la mayoría de las variables medidas en la canal, con una tendencia a favor de los Criollos para pH (p < 0,05). Se observaron diferencias significativas en porcentaje de músculo y hueso a nivel de la 10va costilla a favor del Criollo (p < 0,05), y una diferencia apenas significativa en porcentaje de grasa visible a favor de Hereford (p = 0,049). No se observaron diferencias significativas entre las dos razas para variables de calidad de carne. Hereford mostró una tendencia hacia un mayor porcentaje de ácidos grasos insaturados que Criollo, en el cual se observó un mayor porcentaje de ácido linoleico conjugado (CLA). No hubo diferencias significativas a nivel de las apreciaciones de un panel de consumidores. Se requiere una muestra más grande para sacar conclusiones firmes, pero estos resultados indicarían un muy buen potencial del BCU para la producción de carne, en comparación con una raza altamente seleccionada.

Background and Aim: Canine degenerative myelopathy (DM) is an autosomal recessive inherited disease that affects different dog breeds. It has an invariably fatal outcome once the clinical symptoms begin. This study aimed to investigate the population behavior of the mutation superoxide dismutase 1 (SOD1) c.118: G˃A responsible for the high risk of developing DM in two populations of German Shepherd dogs from Uruguay and Paraguay. Materials and Methods: A total of 158 German Shepherd dogs from Uruguay (n = 114) and Paraguay (n = 44) were analyzed. Genomic DNA was extracted from peripheral whole blood. The SOD1 c.118: G˃A mutation was identified by polymerase chain reaction-restriction fragment length polymorphism and subsequently validated using sequencing. Allelic and genotypic frequencies and Hardy–Weinberg equilibrium were calculated for both populations. The rate of clinical progression was evaluated in animals homozygous for the mutation. Results: The frequencies of allele A associated with a higher risk of DM, were 0.15 and 0.23 in Paraguay and Uruguay, respectively. Paraguay’s population was found to be in Hardy–Weinberg equilibrium (p = 1.00), whereas the population of dogs from Uruguay deviated from equilibrium (p = 0.008). When comparing the populations, no significant difference was observed in the distribution of genotypes (p = 0.26). When evaluating the clinical progression rate, all animals aged >10 years showed clinical symptoms compatible with DM. Conclusion: This study demonstrated for the first time the presence of the SOD1:c118 G>A mutation in German Shepherd dogs from Uruguay and Paraguay. The frequency detected in Uruguay was significant. Although the frequency was lower in Paraguay, the allele was present. This demonstrates the need to implement genotyping tests as part of a possible DM control program in both countries studied. Keywords: degenerative myelopathy, genetic disease, German Shepherd dog, superoxide dismutase 1 gene.

This study evaluated the effects of two milk replacer-based diets, one supplemented with starter feed and the other with alfalfa hay, on rumen development in preweaned Holstein calves. Twenty newborn male calves were fed 8 L/day of milk replacer plus either starter feed (group A) or alfalfa hay (group B) ad libitum for 10 weeks. Rumen morphometry and histological features were assessed via gross anatomical evaluation, histology, and scanning electron microscopy. The calves in group A consumed significantly more solid feed and exhibited greater papillae development, with higher papillae height, width, and density per cm2, than those in group B. Moreover, the surface enlargement factor was consistently greater in group A across ruminal regions, except in the caudodorsal blind sac (saccus cecus caudodorsalis; p < 0.05). Empty rumen weight was also higher in starter-fed calves, suggesting enhanced mucosal development and absorptive capacity. Notably, keratin layer thickness did not explain the observed differences between the groups. Despite similar final body weights and growth, calves supplemented with starter feed showed greater rumen papillae development and absorptive surface area than those supplemented with alfalfa hay. These findings suggest that starter feeding during high milk allowance promotes epithelial maturation and enhances post-weaning absorption of fermentation products. Este estudo avaliou os efeitos de duas dietas à base de sucedâneo do leite — uma suplementada com concentrado inicial (starter feed) e a outra com feno de alfafa — sobre o desenvolvimento do rúmen em bezerros Holandeses não desmamados. Vinte bezerros machos recém-nascidos receberam 8 L/dia de sucedâneo do leite mais concentrado inicial ad libitum (Grupo A) ou feno de alfafa ad libitum (Grupo B) durante 10 semanas. A morfometria e as características histológicas do rúmen foram avaliadas por meio de exame anatômico macroscópico, histologia e microscopia eletrônica de varredura. Os bezerros do Grupo A consumiram significativamente mais alimento sólido e apresentaram maior desenvolvimento papilar, com maior altura, largura e densidade de papilas por cm2. O fator de ampliação da superfície (SEF) foi consistentemente superior no Grupo A em todas as regiões ruminais, exceto no saco-cego caudodorsal (saccus cecus caudodorsalis) (p < 0,05). O peso vazio do rúmen também foi maior nos bezerros alimentados com concentrado, sugerindo maior desenvolvimento da mucosa e capacidade absortiva. Em contraste, a espessura da camada de queratina não explicou as diferenças observadas entre os grupos. Apesar do peso corporal final e do crescimento semelhantes, os bezerros suplementados com concentrado inicial apresentaram maior desenvolvimento papilar ruminal e área de superfície absortiva. Esses resultados indicam que a oferta de concentrado durante programas de alta ingestão de leite promove a maturação epitelial e pode potencializar a absorção de produtos de fermentação no período pós-desmame.

El scrapie es una enfermedad neurodegenerativa transmisible de ovinos y caprinos. Se caracteriza por la acumulación en el sistema nervioso central de una isoforma anómala de una proteína celular normal (PrPc) codificada por el gen PrP. En el exón 2 del gen se han identificado mutaciones en los codones 136, 154 y 171. La combinación de estos codones muestran diferentes niveles de asociación con la susceptibilidad a la enfermedad, desde muy resistentes (ARR/ ARR) a muy susceptibles (VRQ/VRQ). Los codones 171 y 136 son los mayores determinantes de la susceptibilidad al scrapie, mientras que el codón 154 juega un rol menor. En el presente trabajo se estudió una muestra de ovinos Criollos Uruguayos (N=28) para los codones 136 y 171. Las muestras de ADN genómico se procesaron por PCR-RFLP. Los resultados se obtuvieron por electroforesis en geles de poliacrilamida (10,5%) teñidos con AgNO3. Se analizaron las frecuencias genotípicas para los codones 136 y 171. Cinco genotipos diferentes fueron obtenidos, encontrándose en mayor frecuencia los genotipos de alta susceptibilidad: VQ/AQ= 0,39 y AQ/AQ= 0,29. El análisis de riesgo genético de esta majada según los genotipos obtenidos, reveló un 72% de animales muy susceptibles a la enfermedad en caso de manifestarse las condiciones ambientales propicias.