Segundo Melecio Portocarrero Villegas

This study evaluated the short-term response of the fecal microbiota of wild Cavia tschudii during its transition from natural conditions to captivity under a standardized alfalfa-based diet. Fecal samples were collected over a 21-day period and analyzed using 16S rRNA gene sequencing to assess microbial diversity, community structure, and taxonomic composition. Rarefaction analysis indicated sufficient sequencing coverage; however, samples were normalized to 500 reads per sample, and results should be interpreted cautiously. No significant changes were detected in alpha diversity, beta diversity, or dominant taxonomic composition across sampling time points. The microbiota was consistently dominated by Bacteroidota and Firmicutes, accounting for more than 85% of total relative abundance. Minor taxa such as Methanobacteriales and Spirochaetales were present at low and stable abundances. Despite differences between natural forage and the alfalfa-based diet, microbial community structure showed limited temporal variation during the study period. The absence of detectable parasitic infections further supports that observed patterns reflect host–microbiota dynamics under controlled conditions. Functional predictions suggested variation in metabolic pathways but should be interpreted cautiously due to the limitations of 16S rRNA-based inference. Overall, these findings suggest limited temporal variation in the fecal microbiota of Cavia tschudii during the first three weeks of captivity under the conditions evaluated. However, due to the exploratory nature of the study and its methodological limitations, these results should be interpreted with caution. This study provides baseline insights into limited temporal variation in the fecal microbiota of a wild caviid species and contributes to understanding host–microbiome interactions relevant to conservation and potential domestication processes.

El objetivo de este estudio fue evaluar el efecto del cultivar y la fertilización nitrogenada sobre el rendimiento de materia seca (MS) y la composición nutricional de Pennisetum sp. comúnmente utilizado para la alimentación del ganado. Se analizó la proteína cruda (PC), cenizas (As), fibra cruda (FC), fibra detergente neutra y ácida (FDN, FDA), digestibilidad in vitro (DIV) y energía bruta (EB) sobre la MS. Los datos se recolectaron los días 30, 45, 60, 75 y 90 después de un corte uniforme. Se aplicó un diseño completamente aleatorizado con un arreglo factorial 3x2 que consta de tres cultivares (CT 115, Cuba 22, Cuba 51) y dos fertilizaciones (con y sin fertilizante) (seis tratamientos con tres repeticiones cada uno). El tipo de cultivar influyó significativamente en el rendimiento de materia seca y la composición nutricional de Pennisetum sp., mientras que los niveles de fertilización nitrogenada no tuvieron efecto sobre las variables evaluadas. CT 115 mostró un mayor rendimiento de MS. La PC se mantuvo similar entre cultivares del día 30 al 60, con un aumento el día 75 en Cuba 51. El contenido de cenizas de CT 115 fue mayor. El contenido de FC aumentó en Cuba 22 del día 45 al 75 y fue más alto en CT 115 el día 90. Las diferencias en FDN solo se observaron el día 90, con niveles más bajos encontrados en Cuba 51 y CT 115. Sin embargo, FDA fue más alto en Cuba 51 el día 30 y en Cuba 22 los días 75 y 90. El cultivar Cuba 51 exhibió mayor DIV y EB en los días 60, 75 y 90 en comparación con los otros dos cultivares. DIV mostró una correlación positiva con MS, fibra y EB y una correlación negativa con fibra detergente. Estos hallazgos resaltan el potencial de Cuba 51 para mejorar el desarrollo ganadero en la región de Amazonas.

This study aimed to quantify the carbon footprint (CF) from Fleckvieh cattle production systems in the Amazon region of Peru. Ten farms distributed across four provinces: Chachapoyas (System I; n = 2), Bongara (System II; n = 4), Rodriguez de Mendoza (System III; n = 2), and Utcubamba (System IV; n = 2) were assessed. Parameters such as average live weight, animal units (AU), dry matter intake, fat and protein-corrected milk (FPCM), digestibility, and protein content of consumed forage were analyzed. CF was calculated using the 2019 Refinement to 2006 IPCC guidelines. The database was analyzed using analysis of variance and Duncan’s statistical test (p < 0.05) to compare the systems. A Pearson correlation was carried out to observe the variables association level. Results revealed a CF of 2.50, 2.70 and 2.65 kg CO₂eq/kg FPCM by biophysical allocation, according to Global Warming Potential 2007, 2014 and 2021, respectively. Enteric methane (82.6%) and nitrous oxide from manure management (17.2%) were the main contributors to greenhouse gas emissions. Positive correlations were found between methane and nitrous oxide emissions whit total FPCM (r = 0.94), total AU (r = 0.99), and low-producing animals (r = 0.96). System I exhibited the lowest enteric methane emissions, suggesting better livestock and feed management. The study highlights the need to optimize herd composition, increase production levels, and reduce low-producing animals to mitigate CF. Additionally, improving forage quality (increasing the digestibility) enhances milk production, securing the economic well-being of smallholder farmers and agricultural sustainability in the Amazon region.

Anaplasmosis, transmitted biologically and mechanically, is one of the most prevalent diseases responsible for high production costs worldwide. In this research, the prevalence and risk factors of anaplasmosis in Simmental cattle raised in the Peruvian Amazon were evaluated. 266 blood samples were collected from bovines of different categories such as calves male, calves females, heifers 1.3 years, steers, bulls, and cows from the districts of Omia and Molinopampa. The enzyme‐linked immunosorbent assay (ELISA) technique was used to detect antibodies against Anaplasma marginale. Of the 266 animals sampled, 67% were positive for A. marginale. A higher prevalence was determined in the district of Omia (99.3%), while in the district of Molinopampa, 28.7% was obtained. A prevalence of A. marginale was recorded in females (67.7%) and in males (64.8%) (p > 0.05). There is a significant association of the disease with the category of cattle, verifying the highest prevalence of A. marginale in calves male, heifer >1.3 years, and bull. The multiple correspondence analysis shows that San Mateo, Puma Marca, Mashuyacu, Primavera, and Los Olivos have a higher prevalence of anaplasmosis, associated with altitude of 1701–2000 m, spray baths and paddock rotation. Anaplasmosis is prevalent in Simmental cattle from the Peruvian Amazon, with a higher incidence in Omia and in females, considering May to August the critical months and the altitude less than 2000 meters above sea level.

Single nucleotide polymorphisms are variations of a single nucleotide base pair and can be associated to phenotypic characteristics. This study aimed to determine the association of CAPN1 and CAST gene polymorphisms with the tenderness of Creole cattle meat from the Amazonas region, Peru. The texture profile (adhesiveness, cohesiveness, Warner-Bratzler shear force, elasticity, gumminess, and chewiness) of 100 animals was determined in 100 g of Longissimus dorsi et lumborum muscle. Allelic frequencies, genotypic frequencies, and Hardy-Weinberg equilibrium (HWE) of calpain (CAPN-316, CAPN-530) and calpastatin (CAST-2959) gene polymorphisms were studied. Allelic and genotypic frequencies were calculated, as well as the Hardy-Weinberg equilibrium with the Chi-square test. The texture profile of each group of samples corresponding to a polymorphism was compared with the Duncan’s test and the t-test for independent samples (p < 0.05). Genotypic frequencies were 78 % GG and 22 % CC for CAPN-316; 68 % GG, 5 % GA, and 27 % AA for CAPN-530; and 74 % AA, 18 % AG, and 8 % GG for CAST-2959. The CAPN-316, CAPN-530, and CAST-2959 polymorphisms were not in Hardy-Weinberg equilibrium. The CC genotype of CAPN-316 marker influences meat tenderness on day 21 of meat aging. In contrast, the GG genotype of CAST-2959 marker affects meat tenderness at days 14 and 21 of meat aging concerning the other genotypes.

The objective of this research was to evaluate the physicochemical and sanitary parameters of raw cow's milk intended for consumption in the Amazonas region, Peru. We sampled 31 collection centers and dairy processors. We evaluated physicochemical parameters (fat, protein, solids not fat, lactose, ash, pH, and density), somatic cell count, and microbiology (mesophilic aerobic bacteria and total coliforms) of raw milk. We applied an analysis of variance (α=0.05) and the comparison of means between the collection centers and livestock basins (p<0.05). In addition, we performed a cluster analysis, principal components and correlation. Depending on the collection center, we found differences in all the physicochemical parameters, somatic cell count and milk microbiology. In the livestock basin analysis, we found differences for somatic cells, fat, protein, solids, pH, coliforms and bacteria. The Jumbilla basin presented less somatic cells, less fat was found in the Levanto basin and higher protein in the Yambrasbamba basin. Lactose, ash, density, total coliforms and mesophilic aerobic bacteria did not vary according to basin. The cluster analysis yielded four groups, Group 1 is higher in ash and density, Group 2 and 3 are higher in fat, Group 3 with higher protein, but higher in total coliforms and mesophilic aerobic bacteria. Group 4 registered the highest pH and the lowest protein concentration. There was a positive correlation of fat with protein and solids not fat, lactose with solids not fat, ash with density. Negative correlations of somatic cells with fat and, protein and solids not fat with pH.

Con el objetivo de evaluar la influencia de la calidad del agua y el manejo en la condición sanitaria de la trucha arcoíris (Oncorhynchus mykiss) en piscigranjas de la región Amazonas se realizó el análisis físico-químico y microbiológico del agua en 14 piscigranjas de la región Amazonas, una encuesta a los productores y se evaluaron 140 muestras de trucha en etapa comercial con el fin de identificar lesiones macroscópicas. Los datos fueron analizados usando el software Statistix versión 8.0 mediante el análisis de varianza, prueba t de Student, prueba de comparación de Tuckey y la correlación de rangos de Spearman. El análisis microbiológico muestra que 6 piscigranjas evaluadas se encuentran por encima de los límites máximos permitidos para coliformes fecales (200 NMP/ml) y los análisis de correlación evidencian asociación altamente significativa (p<0.01) entre parámetros físico-químicos del agua y el manejo con las lesiones encontradas en las truchas.