Examinando por Autor "Maicelo, Jorge L."

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Agronomic and nutritional evaluation of INIA 910—Kumymarca ryegrass (Lolium multiflorum Lam.): An alternative for sustainable forage production in department of Amazonas (NW Peru)
(MDPI, 2025-01-01) Vásquez, Héctor V.; Valqui, Leandro; Bobadilla, Leidy G.; Meseth Macchiavello, Enrique; Trigoso, Milton J.; Zagaceta, Luis H.; Valqui Valqui, Lamberto; Saravia Navarro, David; Barboza, Elgar; Maicelo, Jorge L.
Grassland ecosystems cover about 25% of the Earth’s surface, providing essential ecosystem services that benefit nature, people, and food security. This study evaluated agronomic and nutritional parameters of ryegrass (Lolium multiflorum Lam.) based on fertilization levels and cutting frequency in the Amazonas department. The INIA 910—Kumymarca variety was used with nitrogen fertilization rates (0, 60, 120, 180 kg/ha) and cutting intervals of 30 and 45 days for agronomic traits and 30, 45, and 60 days for nutritional traits. A randomized complete block design with eight treatments and three replications was applied. Repeated measures analysis and Tukey’s mean comparison tests (p < 0.005) were performed, along with Pearson correlation and response surface analysis using the central composite design in R. The results showed that applying 180 kg/ha of nitrogen with a 45-day cutting interval provided the highest dry matter yield (460 kg/m2 ) and superior agronomic traits, including plant height (96.73 cm), number of tillers, and stem diameter. Non-fertilized treatments had the highest crude protein content (17.45%) and digestibility, while higher nitrogen doses increased crude fiber and acid detergent fiber, reducing digestibility. Significant correlations were observed between fresh and dry weight with plant height (p = 0.000; r = 0.84), fiber contents (p = 0.000; r = 1), and ash and protein content (p = 0.000; r = 0.85). The optimal management practice was cutting every 45 days with 180 kg/ha of nitrogen (T8), maximizing forage yield and quality. Proper fertilization and cutting management can improve ryegrass production, benefiting livestock feeding and rural economies.
Agronomic and Nutritional Potential of Ryegrass (Lolium multiflorum Lam.) Accessions as Raw Material for Silage in the Tropical Andes of Peru
(MDPI, 2026-01-22) Bobadilla , Leidy G.; Altamirano Tantalean, Miguel A.; Carrasco Chilón, William Leoncio; Silva Baca, Vanesa Lizbeth; Mejía, Flor L.; Paucar, Ysai; Valqui, Leandro; Bardales, William; Maicelo, Jorge L.; Vásquez, Héctor V.
In the tropical Andes, rangeland degradation has become one of the main threats to the sustainability of livestock production in the face of climate change. In this context, optimizing the yield and nutritional quality of raw material for silage is essential to sustain livestock productivity. The aim of this study was to identify local accessions (LM) of Lolium multiflorum Lam. with greater forage potential through evaluations in consecutive cuts made at the anthesis phenological stage, using a randomized complete block design with four replicates and ten local accessions (LM1, LM2, LM3, LM4, LM6, LM7, LM8, LM11, LM12 and LM13). The statistical analysis, based on linear mixed models, showed that cuts at anthesis had a significant effect among accessions, revealing high variability in agronomic and nutritional performance across cuts. In LM4, plant height at the fourth cut was 2.48-fold higher than at the first cut. Likewise, LM4 and LM13 were identified as the latest accessions to reach anthesis in the first cut, with a decreasing trend across cuts and stabilization from the third cut onward. These accessions also showed the greatest basal coverage area, increasing 9.94- and 8.18-fold in the fourth cut relative to the first. Fresh forage yields in LM4 and LM13 increased 13.2- and 10.1-fold, and dry matter yields 13.98- and 9.86-fold, compared with the first cut. They also exhibited the highest average daily dry matter accumulation rate. By contrast, the fresh forage and dry matter yields of the remaining accessions were significantly lower than those of LM4 and LM13. The main difference between these two accessions was observed in dry matter percentage, with higher values and a stable trend in LM4 across all cuts. In terms of nutritional quality, LM4 presented crude protein of 24.2% in the second cut and 24.0% in the fourth cut, while digestibility was 86.2% in the second cut and 85.0% in the fourth cut. In conclusion, although the ensiling process was not evaluated in this study, LM4 showed the most stable and outstanding values in both agronomic and nutritional performance, thus emerging as a promising accession for selection and use as raw material for silage production in the tropical Andes.
Changes in gut microbiota in peruvian cattle genetic nucleus by breed and correlations with beef quality
(MDPI, 2024-11-29) Quilcate Pairazamán, Carlos Enrique; Estrada Cañari, Richard; Romero Avila, Yolanda Madelein; Rojas Cruz, Diorman; Mamani Chullo, Rolando; Hañari Quispe, Renán Dilton; Aliaga, Mery; Galindo, Walter; Vásquez, Héctor V.; Maicelo, Jorge L.; Arbizu, Carlos I.
This study evaluated the gut microbiota and meat quality traits in 11 healthy female cattle from the Huaral region of Peru, including 5 Angus, 3 Braunvieh, and 3 F1 Simmental × Braunvieh. All cattle were 18 months old and maintained on a consistent lifelong diet. Meat quality traits, including loin area, fat thickness, muscle depth, and marbling, were assessed in vivo using ultrasonography. Fecal samples were collected for microbiota analysis, and DNA was extracted for 16S and 18S rRNA sequencing to characterize bacterial, fungal, and protist communities. Significant correlations were observed between microbial genera and meat traits: Christensenellaceae R-7 and Alistipes were positively associated with marbling and muscle area, while Rikenellaceae RC9 showed a negative correlation with fat thickness. Among fungi, Candida positively correlated with marbling, while Trichosporon was negatively associated with muscle depth. For protists, Entodinium negatively correlated with fat thickness and marbling. Alpha diversity varied by breed, with Angus showing greater bacterial diversity, and beta diversity analyses indicated a strong breed influence on microbial composition. These findings suggest that microbial composition, shaped by breed and dietary consistency, could serve as an indicator of meat quality, offering insights into gut microbiota’s role in optimizing cattle production.
Complete mitogenome, phylogenetic and SNP-data analysis of jakumaru (Bos taurus), a prime bull from a Peruvian breeding core herd
(Unique Scientific Publishers, 2025-01-22) Estrada Cañari, Richard; Romero Avila, Yolanda Madelein; Figueroa Venegas, Deyanira Antonella; Quilcate Pairazamán, Carlos Enrique; León Trinidad, Silvia Eliana; Casanova Nuñez Melgar, David pavel; Maicelo, Jorge L.; Arbizu, Carlos I.
This study provides a comprehensive mitochondrial genome sequence and a phylogenetic analysis of Jakumaru (Bos taurus), a prominent bull from a Peruvian breeding program. The mitochondrial genome, spanning 16,340bp, comprises 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes, with a GC content of 40%. The gene arrangement and structural organization are highly conserved, closely resembling those of related Bovine species, indicating a stable genomic architecture essential for mitochondrial function. Phylogenetic analysis, incorporating 35 complete bovine mitochondrial genomes, positions Jakumaru within Subclade I, revealing a close relationship with European Simmental cattle. The study emphasizes the biological diversity and the evolution of the Simmental breed, influenced by natural selection, breeding practices, and genetic drift. These findings enhance our understanding of the breed's genetic variation and its evolution, particularly in the context of its importance in Peru
Effects of Diet and Altitude on the Microbiota of the First Compartment of the Stomach in Peruvian Alpacas in Highland Puna Regions and Their Correlations with Blood Parameters
(MDPI, 2026-01-08) Flores Huarco, Nils H.; Estrada Cañari, Richard; Romero Avila, Yolanda Madelein; Coila, Pedro; Sanchez, Diana; Maicelo, Jorge L.; Alvarado, Wigoberto C.; Quilcate Pairazaman, Carlos Enrique; Aliaga, Mery; Galindo, Walter; Saavedra Ramírez, Jorge; Apaza, Henry; Arbizu, Carlos I.
This study explores the intestinal microbiota of eight 18-month-old male alpacas from two distinct high-altitude regions in Peru: the Wet Puna (4200 m above sea level) and the Dry Puna (4900 m above sea level). Using 16S rRNA and 18S rRNA metabarcoding, microbial communities of bacteria, archaea, fungi, and protists were analyzed from the first compartment of the stomach (C1) to investigate the diversity, taxonomic composition, and correlations with hematological parameters. Significant differences in microbial diversity and composition were observed between regions, driven by dietary and environmental factors. The Wet Puna exhibited greater alpha diversity in bacterial and fungal communities, while beta diversity highlighted distinct microbial compositions. Key taxa, such as Prevotella ruminicola and Acetitomaculum, were associated with energy metabolism and host adaptation, whereas methanogenic archaea (Methanobrevibacter, Methanosphaera) dominated in the Dry Puna, reflecting adaptations to arid conditions. Correlations between microbial taxa and hematological variables, such as Acetitomaculum with red blood cell count and Eremoplastron with neutrophil percentage, emphasize the complex interplay between microbiota and host physiology. These findings contribute to understanding microbial adaptations in high-altitude livestock and provide practical insights for enhancing alpaca management and conservation strategies through tailored nutritional approaches and sustainable grazing practices.
Effects of Planting Methods on the Establishment, Yield, and Nutritional Composition of Hybrid Grass Cuba OM-22 in the Dry Tropics of Peru
(MDPI, 2025-10-28) Vásquez, Héctor V.; Valqui, Leandro; Valqui Valqui, Lamberto; Bobadilla, Leidy G.; Maicelo, Jorge L.; Altamirano Tantalean, Miguel A.; Ampuero Trigoso, Gustavo; Yalta Vera, Juan
Climate change and livestock expansion have affected forage supply in the dry tropics. Therefore, optimizing planting methods adapted to adverse tropical environments is essential for establishment and yield. The objective of this study was to evaluate the effect of different planting methods on the establishment rate, morphology, yield, and nutritional composition of Cuba OM-22 under the soil and climate conditions of the dry tropics of Peru, using a block design with four replicates and five methods for propagation by cuttings. The S4 (two-node cuttings, 25 cm in length; horizontal position 180°, parallel to the soil surface; fully buried at 8 cm depth; no spacing between cuttings along the furrow) method offered the best balance between yield and quality, with higher establishment rate (55.93%), height (182.15 cm; higher than S1 and S5), and more tillers (surpassing S1 and S2 by 16.97% and 18.86%). In addition, it obtained good green forage yields (137.43 t ha⁻¹) and was better than all planting methods in dry matter yield (37.45 t ha⁻¹). In nutritional composition, S4 ranked among the highest averages for nitrogen-free extract (NFE) (43.22%) and ash (11.06%). However, protein, crude fiber, and fat content did not differ between methods. On the other hand, planting methods showed negative correlations between the number of tillers and ash content (p = 0.006; r = −0.79), ash and NFE (p = 0.000; r = −0.92), and protein with crude fiber (p = 0.029; r = −0.68). These findings highlight S4 as a key strategy for optimizing establishment, yield, and quality in Cuba OM-22 in the dry tropics.
Impact of the Association of Maize with Native Beans on the Morphological Growth, Yield, and Nutritional Composition of Forage Intended for Silage in the Peruvian Amazon
(MDPI, 2025-10-22) Vásquez, Héctor V.; Reyna, Manuel; Valqui Valqui, Lamberto; Bobadilla, Leidy G.; Maicelo, Jorge L.; Zagaceta Llanca, Luis Homero; Yalta Vela, Juan; Isla Pérez, José Manuel; Paucar, Ysai; Altamirano Tantalean, Miguel A.; Valqui, Leandro
Scenarios of climate change, extensive land use, soil degradation, the loss of native forest cover due to monoculture expansion, and pasture scarcity pose new challenges to livestock farming worldwide. Associated crops emerge as an alternative to mitigate these factors; however, selecting compatible species that do not generate competition and optimize the attributes of the forage is a necessity. Therefore, this study evaluated the effect of a maize and bean association, and cutting time on the morphological variables, yield, and nutritional composition of forage. A randomized complete block design (RCBD) with a 3A × 3C factorial arrangement and three blocks was used. Factor A (associations) had three levels: INIA-604-Morocho maize monoculture (M), M+PER1003544 chaucha bean association (M+F1), and M+PER1003551 chaucha bean association (M+F2). Factor C (maize cutting stage) had three levels: R2 (blister grain), R3 (milky grain), and R4 (pasty grain). A total of 27 experimental units were established. No silage was made; the nutritional quality was evaluated as the raw material for silage. The treatments modulated key attributes for silage. In R4, the M+F2 association (INIA-604-Morocho + PER1003551) showed a higher percentage of dry matter in the system (32.36%) and better mixture quality due to a lower NDF and ADF (48.22% and 23.29%) and higher digestibility and protein values (62.10% and 9.53%). In addition, dry matter yields increased compared with R2 in M+F1 (134.16%), M+F2 (90.56%), and M (138.48%). Although R3 maximized green forage, R4 offered the best combination of quantity and quality for silage (as raw material), reducing the risk of deterioration and improving forage use efficiency. In general, combining maize with beans and adjusting the cut to R4 optimizes the production and quality of the raw material for silage, with the criterion that these findings pertain to pre-ensiled material and should be validated in future studies.