Artículos científicos

URI permanente para esta colecciónhttps://repositorio.inia.gob.pe/handle/20.500.12955/8

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Influence of reproductive season and testicular volume on seminal parameters of alpacas (Vicugna pacos)
(Springer Nature, 2025-05-22) Contreras Huamani, Mijail; Guillen Palomino, Crissthel Yverlin; Orellana Berrocal, Harumi Rebeca; Laines Arcce, Irwin Mitchell; Bellido Quispe, Dionet Keny; Acuña Leiva, Alex Yony; Silva Chaves, Maiana; de Figueirêdo Freitas, Vicente José
The male alpaca plays an important role in the reproductive process and, consequently, in genetic improvement. South American camelids (SACs) have a well-defined reproductive season, particularly in the Andean region. The objective was to evaluate the influence of reproductive and non-reproductive seasons, as well as testicular volume, on seminal parameters in alpacas. Nine healthy male alpacas, over 4 years old, were selected for this experiment. Semen samples were taken every two days using an artificial vagina incorporated into a dummy. The collected were in the reproductive (November to April) and non-reproductive (May to October) seasons, from breeders with testicular volumes that range between 63–70 cm3 and 83–94 cm3. The total number of ejaculates collected was 72 per season, with 8 samples collected from each male. Macroscopic aspects such as color, volume (ml), thread formation (cm) and foam (cm) were evaluated, in addition to microscopic aspects such as sperm motility (%), viability (%) concentration (sperm/ml) and total number of sperm. The results were analyzed with the Mann–Whitney non-parametric test, using the R 3.4.3 software, considering P < 0.05 as the significance level. A decrease in thread formation was observed in semen collected during the reproductive season compared to the non-reproductive season (P < 0.05). On the other hand, sperm motility and viability in semen collected during the reproductive period was higher (p < 0.05). Regarding testicular volume, alpacas with larger testicular volume had greater ejaculate volume, sperm concentration and total number of sperm (p < 0.05). Based on these results, it is possible to conclude that the semen of alpaca breeders is influenced by the season, and that testicular volume can predict their reproductive capacity, being a parameter to be considered when selecting the best breeding male.
Morphometric Characterization and Zoometric Indices of High-Andean Creole Cows from Southern Peru
(MDPI, 2025-08-20) Ccalta Hancco, Ruth; Huayta Arizaca, Rito Felipe; Salcedo Quispe, Elvis Lizandro; Valverde, Anthony; Cucho Dolmos, Hernán Carlos; Canaza-Cayo, Ali William; Acuña Leiva, Alex Yony; Estrada Cañari, Richard
High-Andean Creole cattle represent a genetic resource with significant adaptive value in high-altitude ecosystems. In this study, 151 Creole cows from the provinces of Canas and Quispicanchis (Cusco, Peru) were evaluated to characterize their morphometry, calculate zoometric indices, and establish functional biotypes. Ten morphometric parameters were measured, and eight structural indices were calculated. Four differentiated biotypes were identified through the multivariate analysis and hierarchical clustering of quantitative variables (BI, BII, BIII, and BIV). Morphological differences were statistically significant (p < 0.05) and associated with different productive orientations. Biotype I showed greater thoracic development and a compact structure, which is compatible with intermediate beefaptitude; Biotype II exhibited more elongated proportions and a lower weight, indicating a dairy tendency; Biotype III stood out for its muscle mass, thoracic depth, and pelvic width, evidencing a clear beef orientation; and Biotype IV combined a higher weight, rectangular conformation, and wide pelvis, showing potential for beef production and ease of calving. Functional differentiation was supported by Principal Coordinates Analysis (PCoA) and PERMANOVA tests. Correlations between morphometric variables and zoometric indices revealed anatomical patterns consistent with the productive functions proposed. The results highlight the morpho-functional diversity of Andean Creole cattle and their potential for conservation and improvement programs in extensive highland systems.

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Examinando Artículos científicos por Autor "Acuña Leiva, Alex Yony"