Examinando por Autor "Contreras Huamaní, Mijail"

Mostrando 1 - 4 de 4

Electrophoretic profiles of alpaca seminal plasma proteins and their association with sperm quality parameters during cryopreservation processes
(John Wiley & Sons Ltd., 2026-03-24) Guillen Palomino, Crissthel Yverlin; Mujica Lengua, Fidel Rodolfo; Contreras Huamaní, Mijail; Carretero , María Ignacia; Rueda Alfonso, Fabian Leonardo; Orellana Berrocal, Harumi
The aim of the study was to characterize the electrophoretic profiles of alpaca seminal plasma (SP) proteins and establish their association with sperm quality parameters at different cryopreservation stages. Sperm quality was assessed in raw, cooled, and thawed semen from 128 ejaculates collected from 16 Huacaya alpacas, and SP proteins were analysed by SDS-PAGE in raw samples. Statistical associations were determined using Spearman's rank correlation (p ≤ 0.05). Twenty-three protein bands were identified: 21 bands ranging from 9.23 to 138.38 kDa, and 2 below 6.5 kDa. Notably, the 21.03 kDa protein was absent in six males, five of whom also lacked the 18.88 kDa band. These individuals exhibited superior post-thaw sperm quality, particularly higher motility. The 21.03 kDa protein showed a negative correlation (p ≤ 0.05) with sperm motility and membrane function in raw, cooled, and thawed semen, and a positive correlation with acrosome integrity in thawed semen. Similarly, the 18.88 kDa protein showed a negative correlation with sperm motility and membrane function, but a positive correlation with acrosome integrity in thawed semen (p ≤ 0.05). In conclusion, these findings suggest that specific SP proteins may serve as potential biomarkers for sperm quality and cryotolerance in alpacas, reflecting individual variability in response to cryopreservation.
Evaluation of probiotic supplementation to enhance growth, immune response, intestinal function, and survival in extensively raised neonatal alpacas in the Peruvian Central-southern Andes
(Elsevier Ltd., 2026-04-15) Palomino Guerrera, Walter; Mariño Huaraca, Wenfil Daisi; Contreras Huamaní, Mijail; Coila, Pedro; Taboada, Natalia Verónica
This study aimed to evaluate the effects of multi-strain probiotics on growth, immune response, intestinal function, and survival in neonatal alpacas in the Peruvian Central-southern Andes. A total of 96 neonatal alpacas were selected, with an average weight of 7.89 ± 0.93 kg, regardless of breed (Huacaya and Suri). The study employed a completely randomized design. The neonates were randomly assigned to three groups (n = 32): control (T1), Probiolyte® WS (T2), and Polimeve Solúve (T3). Probiotics were administered orally on days 1, 7, 14, 21, and 30 of age. Body weight gain and size were recorded on days 1, 15, 30, 60, and 90; immune response was assessed on 30 and 90 days; and intestinal functional status was evaluated on day 90. The neonates supplemented with Polimeve exhibited greater thoracic circumference after 60 days of age, and increased height at the withers and rump at 15 days (p < 0.05). At 90 days, the Polimeve group had a higher proportion of basophils, while the Probiolyte and control groups showed higher proportions of monocytes (p < 0.05). IgG concentrations at 30 and 90 days did not differ significantly among groups. Probiotic supplementation did not affect ileal villus length; however, it influenced the depth of jejunal and cecal crypts (p < 0.05). Morbidity and mortality rates did not differ significantly between groups. In conclusion, probiotics did not significantly influence growth, immune response, or intestinal function; however, Polimeve may improve weight gain in neonates, while Probiolyte can increase IgG concentrations during the first 30 days of life.
Impact of three field-practical thawing methods on bovine semen motility, viability, and membrane and acrosome integrity at 0 and 2 hours post-thaw
(Sociedade de Medicina Veterinária do Estado do Rio de Janeiro (SOMVERJ), 2026-08-04) Pozo Curo, Alfredo; Bellido Quispe, Dionet Keny; Tacza Paquiyauri, Katherine Milagros; Sobero Ballardo, Rogelio; Rodríguez Zamora, Luis Arturo; Contreras Huamaní, Mijail; Youngs, Curtis R.
The effectiveness of artificial insemination with frozen semen depends largely on semen quality, which can be influenced by the thawing method. This study evaluated the effect of three field-practical semen thawing methods on bovine sperm motility, viability, and plasma membrane and acrosome integrity at 0 and 2h post-thaw. The treatments were: T1 (water at 37 °C), T2 (axilla at 36.1°C), and T3 (room temperature at 23.4 °C). A total of 42 frozen semen straws was analyzed. Motility was assessed using a CASA system, viability was evaluated with Hoechst/propidium iodide staining, and plasma membrane and acrosome integrity were examined using the hypoosmotic swelling (HOS) test and Coomassie blue (CB) staining, respectively. Statistical analysis included ANOVA and t-tests. At 0h, thawing using a water bath (T1) or the axilla (T2) resulted in higher (P < 0.05) total motility, progressive motility, rapid motility, and number of rapidly motile sperm compared to thawing at room temperature (T3). Thawing using a water bath also resulted in higher (P<0.05) sperm viability and percentage of HOS+/CB+ cells at 0h than thawing with T2 or T3. At 2h, post-thaw, T1 resulted in superior (P<0.05) total motility, progressive motility, rapid motility, and viability compared with T2 and T3 thawing methods. Holding samples from 0 to 2h reduced sperm quality parameters in all three thawing methods. In conclusion, thawing semen in warm water at 37 °C yielded better sperm quality parameters at both 0 and 2h post-thaw than thawing in the axilla or at room temperature.
Morphostructural, phaneroptic characterization, and zoometric indices of Creole cattle (Bos taurus) from the high Andean region of Ayacucho, Peru
(MDPI, 2026-07-07) Contreras Huamaní, Mijail; Mendoza Leiva, César Jorge; Alvaro Peralta, Jhoel Kevin; Guzman Santaria, Hamilton; Palomino Guerrera, Walter; Quispe Ccasa, Hurley Abel
Morphostructural characterization of Creole cattle is essential for assessing the diversity and productive potential in the highland livestock systems. The study was conducted in Chuschi and Chipao districts, at 3800 m above sea level, with the objective of morphostructurally characterizing 154 Creole cows. Seventeen phaneroptic variables and twenty-one morphometric variables were recorded. The multivariate analysis identified three cattle biotypes. Based on proportionality, compactness, and cannon bone load indices, Biotype 1 (16.9%) comprised more compact, robust, and heavier animals with a greater tendency toward meat production aptitude, followed by Biotype 2 (48.1%) and Biotype 3 (35.1%), which were more slender but with a stronger bone structure. No association was found between biotypes and phaneroptic characteristics, except for teat type (p < 0.05). The proportions of red, black, dull black, qosca, and roan coat colors were common across all biotypes; however, Biotype 1 predominated in callejon (15.38%), Biotype 2 in qosne (8.11%) and in other less frequent coat colors (10.81%), while Biotype 3 predominated in dark roan (16.67%) and jet black (11.11%). In the high-Andean region of Ayacucho, three subpopulations of Creole cattle were identified with potential for beef production dual-purpose use, and adaptation to rugged terrain, highlighting the need to investigate their genetic diversity