Browsing by Author "Jacome Aucay, Andres Santiago"

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Accuracy of ultrasound and visual inspection in antral follicular count in crossbred Holstein cows raised under grazing systems at high altitude
(2023) Astiz, Susana
The objective of this research was to investigate the diagnostic accuracy of post- mortem ultrasound in antral follicle count (AFC) determination and compare it with visual AFC in grazing crossbred Holstein cows, at high altitude in Ecuador. Pre- mortem blood from 80 cows was collected, and AFC and ovarian characteristics were ana-lysed post- mortem by ultrasound and visual techniques. AFC counts were stratified as high, medium or low by terciles. Mean AMH concentration in pre- mortem blood was 280.1 ± 15.53 pg/mL. The AFC obtained by visual inspection (26.9 ± 9.49 follicles) was 23.8% higher than by ultrasound (20.5 ± 7.53 follicles) in all ovaries. Body condi-tion score, age and weight of the cattle did not interact with the count technique. In the low AFC group, visual inspection and ultrasound provided similar AFC results. However, in the Medium- and High-AFC groups, AFC by ultrasound was 14.9% lower than AFC by visual inspection. We confirm that ultrasound can be used with great accuracy for AFC >3 mm (close to the resolution limit) in grazing crossbred Holstein cows at high altitude.
Assessment of different diets in the productive behavior of native guinea pigs (Cavia porcellus) from the Andes of Ecuador
(2023) Jacome Aucay, Andres Santiago; Velesaca Ayala, Pablo Geovanny; Garay Peña, Gabriela Sofía; Murillo Apolo, Yury Agapito; Rosales Jaramillo, Cornelio Alejandro; Nieto Escandón, Pedro Emilio
The objective of this study was to evaluate the productive performance of native guinea pigs fed forage and forage plus concentrate diets. Thirty-six native weaned guinea pigs from the Provinces of Azuay and Cañar were distributed under a completely randomized design consisting of six diets with different levels of inclusion of grass (Lolium multiflorum) and legume (Medicago sativa) with or without the addition of concentrate (D1, D2, D3 and D4, D5, D6, respectively), where productive performance: total feed intake (CTA), total protein intake (CTP), feed conversion (CA), final live weight (PF), total weight gain (GPT), average daily weight gain (GDP) and economic parameters (Production cost, net profit, merit economic) was evaluated in the different treatments. Diets 3 (20 % L. multiflorum; 70 % M. sativa and 10 % commercial feed) and 4 (20 % L. multiflorum; 80 % M. sativa) had the best CA (8.21 and 8.59; P<0.05, respectively); GPT (624.47 and 593.78 g; P<0.05, respectively) and daily GDP compared to the other treatments (5.95 and 5.66 g·d-1; P<0.05, respectively). Therefore, although native guinea pigs have lower productive yields with respect to improved lines, the diets that allow expressing their maximum performance in reference to CA, GPT, GDP, PF and economic merit, are those containing levels greater than 50 % of alfalfa inclusion with or without commercial concentrate.
Relación de la hormona anti-mülleriana con la cantidad y calidad de ovocitos colectados por aspiración ecoguiada en vaquillas Holstein
(2023) Dutan Sanango, Jorge Bolivar; Garay Pena, Gabriela Sofia; Pesántez Pacheco, José Luis; Jacome Aucay, Andres Santiago; Ayala Guanga, Luis Eduardo; Samaniego Campoverde, Jorge Xavier
The experiment had two phases, the first one determined the relationship between the antral follicle count (AFC) and the concentration of Anti-Müllerian hormone (AMH) valued on the day the follicular wave restarted in 61 crossbred Holstein heifers, raised on farms, from the high tropics of Ecuador. The second phase compared the AFC assessed on the day of ultrasound-guided aspiration (OPU); as well as the quantity and quality of Cumulus Oocyte Complexes (COCs) recovered in animals with high (n=8) and low (n=8) concentrations of AMH. Follicular wave synchronization in the first phase of the study was performed with estradiol benzoate plus an intravaginal progesterone (IVD) and prostaglandin (PG) implant. The AFC and the taking of the blood samples in the first phase of the experiment were carried out on day 11 of the protocol. AMH cut-off values of greater than 0.12 ng·mL-1were established for the high AMH group and 0.05 ng·mL-1for the low AMH concentration group. The AMH concentration on day 0 (start of the follicular wave) was 0.13 ± 0.01 ng·mL-1, with an AFC of 17.31 ± 0.69 follicles and a high and positive correlation between AMH and the AFC of r=0.93; P<0.001. In the second phase of the experiment, it was observed that the heifers with a high concentration of AMH had double the number of follicles and COCs compared to those with a low concentration; however, the recovery rate was similar (57 %) in the two groups. The existence of a high and positive correlation between AFC and AMH concentration was confirmed; Furthermore, a strong relationship was observed between AMH and the quantity and quality of COCs recovered by OPU. Heifers with greater than 12 ng·mL-1should be selected as oocyte donors, since they provided double the COC's suitable for the production of embryos in vitro (PIVE), which will influence the quantity and quality of embryos obtained at the end of the PIVE.