Marco Antonio Estrada - Academia.edu (original) (raw)

Uploads

Papers by Marco Antonio Estrada

ECS Transactions, 2007

Page 82. ECS Transactions, 9 (1) 67-73 (2007) 10.1149/1.2766875© The Electrochemical Society Dist... more Page 82. ECS Transactions, 9 (1) 67-73 (2007) 10.1149/1.2766875© The Electrochemical Society Distortion Analysis of Triple-Gate Transistor in Saturation Jorge E. Conde, Antonio Cerdeira and Magali Estrada Sección de ...

ECS Transactions, 2007

El presente trabajo muestra los resultados obtenidos en dos estudios transversales realizados en ... more El presente trabajo muestra los resultados obtenidos en dos estudios transversales realizados en los meses de julio de 2001 y diciembre de 2003 en la comunidad Almeya ubicada al del Norte del estado de Puebla, los cuales tuvieron como fin identificar las características y limitaciones de la avicultura familiar en la comunidad. La evaluación incluyó parámetros productivos, costos de producción, consumo y mercado. También se realizó un muestreo serológico para determinar las enfermedades de mayor importancia epidemiológica en las aves de la comunidad. La finalidad principal de la producción de huevo y carne de pollo es el autoconsumo. Entre 2001 -2003 se presentó una reducción del 14.2 % en el número de familias que crían aves y de 43.3 % en el total de aves. Todos los sueros analizados en 2003 resultaron positivos a Influenza aviar y enfermedad de Newcastle. Las principales causas de mortalidad fueron los problemas respiratorios y los depredadores. Los costos de producción son competitivos en el caso del huevo pero no en carne de pollo. Finalmente, las principales limitaciones identificadas son las deficiencias en la alimentación, la ausencia de asistencia técnica veterinaria, la presencia de enfermedades y depredadores y la falta de una estructura organizada de mercado. Los resultados sugieren que la avicultura familiar representa una oportunidad para contribuir al mejoramiento de las condiciones de vida de las familias campesinas, especialmente de las mujeres, para lo cual se requiere que la actividad ocupe un lugar relevante en la agenda de las instituciones de desarrollo e investigación agropecuaria en México. ABSTRACT This paper shows results of a research project related to household poultry production carried out in the peasant community of Almeya in the north of the state of Puebla, to characterize backyard poultry production and to identify major diseases and other factors limiting production. To this end, two surveys were performed, the first in July 2001 and the second in December 2003. Information on poultry production, marketing, technological level, consumption, costs and contribution in cash to household income was collected through identified farmer interviews. Blood samples were collected to determine which fowl diseases were predominant. The main purpose of this production system is as food for the household. in the number of households raising poultry and in the total flock (43.3 %). All of the 2003 serum samples showed positive for Newcastle and Avian Influenza. Several respiratory diseases and attacks by predators were mentioned as the main causes of mortality. Costs are competitive only in egg production. Finally, shortcomings in poultry feeding and nutrition, a scarcity of veterinary advice, the presence of diseases and predators and the lack of an organized market structure were identified as the most important constraints of household poultry production. Results suggest that backyard poultry production contributes to improve the living standard of peasant households, especially that of women, and therefore should be included as a priority in the research agenda of Mexico's agricultural research and development organizations.

Research evaluation regarding Eimeria spp requires a trustworthy oocyst count technique. The aim ... more Research evaluation regarding Eimeria spp requires a trustworthy oocyst count technique. The aim of this study was to determine the efficacy of total oocyst count using the Neubauer haemocytometer and the McMaster camera. E. tenella sporulate oocysts were inoculated per os to two groups of Leghorn chicks. Faecal samples were collected at seven days postinoculation, and different technicians counted oocysts in both cameras. The Hartley test was used to analyze homocedasticity variance level within counts with each camera. One counting, set by the same technician, showed variance heterocedasticity in one from two counting samples with the haemocyto- meter but not with the McMaster camera. Furthermore, there was a significant difference in the total oocyst counts carried out with the McMaster camera between two technicians but not with the Neubauer haemocyto- meter. It is concluded that the Hartley test is a trustworthy statistical method to evaluate laboratory techniques.

Se determinó el peso promedio óptimo de huevos de avestruz que eclosionaron favorablemente y los ... more Se determinó el peso promedio óptimo de huevos de avestruz que eclosionaron favorablemente y los que no durante dos ciclos de producción. De los primeros, el peso promedio de huevos antes de incubar, del primer ciclo fue de 1.526 ± 0.147 kg, y del segundo 1.536 ± 0.155 ...

The effect of an anticoccidial vaccine on broiler chickens challenged at 21 st day of age with 6.... more The effect of an anticoccidial vaccine on broiler chickens challenged at 21 st day of age with 6.0 x 10 4 E. acervulina; 5.0 x 10 3 E. maxima; and 4.0 x 10 4 E. tenella sporulated oocysts/bird, was evaluated. Four groups of 20 chicks each, one day old, were ran- domly assigned to: 1) unvaccinated, unchallenged control (UUC); 2) unvaccinated, challenged control (UCC); 3) vaccinated, chal- lenged (VC); and 4) vaccinated, unchallenged (VU). All birds were weekly weighed. At 7 days post-challenged (PC), weight gain % (WG), intestinal pH (IpH), gut weight (GW), intestinal IgA concentration (IgAC), gut lesion score (GLS), oocyst output (OO) and percentage of specifi c coccidia species (SCS) in feces were recorded. At 14 and 26 days, gastrointestinal passage time (GPT) was measured. At 21 days of age, body weight from groups VC (544.8 ± 105) and VU (504.9 ± 88) were lower (P < 0.05) than group UUC (615.6 ± 100). At 28 days, group UUC was the heaviest (923.3 ± 126), and with the highest WG (49.97%). Group UCC had the lowest WG (24.60%), and at 26 days, it had the lowest GSF (212.4 ± 31), different (P < 0.05) from group VU with 43.81% of WG and 158.4 ± 52 for GSF. Both, IpH and GW did not differ among groups. The lowest IgAC was seen in ceca from group UUC. Group UCC had the highest GLS, whereas groups UUC and VU had the lowest GLS. Group VC showed higher GLS for E. maxima and E. tenella than groups UUC and VU. At 28 days, group UCC elicit higher OO; however, group VC showed higher OO than groups UUC and VU. At 7th day PC, the E. acervulina SAC for group VC was lower than groups UCC and VU, even though E. maxima and E. tenella SACs for this group (VC) had increased. Molecular characterization for fi eld strains and their comparison with commercial vaccines must be held forward to understanding antigenic differences.

ECS Transactions, 2007