Ecosistemas y Recursos Agropecuarios

87-96

Authors: Adrian Gloria Trujillo, David Hernández Sánchez, Omar Hernández Mendo, María Magdalena Crosby Galván, René Pinto Ruiz, Edgar Meraz Romero, J Efrén Ramírez Bribiesca

Saturated fatty acids (FA) in the carcass of ruminants represent a critical topic in human alimentation given by their relationship with cardiovascular diseases. In view of this, Saccharomyces cerevisiae (Sc) represents an alternative to modify the meat FA profile by increasing the ratio of deposited unsaturated FA, because of its high levels of unsaturated fatty acids. An experiment was carried out using 30 commercial growing lambs (20 ± 0.9 kg LW), distributed into three groups with 10 animals each, which was placed into one of three evaluated treatments: 0, 3, and 5g Sc animal-1 d-1, in order to determine the productive performance of the animals, plasmatic cholesterol levels, and FA deposited in the carcass. A totally random design was used. Data were analyzed using the PROC GLM, considering ten repetitions per treatment. Mean comparison of the treatments was done through the Tukey test. The results show that adding 3g animal-1 d-1 Sc partially decreased (p < 0.05) DM intake and food conversion in the evaluated periods without affecting (P > 0.05) daily weight gain. It also did not affect (p > 0.05) muscle area of the Longissimus dorsi, fat thickness and total cholesterol in the blood. As the Sc dose increased, the levels of myristic, palmitic, oleic, and linoleic acids decreased (p < 0.05). Sc doesnt affect the animal performance, neither improvement the carcass unsaturated FA profile, however, saturated FA concentrations decreases.

107-122

Authors: Antonio Trujillo-Narcía, María del Carmen Rivera-Cruz, Luz del Carmen Lagunes-Espinoza, David Jesús Palma-López, Saúl Sánchez-Soto, Gustavo Ramírez-Valverde

El objetivo de este trabajo fue identificar parámetros de la microflora rizosférica, la fauna del suelo y de la planta de rábano para medir la eficacia de la descontaminación de un Fluvisol afectado por petróleo crudo. En 0.85 ha de suelo restaurado y en 0.377 ha de suelo testigo aledaño, localizados en Cunduacán, estado de Tabasco, México, se establecieron bioensayos con plantas de rábano (Raphanus sativus L.) en tres épocas climáticas del año: nortes (noviembre a febrero), sures o sequía (marzo a mayo) y lluvias (junio a octubre). El diseño fue completamente al azar con arreglo factorial (tipo de suelo y época del año) y con cuatro repeticiones. Se evaluaron cinco variables de la microflora, la diversidad de la fauna del suelo y siete variables de la planta. Los datos se analizaron con contrastes ortogonales, ANDEVA y correlaciones múltiples, además se calcularon índices de impacto ecotoxicológico (IIE). El suelo superficial restaurado aún tiene 6 480 a 11 210 mg kg−1 de hidrocarburos totales del petróleo (HTP) que causó necrosis y hasta 92 % de mortalidad de las plantas. No se formó el bulbo (-0.658**) y en consecuencia disminuyó la biomasa vegetal (-0.691**), ambos fueron los parámetros más sensibles en la época de sures. La variable más afectada (p ≤ 0.01) en las épocas de nortes y de lluvias fue la densidad de la fauna del suelo (-0.729**).

139-150

Authors: Héctor Osbaldo Rubio Arias, Roberto Carlos Ortiz Delgado, Rey Manuel Quintana Martínez, Rubén Alfonso Saucedo Terán, Jesús Manuel Ochoa Rivero, Nora Ivet Rey Burciaga

Un Índice de Calidad de Agua (ICA) es una herramienta estadística para estimar la calidad de un cuerpo de agua. El objetivo fue determinar un ICA para la presa La Boquilla en Chihuahua, México. Seis puntos de muestreo fueron seleccionados aleatoriamente y muestras de agua se colectaron mensualmente, a cuatro profundidades: 0.30 m, 5.0 m, 10.0 m y 15.0 m. Se cuanti

163-174

Authors: Alejandro Moreno-Reséndez

Se determinó el efecto del vermicompost (VC) sobre el desarrollo del melón en invernadero utilizando como sustratos cuatro tipos de VC mezclados con arena de río (AR), con relaciones 25 : 75, 30 : 70, 35 : 65 y 40 : 60 (% en volumen). Los VC se prepararon a partir de estiércoles de caballo, cabra, conejo y bovino. Los sustratos se colocaron en bolsas de polietileno negro, de 20 kg de capacidad, en donde se sembraron semillas del melón Cantaloupe. Las plantas se condujeron a un solo tallo, tutorando con ra

181-188

Authors: Daniela Elizabeth Briones Martín del Cam, Claudia Patricia Pérez Camacho, Felipe Alonso Rodríguez Almeida, Alfredo Anchondo Garay, Hipólito Hernández Cano, Alberto Flores Mariñelarena

Con el objeto de evaluar genéticamente bovinos Angus importados a México como embriones, en com- paración con una población de referencia internacional y bovinos concebidos localmente, se genotipificaron 143 animales Angus y Angus Rojo con la plataforma BeadChipIllumina BovineSNP50⃝R y se predijeron sus valores de cría genómicos (MVP). En promedio fueron superiores a la media de la población de referencia para características de facilidad de parto directa y materna, habilidad lechera, crecimiento desde el destete hasta el año de edad, peso de la canal, desarrollo muscular, marmoleo y el índice económico de engorda en confinamiento. Los animales originados con germoplasma importado fueron superiores a los concebidos localmente para las características de crecimiento desde el destete hasta el año de edad, desarrollo muscular, marmoleo, terneza de la carne y el índice económico. La población de bovinos Angus evaluada mostró tener potencial genético para seleccionar y utilizar reproductores mejorados.

1-8

Authors: Verónica Rosales-Martínez, Juan Pablo Martínez-Dávila, Diego Esteban Platas-Rosado, Adalberto Rosendo-Ponce, Víctor Córdova-Ávalos

Migration is a survival strategy that is applied in situations of poverty, to lighten the problem of low salaries and inefficiently managed family needs. The purpose of this study was to compare the technological management of farming activities, applied by families before and after migrating, from 1979 to 2008 in the municipality of Jamapa, Veracruz. A survey was applied to 45 families with migrants, with a questionnaire of 115 closed questions, during the year 2009. Statistically significant changes were observed (McNemar, Chi2 = 18.91 and p < 0.001) with negative results for all technology used in activities related to maize, beans and cattle. The definition of a negative change was based on the fact that the technological elements that the producers used before migrating and no longer used afterwards were 265; the group of technological elements with a positive change, that is, which they did not use before and did use afterwards was 173. It may be concluded that migration has had a negative effect on maize (Chi2 = 122.49, p < 0.001) and bean (Chi2 = 98.09, p < 0.001) crops, and a positive effect on cattle ranching (Chi2 = 116.48, p < 0.001). Thus, the economy of families with migrants, in the agroecosystems of Jamapa, has improved, but the diversity of farm activities has decreased.

19-32

Authors: Yamilé Comabella, Andrés Hurtado, Javier Canabal, Tsai García-Galano

Hatching success, growth, development and survival of Cuban gar (Atractosteus tristoechus) larvae were examined at different temperatures (26, 28 and 30 ºC) up to 18 days after hatching (DAH). The time to hatching was inversely related to the incubation temperature (87, 100 and 111 h). Larval survival at the time of hatching was significantly lower at 30 oC (50.3 %), coinciding with the highest larval mortality (30.2 %). Growth rates were 1.75 mmd-1 -10.4 % d-1 at 26 ºC,1.30 mm d-1 -10.2 % d-1-1 at 28 ºC and 1.40 mm d-1 -10 % d -1 at 30 ºC. Three similar critical periods were identified: 0-6, 7-11 and 12-18 DAH. During the first period, a similar increase in weight and a significant increase in total length occurred, mainly at 30 ºC, indicating a more efficient reconversion of the yolk reserves. Later, growth was equally slow, corresponding with the transitional period from endogenous to exogenous feeding, indicating a similar physiologic pattern regardless of incubation temperature. Weight and length increased during the last period, with the greatest increase at 26 ºC in contrast with the lowest gain at 30 ºC. The inflexion points of many morphometric characters and the developmental stages accelerated with the increasing temperature. Although it was impossible to determine the optimal temperature, it was evident that 26 ºC favored hatching success and larval growth.

41-48

Authors: Gaspar Manuel Parra-Bracamonte, Ana María Sifuentes-Rincón, Williams Arellano-Vera, Juan Gabriel Magaña-Monforte, José Alberto Ramírez-De León, Gonzalo Velázquez

Beef tenderness is an important trait in consumer satisfaction and has been considered as the main trait for palatability, for which reason it is important to evaluate its variability in different cattle breeds. An experiment was designed to evaluate the Warner Bratzler Shear Force (WBSF) of Red Brangus cattle rib eye steaks and consumer acceptance. The tenderness of beef rib eye steaks was evaluated by the WBSF. A consumer preference evaluation test was carried out to quantitatively estimate tenderness, juiciness, flavor, doneness and general acceptance of the evaluated steaks. Mean WBSF was 5.03 kg ± 0.93 kg, theoretically indicating a tough beef. The distribution of the samples showed 21 % and 11 % of moderately tender and tender beef cuts, respectively. Cattle condition (bulls and steers) was not significant for the WBSF (p > 0.5). All the traits evaluated in the hedonic evaluation had approximately 6 points of a total of 8 (8 was best). Tenderness, juiciness and flavor presented a high and significant correlation (p < 0.5). None of the subjective traits was correlated with total acceptance. Under theoretical criteria, tender Red Brangus beef cuts are infrequent; however the beef has a good acceptance. Characterization studies may be necessary and useful to create marketing niches specific for this and other cattle breeds.

59-72

Authors: Rodolfo Ramírez-Valverde, Rafael Núñez-Domínguez, Enelvi Fabián-Barrios

The purpose of this study was to characterise papers on animal breeding published by Mexican researchers in the scientific journals that belong to the índice de Revistas Mexicanas de Investigación Científica y Tecnológica of the Consejo Nacional de Ciencia y Tecnología. The papers considered were published in the journals Agrociencia (n = 48), Revista Mexicana de Ciencias Pecuarias (n = 119), Tropical and Subtropical Agroecosystems (n = 17) and Veterinaria México (n = 78) up to the year 2012. Studies on animal breeding focused mainly on cattle, tropical zones and the states of Veracruz, México and Yucatán. Quantitative genetics was the most studied area and the most researched traits were those directly related to production. The most studied topics were phenotypical and environmental characterisations, estimations of genetic parameters, comparisons of genotypes, and methods to carry out genetic evaluations. Half of the research was published by two or more institutions and most (93 %) were prepared by two or more researchers (average 3.8 authors per article). The institutions with most published papers (64 %) in animal breeding were the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, the Universidad Nacional Autónoma de México, the Colegio de Postgraduados, the Universidad Autónoma Chapingo, the Universidad Autónoma de Yucatán and the Universidad Autónoma de Baja California Sur. The characterisation and analysis of the evolution of scientific publications are important in order to design animal breeding strategies and prioritise future research.

81-86

Authors: Juan Carlos García López, Juan Manuel Pinos Rodríguez, Gregorio Álvarez Fuentes, Marco Antonio Camacho Escobar, Yolanda Jasso Pineda

The use of mannan-oligosaccharides (MOS) was evaluated for coccidian control in broilers. Treatments: 1) Control: Nicarbazine (120 g t-1) and Salinomycin (66 g t-1); Bacitracin (55 g t-1); 2) Control + challenge; 3) MOS 1 kg t-1. Treatments 2 and 3 included oocysts (E. acervulina). Oocyst count was higher (p < 0.05) for broilers in T2 and T3. No lesions due to E. acervulina were recorded (p > 0.05). MOS may be used as an alternative to antibiotic growth promoters.

189-203

Authors: María Concepción Torres Díaz, Yanet Yahaira Basulto Solis, Jorge Cortés Esquivel, Karla García Uitz, Ángel Koh Sosa, Franklin Puerto Romero, Julia Ávila

The objective of this study was to evaluate the risk of groundwater pollution through a risk map creation and analysis from the "Semicírculo de cenotes" and "Zona costera" hydrogeological regions in the State of Yucatan, Mexico. The risk map was obtained from vulnerability and hazard maps. The vulnerability was evaluated considering the seven variables that compose the DRASTIC method: D, depth; R, net recharge; A, lithology and media structure of the aquifer; S, soil type; T, topography; I, impact of vadose zone; and C, hydraulic conductivity. The information used in the application of this methodology was obtained from public sources and through literature review. The hazard map was developed based on the potential sources of hazardous waste generation in the region of study. The results showed the presence of a vulnerability classified as high, very high and extreme; additionally, a greater hazard was observed for the municipalities of Merida, Progreso and Dzidzantún, representing a very high risk of aquifer contamination. Key words: Risk, contamination, karstic aquifer, intrinsic vulnerability, hazard.

219-231

Authors: Rosalía Castelán Vega, Víctor Tamaríz Flores, Jesús Ruiz Careaga, Gladys Linares Fleites

Despite the global consensus towards sustainability, there is still no agreement on how to quantify it in order to make practical decisions that will lead to a sustainable development. In its assessment with regards to agroecosystems, it is required to make complex aspects into clearer aspects, that discern trends on a system level, known as indices. The investigation assessed the sustainability of the agroecosystems pertaining to three districts in the municipality of Pahuatlán, Puebla, through the estimation of the sustainable development index (s3). A descriptive longitudinal field study of the year 2009 to 2012, on a total population of 506 agroecosystems in the districts of San Pablito, Xilepa and Tlalcruz, belonging to the municipality of Pahuatlán, Puebla; of the whole, a stratified sample population of 288 agroecosystems was taken as well as their producers, to whom a socioeconomic questionnaire structured to measure the three dimensions of sustainable development (environmental, economic and social) was administered. The results showed that all the districts of Xilepa and Tlalcruz find themselves at a critical level of sustainability with values of 0.34 and 0.40, while San Pablito showed to be at an unstable level with a value of 0.52. The environmental dimension presented the largest limitation for sustainability in these districts. These results are an indication to the need to design and implement plans and programs for rural development, the likes of which promote and improve the level of sustainability in these districts, so as to assure their long-term existence and increase their quality of living. Key words: Agroecosystems, Marginalization, Index, Degradation, Sierra Norte.

249-260

Authors: Leonor Sanginés García, Paulina Dávila Solarte, Lourdes Solano, Romo Fernando Pérez-Gil

The goal of this work was to taxonomically identify different species of forbs that grow in coffee plantations, analyze their chemical composition and evaluate the behavior of free range lambs compared to animals grazing in pasture. The taxonomic classification was done in both the rain and dry season. The whole plantation was studied while the animals grazed. All the existing plant species were registered, observed and separated between those ones eaten by the animals, which were called selected forbs, and the no eaten ones, called rejected ones. Chemical composition and in vitro and in situ digestibility were studied as well as the grazing ovine behavior, which was closely observed. 58 different plant species were found, belonging mainly to the Fabaceae, Mimosaceae, Caesalpinaseae, Gramineae and Asteraceae families. The selected forbs and grass fodder showed: 14 and 7.8 % CP; 45.9 and 47.7 % NDF(p < 0.05); 3.2 and 2.3 Mcal GE(p < 0.05); a=9.3a and 8.8a, b= 74.3a and 74.6a c = 61.1a and 60.4b respectively. The feed intake frequency of the animals grazing in the coffee plantation was higher and produced no damage to the leaves, branches, stems nor beans. In conclusion, there is more feed diversity in coffee plantations than in pastures and animals are capable to select those fodders of better nutritional quality without producing any damage to the coffee plants. Key words: Etology, forbs, coffee plantation, chemical composition, digestibility.

269-279

Authors: Jesús Rodríguez-Miranda, José Manuel Juárez-Barrientos, Betsabé Hernández-Santos, Erasmo Herman-Lara, Cecilia Eugenia Martínez-Sánchez, Juan Gabriel Torruco-Uco, Ernestina Paz Gamboa, Emmanuel de Jesús Ramírez-Rivera

The aim of this study was to obtain the sensory characteristics of some commercial milk consumed in the city of Tuxtepec, Oaxaca, Mexico by a consumer panel , using the technique of categorization and statistical techniques, such as the FAST methodology (Factorial Approach for Sorting Task), WordCountAna and confidence ellipses, in order to generate the product map, identify consensual words that help describe milks, evaluate the effect of discrimination consumer panel and stability of the product map. Eight brands of commercial milk were evaluated, the results showed that it was possible to describe the major sensory characteristics of milk by the consumer panel, generating 209 words, of which the white and yellow colours and sour, sweet and salty taste were consensual, describing the characteristics main of the milks analyzed. The confidence ellipses revealed that the consumer panel was discriminating, generating map product stability and reliability in the results at p < 0.05. Key words: Categorization, sensorial description, confidence ellipses, consensual words.

295-308

Authors: Roger Iván Rodríguez-Vivas, José Alberto Rosado-Aguilar, Melina Maribel Ojeda-Chi, Luis Carlos Pérez-Cogollo, Iris Trinidad-Martínez, Manuel Emilio Bolio-González

Infestations with cattle tick, Rhipicephalus microplus constitute the most important ectoparasite problem in the tropical and subtropical regions of the globe, resulting in major economic losses in the cattle production. The control of R. microplus is mostly based on the use of ixodicides. Nevertheless, the irrational use of such products has resulted in tick populations exhibiting resistance to all major ixodicide drug classes. This has urged the development of control alternatives, including the use of animal husbandry practices, selection of tick-resistant cattle breeds, plant extracts, grassland management, vaccination (anti-tick vaccine) and biological control. Integrated tick management consists of the proper combination of at least two control tools aiming to destabilize the constitution of populations with higher proportions of genetically-resistant individuals, while maintaining adequate levels of animal production. The purpose of this paper is to present an updated review on the use of different integrated tick control for the control of R. microplus in the cattle livestock. Key words: Ticks, ixodicides, resistance, integrated management.