En esta cartilla se identifican las diferentes razas de cerdos y se enseña cómo seleccionar las cerdas que sirvan como pie de cría.

Por el cual se deroga el Titulo 9 de la Parte 13 del Libro 2 del Decreto 1071 de 2015 Decreto Unico Reglamentario del Sector Administrativo Agropecuario Pesquero y de Desarrollo Rural en lo relacionado con la politica de precios de insumas agropecuario

The series of studies accomplished and compiled in the present thesis had as a main objective the evaluation of the suitability of the Colombian Artemia franciscana for the aquaculture industry. Further, an evaluation of six newly reported populations (Salina Cero, Kangarú, Tayrona, Bahía Hondita, Pusheo and Warrego) is included. In addition to the description of biotypes, physicochemical parameters were recorded for each population studied. The habitats where Artemia has actually been registered in Colombia are of marine (thalassohaline) origin, thus they are sodium and chloride rich. The application of biometric tools to determine possible cyst and nauplius size differences among the different Colombian populations has been successful at further separating some of the most promising Artemia populations of potential aquaculture use. Further, cysts from Tayrona show the smallest size, followed by Galerazamba, Kangarú, Manaure, Salina Cero and Pozos Colorados. Galerazamba has the thinnest chorion, followed by Tayrona, Salina Cero, Manaure, Pozos Colorados and Kangarú. Additionally, nauplii from Galerazamba present a small size followed by Manaure, Salina Cero, Pozos Colorados and Tayrona. The determination of FAME from Manaure, Galerazamba, Salina Cero and Tayrona, suggested high EPAs but low DHAs. Hence, all four populations sampled are not considered suitable for marine aquaculture unless fortified with DHA rich emulsions, according to actual aquaculture quality standards. The cyst quality study, conducted on cysts batches, shows that cyst collection and processing techniques need to be improved in order for them to be suitable for the growing Colombian aquaculture industry. The outcome of the population distribution study, shows Manaure, Galerazamba and Salina Cero as having a stable mean population distribution with a balanced adult (38%, 36% and 19%, respectively) to juvenile+nauplius proportion (62%, 64% and 81%, respectively), as well as a stable female:male sex ratio (1:0.84, 1:0.88 and 1:0.84, respectively). In contrast, Tayrona exhibits an unstable population distribution with a high proportion of adults (82%) and low juvenile+nauplius (18%) and female:male ratio (0.88:1), thus recruitment of the juvenile and nauplius cohort to assure continuity of the species in this biotope is below sustainable levels. The results for the reproductive experiments (mean cyst production per female) do not entirely agree with the estimated cyst production potential at each site (field work results). These results difference is likely to be due to the interaction in the field among the three parameters (salinity, percent O2 saturation, and nitrate) on cyst production, particularly in the case of Salina Cero. Similarly, nitrate levels might have been affected by salinity. The latter may be supported, in part, by the observation of low nitrate levels during the peak of cyst production during this study. The genetic study on some Caribbean Artemia franciscana strains based on RAPDs generated two similar dendrograms with the same separation for the two Caribbean population clusters (middle Caribbean: Pozos Colorados, Tayrona, Manaure, Venezuela-PAV, Bonaire and Curaçao and lower Caribbean: Galerazamba and Salina Cero). Moreover, the clustering pattern obtained suggests that the populations in these two clusters are not genetically identical. Further, the splitting of the Artemia populations coincides with the existence of a geographical barrier in Colombia named the Sierra Nevada de Santa Marta. The Sierra Nevada might constitute a geographic barrier to shorebirds and hence Artemia cyst dispersal further south. The discriminant analysis based on morphometric characters, assigns male and female individuals into their proper population group (North American and Caribbean coast) to which they belong by only one discriminant function (100% confidence). However, male morphometric characters separate better population groups than the female characters, since all Colombian populations are correctly clustered in the Caribbean coast whereas the SFB population fall into the North American group, with no overlapping between both, as it happens with females. Similarly, for Artemia populations classified by their geographic origin, male and female individuals again separate the Colombian populations from the North American (SFB) populations. According to the analysis, Salina Cero male population is similar to its neighboring Galerazamba population and is also related to the other Colombian populations, and this is consistent with the previous findings using RAPDs and also likely to be explained by the existence of a geographic barrier (Sierra Nevada de Santa Marta). Apparently, as deduced from the influence of lunar cycles and sampling time study the conglomerates formed by brine shrimp are asynchronous. Finally, it is recommended to conduct Artemia surveys preferably late in the evening or alternatively during early morning since Artemia tends to distribute more uniformly during the evening (dark and cool), when water temperature is lower, particularly in saltworks, where the evaporation basins are shallow.

Bovine viral diarrhea virus (BVDV) is an important pathogen of cattle that has been frequently associated with in vitro produced (IVP) embryos. The zona pellucida (ZP) of IVP embryos shows higher affinity for BVDV than the ZP of in vivo produced embryos and treatments that can eliminate BVDV from in vivo produced embryos are unsuccessful in the case of the IVP embryos. The aim of the present study was to investigate whether different culture conditions change the affinity of the ZP of day-7 IVP bovine embryos to BVDV. Morula and blastocysts were produced under four different culture systems: 1) in vitro culture in Menezo's B2 media and coculture with bovine oviductal epithelial cells (B2-BOEC culture); 2) in vitro culture in modified synthetic oviductai fluid with aminoacids (mSOFaa culture); 3) in vivo culture in ligated oviducts of synchronized sheep; and 4) in vivo produced embryos flushed from superovulated cows seven days after breeding. The embryos were exposed to BVDV for 24 hours, and washed 10 times and treated with trypsin, according to the recommendations of the international Embryo Transfer Society. After pooling the embryos in groups of five, the samples were homogenized and tested for the presence of BVDV by indirect immimoperoxidase assay (IIP) or reverse transcription-polymerase chah reaction (RT-PCR). No significant differences were found between the two detection systems but the IIP assay tended to detect a higher number of positive sarnples. According to the IIP assay, the mSOFaa group had a significantliy higher number of positive findings (78.6%) followed by the B2-BOEC group (32.1%), and the oviductal culture group (7.1%). None of the in vivo embryos tested positive for BVDV. These results show that different culture conditions in which embryos develop alter the way the ZP interacts with pathogens. The oviductal culture of in vitro produced zygotes seems to be beneficial in reducing the affinity of the ZP to BVDV and the washes and trypsin treatments applied to these embryos after culture appear to be more effective than in embryos completely produced in vitro.

Coliflor-Brassica oleracea

Algunas prácticas de manejo del cultivo del algodón, enmarcadas en un contexto ambiental y económicamente aplicable, para disminuir el impacto negativo del cultivo en el medio ambiente. De esta forma se pretende orientar al productor en la sustitución gradual de la aplicación de productos químicos en la fertilización y en el control de plagas, por alternativas ecológicas como el uso de biofertilizantes, prácticas de manejo cultural del cultivo y uso de insecticidas naturales elaborados a partir de extractos de platas que representarán la reducción de costos y el mejoramiento de la calidad de vida del productor de algodón.

Tomate-Solanum lycopersicum

El crecimiento y desarrollo de la planta de arroz es proceso fisiológico continuo que comprende un cilo completo desde la germinación de la semilla hasta la maduración del grano. Este. proceso muestra un patrón común en el tiempo que suele tener variaciones dependiendo de las características genéticasi de la planta o la influencia del ambiente

Los microorganismos anaerobios obligados demandan para su crecimiento condiciones especiales asociadas a bajos potenciales redox, que les permiten sobrevivir y proliferar en ambientes con ausencia total de oxígeno. Uno de los ambientes anaerobios más estudiados es el rumen, órgano digestivo de algunos herbívoros que ha sido considerado como el biorreactor de la naturaleza, con una capacidad sin precedentes de autorregulación y control. Las herramientas moleculares hoy disponibles develan que solo conocemos entre el 1% y el 5% de las especies que hoy habitan el rumen; sin embargo, y gracias a la microbiología clásica y los métodos de cultivo tradicional, se cuenta hoy con el mayor conocimiento bioquímico y fisiológico de las especies más abundantes de este ecosistema, y probablemente de su función en el complejo interactoma microbio-hospedero.

Aguacate-Persea americana