núm. 19 (2010)

In tropical regions, Gyr and Guzerat breeds (Bos indicus) are most explored for dairy industry and are much more adapted to climate. Gyr and Guzerat are Zebu breeds very common in Brazil and they are being used to generate Bos taurus x Bos indicus crosses in order to combine good production, heat and parasite tolerance on the tropics. Breeding programs for the main economically important traits of Zebu dairy cattle have been recently introduced in Brazil and is based on the use of genetically superior sires in the herds. A major objective of QTL (Quantitative Trait Loci) and candidate genes is to find genes and markers that can be implemented in breeding programs across marker assisted selection (MAS). In Zebu dairy cattle MAS could be used to pre-select young candidate bulls to progeny testing, thus increasing selection differentials, shortening generation interval and increasing genetic gain

The lipopolysaccharide (LPS) or endotoxin is the major component of the outer membrane in Gram negative bacterial pathogens; it plays an important role in the activation of the immune system to be the most important surface antigen of Gram negative bacteria. The LPS consist of a lipophilic component and a polysaccharide portion with different function that makes this molecule one of the virulence factors more complex to understand, this review make an approach to measure the diversity effects and universality of LPS.

For Veterinary Medicine, animal survival is the functional guide-light in order to fulfill its professional purpose. Secondary events, such as allowing feeding or companion, are in fact results derived from the first objective. This article proposes that the most important obligation (Categorical Supraimperative) of all knowledge or human action is life care, including that of animals. This idea means the antitheses for Utilitarian Ethics upon which progressive exploitation and reification of animals have been based. Survival chances for our patients have diminished as a consequence of this phenomenon. A biopolitical correlation between human and bovine population dynamics is shown to contradict deleterious cultural viewpoints for the symbiotic relationships among species. Present bioethical analysis claims for a reformulated Aristotelian vitalism and bovines as worth-to-be-well-treated life forms from humans. Metaphysic figure “temple” as place of respect where life is located is used along the writing.

In Colombia the rearing of hair sheep and goats are expanding in various regions for being an alternative for meat and milk production at competitive prices due to their adaptability and easiness to digest rough fodder. Among the ectoparasites that affect small ruminants traditionally are recognized the lice and the sheep keds Melophagus ovinus (Díptera: Hippoboscidae), however fleas are not included. Here the occurrence of the common cat flea Ctenocephalides felis felis (Díptera: Siphonaptera) affecting sheep and goats in a farm at the Sabana de Bogotá are described an so there was performed an epidemiological and parasitological evaluation. The barn maintained animals in rotational grazing at an approximated stocking rate of 25 head/ha, receiving additional supplements of hay and silage. The presence of the flea was confirmed in sheep and goats, young and adult, as well as in dogs. Diverse degrees of anemia were evidenced but the association between flea infestation and anemia, or the presence of other anemia producing agents could not be studied. In the farm synthetic parasiticides are not used, extracts of Ruda (Ruta graveolens) are administered to mitigate parasitosis, without major efficacy. Sheep and goat breeders in the tropics should consider flea infestation as an agent causing adverse animal welfare situations in their farms. Control should start from the knowledge of the life cycle of the flea, trying to interrupt it.

This study was conducted in Hacienda Bufalera La Suiza, municipio de Puerto Nare Antioquia (the Colombian Middle Magdalena). The objective was to determine variations in the elimination of eggs per gram (epg) of faeces of gastrointestinal parasites during the months of January to December to a total of 150 water buffalo (Bubalus bubalis), which were divided into three groups of 50 (animals under 12 months of age, 13 to 36 months of age and over 37 months of age). These animals were randomly selected from a total of 4.200 buffalos. Faeces were collected directly from the rectum every month for a year, and then samples were processed by the technique of Mc-Master modified by Scmidht to count eggs. Statistix software was used to calculate descriptive statistics and correlation between climatic variables (temperature, sunlight and precipitation) and each parasite group. Analysis of variance was calculated in Microsoft Excel. Annual elimination curves of eggs per gram of faeces of Strongylida order and Strongyloides, Toxocara and Eimeria gender were established. In group of animals under 12 months of age, the most constant parasite eggs throughout the year were Strongyloides spp. and oocysts of Eimeria spp. In groups of 13 to 36 months of age and older than 37 months, the most constant parasites were Strongylida order and Eimeria spp., where the eggs of Trichuris spp. were the smaller elimination. As for the elimination of Toxocara eggs was only found in the group younger than 12 months of age, with a single presentation in january, june and august.

Congestive heart failure is related to contraction and relaxation ventricle abnormalities. Recent studies had shown that in the majority of the patients with congestive cardiac failure coexist alteration of systolic and diastolic function and in many cases the systolic function is normal and the cardiac failure is supported only by the diastolic dysfunction. A combined myocardial performance index (isovolumetric contraction time plus isovolumetric relaxation time divided by ejection time, ‘Tei-Index’) has been described which may be more effective for analysis of global cardiac dysfunction than systolic and diastolic measures alone. Supported by these previous information, the authors determined the normal value of the left ventricular Tei index in healthy dogs at Bogotá (at an altitude of 2600 mosl) in order to evaluate the systodiatolic function. A mean value of 33 with a standard deviation of 10 was obtained. No correlation exists with cardiac rate), body weight neither with ejection fraction (P> 05).

Dioxinas are synthesis contaminants, formed spontaneously in diverse industrial processes. Dioxinas are organoclorades compounds, very stable in the environment, capable of remain on human and animal tissue and therefore capable of producing chronic toxicity, like carcinogenicity and mutagenicity and endocrine disruptor effect. This compounds’ physical and chemical characteristics, its toxicity and adverse effects, are referred in this article, so we will be able to relate this compounds toxicity, to human health and production of innocuous food for human beings.

The purpose of this study was to determine the daily follicular growth and the time in which ovulation will occur, in Paso Fino Colombian mares who were pastured at the Sabana de Bogotá Colombia in tropical conditions, with an altitude of 2.652 meters over sea level, average temperature of 12º C and 1500 mm3 of rainfall. As previously stated, reproduction’s biotechnologies used in Colombia have led to manage and follow all the mares cycle, by monitoring follicular dynamics in order to obtain better results and therefore there is not information about some follicular aspects in this Colombian breed. For this project, fifty (50), mares were used with ages ranged between 5 and 10 years. To collect data from the selected mares, regular intervals of ultrasound were done every other day until the ovulation occurred, in order to keep track of follicular growth, taking into account the dominant follicle (25-30 mm), and detectable uterus edema, since its recognition until their ovulation, performing the same measurements on the scale that is found on the ultrasound screen. The data was analyzed by descriptive statistics, with deviation standard, plus an F test for unequal and equal variances, to determine differences in the follicular size of ovulation and daily follicular growth between the right and left ovary. It was concluded that paso fino colombian mares had a daily follicular growth of 2,04 + /-63 mm, a size follicular to ovulation of 41,34 + /-2,14 mm, of the 50 estrous cycles analyzed, 60% was by the left ovary and 40% by the right ovary. Differences in size of follicular ovulation were not significant (P> 50) among the ovaries. But in the daily follicular growth there were some mayor significant differences (P <02) meaning that the right ovarian follicles had a greater growth than those of the left ovary. With these results it was demonstrated that ovarian activity of Colombian paso fino mares in tropical conditions is similar to other breeds in other countries with similar sizes. Finally we concluded that the paso criollo colombiano’s mares have more ovulations in the left ovary, according to these results.

Livestock systems in Colombia have been developed taking concepts and technologies from the green revolution, where gramineous monocrop is privileged over arboreal cover in grazing lands. This model has not taken into account the climatic conditions of the different tropical ecosystems, in which variables as temperature, relative humidity and evaporation can limit the animal´s productive and reproductive efficiency, besides being a risk factor for illness occurrence in the herd. Bos Taurus and Bos Indicus breeds show termoneutral ranges where its genetic potential can be express. However, out of this comfort area animals can enter in caloric stress which in consequence reduces its performance and sometimes can end up causing death. Silvopastoral systems comprise several functions; it contributes to lessen caloric stress since temperature under the tree canopy can reach between 2 and 9°C lower in comparison to open pastures. Differences in temperature reduction have been found among silvopastoral systems and species, being the tree group arrangements and the species with high density canopy, those with superior effect. Interactions among components should be analyzed in order to design systems that incorporate enough arboreal cover to achieve caloric stress reductions, but without affecting forage production in pastures. Silvopastoral systems contribute to improve animal welfare.

Leptospirosis is a zoonosis disseminated around the world, affecting about 160 wild and domestic species, which are latent reservoirs and a main source of contamination for humans. This zoonosis is caused by Leptospira sp., Gram-negative bacteria have the ability to survive in the urine. In addition, the impact in Public Health is given for the presence of puddles, ponds and standing water that are easily contaminated and that is become a permanent focus of transmission. Leptospirosis is diagnosed by using the conventional technique microglutinación (MAT). However, there are no standardized criteria of titles considered positive, resulting in a significant number of positives and negatives false. Therefore, it is necessary to evaluate new diagnostic strategies highly sensitive and specific to achieve a reliable and accurate diagnosis. This article seeks to review the role of proteins associated with pathogenicity and utility of gene expression studies in the implementation of new diagnostic techniques that allow postulating molecular markers of infection.