Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Performance of three racial groups of grazing steers supplemented with agroindustrial by-products. The main objective of this research was to evaluate the productive performance of three racial groups of steers, receiving or not supplementation with agro-industry by-products under grazing conditions in the humid Colombian Caribbean. Forty-eight steers: Angus x Brahman (AxB), Simmental x Brahman (SxB) and Romosinuano x Brahman (RxB) with average weight of 274± 13,76 kg and 17 months old  were randomly distributed to two types of feed management; with feed supplementation (CSA: 24 animals) and without  feed supplementation (SSA: 24 animals) in each breed group, using a complete randomized design (DCA). The supplementation consisted of a mix of rice bran (56.5%), cottonseed (43.5%) and mineralized salt (100 g/steer/day). The highest daily weight gain (GDP) was observed in the animals of the treatments AxB CSA, SxB CSA and RxB CSA (p= 0.001) with 730, 942 and 650 g/day respectively. The GDP of the animals AxB SSA, SxB SSA and RxB SSA, corresponded to  560, 520, and 608 g/animal/day. Regarding body composition by ultrasound measurements, the greater attributes of the ribeye area (p=0.0175) were observed for the AxB CSA (43.73 2.54 cm2) y RxB CSA treatments (45,51±2,34 cm2) and for the rump fat thickness (p=0.0229), the RxB CSA treatment (3.97 0.25 mm). The highest projected meat production kg/ha in a year, corresponded to the average for the biotypes of CSA treatment with 1,131.33 kilograms/ha/year, surpassing by 27.5% the production of SSA biotypes treatment of 821.26 kilograms. From  the results obtained in this research, the supplementation of grazing steers with by-products of agro-industry  becomes a productive activity to increasing GDP and meat production kg/ha, reflecting the potential of this practice as a valid strategy for the development of more efficient and competitive meat production systems for the humid Colombian Caribbean region.

A trial was carried out to evaluate the extraction of nutrients from the gold button at different regrowth ages (20, 40 and 60 days) and fertilization levels (0, 100 and 200 kg N / ha / year), in the Central Pacific zone of Costa Rica, in a dairy farm located at 15 meters above sea level and with an average rainfall of 265,7 mm / month; the type of soil is classified in the order of Inceptisols. For the 9 treatments evaluated, the foliar concentrations of macro and micronutrients were determined considering the two seasons of the year, rainy and dry. The nitrogen extraction reflected as kg nutrient / ha / harvest, showed a tendency to increase as the fertilization level increased for all the evaluated regrowth ages. The extraction of calcium showed increasing values ​​as the age of the plant and the level of fertilization increased (2-55 kg Ca / ha / cut), which are high compared to other forage crops. For the rest of the macronutrients (phosphorus, magnesium, potassium and sulfur), the trend is the same as with nitrogen and calcium. In the case of micronutrients (boron, manganese, copper, iron and zinc) an increasing trend was found as the regrowth age and the level of nitrogen fertilization increased. Based on the results obtained from this trial, it can be concluded that the gold button is a forage crop with important nutritional requirements, which shows that despite its well-known rusticity and poor agronomic management by producers, it is a crop that responds positively to fertilization.

The seed production capacity to facilitate the adoption and conservation of these species by producers. The objective of this research was to evaluate genotypes of Canavalia brasiliensis Mart. ex Benth. for seed production. The research work was carried out at the Motilonia Research Center of the Colombian Corporation for Agricultural Research - AGROSAVIA. Four accessions of C. brasiliensis (17009, 17462, 21461 and 21825) from the International Center for Tropical Agriculture-CIAT were evaluated. They were established in 3.0 x 3.0 m plots, with 0,5 x 0,5 m between plants and furrows. The statistical effect of the different accessions of C. brasiliensis on the number of pods per capacity, pod length, pod diameter, seeds per pod, weight of 100 seeds, seed diameter and yield was analyzed by means of an ANOVA analysis of a via, complying with a BCA design. The statistical effect of the different accessions of C. brasiliensis on the number of pods per sampling, 0,25 m2, pod length, pod diameter, seeds per pod, weight of 100 seeds, seed diameter and yield, was analyzed using an ANOVA one-way analysis, complying with a BCA design. The accessions of C. brasiliensis, showed a significant statistical effect on the number of pods per sampling, pod diameter, seed diameter, weight of 100 seeds and seed yield. The best result in terms of yield was for accessions 17462, 21825 y 17009 with values of 745,6, 584,9 and 509,9 kg/ha, respectively, indicating the potentialities of C. brasiliensis. The accessions 17462, 21825 and 17009 of C. brasiliensispresented good seed production under conditions of the Colombian dry Caribbean, which constitutes an important characteristic for the selection of promising genotypes for animal feed.

Mineral nutrition is important to determine cattle productivity, for that reason, oral and parenteral mineral supplements promising to improve growth and body development have been introduced to Costa Rica market. The aim of this work was to evaluate the effects of the use of an oral and two parenteral supplements weight and morphology of Bos indicus × Bos taurus heifers. The work was carried out from April 2014 to February 2015, in the Animal Production Farm at Los Diamantes Experimental Station, Guápiles, Costa Rica. 42 heifers, allotted in seven pens, and stratified by weight, received the following treatments: T0 (n=6): common salt + saline solution injection. T1 (n=12): oral mineral supplement (SMO) + injected saline solution. T2 (n=12): SMO + butaphosphan and cyanocobalamin injection. T3 (n=12): SMO + phosphorylcolamine, selenium, iodine and zinc injection. Injections were administered monthly (dose: 1 ml/20 kg BW, intramuscularly administered). Weight and average daily gain were measured monthly, withers height (AC), hip height (ANC), pins width (ANI), body length (LC), transversal pelvian index (IPT) and proportionality (IP) were measured bimonthly. T1 increased ANC one centimetre over T0 (p < 0,001) and T2 increased IP four units over T1 (p=0.009), without differences with T3. In both cases significant time*treatment interactions were detected. Other variables were not affected. Parenteral supplements evaluated did not produce benefits on morphology or weight of heifers, if they received oral mineral supplements.

In adult dairy cattle, rumination patterns have been widely studied and associated with dry matter intake, physical-chemical composition of the diet, estrus, health status and animal welfare. The same does not occur in calves, where available information on rumination time and patterns is very incipient. The objective of this review was to analyze the results obtained in different investigations where the effects of the combination of different feeding programs in calf rearing on the rumination time before and after weaning were evaluated. In addition, growth rate, ruminal environment and animal behavior was analyzed for those treatments that presented greater rumination activity. Seven investigations were considered that recorded rumination, through qualified observers, during the hours after feeding. Rumination time was expressed as a percentage of the total observed time and presented a wide dispersion range between the different nutritional treatments, with values ranging between 2 and 18%. The highest percentages were achieved by supplementing with forages in proportions less than 10-15% of the ration. However, in some investigations, the inclusion of certain forages did not generate effects on rumination time; which suggests that other factors related to the physical-chemical composition of the diet are influencing. In general, animals that presented greater rumination activity showed higher ruminal pH values, concentrate intake and daily weight gain, mainly post-weaning. Consequently, calf rumination time and patterns could be a promising indicator for monitoring feeding, ruminal environment, and animal welfare status. However, in some of the investigations these associations were not found or even a lower concentration of volatile fatty acids was recorded, which could compromise ruminal development.

The high animal densities used in swine production are a challenge to their sanitary status, favoring the spread of diseases. These diseases cause metabolic changes, increasing energy expenditure and shifting nutrients from maintenance, growth and tissue repair towards the immune system. Therefore, the objective of this literature review was to assess the main mechanisms of immune activation in sanitary-challenged pigs and the associated requirements of certain amino acids, in order to consider the immune system as a key part of an effective nutrition. The activation of the immune system induces the release of pro-inflammatory cytokines, which stimulate the synthesis of acute phase proteins. The synthesis of acute phase proteins increases the requirement of certain amino acids. If the requirement of amino acids is above their serum availability, muscle protein catabolism is induced; and the resulting amino acids can be used as energy source and antioxidant precursors. Methionine, threonine and tryptophan are the main amino acids with influence on the immune response to clinical and subclinical diseases. In conclusion, a diet that only supplies maintenance and growth requirements when there is an immunological challenge, without considering the requirements of the immune system, can cause a nutritional deficiency and a reduction in animal performance. Therefore, increasing the supplementation of the amino acids related to the immune system above the recommended ideal protein profile should be evaluated, especially under sanitary stress conditions.

Protein is an essential nutrient in the diet of dairy cows as it provides amino acids for the animal and, at the same time, supplies nitrogen for the rumen microorganisms; therefore, part of the protein available to ruminants comes from microbial protein and dietary sources. In most feeding situations, microbial protein is the primary source of absorbed AA; however, when large amounts of rumen undegradable protein are fed to the animals, microbial protein may not be the primary source. Metabolizable protein is the true protein absorbed as amino acids by the intestine and supplied by microbial protein, endogenous protein and dietary protein that escapes degradation in the rumen. Normally, the concept of crude protein is used; however, this can incur in excess protein that, in addition to being expensive, can cause problems to the animal and the environment, thus the objective of this document is to present an extract of the methodology used by the NRC (2001) model to determine metabolizable protein requirements in dairy cattle. Within the steps, it is required to calculate the maintenance requirement that includes urinary endogenous nitrogen (N), scurf N, fecal metabolic N and endogenous N, and the requirement for milk production. To determine the metabolizable protein contribution of the ration, it is necessary to calculate the amount of total digestible nutrients (TDN) supplied in the ration. Despite the fact that many years have passed since the publication of the nutrient requirements of dairy cattle, and that there are computer programs that perform these calculations, it is intended to detail the way in which the calculations are carried out to make this information more accessible to potential users in Costa Rica and Latin America.

The Metropolitan Area of Bucaramanga -AMB- currently presents a critical situation of mobility generated by different factors whether political, social or territorial, therefore an investment methodology is necessary in terms of road infrastructure that benefits the greatest number of inhabitants possible. This research aims to inform, strengthen, optimize and improve the road conditions present throughout the Colombian territory, showing that with a procedure of road project selection in terms of time, generalized cost of travel and optimization of public resources, it ensures a benefit for the community and not for a private individual. The methodology used was based on the determination of accessibility indices obtained from two scenarios, the current one, (refers to the existing road network in AMB) and the future, (existing road network plus future road projects) modeled through the TransCad software, in which a future road network was obtained that represented savings in Colombian pesos of $ 4.365 million (1,51 million USD)

The lack of territorial planning in the Great Metropolitan Area (GMA) has led to urban growth so dispersed and disordered (Rodríguez, 2017). In addition to this, the inefficient public transport system has caused a dependency on the private vehicle, which generates large costs to the country in economic, social and environmental terms (PEN, 2015). Thus, the main challenge for GAM is to plan land use in conjunction with an efficient transport system. The main proposals for urban development are aimed at joint planning between transport and land use, as well as favouring pedestrian movements (Cardozo, Gutiérrez, & García, 2010). One way of evaluating if the city is planned in terms of mobility is though the TOD (Transit Oriented Development) Standard methodology, which is a tool for assessing whether urban development plans and products adhere to the principles of urban mobility (ITDP, 2017). This article presents the results of a research (Segura, 2019) in which the Standard TOD methodology was applied (ITDP, 2017) to evaluate the area of influence of five bus stops in a section of the San José-Sabanilla-La Campiña mass transit trunk, which is part of the GAM mass transit modernization project. Based on the score obtained, it was determined that the study area was not planned in terms of mobility and were identify some interventions that could significantly improve it. In addition, some recommendations are presented that should be implemented in the planning of the corridor, such as densifying the area, investing in public space and mixed land uses, so that, once the GAM mass transit modernization project is implemented, users will be encouraged to use this system.

Due to the constant increase in the number of road crashes that occur in the country, it was sought to determine the socio-economic characteristics of the population and the variables of land use related to the frequency of road crashes at the district level in the Greater Metropolitan Area (GAM). This will make possible to include road safety criteria in urban planning policies. Statistical models of crash estimation were developed, using the negative binomial distribution based on the land use of the GAM. The socio-economic variables of the population and variables associated with the road network were included. The representative variables in each of the types of crashes analyzed were determined, such as the total population, and the estimation of expected crashes was performed for each of the districts under study. Additionally, the districts with the highest frequency were determined, where the Alajuela district stands out, which proved to be the most problematic. The districts of Heredia, Uruca, Hospital, San Nicolás, Río Segundo, among others, also resulted in significant excesses of crashes.