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

Sheep farming is important because of the growing demand and the benefits it generates. However, to boost its productivity, it is required to know its business characteristics. The objective of the research was to explain the environment in which production takes place and to define the main business models, to specify their development prospects. A semi-structured interview was applied to 32 companies. To analyze the profile of the producer and the production unit, descriptive statistics was used and to typify the companies depending on their business model, a cluster analysis was used. It was found that, due to the proximity to large urban centers, production is located in a peri-urban area with high demand for resources such as land and water, participates in a short-circuit commercial chain and producers carry out the activity in a complementary way. Under this context, three business models were identified: i) the traditional, which offers animals without differentiated attributes, without making productive and commercial improvements, which develops the activity in an inertial way and without prospects for improvement; ii) the intermediate, which shows greater willingness to apply technical, commercial and managerial knowledge, due to the schooling of its producers; and iii) the specialized, where a better productive management is carried out, offering high-value products. It is concluded that, to boost productivity, it is necessary to take into account the business model and the environment, because only once the needs of the market are met, producers will improve their competitiveness.

Flow cytometry is a technology that has helped to rapidly advance many diverse areas of science by allowing the simultaneous measurement of multiple characteristics of each of the individual particles or cells in a sample as they pass at high speed through an area illuminated by one or more lasers. The information obtained includes data on the size and internal complexity, as well as other parameters inherent to each of the particles present in the sample, which are captured by the equipment as light signals. The most common particles analyzed in flow cytometers are cells, so the expression of molecules on their surface and inside, viability, functionality, cell proliferation, DNA content, cytokine production and many others can be analyzed. These determinations can be carried out by using antibodies coupled to fluorochromes or by using molecules whose fluorescence depends on the characteristic to be evaluated. Some flow cytometers are also sorters, which means that the equipment can physically sort those cells that exhibit the characteristics of interest; in addition, it is feasible that once they have been purified, they can be used in subsequent experiments. This review focuses on the fundamentals of flow cytometry and its main applications, which offer a great window of opportunity in the veterinary field, both in research and in the clinic.

Backyard egg production provides food and extra income to rural families. The resulting eggs are produced under conditions analogous to organic eggs, suggesting the possibility of a price premium for backyard eggs. The contingent valuation method was applied in a willingness-to-pay study of backyard eggs in four locations in the State of Mexico, Mexico. Results of a survey of 126 heads-of-household was analyzed using a binomial logit model. Most (70 %) interviewees were willing to pay a premium of 25 % for backyard eggs over the price for commercial eggs. The most significant variables were health awareness, fruit and vegetable consumption, monthly income and age. In the study area, backyard eggs could be sold at a premium price, potentially providing greater income to the rural families producing them.

The objective of this study was to compare the effect of the patent vs. generic sources of zilpaterol hydrochloride (ZH) on the productive performance, carcass characteristics, primary cut yields, and meat quality of lambs finished in feedlot. Thirty (30) Dorper×Pelibuey male lambs were distributed into 10 blocks, each with three lambs of similar initial live weight which were randomly assigned to the following treatments: 1) without ZH (control), 2) with patent ZH (PZH), and 3) with generic ZH (GZH). Treatment means were compared through two orthogonal contrasts: control vs. ZH (PZH+GZH) and PZH vs. GZH. ZH did not affect (P≥0.15) the productive performance, carcass weight, backfat thickness, or fat percentages (kidney-pelvic-heart, mesenteric or omental), but increased (P≤0.05) Longissimus dorsi muscle area and yields of carcass, shoulder, leg, and plain loin. As for the meat quality, ZH did not affect (P≥0.24) pH and shear force, but reduced (P<0.05) redness, yellowness, and chroma color values at 24 h post mortem, as well as the redness value (P<0.01) at 14 days of aging. With exception of carcass yield which tended (P=0.07) to increase with PZH, all measured variables were similar (P³0.14) between PZH and GZH. It has been concluded that both types of ZH at a dose of 0.10 mg per kg of live weight promote muscular hypertrophy in finishing lambs; however, this dosage is not sufficient to result in a better productive performance or carcass weight.

Silvopastoral systems (SPS) are an alternative for sustainable livestock production. For this reason, the present study was developed with the aim of evaluating productive and nutritional parameters of the forage component (FC) in different silvopastoral arrangements with Alnus acuminata and their comparison with open field systems. A randomized complete block design was established, for which 16 plots with characteristics of homogeneity in age and type of FC were selected. The floristic composition, functional classification of herbaceous species, biomass, dry matter and nutritional composition were evaluated. The results obtained recorded the presence of 22 species, with the family Poaceae (8 species) predominating, it was also found that silvopastoral arrangements have the highest percentage of desirable species, a situation contrary to what happened in open field systems. On the other hand, the productive and nutritional parameters showed significant differences (P<0.05) between the production systems, being the arrangement with trees in alleys the one that registered better yields of biomass (16.60 t /ha), dry matter (3.65 t/ha), crude fiber (27.23 %), total protein (17.39 %) and gross energy (4,864 kcal/kg).

Wild white-tailed deer Odocoileus virginianus consume a diversity of high energy plants. Captive deer, however, do not have access to this diversity, which may affect their productive capacity. A cafeteria test was used to evaluate intake of and preference for eight plant species among captive deer in Veracruz, Mexico. Three replicates were done of five consecutive days of feeding with the selected plants followed by a 15-d evaluation period. One kilogram of material from each plant species was offered each day and intake recorded. Physicochemical analyses were done of all eight species. Intake results were evaluated with an analysis of variance and a Tukey test, and a partial least squares regression analysis was applied to relate intake to plant characteristics. Intake was highest for four plants: Zapoteca acuelata, Bidens pilosa, Pennisetum purpureum and Parthenium hysterophorus. Preference for these species was determined by their fiber and protein contents, and °Brix and pH levels. Diversifying the diet of captive deer could provide additional feed options for producers and increase animal productivity parameters.

The species that make up the genus Chlamydia affect a wide range of animal hosts, causing various pathologies. Chlamydia abortus (C. abortus), Chlamydia psittaci (C. psittaci) and Chlamydia pecorum (C. pecorum) are the most clinically relevant in small ruminants worldwide, since they have been related to reproductive, ocular and digestive tract problems respectively; two of these (C. abortus and C. psittaci) represent a potential zoonotic risk to humans. The diagnosis of infections by organisms of this genus is complicated; since, in most cases, there are no clinical signs that indicate the presence of the agent in affected animals. Currently, in European countries, the prevention and control mainly of C. abortus is carried out through the administration of commercial attenuated immunogens; however, their use has not shown satisfactory results in the protection of susceptible animals. Therefore, the implementation of new immunization options based on the utilization of recombinant proteins is the line of research that is currently taking the most prominence. Additionally, the use of proteins with immunogenic potential could be important tools for the diagnosis, prevention and control of these pathogens. Due to this, the present review focused on recapitulating the most current studies focused on the experimental use of different immunogenic proteins of Chlamydia spp. used worldwide, highlighting their innovation and results obtained in experimental models.

The use, as well as the productive and economic effect of herbal compounds on rabbit production has been little studied, for this reason, the objective was to evaluate the effect of a polyherbal mixture rich in choline conjugates based on Trachyspermum ammi, Achyranthes aspera, Azadirachta indica and Citrullus colocynthis, on the economic and productive response of meat rabbits. For this, 40 New Zealand X California rabbits (30-d old) were used, which were randomized into five groups (0.0, 200, 400, 600 and 800 mg kg-1 of polyherbal DM, BioCholina®), the experiment lasted 34 days. The productive response, meat quality and economic indicators were evaluated. A completely randomized design with an arrangement of orthogonal polynomials was used to determine linear and quadratic effects, with a significance level of P<0.05. The results in terms of production parameters were similar between treatments, except for feed consumption (P=0.006) and feed conversion (P=0.005) with a linear effect at higher concentration of the polyherbal. The inclusion of the polyherbal increased pH in meat (linear, P=0.004) and coordinate b* (linear, P=0.009), it was observed that the treatment with 200 mg showed the best economic indicators, improving the income-expense ratio by 9 percentage units. It is concluded that the addition of polyherbal mixtures based on natural choline conjugate did not improve the productive variables, however, a favorable economic trend is marked with the addition of 200 mg kg-1 of DM.

The objective was to evaluate the hygienic behavior (HB) of Africanized honeybees (Apis mellifera) and its impact on resistance to ascospherosis caused by Ascosphaera apis. The HB and the population of adult bees and brood of 50 colonies were evaluated. In addition, colonies with high (>95 %) and low (<50 %) HB were inoculated with A. apis and in them, the number of broods with signs of ascospherosis (mummies) was determined for 17 days, data that correlated with their degree of HB. The susceptibility to A. apis of larvae from colonies with high and low HB in a common environment was also evaluated to separate environmental from genotypic effects. The degree of HB between colonies varied significantly (CV>36 %), with 20 % of the colonies showing high HB (≥95 %) and this did not correlate with the population of adult bees and brood. Colonies with high HB had significantly fewer mummies than colonies with low HB and there was a negative correlation between HB and number of mummies (r= -0.63, P= 0.02). In addition, larvae from colonies with high or low HB were equally susceptible to the fungus. These results suggest that HB and larval susceptibility are not associated and that the main protection mechanism against A. apis in Africanized bee populations is HB. Therefore, the selection of colonies with high hygienic behavior could contribute to improving the health and productivity of honeybees.

Consecuentemente con las transformaciones registradas en Europa después de 1948, año de la creación de la Organización Europea de Co­operación Económica, al 30 de septiembre de 1961 se acordó sustituir dicha institución, por una nueva denominada Organización de Coopera­ ción y de Desarrollo Económico (OCDE). Durante los años siguientes a la Segunda Gran Guerra, los países europeos se encontraron frente a una carencia de medios económicos imprescindibles para su reconstrucción, y la OECE se propuso como meta la coordinación de los diferentes países de la zona, con miras a lograr un crecimiento de la producción industrial y agrícola y a estable­cer un amplio mercado en el cual se pudiesen intercambiar libremente los bienes y servicios. Para hacer frente a la insuficiencia de medios de pago internacionales, la OECE, creó la Unión Europea de Pagos, sis­tema original de compensación de deudas y de créditos. Por lo que toca a las restricciones que se imponían al intercambio comercial europeo de esa época, hay que señalar que la OECE adoptó un Código de Liberalización que permitió reducir de una manera considerable, la impor­ tancia y vigencia de tales restricciones; este Código de Liberalización realizó una labor persistente y efectiva a tal punto, que actualmente se cuentan ya bastantes años desde su abolición. Como efecto indirecto, se puede citar que la Unión Europea de Pagos fue reemplazada en 1958, por el Acuerdo Monetario Europeo.