GRAZING MANAGEMENT STRATEGIES ADAPTED TO DAIRY CATTLE ON PASTURE IN THE ECUADORIAN SIERRA

The Ecuadorian inter-Andean valley maintains large agricultural areas called haciendas whose main activity is milk production, surrounding these, we find small and medium producers also considered ranchers. Although both are oriented towards the same markets and implement a clear trend towards intensive production systems, they show a marked difference in the dynamics of productive activity despite sharing similar constraints in term namely of altitude and marked slopes for their pastures. To enhance productive yields, the most extensive and effective application of improved management is sought for by farmers. Options to reach this objective include the composition of herds, the size of the paddocks, the stocking rate and resting times of the meadows, the use of fertilizers, an efficient combination between agricultural crops and pasture renewal and stoking management methods, the latter being possibly one low cost short-term action lever to act upon in order to potentiate dairy farming productivity. However, it is difficult to predict the efficiency and profitability of such efforts, particularly when there is such a distant economic and cultural gap between ranchers in the same country. To the best of our knowledge, the link between grazing management and milk productivity has not been documented in high-relief situations. Our thesis aims to analyze the impact of stocking management methods on the productive performance of grazing cows, in intensive milk production in the Ecuadorian highlands. In addition to analyzing the influence of the relief in the decision making for the conformation of paddocks, in the context of different degrees of slope on the properties. We hypothesized that a grazing management system can be found that is better adapted to the organizational practices of dairy systems in the Ecuadorian tropical highlands, as well as identify some practices that better compensate for the detrimental effects of slopes on animal productivity. To do this, first, 42 milk-producing farms were characterized in different cantons of the rural area of the province of Pichincha (Quito, Mejía, Rumiñahui and Cayambe) of Ecuador. Through a questionnaire to identify the productive and management activities in the herds and evaluate the average slope of the pastures of the farms based on GIS data. The results showed that the farms had an average area of 40 ha, the herds were composed of 60 ± 63 milking cows, predominantly of the Holstein Friesian breed (65 %), and the daily production of cows in milk reached 15.1 ± 3.4 kg. The highest productivity was found in the farms using rotational stocking with high intensity of instantaneous grazing with very short occupation times (< 12 h), cultural tasks in the meadows (reseeding, resting time, equalization cuts, soil aeration, fertilization, manure dispersion) and a flat topography of the pastures (p < 0.05). The steepness of the slopes was not a limitation to establish pastures for grazing animals since pastures were observed in the entire range of slopes, including very steep ones (up to 55 %). The daily production of individual cows was negatively correlated (r = - 0.323, p = 0.037) with the average slope of the surveyed farms. Subsequently, we conducted two grazing experiments to determine the ingestive behavior of dairy cows, under the types of pasture rotation mostly used by farmers in the survey (from rotational stocking with long occupation time to grazing with very short occupation times of 3 hours), to test the relevance of rotations with shorter occupation times on the performance of the system. A first experiment was done on flat paddocks applying three rotational stocking contrasting treatments ranging from very short to long occupation times: three hours, 24 hours and seven days respectively of 7 days. Cows in the long occupancy time treatment spent more time eating, tended to have a higher average speed during forage intake, attributed to a greater displacement per exploration of the entire area assigned for the experimentation time. In the 3-h treatment, greater inactivity was perceived in anticipation of the opening of new areas for grazing during the day. Despite these differences in activity, milk production did not differ in quantity or quality (ie, fat, protein, non-fat solids, total solids). Showing that under grazing conditions with an intermediate forage allocation on flat paddocks and with low producing cows, the application of a labor-intensive stocking method that requires opening new areas every 3 hours does not lead to a significant increase in the production. Next, we carried out a second grazing experiment in which two stocking methods (long occupancy and very short occupation) on a terrain with moderate relief and with up and downhill displacement of cows on the pastures to harvest the forage. Results showed that cows that grazed the very short time treatment moved more during meals than those placed in the long occupation time treatment. This is explained by the fact that the sub-paddocks 3 hours were designed horizontally to favor lateral walking and avoid the effect of the slope on displacement. While the herd that had freedom of movement throughout the paddock (long occupation time), traveled less (-27 %), leaving higher stubble height in postgrazing (7 cm). Higher volumes and concentration in solids were found in milk for the herd that grazed in the treatment with assignment of new subpaddocks every three hours. In conclusion, the combination of grazing management systems with operations that better compensate for the detrimental effects of slopes promote productive yields in dairy farms in the Ecuadorian highlands. The allocation of forage material must be based on a rotation with occupation times that adjust to the slope of the paddocks. Avoiding the unnecessary use of human and economic capital where it does not justify the implementation of shorter rotation times (flat paddocks), guaranteeing the optimization of resources, higher volumes and better quality of the milk produced. Finally, farmers can manage their agricultural processes using the proposals developed in this research according to the resources available in their environment

EFECTO DE LA SUPLEMENTACIÓN CON LEVADURA DE CERVEZA (Saccharomyces cerevisiae) Y PROMOTORES EN LA GESTACIÓN Y RECRÍA DE CUYES (Cavia porcellus)

En Tumbaco, Pichincha a 2460 m.s.n.m., se evaluó el efecto de la suplementación alimenticia con sistemas nutricionales constituidos por la combinación de: levadura de cerveza (Saccharomyces cerevisiae), Indumix (mezcla mineral y vitamínica) y A-V 25 (complejo vitamínico con antibiótico) durante las etapas de gestación y recría de cuyes (Cavia porcellus). Se utilizó un diseño completamente al azar, el número de tratamientos fueron ocho, durante la etapa de gestación se utilizaron de cuatro a cinco animales por tratamiento y durante la etapa de recría se utilizaron cuatro animales machos y cuatro animales hembra por tratamiento que fueron seleccionados al azar. Las Variables analizadas fueron: incremento de peso, incremento de longitud, conversión alimenticia, consumo de balanceado, consumo de forraje,mortalidad, peso de los gazapos al nacer y análisis financiero. Durante la etapa de gestación no se presentó significancia estadística en incrementos de peso; durante la etapa de recría en gazapos machos, el tratamiento que alcanzó mayor incremento de peso y longitud fue t7 (Testigo + Levadura de cerveza + Indumix + A-V 25) con 821 g/cuy y 11,92 cm/cuy respectivamente; para el caso de gazapos hembras, el mejor tratamiento fue t7 (Testigo + Levadura de cerveza + Indumix + A-V 25) con incremento de peso de 816,5 g/cuy y un incremento de longitud de 11,80 cm/cuy . Finalmente la mejor Relación Beneficio/Costo tuvo el tratamiento t7 (Testigo + Levadura de cerveza + Indumix + A-V 25) y t6 (Testigo + Indumix + A-V 25) con un valor de 1,13 USD,B/C. // In Tumbaco, Pichincha, at 2460 meters above sea level,we assessed the effect of food supplementationwith nutritional systems constituted by the combination of: brewer’s yeast (Saccharomyces cerevisiae), Indumix (mineral and vitamins mix) and A-V 25 (vitamin complex with an antibiotic) during the gestation and rearing stages of guinea pigs (Cavia porcellus). A completely randomized design was used, with eight treatments; 4 to 5 animals were used per treatment during the gestation stage, and 4 male and 4 female subjects were used per treatment for the rearing stage; these animalswere selected randomly. The variables analyzed were:weight-gain, length increase, food conversion, concentrate consumption, fodder consumption, mortality, weight of newborns and financial analysis. There was no statistical significance during the gestation stage for weight-gain; during the rearing stage in male pups, the treatment with highest weight-gain and length increase was t7 (Control + brewer’s yeast + Indumix + A - V 25) with 821,00 g/guinea pig and 11,92 cm/guinea pig, respectively; for female pups, the best treatment was t7 (Control + brewer’s yeast + Indumix + A - V 25) with a weight-gain of 816,50g/guinea pig and length increase of 11,80 cm/guinea pig. The best Benefit/Cost ratio corresponded to t7 (Control + brewer’s yeast + Indumix + A -V 25) and t6 (Control + Indumix + A - V 25), with a B/C ratio of 1.13 USD

Analysis of the nutritional and productive behaviour of dairy cows under three rotation bands of pastures, Pichincha, Ecuador

This research was carried out on Pennisetum clandestinum-based pastures to identify the effect of three (3) types of stocking methods with similar forage allowance (8.2 kg of dry matter for 100 kg of live weight) but differing by the occupation times of the rotations (3 h, 24 h, and continuous) on the behaviour and the production of dairy cows. The experimental scheme consisted in three herds of four Holstein Friesian cows grazing three paddocks, one per rotationtype, for one week and replicated three times in a cross-over design. Pasture height and biomass were measured before and after each grazing week and on a daily basis, two cows per herd were monitored during daytime with activity sensors and their milk production was recorded. The main results showed that in all treatments the cows reduced the height of the sward by 40% on average. The cows in the continuous treatment spent more time in meals and tended to have higher average speed during the day than in the 3-h rotation ascribed to a higher exploration of the whole gradable area every day in the continuous treatment and to more time idling animals in the 3-h treatment in anticipation of the opening of new areas to graze over the course of day. Despite those difference in activity, milk production did not differ neither in quantity with an average of 12.4 0.14 kg per day, nor in quality (i.e., fat, protein, non-fatty solids, total solids). We conclude that under our grazing conditions with an intermediate forage allowance and low producing cows, applying a labour intensive stocking method requiring to open new areas every 3 hours does not lead to a significant production increase

Low dose of sublingual immunotherapy in patients with allergic rhinitis in a randomized double-blind placebocontrolled study

Background: Few placebo controlled studies for sublingual immunotherapy (SLIT) have been performed so far in Latin America, and some issues like treatment scheme and doses remain uncertain Objective: to asses improvement in nasal, pharyngeal and ocular symptoms with low doses of SLIT to Dermatophagoides pteronyssinus comparing it with a placebo, in a Mexican population with allergic rhinitis (AR). Methods: a prospective, double-blind placebo-controlled, randomized study, with 32, patients with chronic, moderate to severe AR; 16 patients were treated with SLIT and 16 with placebo for 6 months with a total dose of D. pteronyssinus (Der p1) of 50.4 mcg. Nasal, pharyngeal and ocular symptoms were monitored using a symptoms diary to evaluate the degree of improvement and reduction in the use of medication. Results: Significant lower symptom and drug scores were found in SLIT group where 85% of patients showed clinical improvement. On the placebo group, 24% of patients improved and 76% had no response or worsened; 94% of patients on SLIT required less symptomatic medication compared with the placebo group. There was a reduction in positivity to cutaneous test to D. pteronyssinus in 50% of the patients on SLIT, whereas placebo patients remained all positiv

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

Biodigestores, alternativa energética y fertilización ecológica, como tecnología vigente

Biodigestores, alternativa energética y fertilización ecológica, como tecnología vigent

Activités et production de méthane des bovins au pâturage

Quels sont les liens entre les comportements des bovins et les caractéristiques de la prairie sur la dynamique de production de méthane (CH4)?AgriGES funded by an ARC grant for Concerted Research Actions, financed by Wallonia-Brussels Federatio