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A study was carried out for two years in Northwest Quintana Roo, México, using scat analysis to determine the diet and prey preferences of pumas and jaguars. Cat species and gender were determined using molecular techniques (rapid classificatory protocol: polymerise chain reaction, RCP–PCR), and prey abundance was estimated from camera trapping. The scats contained remains from 16 wild mammal species, but there was no evidence of livestock or other taxa. The diet breadths of jaguar (0.32) and puma (0.29) indicated a high degree of prey specialization, which combined with their dietary overlap (Pianka index 0.77) suggested competition between them. However, both felids showed a preference for red brocket deer Mazama temama, and frequently consumed collared peccaries Pecari tajacu. The importance of such large ungulates in the felids’ diets is similar to the expected patterns of wild meat consumption in rural areas of the Northern Yucatan Peninsula. Therefore, future conservation management plan initiatives should involve local rural communities in the management of sustainable hunting, considering these ungulates are also the felid prey species.

Copyright of Arquivo Brasileiro de Medicina Veterinaria e Zootecnia is the property of Universidade Federal de Minas Gerais, Escola de Veterinaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eight Holstein steers (216±48 kg body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked cornbased finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous 4×4 Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect (p≥0.48) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected (p=0.27). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steamflaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However, microbial N flow to the small intestine and ruminal N efficiency (non-ammonia N flow to the small intestine/N intake) were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal pH and total VFA concentration were not affected (p= 0.16) by corn processing method. Compared with dry rolled corn, steam-flaked corn-based diets resulted in decreased acetate:propionate molar ratio (p = 0.02). It is concluded that at 7% or 14% straw inclusion rate, changes in physical characteristics of wheat straw brought about by pelleting negatively impact OM digestion of both steam-flaked and dry-rolled corn-based finishing diets. This effect is due to decreased postruminal starch digestion. Replacement of ground straw with pelleted straw also may decrease ruminal pH. [ABSTRACT FROM AUTHOR]

The new electricity industry is evolving in market activities. The first electricity market models considering only one traded commodity: energy. All the supportive services, ancillary services (SA), were imputed in the energy price. Currently, the supportive services are clearly defined. In some electricity markets concurrent spot markets exist for some of the supportive services. In an unbundled electricity market, Generation Companies (GenCos) may participate in the provision of different services. Two concurrent spot markets are considered in this paper: energy and spinning reserve. Optimal self-scheduling for a GenCo is formulated in a real options framework. In the context of electricity producing firms, real options approach (ROA) can be used as a method of identifying and quantifying the contingent decisions embedded in owning generation assets. It enhances the potential to improve greatly the effectiveness of operating decisions and to unlock hidden assets. The bids for reserve are submitted on a day-to-day basis. The bids consist of a capacity and energy price. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Medicina Veterinaria is the property of Universidad Austral de Chile, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to evaluate the effects of slow-release α-amylase in ruminal in vitro digestion of maize and sorghum grains. Digestibility was measured using an in vitro procedure with 40 mL of buffer and 10 mL of ruminal fluid, flushed with CO2 and incubated at 39 °C. The digestibility of sorghum and maize grain was measured after 6 and 12 hours of fermentation with or without exogenous α-amylase in powder form or dispersed in a matrix system for slow release by a diffusional mechanism. Tablets were used as the drug release matrix system, and were formulated with barium sulphate and ethylcellulose as the core of the final tablet. Treatments consisted of incubation of sorghum or maize grains with four doses of enzyme, using a-amylase in powder or in the press-coated tablet (16 treatments). The results showed that with a higher dose of exogenous enzyme, the digestibility of the grains was improved. Sorghum and maize digestion with tablets were improved compared with a-amylase in powder form. Releasing a-amylase from matrix tablets represents a potential technology to improve grain digestion in ruminants. [ABSTRACT FROM AUTHOR]

Se realizó análisis de sensibilidad del modelo de balance calórico para bovinos. Los factores relacionados con la radiación (horas de exposición a la radiación solar) fueron de mayor influencia en la carga calórica estimada. El consumo de energía, peso vivo y temperatura del bulbo húmedo tuvieron menor efecto. El resto de las variables influyeron poco en el resultado del modelo. La estimación del modelo original resultó en una carga calórica excesiva (de 9.8 a 16.9 Mcal/d), lo que es poco viable biológicamente, por lo que se modificó el modelo en términos de radiación solar de acuerdo con la hora del día. Una vez modificado, las estimaciones estuvieron en el rango de 1.3 a 4.8 Mcal/d, lo que es más probable desde el punto de vista biológico. [ABSTRACT FROM AUTHOR]

A sensibility analysis of the model of caloric balance was performed in cattle. The factors related to the radiation (sun radiation exposure hours) were of greater influence on the estimated caloric load. The intake of energy, the liveweight, and the temperature of the humid bulb had lower effect. The rest of the variables had little effect on the outcome of the model. The estimation of the original model resulted in an excessive caloric load (from 9.8 to 16.9 Mcal/d), which was little viable biologically, thus, the model was modified in terms of sun radiation according to the day time. Once modified, the estimations were within the range from 1.3 to 4.8 Mcal/d, which was more likeable from the biological point of view. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Medicina Veterinaria is the property of Universidad Austral de Chile, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Para conocer el efecto del nivel de sustitución del suplemento por el bagacillo de retorno, fermentado en estado sólido y ensilado, en el comportamiento de vaquillas en crecimiento en el trópico, se utilizaron 18 vaquillas Bos taurus x Bos indicus (230 ± 40 kg peso vivo). Se alojaron en corraletas individuales, en un diseño completamente al azar con tres combinaciones de suplemento: ensilado 100:0, 50:50 y 0:100 %. Durante el ensayo (90 d) se registró la ganancia diaria de peso (GDP), consumo de materia seca (MS) y conversión alimentaria. La GDP tuvo efecto cuadrático (P < 0.01) y mostró la mejor respuesta en la combinación 50:50 (0.58, 0.74 y 0.46 kg/d), mientras que la conversión se afectó (cuadrático, P < 0.01) al incrementar la proporción de ensilado (12.18, 10.33 y 16.04). No se encontraron diferencias en el consumo de MS para las combinaciones 100:0, 50:50 y 0:100 % (7.07, 7.65, 7.38 kg/d), respectivamente. Se concluye que con la sustitución de 50 % del suplemento por el BRFESE hay mejor comportamiento de las vaquillas en crecimiento en el trópico, con la utilización de dietas basadas en caña de azúcar con urea al 1 %. [ABSTRACT FROM AUTHOR]

In order to know the effect of the supplement level substitution by return bagasse, fermented in solid state and ensiled, on the performance of growing cows in the tropics, eighteen Bos taurus x Bos indicus cows were used (230 ± 40 kg liveweight). They were allocated in individual pens, in completely randomized design with three supplement combinations: silage 100:0, 50:50, and 0:100 %. During the assay (90 d), daily weight gain (DWG), dry matter intake (DM), and feed conversion were recorded. DWG had quadratic effect (P < 0.01) and showed the best response in the 50:50 combination (0.58, 0.74 and 0.46 kg/d), whereas the conversion was affected (quadratic, P < 0.01) by increasing the rate of silage (12.18, 10.33 and 16.04). No differences were found in the DM intake for the 100:0, 50:50, and 0:100 % combinations (7.07, 7.65 and 7.38 kg/d), respectively. It was concluded that, with the substitution of 50 % of the supplement by RBFSSE, there is better behavior in growing cows in the tropics, using sugarcane diets with 1 % urea. [ABSTRACT FROM AUTHOR]

This work was carried out in order to understand the acceptance of whole sugarcane grass in the diet of grazing adult cattle with rumen and duodenal fistula. The animals were placed in pens and a test of acceptance was carried out. African star grass (Cynodon plectostachyus) and sugarcane (Saccharum officinarum) mixed with 1 % of urea were offered at will separately. Food composition, dry matter intake, and rumen and duodenal pH were measured. Arithmetic mean and standard error were used as descriptive statistics techniques. The protein, cell wall and hemicellulose contents were higher for star grass. DM intake was 46.6% and 38.1% for sugar cane and grass, respectively. Rumen pH showed values between 7.3 and 6.7 after 12 hours. The pH of the duodenal digest ranged from 3.7 to 4.7. We concluded that there was greater acceptance for sugarcane and the rumen pH does not indicate values that affect the degradation of cellulose in the rumen. [ABSTRACT FROM AUTHOR]