Juan Manuel Pinos-Rodríguez

Quantitative characterization of nonstructural carbohydrates of mezcal Agave (Agave salmiana Otto ex Salm-Dick).

Fructans are the reserve carbohydrates in Agave spp. plants. In mezcal factories, fructans undergoes thermal hydrolysis to release fructose and glucose, which are the basis to produce this spirit. Carbohydrate content determines the yield of the final product, which depends on plant organ, ripeness stage, and thermal hydrolysis. Thus, a qualitative and quantitative characterization of nonstructural carbohydrates was conducted in raw and hydrolyzed juices extracted from Agave salmiana stems and leaves under three ripeness stages. By high-performance liquid chromatography (HPLC), fructose, glucose, sucrose, xylose, and maltose were identified in agave juice. Only the plant fraction with hydrolysis interaction was found to be significant in the glucose concentration plant. Interactions of the fraction with hydrolysis and ripeness with hydrolysis were statistically significant in fructose concentration. Fructose concentration rose considerably with hydrolysis, but only in juice extracted from ripe agave stems (early mature and castrated). This increase was statistically significant only with acid hydrolysis.

Effects of different sources of fructans on body weight, blood metabolites and fecal bacteria in normal and obese non-diabetic and diabetic rats.

Fructans contribute significantly to dietary fiber with beneficial effects on gastrointestinal physiology in healthy individuals and offer a promising approach to treating some diseases. Two experiments (Experiment 1 = rats with normal weight; Experiment 2 = obese rats) were developed to compare the effects of three fructan sources (Cichorium intybus L. Asteraceae, Helianthus tuberosus L. Asteraceae and Agave angustifolia ssp. tequilana Haw, Agavaceae) on body weight change, blood metabolites and fecal bacteria in non-diabetic (ND) and diabetic (D) rats. In Experiment 1 total body weight gain and daily feed intake in D and ND rats decreased (P < 0.05) with supplements of fructan. Only in D rats, blood glucose concentrations, fecal Clostrodium spp. counts, and liver steatosis decreased, while blood HDL concentrations and fecal Lactobacillus spp. and Bifidobacterium spp. counts increased due to fructans. In Experiment 2, total body weight gain and feed intake in ND and D rats were also decreased by fructans. In ND rats, fructan decreased blood glucose concentrations. In D rats, fructans from A. angustifolia ssp. tequilana decreased blood cholesterol and LDL and liver steatosis. For both ND and D rats, fecal Lactobacillus spp. and Bifidobacterium spp. counts were higher (P < 0.05) with fructan supplements.

Effects of a slow-release coated urea product on growth performance and ruminal fermentation in beef steers

The objective of this study was to evaluate the effects of a slow-release coated urea product (CU, 1% as dry matter of diet) on ruminal disappearance and fermentation, as well as on growth performance of beef steers. Soybean meal in control diet was replaced by CU and steam-rolled corn. For the growth performance trial, 20 beef steers (330±20 kg) were used. For the ruminal trial, four ruminally cannulated steers (230±20 kg) were used. Dry matter intake, daily gain, feed efficiency and carcass dressing were not affected (P>0.05) by CU. Ruminal ammonia N was higher (P<0.05) with CU than control diet. Potential disappearance and total ruminal disappearance of dry matter were increased, while the potential disappearance rate of neutral detergent fibre was reduced with CU. Slow coated urea at 1% of total diet did not affect growth performance and carcass dressing of beef steers.

Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens.

Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host–pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host–pathogen interactions.

Influence of exogenous fibrolytic enzymes on in vitro and in sacco degradation of forages for ruminants

An in vitro assay was carried out to evaluate the effects of exogenous fibrolytic enzymes (1, 2, 3 and 4 g/kg DM) powder preparation containing xylanase and cellulase from Aspergillus niger and Trichoderma viride on DM, NDF and ADF degradation of alfalfa hay, corn silage, corn stover, elephant grass, Guinea grass and oat straw. Kinetics data of in vitro degradations were analyzed. The potentially degradable fraction and degradation rate of NDF and ADF of alfalfa increased quadratically (P<0.05) as the inclusion level of enzyme increased up to 3 g. The others forages were not affected by the enzyme. An in sacco trail was performed using four Holstein steers fitted with ruminal cannulas to evaluate the effects of the exogenous fibrolytic enzymes (3 g/kg DM) on DM, NDF and ADF degradation of alfalfa hay and corn stover. Kinetics data were also analyzed. The potentially degradable fraction degradation of NDF (62.0 vs 65.7%) and ADF (52.8 vs 56.9%), of alfalfa hay were increased (P<0.05) by the exogenous fibrolytic enzymes, but no differences were found for corn stover. These results suggest that the enzymes increased in vitro and in sacco fibre degradation only for alfalfa hay.

Chemical and Digestibility Characteristics of Some Woody Species Browsed by Goats in Central Mexico

Abstract Pinos-Rodriguez, J.M., Aguirre-Rivera, J.R., Mellado, M., García-López, J.C., Álvarez-Fuentes, G., Méndez-Villazana, J.C. 2007. Chemical and digestibility characteristics of some woody species browsed by goats in Central Mexico. J. Appl. Anim. Res., 32: 149–153. A study was conducted during fall in Central Mexico to determine the chemical composition, the in situ disappearance and rate of in situ fermentation of ten common woody species used by goats in a semi-humid landscape. Leaves of Parkinsonia aculeata, Pithecellobium dulce, Ceratonia siliqua, Leucaena glauca, Crataegus pubescens, Calliandra eriophylla, Dalea bicolor, Eysenhardtia texana, Atriplex canescens and Amelanchier denticulata were analyzed. Dry matter (DM), crude protein (CP) and ash content of fodder tree leaves ranged between 29.3 and 63.9, 8.5 and 28.2 and 3 and 18.9, respectively. Both acid detergent fiber (21–47%) and neutral detergent fiber (56.4–81.2%) contents were high. DM disappearance of shrubs and trees was in the range 48–85%, with the highest (P<0.05) disappearance rate at all incubation time for Atriplex canescens, Pithecellobium dulce and Leucaena glauca. These data reaffirm the considerable potential of Atriplex canescens, Leucaena glauca and Pithecellobium dulce as high quality forages for ruminants.

Effects of exogenous fibrolytic enzymes on in sacco and in vitro degradation of diets and on growth performance of lambs

This study evaluated the effects of doses of exogenous fibrolytic enzymes (enzyme) on in vitro (IVD) and in sacco degradation (ISD) of dry matter (DM) and neutral detergent fibre (NDF) of diets with 70% concentrate (as DM), as well as their effects on growth performance in lambs. A gas production technique was used to determine IVD. Six ruminally cannulated lambs in a replicated 3×3 Latin Square were used to determine ISD. Three diets (treatments) added with enzyme (0, 3 and 6 g enzyme/kg DM) were evaluated for IVD and ISD. For the growth assay, 48 lambs (17.6±2.5 kg of body weight) fed on two diets with 0 or 3 g enzyme/kg DM were used. There were linear increases of gas production rate as enzyme level in the diets increased. At 48 h of fermentation, there were quadratic increases of IVD as enzyme level increased in the diets. A quadratic change was observed in volatile fatty acids and ammonia N as enzyme was increased in the diet. At 12 h, the highest enzyme level (6 g) increased ISD of DM as compared with the control. There was a quadratic effect on the disappearance rate as enzyme level in the diet increased. Exogenous fibrolytic enzymes improved IVD degradation and fermentation characteristics as well as ISD rate of DM, but there were not any effect of these enzymes on ISD of NDF of diets and growth performance of finishing lambs.

Effects of rumen-protected methionine on milk production of dairy goats

Abstract Twelve lactating Saanen goats were fed with a total mixed ration (forage:concentrate 67:33) and directly supplemented (administered orally) with 0, 2.5 and 5.0g/head/day of rumen-protected methionine (RPM) for 30d. Body weight was not affected by RPM. There were quadratic (P<0.05) effects on milk yield, fact-corrected milk, energy-corrected milk and milk protein as RPM increased; thus, the highest values of milk yield, fact-corrected milk, energy-corrected milk and milk protein were observed with 2.5g of RPM. Percentage of fat increased quadratically (P<0.05) as RPM doses increased, while fat expressed as grams per day was not affected with RPM. It was possible to improve milk production and milk protein in dairy goats with a daily supplemented dose of 2.5g of RPM. Further studies with more animals should be developed.

Use of “Maguey” (Agave salmiana Otto ex. Salm-Dick) as Forage for Ewes

Abstract Pinos-Rodríguez, J.M., Aguirre-Rivera, J.R., García-López, J.C, Rivera-Miranda, M.T., González-Muñoz, S., López-Aguirre, S. and Chávez-Villalobos, D. 2006 Use of “maguey” (Agave salmiana Otto ex. Salm-Dick) as forage for ewes. J. Appl. Anim. Res., 30: 101–107. Nutritive value of various parts of maguey (Agave salmiana) was estimated. Results suggest that heads of nine months old castrate maguey showed a better nutrient composition. On sheep feeding trial, body weight (BW) gain was observed to be larger (P<0.05) for ewes fed chopped bagasse as compared to whole ones. In another trial, ewes were fed whole maguey, upper portion maguey leaves or immature flowering stalk, plus concentrate (300 g/ewe); BW gain was larger (P<0.05) for ewes fed flowering stalk (quiotes), as compared to those fed whole maguey, and ewes showed no digestive problems. Maguey bagasse and quiotes with little supplemental concentrate constitute maintenance ration for sheep.

Influence of fibrolytic enzymes on growth performance and digestion in steers grazing stargrass and supplemented with fermented sugarcane

An experiment was conducted to evaluate the influence of exogenous fibrolytic enzymes on growth performance and digestion in steers grazing stargrass and supplemented with concentrate and sugarcane fermented. Solid state fermentation of sugar cane (SSFSC) was whole sugarcane chopped, added (dry matter basis) with urea (1.5%) and mineral premix (0.5%), and kept under shadow for 24 h. Twenty crossbreed (Brahman × Brown Swiss) steers (287±14.1 kg) grazing stargrass were individually supplemented with SSFSC (free access for 1-h period) and concentrate (1 kg/head) by 100 d. Steer were randomly assigned to concentrate with 0, 15 or 30 g fibrolytic enzyme/kg concentrate. As enzyme level increased, daily gain, intake, digestion, and improved feed conversion were linearly improved.