Valoración amperométrica de aminas simpaticomiméticas mediante tetrafenilborato. I. Propiedades físicos y físico-químicas de las sales

Se han obtenido los tetrafenilboratos de cuatro derivados de hidroxifeniletilaminas, cuyos puntos de fusión y espectros UV e IR pueden utilizarse para la caracterización de las aminas originales. Asimismo se han efectuado las valoraciones amperométricas, con ehctrodo de grafito en equipo polarográfico, de cada una de las sustancias.It is attained the tetraphenylboranes of four derivative hidroxyphenylethylamines, wich melting pcint, UV and IR sp.ectres can be used for the characteritation of the origina.! amines. Also it is made amperometric titration of every amine with graphitic electro de in polarographyc connection

Effect of beet pulp on growing performance, digestibility, N balance, and ammonia emission in the heavy pig

A relevant aspect of pig farm units concerning the environmental impact is the ammonia emission from slurries, which is detrimental for animal (and sometimes also for human) welfare. This emission is co-responsible for acid rains, for the increase of bad smells and is detrimental for the respiratory apparatus (Portejoie et al., 2002)

A stretching model to explain the salado basin (Argentina)

Salado Basin, placed in Buenos Aires province, Argentina, is one of the most studiedsedimentary basins of the area because it curiously presents a significative positive residual Bouguer anomaly.Several models were proposed to explain this gravimetric anomaly in the last 50 years. Recently, some worksincorporated geoid undulations, revealing also a positive geoid anomaly over the basin. In this work, wepropose a stretching model in perfect Airy isostatic balance to study the Salado Basin. We make a three-dimensional study of the basin's balance from gravity anomalies and geoid undulations, finding a strongoverbalance on it.Un modelo de estiramiento para la Cuenca del Salado (Argentina) La cuenca del Salado, ubicada en la provincia de Buenos Aires, Argentina, es una de las cuencas sedimentarias más estudiadas del área debido a que curiosamente presenta significativos valores positivos de anomalías de Bouguer. Varios modelos han sido propuestos para explicar esta anomalía de gravedad en los últimos 50 años. Recientemente, algunos trabajos han incorporado las ondulaciones del geoide, revelando también una anomalía de geoide positiva sobre la cuenca. En este trabajo, se propone un modelo de estiramiento en perfecto equilibrio isostático de Airy para estudiar la Cuenca del Salado. Se presenta un estudio en tres dimensiones, en donde el equilibrio de la cuenca se analiza a partir de las anomalías de gravedad y ondulaciones del geoide, encontrando una fuerte sobrecompensación debajo de la misma

Growth and slaughter performance, nitrogen balance and ammonia emission from slurry in pigs fed high fibre diets

The aim of the work was to determine digestibility, nitrogen balance and ammonia emission from excreta, in the typical Italian heavy pig during the last phase of growth, when fed diets with a high fibre content. In comparison with a traditional control diet (C), two diets with 12 and 24% wheat bran (WB12 and WB24) and two other diets with 12 and 24% dried beet pulp (BP12 and BP24) were tested. Totally 76 Landrace x Large White fattening barrows, from 45 to 170 kg live weight distributed in 16 pens, were utilized in the trial. Thirty pigs were allocated to 6 metabolic cages in 5 consecutive periods in order to have 6 observations per treatment. For diets C, WB12 and WB24 daily weight gain (DWG), feed conversion ratio (FCR) and slaughtering performances were also registered, on 20 pigs per dietary treatment. Growing and slaughter performances were similar for pigs fed C and WB12 diets, whilst diet WB24 determined a significant (P<0.05) decrease in performances (growth and feed conversion) in the first period of fattening and a lower dressing percentage at slaughter (85.5, 84.4 and 82.5% for C, WB12 and WB24, respectively). Comparing the diets with the same level of inclusion of the fibrous feeds, WB diets had a lower OM and energy digestibility, while BP diets registered a lower protein but a higher fibre digestibility. Consistently with other experiments, BP diets determined an increase of faecal and a reduction of urinary N, as a percentage of the intake N, as well as a decrease of ammonia emission from the slurries (- 16.6 and -25.3% for BP12 and BP24, in comparison with C diet). For the WB diets the reduction of urinary N and the increase in faecal N were less marked and a reduction of ammonia emissions was not registered

Feeding behaviour, digestibility, energy balance and productive performance of lactating goats fed forage-based and forage-free diets

Six lactating Saanen goats have been used in a Latin Square design to evaluate a grass-based diet (G), a hay-based diet(H) and a nonforage diet (NF). On dry matter, grass and hay contributed for 55% of the diets and had 13.7 and 16.1%CP, 55.4 and 49.4% NDF, 38.0 and 31.6% ADF, respectively. Diet NF had beet pulp, cracked carob beans and whole cottonseedas main ingredients, with more than 75% of the particles greater than 2 mm.Independently of the dietary treatment, the goats spent more time eating than ruminating. Diet NF proved to be effectivein stimulating chewing activity, despite a trend for a lower chewing activity for eating (178, 185, 125 min/kg DMIfor diets G, H and NF, respectively), but not for ruminating (84, 80, 80 min/kg DMI for diets G, H and NF, respectively).Feed intake did not differ among diets, while regarding digestibility diet NF had the highest values for DM (74.1%), OM(75.7%) and non-fibrous carbohydrates (92.0%), but the lowest for ADF (44.5%). For treatments G, H and NF milk yieldswere 3011, 3688 and 3212 g/d (P<0.05 between H and G), while milk fat and protein were respectively 3.37, 3.24,2.96% (P<0.05 between G and NF) and 3.11, 3.32, 3.29%. Milk urea N was lower for diet NF (18.8, 18.6, 12.7 mg/100ml, P<0.001). Diet NF increased the concentration of the short chain fatty acids of milk fat and decreased the content ofC18:0, C18:1 and C18:3 in comparison to the other two diets. No difference among treatments was recorded for CLA.Intake energy was digested to a lesser extent for diet G (68.9, 70.0, 72.7%, P<0.05 between G and NF) due to its poorquality forage. Urinary energy losses reflected the corresponding protein contents of the diets, while no difference wasrecorded for methane production. ME resulted higher for diet NF (60.0, 60.7, 65.1% of the intake energy, P<0.01), whileheat production and milk energy yield were similar in the three treatments. Diet NF had a higher ME content (11.13,11.26, 11.93 MJ/kg DM, P<0.05), while no significant difference among the diets was recorded in terms of kl (0.64, 0.70,0.69) and NEl (7.20, 7.93, 8.30 MJ/kg DM).It is concluded from the study that a nonforage diet with an adequate amount of structured fibre could substitute a rationbased on poor quality forage in lactating goats; however, good forage seems to enhance milk performance to a greaterextent

Effects of constant vs variable dietary protein content on milk production and N utilization in dairy cows.

Forty-two lactating Holstein cows were divided into two groups, control (C) and test (T), and used in a cross-over design. In each group cows were also divided in three subgroups on the basis of milk yield: low (L), medium (M) and high (H). C cows were fed a diet with 15.4% CP on DM. T cows were fed three diets with the CP content (% DM) adjusted to milk yield (13.6, 15.2 and 17.2 for diets TL, TM and TH). At the highest level of production TH diet improved milk yield (kg/d) (38.9 C vs 41.0 TH) and FCM (kg/d) (39.6 C vs 40.6 TH) (P<0.05). No differences were detected for TL and TM diets compared to C. For L and H subgroups milk urea (mg/dl) was increased by the higher CP diets (28 C vs 24 TL; 30 C vs 36 TH; P<0.05). N efficiency (milk N, %N intake) was higher with lower CP diets (22 C vs 25 TL; 32 C vs 29 TH) and for increased milk yield. An adequate CP content of the diet enhances milk production in high yielding dairy cows, but an excessive amount of dietary N increases milk urea and N excretion

Nutritive value of different hybrids of sorghum forage determinedin vitro

Eight hybrids of sorghum forage were tested in large plots of two farms in two consecutive years to evaluate their chemical characteristics, nutritive value and yield as a possible substitute for maize silage. Two or three cuts were made depending on climatic conditions. On forage samples taken at ensiling chemical analyses and 24 h gas production were performed, to predict the NEl content. In comparison with maize silage, the sorghum hybrids registered higher protein (13.7% on DM) and NDF (62.6% on DM) contents. Interestingly, the fibre fraction had a low lignin content (3.1% on DM). NEl content ranged from 4.53 to 5.28 MJ/kg DM, the latter for the hybrid with the lowest NDF content. Hybrid effect was significant for ash, NDF, ADF and NEl contents, whilst cut effect was significant for EE, CP, NDF and ADF. Yield was strongly influenced by fertilisation; when the latter was applied, it was in the range of 10-18 t DM, 1.7-2.8 t CP and 47-88 thousand MJ NEl per hectare, as a sum of the 2- 3 cuts. Sorghum forage seems to be a possible alternative to the fibrous maize silage fraction in diets of lactating cows, and an excellent forage for the rations of dry cows and heifers

Prediction of the nutritive value of maize silage using in vitro and near infrared reflectance spectroscopy (NIRS) techniques

Maize silage is by far the most used forage in the diets for dairy cows and beef cattle in a large part of the Po plain, Italy. However, its chemical composition and its nutritive value range widely according to the genotype and to the climatic and agronomic conditions, particularly with regards to the plant maturity at harvest

Determinación de Hidroxifeniletanolaminas mediante formación de Ditiocarbamatos de Cobre (II)

A colorimetric method for the assay of hydroxyphenylethanolamines is proposed. The reaction of amines with carbqn disulfide is utilized as a basis for their analysis.Se ha estudiado, por método espectrofotométrico, la posibilidad de valorar hidroxifeniletilaminas haciendo uso de la reacción coloreada que tiene lugar al tratarlas con S2C, para formar el ácido ditiocarbámico, y su posterior complejación con Cu(II)

Tannin treated lucerne silage in dairy cow feeding

The effects of the addition of tannins to lucerne silage were investigated. At ensiling, chestnut hydrolyzable tannins were added to lucerne forage (T=tannins treated lucerne silage vs C=control lucerne silage). Fifty lactating Holstein cows, fed two diets different for lucerne silage treatment (C or T), were used in a cross-over design. In situ rumen soluble protein fraction (%CP) was higher for C (67.9 vs 59.4; P<0.01), whereas potentially rumen degradable protein (%CP) was lower (24.5 vs 32.1 for C and T; P<0.01). Intestinal rumen escape protein digestibility (%) was numerically higher for T (48.3 vs 54.3). Dry matter intake (21.5 kg/d for both diets) and milk yield (29.8 and 30.2 kg/d for C and T) were not affected by dietary treatment, whereas FCM was slightly higher for T diet (27.5 vs 27.9 kg/d for C and T; P<0.10). Adding tannins to lucerne silage is effective in shifting part of N utilization from the rumen to the intestine, leading to similar productive performance in lactating cows