Replacing maize silage with hydroponic barley forage in lactating water buffalo diet: impact on milk yield and composition, water and energy footprint, and economics.

This study investigated the feasibility of integrating hydroponic barley forage (HBF) production into dairy ruminant production, focusing on its effect on milk yield and components, energy and water footprints, and economic implications. Maize silage (MS) was used as a benchmark for comparison. The research was conducted on a water buffalo dairy farm equipped with a fully automated hydroponic system producing approximately 6,000 kg/d of HBF as fed (up 1,000 kg/d on DM basis). Thirty-three lactating water buffaloes were assigned to 3 dietary treatments based on the level of MS or HBF in the diet: D0 (100% MS), D50 (50% MS and 50% HBF), and D100 (100% HBF). The feeding trial lasted 5 weeks plus a 2-week adaptation period during which each cow underwent a weighing, BCS scoring, recording of milk yield and components, including somatic cell count and coagulation characteristics. Based on the data obtained from the in vivo study, the water and energy footprints for the production of MS and HBF and buffalo milk, as well as income over feed cost, were evaluated. Complete replacement of MS with HBF resulted in a slight increase in milk yield without significant impact on milk component. The resource footprint analysis showed potential benefits associated with HBF in terms of water consumption. However, the energy footprint assessment showed that the energy ratio of HBF was less than 1 (0.88) compared with 11.89 for MS. This affected the energy efficiency of milk yield in the 3 diets, with the D50 diet showing poorer performance due to similar milk yield compared with D0, but higher energy costs due to the inclusion of HBF. The production cost of HBF was about 4 times higher than that of farm-produced MS, making feed costs for milk yield more expensive. Nevertheless, HBF can potentially improve income over feed costs if it increases milk yield enough to offset its higher production costs. Overall, the results suggest that the current practice of using HBF to replace high quality feedstuffs as concentrates is likely to result in energy and economic losses.

Two-Color Radiation Generated in a Seeded Free-Electron Laser with Two Electron Beams.

We present the experimental evidence of the generation of coherent and statistically stable two-color free-electron laser radiation obtained by seeding an electron beam double peaked in energy with a laser pulse single spiked in frequency. The radiation presents two neat spectral lines, with time delay, frequency separation, and relative intensity that can be accurately controlled. The analysis of the emitted radiation shows a temporal coherence and a shot-to-shot regularity in frequency significantly enhanced with respect to the self-amplified spontaneous emission.

Two color free-electron laser and frequency beating.

We review the theory of two color high gain free-electron laser emission, derive the integral equation characterizing the evolution of the optical intensities, and provide a description of the relevant dynamics. The characteristic feature of this regime is the existence of a mutual bunching, whose origin and role are discussed.

Observation of time-domain modulation of free-electron-laser pulses by multipeaked electron-energy spectrum.

We present the experimental demonstration of a new scheme for the generation of ultrashort pulse trains based on free-electron-laser (FEL) emission from a multipeaked electron energy distribution. Two electron beamlets with energy difference larger than the FEL parameter ρ have been generated by illuminating the cathode with two ps-spaced laser pulses, followed by a rotation of the longitudinal phase space by velocity bunching in the linac. The resulting self-amplified spontaneous emission FEL radiation, measured through frequency-resolved optical gating diagnostics, reveals a double-peaked spectrum and a temporally modulated pulse structure.

High-order-harmonic generation and superradiance in a seeded free-electron laser.

Higher order harmonic generation in a free-electron laser amplifier operating in the superradiant regime [R. H. Dicke, Phys. Rev. 93, 99 (1954).] has been observed. Superradiance has been induced by seeding a single-pass amplifier with the second harmonic of a Ti:sapphire laser, generated in a ß-Barium borate crystal, at seed intensities comparable to the free-electron laser saturation intensity. Pulse energy and spectral distributions of the harmonics up to the 11th order have been measured and compared with simulations.

Self-amplified spontaneous emission free-electron laser with an energy-chirped electron beam and undulator tapering.

We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a self-amplified spontaneous emission mode free-electron laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. An increase of more than 1 order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.

High-gain harmonic-generation free-electron laser seeded by harmonics generated in gas.

The injection of a seed in a free-electron laser (FEL) amplifier reduces the saturation length and improves the longitudinal coherence. A cascaded FEL, operating in the high-gain harmonic-generation regime, allows us to extend the beneficial effects of the seed to shorter wavelengths. We report on the first operation of a high-gain harmonic-generation free-electron laser, seeded with harmonics generated in gas. The third harmonics of a Ti:sapphire laser, generated in a gas cell, has been amplified and up-converted to its second harmonic (λ(rad)=133 nm) in a FEL cascaded configuration based on a variable number of modulators and radiators. We studied the transition between coherent harmonic generation and superradiant regime, optimizing the laser performances with respect to the number of modulators and radiators.

Bradykinin potentiating and sensitizing activities of new synthetic analogues of snake venom peptides.

The structural requirements for prolonged residual ("sensitizing") activity in bradykinin-potentiating peptides (BPP's) were investigated through a study of seven synthetic BPP's including three not previously described: [Lys6]-BPP9a, [Gly6]potentiator B, and [Lys6,Gln8]potentiator B. The quantitation of the sensitizing activities in the isolated guinea pig ileum indicated that the structural requirements for bradykinin potentiation and for sensitization were not the same. The most potent sensitizers were potentiator B and [Lys6]-BPP9a.

Effect of stretching on the sensitivity of the guinea pig ileum to bradykinin and on its modification by bradykinin potentiating peptides.

The sensitivity of the guinea pig isolated ileum to bradykinin, but not to other agonists, was increased ca. 2-fold during the 3-4 h following mounting of the preparation under 1 g load. Concomitantly, a decrease was observed in the bradykinin potentiating effect of BPP9a, and of potentiator B but not potentiator C. This decrease was observed only with analogues of BPP9a or potentiator B which retained one or both of the basic amino acid residues in these peptides. Similar stretching of the rat isolated uterus did not affect bradykinin sensitivity or the potency of bradykinin potentiating peptides. Kininase activity of the ileum significantly increased during the 4 h period after mounting of the loaded preparation, but was not affected by treatment with BPP9a. It is proposed that bradykinin sensitivity is favoured by the changes in sodium and potassium transport in the cell membrane caused by stretching of the ileum, and that a similar mechanism may be partly responsible for the action of bradykinin potentiating peptides.

Efficiency to reach age of puberty and behaviour of buffalo heifers (Bubalus bubalis) kept on pasture or in confinement.

In order to evaluate the influence of rearing system (free-ranging (FR) v. confinement (C)) on buffalo heifer efficiency to reach age of puberty and on behavioural and immune functions, two experiments were conducted from September 2010 to October 2011. In Experiment I, 32 subjects aged 8 to 9 months at the start of experiment were used. A total of 16 animals (group C) were group housed in an indoor slatted floor pen (4 m2/animal) with an outdoor paddock (4 m2/animal); 16 others grazed on a Mediterranean natural pasture of 40 ha (group FR). Behavioural data were collected and organic matter digestibility, blood metabolites and progesterone were determined. At the end of the experiment, a novel object test and a skin test were conducted, and the avoidance distance (AD) at the manger was measured. Free-ranging animals were able to express natural behaviours such as wallowing and grazing. C animals devoted more time to the novel object than FR animals, whereas AD at manger was lower in group FR than in group C (P<0.01). Cellular immune response was higher in FR heifers than in C animals (P<0.01). FR animals also showed a higher digestibility of organic matter (P<0.01). Heifers from group FR had higher plasma concentrations of non-esterified fatty acids (P<0.001) and lower concentrations of glucose than heifers from group C (P<0.001). C animals showed higher daily weight gains (P<0.01) and weight at the puberty (P<0.05), but there were no differences in terms of age of puberty between the two groups. The intakes of dry matter (DM), CP and energy to reach the age of puberty were similar in both groups. In order to verify whether the results obtained in Experiment I could be replicated in different rearing conditions (reduced pasture availability, different location and altitude), a second experiment was conducted on 26 animals, where only onset of age of puberty and metabolic profile were monitored. In Experiment II, 13 heifers grazed on a natural pasture of 5 ha, other 13 received the same space as indicated for Experiment I. Results from Experiment II generally confirmed those of Experiment I. Only the intakes of DM and energy to reach the age of puberty were higher in group C than in FR (P<0.001). A lower competition with human nutrition, reproductive performances similar to those shown by confined animals and the indications given by immune and behavioural variables, suggest that a free-range-based system may be conveniently used for buffalo heifer farming purposes.