Effects of total replacement of corn silage with sorghum silage on milk yield, composition, and quality

BACKGROUND: In the last years, difficulties occurring in corn cultivation (i.e., groundwater shortages, mycotoxin contamination) have been forcing dairy farmers to consider alternative silages. Some experiments conducted on lactating cows have proven that the total replacement of corn silage with sorghum silage did not reduce milk yield. However, this kind of substitution involves supplementing sorghum-based diets with grains, to compensate for the lower starch content of sorghum silage compared to corn silage. Change of silage type and inclusion of starch sources in the diet would influence rumen fermentations, with possible effects on milk composition (i.e., fatty acid profile) and coagulation properties. A worsening of milk coagulation properties would have a negative economic impact in Italy, where most of the milk produced is processed into cheese. This study was designed to compare milk composition and quality, with emphasis on fatty acid profile and coagulation properties, in dairy cows fed two diets based on corn or sorghum silage. RESULTS: The sorghum diet reduced milk yield (P = 0.043) but not 4% fat corrected milk (P = 0.85). Feeding sorghum silage did not influence milk contents of protein (P = 0.07) and lactose (P = 0.65), and increased fat content (P = 0.024). No differences emerged for milk concentrations of saturated (P = 0.61) and monounsaturated fatty acids (P = 0.50), whereas polyunsaturated fatty acids were lower (P < 0.001) for the sorghum diet. Concentrations of n-6 (P < 0.001) and n-3 fatty acids (P = 0.017) were lower in milk of cows fed the sorghum diet. Milk coagulation properties did not differ between the two diets, except the “a30” (the curd firmness, expressed in mm, 30 min after rennet addition), that was lower (P = 0.042) for the sorghum diet. CONCLUSIONS: Feeding a forage sorghum silage, properly supplemented with corn meal, as total replacement of corn silage maintained milk composition and did not influence negatively milk coagulation properties, which have a great economic relevance for the Italian dairy industry. Thus, silages obtained from forage sorghums could have a potential as substitute of corn silages in dairy cow diets

Large mixing angle solution to the solar neutrino problem and random matter density perturbations

There are reasons to believe that mechanisms exist in the solar interior which lead to random density perturbations in the resonant region of the Large Mixing Angle solution to the solar neutrino problem. We find that, in the presence of these density perturbations, the best fit point in the (sin^2(2\theta), Delta_m^2) parameter space moves to smaller values, compared with the values obtained for the standard LMA solution. Combining solar data with KamLAND results, we find a new compatibility region, which we call VERY-LOW LMA, where sin^2(2\theta) ~ 0.6 and Delta_m^2~2e-5 eV^2, for random density fluctuations of order 5% < \xi< 8%. We argue that such values of density fluctuations are still allowed by helioseismological observations at small scales of order 10 - 1000 km deep inside the solar core.Comment: References and discussion added, with some small numerical corrections implemente

Quantum Dissipation in a Neutrino System Propagating in Vacuum and in Matter

Considering the neutrino state like an open quantum system, we analyze its propagation in vacuum or in matter. After defining what can be called decoherence and relaxation effects, we show that in general the probabilities in vacuum and in constant matter can be written in a similar way, which is not an obvious result in this approach. From this result, we analyze the situation where neutrinos evolution satisfies the adiabatic limit and use this formalim to study solar neutrinos. We show that the decoherence effect may not be bounded by the solar neutrino data and review some results in the literature. We discuss the current results where solar neutrinos were used to put bounds on decoherence effects through a model-dependent approach. We conclude explaining how and why this models are not general and we reinterpret these constraints.Comment: new version: title was changend and was added a table. To appear at Nucl. Physic.

A new estimate on Evans' Weak KAM approach

We consider a recent formulation of weak KAM theory proposed by Evans. As well as for classical integrability, for one dimensional mechanical Hamiltonian systems all the computations can be explicitly done. This allows us on the one hand to illustrate the geometric content of the theory, on the other hand to prove new lower bounds which extend also to the generic n degrees of freedom case

Effects of magnetohydrodynamics matter density fluctuations on the solar neutrino resonant spin-flavor precession

Taking into account the stringent limits from helioseismology observations on possible matter density fluctuations described by magnetohydrodynamics theory, we find the corresponding time variations of solar neutrino survival probability due to the resonant spin-flavor precession phenomenon with amplitude of order O(10%). We discuss the physics potential of high statistics real time experiments, like as Superkamiokande, to observe the effects of such magnetohydrodynamics fluctuations on their data. We conclude that these observations could be thought as a test of the resonant spin-flavor precession solution to the solar neutrino anomaly.Comment: 16 pages, 3 figure

Slow Solar Magnetosonic Waves And Time Variation In The Solar Neutrino Data

We analyze the perturbations of the solar magnetic field generated by general solar plasma displacements and investigate their consequences in the left-right conversion probability of neutrinos produced in the Sun. We solve the Hain-Lüst equation and the evolution equations of neutrinos interacting with the solar magnetic field through a nonvanishing neutrino magnetic moment to conclude that the appearance of slow magnetosonic waves (with a period around 100 days) simulate the time behavior of solar neutrino data. © 1995.3574602607Davis, (1990) Proc. of the XXI Int. Cosmic Ray Conference, 7, p. 155. , Adelaide, AustraliaHirata, (1991) Phys. Rev. D, 44, p. 2241Anselmann, (1992) Phys. Lett. B, 285, p. 390Abazov, (1991) Phys. Rev. Lett., 67, p. 3332Voloshin, Vysotsky, Okun, (1986) Yad. Fiz., 44, p. 677Voloshin, Vysotsky, Okun, (1986) Sov. J. Nucl. Phys., 44, p. 440Mikheyev, Smirnov, (1986) Nuovo Cimento C, 9, p. 17Mikheyev, Smirnov, (1985) Yad. Fiz., 42Mikheyev, Smirnov, (1985) Sov. J. Nucl. Phys., 42, p. 913Wolfenstein, (1978) Phys. Rev. D, 17, p. 2369Wolfenstein, (1979) Phys. Rev. D, 20, p. 2634Bahcall, Ulrich, Solar models, neutrino experiments, and helioseismology (1988) Reviews of Modern Physics, 60, p. 298Gloedbloed, Sakanaka, New approach to magnetohydrodynamic stability: I. A practical stability concept (1974) Physics of Fluids, 17, p. 908Bernstein, Frieman, Kruskal, Kulsrud, (1958) Proc. Roy. Soc. A, 224, p. 1Hain, Lüst, (1958) Z. Naturforsch., 13 a, p. 936Akhmedov, Bychuk, (1989) Sov. Phys. JETP, 68, p. 250Smirnov, (1991) Phys. Lett. B, 260, p. 161Future Solar Neutrino Experiments (1995) Nuclear Physics B - Proceedings Supplements, 38, pp. 90-95Tatsuka, Superkamiokande (1990) ICCR-Report 227-90-20Chen, (1985) Phys. Rev. Lett., 55, p. 153

Observational Constraints on General Relativistic Energy Conditions, Cosmic Matter Density and Dark Energy from X-Ray Clusters of Galaxies and Type-Ia Supernovae

New observational constraints on the cosmic matter density $\Omega_m$ and an effectively redshift-independent equation of state parameter $w_x$ of the dark energy are obtained while simultaneously testing the strong and null energy conditions of general relativity on macroscopic scales. The combination of REFLEX X-ray cluster and type-Ia supernova data shows that for a flat Universe the strong energy condition might presently be violated whereas the null energy condition seems to be fulfilled. This provides another observational argument for the present accelerated cosmic expansion and the absence of exotic physical phenomena related to a broken null energy condition. The marginalization of the likelihood distributions is performed in a manner to include a large fraction of the recently discussed possible systematic errors involved in the application of X-ray clusters as cosmological probes. This yields for a flat Universe, $\Omega_m=0.29^{+0.08}_{-0.12}$ and $w_x=-0.95^{+0.30}_{-0.35}$ ($1\sigma$ errors without cosmic variance). The scatter in the different analyses indicates a quite robust result around $w_x=-1$, leaving little room for the introduction of new energy components described by quintessence-like models or phantom energy. The most natural interpretation of the data is a positive cosmological constant with $w_x=-1 or something like it.Comment: 11 pages, 5 figures, Astron. Astrophys. (in press