Steigerung des Gehaltes an nutzbarem Protein bei Körnerleguminosen mittels ökologisch konformer technischer Bearbeitungsverfahren zur Förderung von Gesundheit und Leistungsfähigkeit von Hochleistungskühen im ökologischen Landbau

Ziel dieses Projekts war durch ökologisch konforme Behandlungsmethoden den Anteil an pansenstabilem Protein bei Körnerleguminosen zu erhöhen, um so einem Defizit an nutzbarem Rohprotein am Dünndarm vorzubeugen. Dafür wurde die thermische Behandlung von Erbsen, der Zerkleinerungsgrad von Lupinen und die Wirkung zweier Ackerbohnensorten mit unterschiedlichem Tanningehalt untersucht. Es konnten z.T. positive Effekte bei den in vitro und in situ Untersuchungen nachgewiesen werden, die sich jedoch wenig auf die tierische Leistung auswirkten. Durch die Hitzebehandlung von Erbsen konnte eine Steigerung der Milchleistung um 1,36 kg erreicht werden, ohne Rückgang der Milchinhaltsstoffe. Es zeigte sich jedoch, dass dieser Leistungsanstieg eher auf eine bessere Energieverfügbarkeit zurückzuführen war. So ergab sich beim in situ Rohproteinabbau nur eine geringe Reduzierung der Abbaubarkeit durch die Behandlung. In vitro erhöhte sich der Anteil an pansenstabilem Protein, der Gehalt blieb jedoch insgesamt niedrig. Bei unterschiedlichem Zerkleinerungsgrad von Lupinen wurden Milchleistung und Milchinhaltsstoffe kaum beeinflusst und auch in den Stoffwechselversuchen zeigten sich nur geringe Unterschiede. Die Verdaulichkeit der Rohfaser war bei der Ration mit den gequetschten Lupinen höher, was u.a. an besseren Bedingungen für die zellulolytischen Bakterien gelegen haben mag durch den im Vergleich höheren und stabileren pH-Wert. Bei dem Vergleich zweier Ackerbohnensorten zeigte sich ein starker Einfluss der Sortenwahl auf das Pansenmilieu der Kühe, welches bei der Ration mit der tanninhaltigen Sorte Samba stabiler war. Dennoch waren Milchleistung und Fettgehalt für beide Rationen gleich. Es kam dagegen zum Anstieg des Eiweißgehalts bei der tanninfreien Sorte Valeria und der insgesamt hohe Harnstoffgehalt der Milch war bei der Sorte Valeria signifikant erhöht

Role of physically effective fiber and estimation of dietary fiber adequacy in high-producing dairy cattle

Highly fermentable diets require the inclusion of adequate amounts of fiber to reduce the risk of subacute rumen acidosis (SARA). To assess the adequacy of dietary fiber in dairy cattle, the concept of physically effective neutral detergent fiber (peNDF) has received increasing attention because it amalgamates information on both chemical fiber content and particle size (PS) of the feedstuffs. The nutritional effects of dietary PS and peNDF are complex and involve feed intake behavior (absolute intake and sorting behavior), ruminal mat formation, rumination and salivation, and ruminal motility. Other effects include fermentation characteristics, digesta passage, and nutrient intake and absorption. Moreover, peNDF requirements depend on the fermentability of the starch source (i.e., starch type and endosperm structure). To date, the incomplete understanding of these complex interactions has prevented the establishment of peNDF as a routine method to determine dietary fiber adequacy so far. Therefore, this review is intended to analyze the quantitative effects of and interactions among forage PS, peNDF, and diet fermentability with regard to rumen metabolism and prevention of SARA, and aims to give an overview of the latest achievements in the estimation of dietary fiber adequacy in high-producing dairy cattle. Recently developed models that synthesize the effects of both peNDF and fermentable starch on rumen metabolism appear to provide an appropriate basis for estimation of dietary fiber adequacy in high-producing dairy cows. Data suggest that a period lasting more than 5 to 6h/d during which ruminal pH is <5.8 should be avoided to minimize health disturbances due to SARA. The knowledge generated from these modeling approaches recommends that average amounts of 31.2% peNDF inclusive particles >1.18mm (i.e., peNDF(>1.18)) or 18.5% peNDF inclusive particles >8mm (i.e., peNDF(>8)) in the diet (DM basis) are required. However, inclusion of a concentration of peNDF(>8) in the diet beyond 14.9% of diet DM may lower DM intake level. As such, more research is warranted to develop efficient feeding strategies that encourage inclusion of energy-dense diets without the need to increase their content in peNDF above the threshold that leads to lower DM intake. The latter would require strategies that modulate the fermentability characteristics of the diet and promote absorption and metabolic capacity of ruminal epithelia of dairy cows

Cross section and analyzing power of pol{p}p -> pn pi+ near threshold

The cross section and analyzing power of the pol{p}p -> pn pi+ reaction near threshold are estimated in terms of data obtained from the pol{p}p -> d pi+ and pp -> pp pi0 reactions. A simple final state interaction theory is developed which depends weakly upon the form of the pion-production operator and includes some Coulomb corrections. Within the uncertainties of the model and the input data, the approach reproduces well the measured energy dependence of the total cross section and the proton analyzing power at a fixed pion c.m. angle of 90deg, from threshold to T_p = 330 MeV. The variation of the differential cross section with pion angle is also very encouraging.Comment: 20 pages, Latex including 4 eps figure

On the close to threshold meson production in neutron-neutron collisions

A method of measuring the close to threshold meson production in neutron-neutron collisions is described where the momenta of the colliding neutrons can be determined with the accuracy obtainable for the proton-proton reaction. The technique is based on the double quasi-free nn --> nn X^0 reaction, where deuterons are used as a source of neutronsComment: 6 pages, 2 figures, to be published in Phys. Lett.

Measurement of p + d -> 3He + eta in S(11) Resonance

We have measured the reaction p + d -> 3He + eta at a proton beam energy of 980 MeV, which is 88.5 MeV above threshold using the new ``germanium wall'' detector system. A missing--mass resolution of the detector system of 2.6% was achieved. The angular distribution of the meson is forward peaked. We found a total cross section of (573 +- 83(stat.) +- 69(syst.))nb. The excitation function for the present reaction is described by a Breit Wigner form with parameters from photoproduction.Comment: 8 pages, 2 figures, corrected typos in heade

Forward K+ production in subthreshold pA collisions at 1.0 GeV

K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.Comment: 4 pages, 3 figure

Also at National Accelerator Centre, Faure, South Africa On leave from ICUF

Abstract A stack of annular detectors made of high-purity germanium was developed. The detectors are position sensitive with radial structures. The first one (&quot;Quirl&quot;) is double-sided position sensitive defining 40 000 pixels, the following three (E1, E2 and E3) have 32 wedges each. The Quirl acts as tracker while the other three act as calorimeter. The stack was successfully operated in meson production reactions close to threshold