Suckling systems in calf rearing in organic dairy farming in the Netherlands

In an on-farm experiment three calf rearing methods were compared: bucket feeding of milk replacer, bucket feeding of tank milk and suckling of mother or nurse cow up to three months of age. Aim was to determine whether the technical results of suckling systems in calf rearing were satisfactory. Calves reared in a suckling system reached significantly higher liveweights at weaning (90 days). Although the average growth rate between weaning and the age of 1 year did not differ significantly, liveweight at 1 year did still differ significantly. Compared to both bucket fed rearing groups, suckling did not have a significant effect on Somatic Cell Count (SCC) of mothers. Suckling systems in calf rearing in organic dairy production show satisfactory technical results. Calves have the potential to grow fast and no negative effect of suckling on SCC or general animal health were observed

Pion-Nucleon Scattering in Kadyshevsky Formalism: II Baryon Exchange Sector

In this paper, which is the second part in a series of two, we construct tree level baryon exchange and resonance amplitudes for $\pi N$ / $MB$-scattering in the framework of the Kadyshevsky formalism. We use this formalism to formally implement absolute pair suppression, where we make use of the method of Takahashi and Umezawa. The resulting amplitudes are Lorentz invariant and causal. We continue studying the frame dependence of the Kadyshevsky integral equation using the method of Gross and Jackiw. The invariant amplitudes, including those for meson exchange, are linked to the phase-shifts using the partial wave basis.Comment: 49 page

Pion-Nucleon Scattering in Kadyshevsky Formalism and Higher Spin Field Quantization

This thesis contains two parts. The first part deals with pion-nucleon/meson-baryon scattering in the Kadyshevsky formalism. This formalism is introduced and discussed. Problems may arise when derivative couplings and/or higher spin fields are used, especially when compared to the results in the Feynman formalism: unwanted contact terms pop-up. These terms are cancelled using the Gross and Jackiw or Takahashi and Umezawa method. The final results in both formalisms are therefore equal, causal and covariant. Formal incorporation of pair suppression in the baryon exchange sector is achieved using a method based on the Takahashi and Umezawa method. For the resulting tree level amplitudes, we have shown, to our knowledge for the first time, that they are causal, covariant and n-independent. Moreover, the amplitudes are just a factor 1/2 of the usual Feynman expressions. The amplitudes contain only posititve energy initial and final states, although it should be mentioned that negative energy is present inside an amplitude via the Delta propagator. The second part of this thesis deals with higher spin field quantization in the framework of Dirac's Constraint analysis. A full constraint analysis and quantization procedure is presented for the free spin 1,3/2 and 2 case and for the situation where these fields are coupled to auxiliary fields. The constructed propagators in the former case are shown to be non-covariant, as is well-known. Therefore, auxiliary fields coupled to gauge conditions of the free case are introduced in the Lagrangian. Now, the resulting propagators are covariant.Comment: 189 page