Sulfur amino acid requirements of broilers from two to five weeks of age

Phase-feeding (PF) in broiler chickens has been researched as a way to reduce feed costs without reducing growth performance and yield. Predicted amino acid requirements for PF are generated using linear regression equations derived from best estimates of lysine (Lys), sulfur amino acid (SAA), and threonine (Thr) requirements. During the late starter and early grower periods, predicted requirements for the SAA methionine (Met) and cysteine (Cys) are higher than levels recommended by the National Research Council (NRC), and previous research suggests that SAA may be lowered during the grower period without sacrificing growth performance or yield. The objective of this study was to estimate Met and Cys requirements for broilers from 2 to 5 weeks of age. In Experiment 1, a Met-deficient corn-peanut meal diet was formulated to contain excess Cys, so that supplemental Met was not utilized for Cys synthesis. The basal diet for Experiment 2 met the Met requirement but was deficient in Cys. Graded levels of Met (0, 0.045, 0.09, 0.135, and 0.225%) and Cys (0, 0.035, 0.070, 0.105, 0.140, 0.175%) were added in Experiments 1 and 2, respectively, and diets were fed to five replicates of five broilers per pen. Broken-line analysis was used to estimate SAA requirements. The digestible Met and Cys requirements from 2 to 5 weeks of age were 0.33% and 0.31%, respectively. Requirement estimates were lower than those predicted by PF or recommended by NRC, indicating that lower SAA levels may be utilized in a PF progra

Further notes on the early stages of Heterocera Bred in the Nakuru District. Series IV.

Volume: XVII

Further notes on the early stages of Heterocera bred in the Nakuru district

Volume: XII

Transport model of nucleon-nucleus reaction

A simplified model of nucleon-nucleus reaction is developed and some of its properties are examined. Comparisons with proton production measured for targets of Al-27, Ni-58, Zr-90, and Bi-209 show some hope for developing an accurate model for these complex reactions. It is suggested that binding effects are the next step required for further development

Miscellaneous notes on the early stages of certain Heterocera

Volume: XII

English names for Kenya Moths

Volume: XXI

Symmetry considerations in the scattering of identical composite bodies

Previous studies of the interactions between composite particles were extended to the case in which the composites are identical. The form of the total interaction potential matrix elements was obtained, and guidelines for their explicit evaluation were given. For the case of elastic scattering of identical composites, the matrix element approach was shown to be equivalent to the scattering amplitude method

Four new Kenya moths

Volume: XX

Second quantization techniques in the scattering of nonidentical composite bodies

Second quantization techniques for describing elastic and inelastic interactions between nonidentical composite bodies are presented and are applied to nucleus-nucleus collisions involving ground-state and one-particle-one-hole excitations. Evaluations of the resultant collision matrix elements are made through use of Wick's theorem

A T-matrix theory of galactic heavy-ion fragmentation

The theory of galactic heavy ion fragmentation is furthered by incorporating a T matrix approach into the description of the three step process of abrasion, ablation, and final state interations. The connection between this T matrix and the interaction potential is derived. For resonant states, the substitution of complex energies for real energies in the transition rate is formerly justified for up to third order processes. The previously developed abrasion-ablation fragmentation theory is rederived from first principles and is shown to result from time ordering, classical probability, and zero width resonance approximations. Improvements in the accuracy of the total fragmentation cross sections require an alternative to the latter two approximations. A Lorentz invariant differential abrasion-ablation cross section is derived which explicitly includes the previously derived abrasion total cross sections. It is demonstrated that spectral and angular distributions can be obtained from the general Lorentz invariant form