Farm Animal Metabolism and Nutrition

investigated were high and the steps between successive dietary concentrations were large. On the other hand, chick liver Mn con ...

Kirchgessner, 1991). Thus, it appears that Fe is unique among the essential trace elements in that endogenous excretion by eithe ...

absorption in humans vary between 53 and 98%, and absorption by ruminants is some- what lower, between 11 and 46%. Homeostatic r ...

complexities of whole-body metabolism. A fairly complete picture of the dynamics of Zn metabolism in young rats receiving defici ...

Kreuzer, M. and Kirchgessner, M. (1991) Endogenous iron excretion: a quantitative means to control iron metabolism? Biological T ...

Windisch, V.W. and Kirchgessner, M. (1994) Distribution and exchange of zinc in different tissue fractions at deficient and exce ...

Part II Feed Evaluation Methodologies ...

Chapter 9 Use of Near Infrared Reflectance Spectroscopy J.B. Reeves III Nutrient Conservation and Metabolism Laboratory, Livesto ...

region (Murray and Williams, 1987). Since NIR absorptions are weaker, longer path- lengths can be used for liquids (particularly ...

sample, it is necessary to develop a calibra- tion for the determination of solid feed composition by NIRS. However, the two pro ...

case of NIRS) involved in finding a calibra- tion equation for the constituent of interest. The field of using multivariate stat ...

is tilting from left to right, also resulting in incorrect absorbance values, but, in this case, the error varies in intensity f ...

those things which commonly cause prob- lems is shown in Table 9.1. While any of these factors can vary from one sample to the n ...

reduced by deliberately including the varia- tion in the calibration; the difficult problem lies in the nature of the samples th ...

and probably the best requires scanning all the samples first, and then choosing samples on the basis of their spectral differen ...

contained several forages, treated with different levels of manure and collected at four or five cuttings over a 2-year period. ...

regression analysis and calibration valida- tion and testing) are available for analysing NIR data. Data exploration Once a set ...

developing a calibration, which can some- times result in improved calibrations. Also, some chemometric procedures, such as Neur ...

calibration spectra and data, which are based partially on random correlations and not true chemical/spectral relationships, or ...

sample left out once) with the sample left out used as the validation set. The results are used to estimate the prediction error ...