R Köhler — Page 8 | PubMed Health

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[Evaluation of the energy concentration of feed mixtures for poultry based on the chemical analytical data].

Based on data material available for 33 feed mixtures, several regression equations were developed which make the estimation of energy concentration (EC) on the basis of the content of crude nutrients possible. The values received from the various equations were compared with those resulting from digestibility experiments with colostomized male and female chickens. An estimation equation is recommended resulting from the regressions for the digestibility of the individual crude nutrients: EC = 0.604 X crude protein content + 2.045 X crude fat content + 0.901 X crude carbohydrate content-158.3.

Animal Feed↗

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[The determination of the rate of protein synthesis of the whole body of growing broilers].

The purpose of the investigations was to prove a method, developed for monogastric mammalians, based on a 3-compartment-model and assuming a proportional growth of the pools of total N, whether it is applicable to growing poultry. The tracer, 15N-L-lysine, was given quasi-continuously for four days. In this time and in the following period of five days without tracer intake, the 15N-excretion in the urine was measured. The average of the live weight of the broiler cockerels was 1724 g. The animals were obliged to be colostomized to sample the urine. Using the fluxes of lysine, the calculation of the whole body protein synthesis rate yields 64.1 g/d. The protein degradation rate yields 54.4 g/d. The adequate values of the fractional rates of protein synthesis and -degradation for the whole body (without feathers) were 23.3% respectively 19.8%. By this it is clearly shown, that the applied method gives real dates of the parameters of the N-metabolism for growing broilers, which are in the range of values for muscle proteins and proteins of the whole body of growing poultry, published by other authors.

Animal Feed↗