STUDIES ON ENERGY AND NITROGEN-METABOLISM OF PREGNANT AND LACTATING SOWS AND SUCKLING PIGLETS .4. CHEMICAL-COMPOSITION AND ENERGY CONTENT OF THE CONCEPTION PRODUCTS, THE REPRODUCTIVE-ORGANS AS WELL AS THE LIVEWEIGHT GAINS OR LOSSES OF PREGNANT AND LACTATING SOWS

The chemical composition and the energy content of the conception prod ucts, the reproductive organs and the live weight gains or losses of p regnant and lactating sows were determined in dependence on the litter number (1, 2 and 4) and the energy supply (120, 100 and 80% of requir ement recommendation) of sows as well as on the course of gestation an d lactation. The results will be used as a basis for factorial derivat ion of requirement recommendation. The deposition of protein and energ y in the conception products in dependence on the time is characterize d by an exponential function. The deposition of nutrients and energy i n the conception products is increased with rising litter size. The de position of nutrients and energy per fetus is lower in the litter numb er 1 than in the litter number 2 and 4. The energy supply in the selec ted limits has no significant influence on the litter size as well as on the intrauterine deposition of nutrients and energy. The litter num ber, the energy supply as well as the course of gestation and lactatio n influence considerably the weight, the chemical composition and the energy content in the mammary gland. The chemical composition and the energy content of the live weight gains or losses of pregnant and lact ating sows are strong affected by the energy supply. The increased ene rgy supply of the pregnant sows is connected with increased live weigh t gains and with increased contents of dry matter, fat and energy howe ver decreased contents of protein in the live weight gains. The live w eight losses of the lactating sows are connected with mobilisation of body Fat and body protein, The proportion of body fat to body protein degradation is increased with increased losses of body weight. Regress ion equations are calculated for the relationships between course of g estation and lactation respectively and deposition of protein and ener gy in the conception products, reproductive organs and maternal live w eight gains or losses of sows.