In 23 litters, each with 10 or 11 piglets, the energy and nitrogen metabolism was measured on base of 218 body analyses in suckling piglets and on base of 96 total metabolism experiments in early weaned piglets, combined with 134 body analyses. The studies were carried out as part of a complex experimental program for the factorial derivation of energy and protein requirement of piglets and for measuring the milk production of lactating sows. The energy maintenance requirement of suckling piglets (sow's milk nutrition, I) and of early weaned piglets (sow's milk replacement on the basis of cow's milk, II) amounted to 468 (I) and 451 kJ (II) metabolizable energy per kg LW(0.75) . d, th, Utilization of metabolizable energy for energy deposition to 70 (I) and 72% (II). With mean live weight gains (LWG) of 161 and 162 g per animal and day the cost per kg LWG amounted to 19.9 and 20.4 MJ gross energy, 19.3 and 19.4 MJ metabolizable energy as well as 14.4 and 14.2 MJ net energy-fat in suckling and early weaned piglets resp. The mean energy content of the LWG amounted to 8.9 (I) and to 7.9 MJ/kg (II).

In 23 litters, each with 10 or 11 piglets, the energy and nitrogen metabolism was measured on base of 218 body analyses in suckling piglets and on base of 96 total metabolism experiments in early weaned piglets, combined with 134 body analyses. The studies were carried out as part of a complex experimental program for the factorial derivation of energy and protein requirement of piglets and for measuring the milk production of lactating sows. The energy maintenance requirement of suckling piglets (sow's milk nutrition, I) and of early weaned piglets (sow's milk replacement on the basis of cow's milk, II) amounted to 468 (I) and 451 kJ (II) metabolizable energy per kg LW0.75 . d, the utilization of of metabolizable energy for energy deposition to 70(I) and 72% (II). With mean live weight gains (LWG) of 161 and 162 g per animal and day the cost per kg LWG amounted to 19.9 and 20.4 MJ gross energy, 19.3 and 19.4 MJ metabolizable energy as well as 14.4 and 14.2 MJ net energy-fat in suckling and early weaned piglets resp. The mean energy content of the LWG amounted to 8.9 (I) and to 7.9 MJ/kg (II).

The chemical composition and the energy content of the conception products, the reproductive organs and the live weight gains or losses of pregnant and lactating sows were determined in dependence on the litter number (1, 2 and 4) and the energy supply (120, 100 and 80% of requirement recommendation) of sows as well as on the course of gestation and lactation. The results will be used as a basis for factorial derivation of requirement recommendation. The deposition of protein and energy in the conception products in dependence on the time is characterized by an exponential function. The deposition of nutrients and energy in the conception products is increased with rising litter size. The deposition of nutrients and energy per fetus is lower in the litter number 1 than in the litter number 2 and 4. The energy supply in the selected limits has no significant influence on the litter size as well as on the intrauterine deposition of nutrients and energy. The litter number, the energy supply as well as the course of gestation and lactation 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 lactating sows are strong affected by the energy supply. The increased energy supply of the pregnant sows is connected with increased live weight gains and with increased contents of dry matter, fat and energy however decreased contents of protein in the live weight gains. The live weight 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. Regression equations are calculated for the relationships between course of gestation and lactation respectively and deposition of protein and energy in the conception products, reproductive organs and maternal live weight gains or losses of sows.

The chemical composition and the energy content of the conception products, the reproductive organs and the live weight gains or losses of pregnant and lactating sows were determined in dependence on the litter number (1, 2 and 4) and the energy supply (120, 100 and 80% of requirement recommendation) of sows as well as on the course of gestation and lactation. The results will be used as a basis for factorial derivation of requirement recommendation. The deposition of protein and energy in the conception products in dependence on the time is characterized by an exponential function. The deposition of nutrients and energy in the conception products is increased with rising litter size. The deposition of nutrients and energy per fetus is lower in the litter number 1 than in the litter number 2 and 4. The energy supply in the selected limits has no significant influence on the litter size as well as on the intrauterine deposition of nutrients and energy. The litter number, the energy supply as well as the course of gestation and lactation 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 lactating sows are strong affected by the energy supply. The increased energy supply of the pregnant sows is connected with increased live weight gains and with increased contents of dry matter, fat and energy however decreased contents of protein in the live weight gains. The live weight 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. Regression equations are calculated for the relationships between course of gestation and lactation respectively and deposition of protein and energy in the conception products, reproductive organs and maternal live weight gains or losses of sows.

The energy and nitrogen metabolism of pregnant sows was measured with the method of indirect calorimetry in dependence on the number of gestation (1,2 and 4), on the energy supply (120, 100 and 80% of the requirement recommendation) and on the gestation stage. Values of maintenance requirement and of energy and nitrogen utilization for body deposition were calculated on the basis of results of energy and nitrogen metabolism. The energy maintenance requirement increased from 389 to 435 and 473 kJ metabolizable energy per kg LW0.75.d with rising number of gestation. The heat production increased from 85th to 115th day of gestation by 6%. The efficiency of the partial energy utilization for the energy deposition amounted to 66% on the average. The efficiency of the partial utilization of digestible nitrogen for the nitrogen deposition was calculated to 75%. The nitrogen maintenance requirement values amounted to 0.5 and 0.4 g digestible nitrogen per kg LW0.75.d in the 1st and 2nd half of gestation.

The study is based on the results obtained from the slaughter of 5 sows on the first day of pregnancy and the first day of the experiment respectively (pregnant and non-pregnant sows resp.), of 43 pregnant sows on the 56th, 84th, 98th, 105th and 113rd day of gestation as well as 17 lactating sows on the 26th day of lactation. The animal bodies of pregnant sows were divided in 15 fractions and those of non-pregnant and lactating sows in 12 fractions. The investigations were carried out with 3 x 3 variants of litter number (1, 2, 4) and energy supply (120, 100, 80% of requirement recommendation). The chemical composition and the energy content of the animal body fractions as well as their relative portions of the empty body were largely constant during the course of gestation with the exception of the reproductive organs and the conception products. The physiological stage of lactation connected with limited mobilization of body reserves resulted in a reduction in fat content of some body fractions as well as a limited increase of the portions of body organs contrary to the portions of body tissues of the empty body. In comparison with sows of litter numbers 1 and 2 the sows of litter number 4 were characterized by higher portions of bones and meat, valuable parts as well as by smaller portions of depotfat and meat from head and belly of empty body. The raising of the energy supply of the pregnant sows increased the portion of the depotfat and decreased the portion of the meat, valuable parts of the empty body. The chemical composition of the reproductive organs and the conception products as well as the portions of these fractions of the empty body were influenced strongly from the course of the gestation and lactation resp. The portions of the reproductive organs and of the conception products are small (related to energy < or = 5.7 and < or = 2.6% resp.)

The energetic utilization of rations with raw and steamed sugar beets, dried sugar beet pulp (16 measured values each), sucrose and apple pectin (8 measured values each) as supplement feed to a basic ration was measured at 4 growing pigs each in the live weight range of between 40 and 130 kg. The utilization of the energy in the rations amounted to 69.1 +/- 5.5, 68.3 +/- 7.1, 60.9 +/- 5.8, 70.5 +/- 4.1 and 69.9 +/- 6.9 % (same sequence as above). The utilization values for the supplemented feedstuffs were 69.2 +/- 7.4, 68.0 +/- 10.0, 55.9 +/- 9.7, 72.2 +/- 7.6 and 71.7 +/- 17.3 %. The average retention value of the digestible pectin was derived from the test results with dried sugar beet pulp and apple pectin as 5.8 kJ/g. An influence of the ontogenetic development on energy utilization cannot be derived from the comparison of the retention effect of digestible nutrients measured at growing pigs and that derived from adult pigs.

Studies of the energy metabolism at maintenance and growth levels after the feeding of rations with a crude protein content of 17-24 % and 44-47 % resp. were carried out with hybrid pigs of line 150 in the live weight range between 10 and approximately 50 kg. This paper gives information on the methods and the outlay of the experiment and presents results concerning feed intake, live weight development and digestibility. Feed intake increased on average with growing live weight by 30-35 g DM/kg live weight. Feed conversion ranged from 1.2 to 1.8 kg DM/kg live weight gain in the first period and from 2.3 to 3.2 kg DM/kg live weight gain in the last period. The digestibility of the energy in the rations with a crude protein content of between 17 and 24 % averaged 80 % and that of the rations with a crude protein content of 44-47 % averaged 86 %. In the course of ontogenetic development the digestibility increased up to about 30 kg LW. The influence of the nutritional level on the level of digestibility was unequal in the experiments. In one experiment a decrease (1 % unit) and in two experiments an increase (1-3 % units) of the digestibility after the feeding of growth level in contrast to maintenance level could be observed.The change of rations with a varying protein content did not result in an influence on the digestibility level in comparison with the constant feeding of one ration.

Results of the measuring of the total metabolism of growing intact pigs (INT) and pigs with ileorectal anastomoses (IRA) are compared. The 16 comparisons are based on studies with rations of dried feedstuffs and rations containing between 30 and 50% of the DM raw or steamed potatoes and sugar beets, sucrose and apple pectin. On an average of all comparisons the relative values for the digestibility of energy, DM and the organic matter as well as for the metabolizability of the energy were between 81 and 82% (values measured at INT animals = 100). The comparison also refers to the crude nutrients, the water-soluble carbohydrates, the starch and the pectin. As a tendency, the IRA utilized the metabolizable energy better than the INT animals. The energy maintenance requirement of the IRA animals was--by 15%--significantly higher than that of the INT animals. There is not yet an answer to the question in how far comparative studies of INT and IRA animals make verified statements with regard to the differences in the energetic utilization of the precaecally and postileally digested nutrients possible. For this, further experiments will be necessary.

Growing pigs, live weight 40 - 120 kg, 4 animals per group were fed in total metabolism experiments the same ration with 215 g/kg DM crude protein. The experimental group in the first experimental time 2 mg in 1 ml Arginine buffer and the 2nd experimental time 4 mg/animal . d recombinant porcine Somatotropin in 2 ml Arginine buffer were injected i.m. and the control group an adequate quantity Arginine buffer. On average of 6 experimental periods (12 weeks) the experimental group with rpST in comparison to the control group had 141 g/animal . d (18 %) higher live weight gain, 8,8 g/animal . d (45 %) higher N deposition, 1,2 MJ/animal . d (40 %) higher protein energy deposition, 4 MJ/animal . d (33 %) lower fat energy deposition with the same feed intake as the control group. By rpST-processing the N-excretion was reduced with the same protein intake.

Investigations were carried out about nitrogen and energy metabolism feeding rations with 17-24 and 44-47 % crude protein content on maintenance and growing level to castrated male hybrid pigs of line 150. In growing periods the N deposition amounted to 10 g/animal.d (15 kg live weight), 18 g/animal.d (30 kg LW) and 21 g/animal.d (> 40 kg LW) on lower protein feeding level. In experiments with higher protein feeding level the corresponding results were 17, 22 and 22 g N deposition/animal . d. The partial utilization of metabolizable energy for deposition amounted to 70 % for the rations with 17-24 % protein content and to 59 % for the rations with 44-47 % protein content, without correlation to the animals development and the alternation in the protein feeding level. The results of regression analysis about maintenance requirement were 814, 775 and 806 kJ metabolizable energy/kg LW0,62.d in trials feeding rations with 17-24 % crude protein content as well as 764, 846 and 818 kJ metabolizable energy/kg LW0,62.d in trials feeding rations with 44-47 % crude protein content. 1,5-1,8 MJ metabolizable energy were used per MJ protein energy deposition and 1,3-1,4 MJ per MJ fat energy deposition respectively. The energy deposition per kg live weight gain amounted to values between 9 (10 kg LW) and 18 MJ (60 kg LW)