[Performance dependent lysine requirement of fattening pigs. 3. Effect of amino acid and energy intake on fat, protein and lysine deposition of swine]

[The energy preservation requirements of growing pigs of different sexes fed normal and high protein diets. 5. Comparison with the results obtained from castrated pigs, sows and boars]

In one experiment each with castrated pigs, sows and boars (hybrid pigs of line 150), two groups of six animals received rations containing 17 and 45% crude protein resp. over the complete test period from 35 to 130 kg (castrated pigs), 150 kg (sows), 170 kg live weight (boars) and passed alternatively through a total of 60 metabolism periods on growth and 48 on maintenance level. There were significant differences between the 3 categories of animals with regard to energy maintenance requirement in the relation of 100:105:110 for castrated pigs less than sows less than boars. In contrast to the estimated values derived from previous studies for energetic maintenance requirement of 650 kJ/kg LW0.62.d the measured values for all 3 animal categories are by approximately 50% higher. The protein content did not have an influence on the maintenance requirement of metabolizable energy of the animals. The utilization of metabolizable energy of the two rations for body energy retention corresponds to the expectations with regard to its dependence on nutrients. The requirement of metabolizable energy for protein and fat retention is 1.7:1.0. The energy content of the weight gain of boars was, on average, 85% of that of castrated pigs and sows. The studies of blood parameters did not show any deviations in the parameters tested.

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 2. Energy and nitrogen metabolism of fattening hybrids in the fattening range of 30 to 120 kg]

In 3 experiments a total of 242 total metabolism experiments with ad libitum feeding (experiment 1), 75% (experiment 2) and 62% (experiment 3) of the energy level of the 1st experiment and approximately equal protein and amino acid doses in experiments 1-3 were carried out with 8 castrated male fattening hybrids each (large white X land race pig) X line 150) in the live weight range between 30 and 120 kg. On average, feed intake over the whole live weight range was 2.24; 1.79 and 1.50 kg/animal and day, the corresponding daily live weight gain was 729, 533 and 396 g. With regard to the digestibility of the energy and the nutrients and the metabolisable energy in % of the gross energy there was no relation to the development of the animals. The intake of metabolisable energy per kg live weight decreased with ad libitum feeding and with the advancing development at the end of the experiment in contrast to the beginning of the experiment to 53%, energy retention to 56%. The utilisation of metabolisable energy for body energy retention, taking account of a maintenance requirement of 450 kJ/kg live weight 0,62 on the average of the 3 experiments was 68.4 +/- 1.9, 70.3 +/- 2.0 and 64.3 +/- 2.6%. Energy retention in experiments 1 to 3 amounted to 8.6, 6.8 and 5.3 MJ at the beginning and to 18.1, 12.2 and 8.0 MJ per animal and day at the end of the experiment. Protein energy retention of the pigs (live weight 40 kg) was 26% of the total energy retention in experiments 1 and 2 and 49% in experiment 3. In experiments 1 and 3 protein retention decreased to 15% of the total energy retention, in experiment 2 protein retention remained constantly at 22% between 60 and 110 kg live weight and then decreased to 18%. Consequently, the N-balances were 23-16 g, 16-20 g and 16-9 g/animal and day. The chemical composition of the carcasses was strongly influenced by the level of nutrition. At the beginning of the experiment the protein content averaged between 49 and 57% and the total fat content between 31 and 38% of the dry matter. At the end of the experiment the carcasses of the animals from experiments 1-3 had crude protein contents of 28, 33 and 42% and total fat contents of 66, 61 and 50% of the dry matter.

[Effect of graded high-energy-level protein supply on fattening performance and retention and utilization of feed energy, protein and amino acids in female fattening swine. 4. Nitrogen and amino acid content in carcasses and parts]

The slaughtering and cutting up of 7 (6) female pigs in each of 3 groups (live weight approximately 113 kg) fed on approximately 80, 100 and 120% protein (lysine) of the norm as well as the determination of nitrogen and amino acids in the individual parts of the body had--in comparison to 6 reference animals (live weight approximately 36 kg) treated in the same way at the beginning of the experiment--the following results: In the course of growth the quota (in % of the slaughter weight) of bacon, belly fat + intestinal fat tissue is more than doubled; the relative quotas of bones, skin + ears, bristles + claws, blood and entrails, however, decrease. The total meat quota is 54% and remains relatively equal independent of the live weight. The N-quotas (in % of the empty body-N) of muscle and fat tissue and of the skin increase in the course of fattening, those of bones, useable organs and offal decrease distinctly. At the end of fattening the muscle protein of the animals amounted to 59% of the empty body protein and to 87% of the carcass protein. The amino acid content (g/16 g N) hardly changes in the individual parts during growth; the percentage amino acid distribution follows the weight-and N-distribution. The lysine content of the edible parts of the carcass is 8.4 g/16 g N. The chosen grades in the protein (lysine) supply of the test animals did not result in any significant changes with regard to the qualitative parameters (protein and amino acid content of the valuable and less valuable parts of the body as well as their percentage distribution in the empty body). The quantitative parameters (live weight gain, protein (amino acid) retention per day) are diminished in approximately the same relation as the insufficiency of the alimentary supply; by excessive supply, however, they do not significantly increase. The results are compared with corresponding data from literature and discussed.

[Effect of graded protein supply at high-energy level on the fattening performance and the retention and utilization of feed energy, protein and amino acids by female fattening swine. 3. N retention and N and lysine metabolism determined by N balance and N analysis of the carcasses]

The slaughtering of female fattening pigs differently supplied with protein and lysine (nearly constant proportions) showed that a high supply (III) in comparison to the standard supply (II) did not bring about better results. The lower consumption of digestible crude protein and lysine (I) resulted in a prolonged fattening period, lower daily protein retention (by 23%) and a lower content in live weight growth (by 5%). The two feeding variants I and III are therefore ineconomical and not recommendable. There are significant positive correlations between N-retention calculated from 3 N-balance measurings in the first fattening period (up to the 44th fattening day) and N-deposit ascertained after the analysis at the carcasses at the beginning and at the end of fattening. By means of the calculated estimate functions (1) y = 4.724 + 0.5432x and (2) y = 7.850 + 0.4961x the level of the real protein deposition (y) in the total fattening period can be derived from the N-balance (x) both in g per animal and day (1) and in g per kg live weight growth (2). The four complexes of causes for the differences in N-retention according to N-balance and N-deposit according to carcass analysis: 1. high N-deposition in the first fattening period; 2. unascertainable N-losses 3. the difference between slaughtering and total body weight and 4. physiologically caused deviations in the N-storage of the living organism, are discussed. Protein and lysine utilisations are comparable with values from literature achieved under similar conditions. In the group supplied according to standard (II) it is 29.5 and 45.6% resp. or, related to the digested quota, 36.6 and 57.7% resp. Here the protein (10.1 kg) and lysine (1,640 g) assigned for a live weight growth of 80 kg (35-115 kg) in 100 fattening days were consumed, which means that 162 g lysine were needed for 1 kg deposited protein.

[Investigations of the lysine requirement of fattening boars in dependence on their performance. 3. Influence of energy consumption on the fat and protein retention of the boars]

The results of the carcass analysis show a distinct influence of the duration of keeping on protein retention. The protein percentage was highest with those animals whose lysine requirement was met 100%. A lysine supplement of 20% of the valid norm had no infuence on the percental protein content. In both cases (100% and 120%) 17.1% protein were determined in the carcass. Concerning the daily protein retention, boars whose protein requirement wes met 120% and with a live weight of more than 90 kg achieved more favourable results than those of the norm variant. Up to 90 kg live weight no difference between the two variants could be detected. Animals which received feed rich in energy showed a very high daily protein retention during the first third of the fattening period, which decreased relatively much, however, in the course of growth.

[Performance dependence of the lysine requirement of fattening sows. 1. Effect of energy and amino acid consumption on fattening performance]

Seven variants with graduated energy and amino acid levels were tested at 105 growing sows in a live weight range between 30 and 120 kg. The weight increase and the energy expenditure showed a distinct dependence on the energy level of the ration and are mainly determined by the energy intake. Up to a live weight of 90 kg a 20% lysine over- or undersupply in comparison with the norm had no influence on the growth intensity of the animals. On the low and medium energy levels there was a tendency of superiority of the animals which received feeds rich in protein in the section between 90 and 120 kg. In the variant with a high energy level, however, a diminishing increase was detected in the last third of the fattening period in connection with the growing lysine level. The overall most suitable result was achieved in variant M 120 with a daily increase of 675 g and an energy expenditure of 2.04 kilo energetic feed units for pigs per kg increase.

[Food value of straw meal in the nutrition of pigs. 1. Digestibility of the nutrients and N-balance after feeding with partially hydrolized straw meal]

Straw Meal was mixed with concentrated HCl at a mass proportion of approximately 10 : 1. After a one-hour duration of action the mixture was diluted with water (in proporation to the added HCl volume the double amount of water) and steamed in an electric steaming caldron for one hour. The partially hydrolised final product was neutralised with calcium hydroxide (3,5 kg per 10 kg HCl). In a digestibility experiment 4 pigs were fed according to the differential method with barley (supplemented with lysine and methionine) without straw meal resp. with straw meal (717 g barley dry matter+386 g straw meal dry matter per animal and day for pigs with an average live weight of 64.3 kg). In this test 21.0% of the organic matter of partially hydrolised straw meal, 0.5% of the crude fibre and 42.3% of the N-free extractives were digestible. When the animals were fed with barley exclusively (1045 g dry matter per day and animal of an average body weight of 61,4 kg), 17,1% of the 26,0 t N per animal and day were excreted in feces. After the feeding with straw meal admixtures, 34,5% of the 20,9 g N per animal and day were excreted in feces. When the feed consisted of 1,99 kg barley, 220 g fish meal and 565 g straw meal (dry matter in each case) per animal and day for the same pigs with an average body weight of 97,1 kg a digestibility of the organic matter of the partially hydrolised straw meal of 24,6% was achieved. 24.3% of the nitrogen consumed (72.9 g) by each animal per day were excreted in feces. After slaughtering, the pH-value in the caecum sould be ascertained as 6.0 to 6.5. The conclusion of this is that partially hydrolised straw meal contains approximately 20% utilisable carbohydrates and has a positive dietic effect in the digestive tract.

[Performance-related lysine requirement of fattening pigs. 4. Effect of energy and amino acid intakes on composition of gain and derivation of lysine requirement]

The results show that protein and fat syntheses proceed simultaneously in growing swine. Reducing the energy intake during the 2nd half of the fattening period in pigs of modern genetic construction (hybrid pig) is likely to cut both fat and protein deposition per day. This will result in lower daily gains, a longer fattening period and higher energy expenditure. Therfore, it is not advisable to restrict energy supply during the 2nd half of fattening of pigs derived from modern breeding lines. The optimum amino acid : energy ratio allows to make full use of the protein deposition capacity in pigs with prefixed slaughter weight. For the limiting amino acid lysine it was found to be 10.5 g/1,000 energetic feed equivalents (swine) or 3 g/Mcal NEF (swine), and, taking into account amino acid digestibility, 9.5 g dig. lysin/1,000 energetic feed equivalents (swine) and 2.7 g dig. lysin/Mcal NEF (swine), respectively.