Joint research on the precise determination of the energy and protein requirements of fattening pigs. 7. The effect of various energy levels on the performance and feed expenditure of fattening pigs

Scientific feeding experiments were carried out with 7 male castrated pigs of the genetic origin land race pig X large white with the test animals fed individually and the rations containing approximately the same amounts of protein, amino acids, minerals and vitamins but varied amounts of energy. Energy intake was adjusted to three levels: 100%, 85% and 70% of semi-ad-libitum intake (group 1 = 100%). With regard to protein supply there was a subdivision into 30-60 and 60-100 kg live weight. In addition to this, the digestibility of the feed mixture used and the N-balance were determined in both fattening periods. Having reached 100 kg live weight, the animals were slaughtered and a number of slaughtering parameters was determined. The average daily live weight gain in the three test groups was 749, 664 and 540 g over the whole fattening period. The feed expenditure was 3.7, 3.9 and 4.3 kg mixed feed per kg live weight gain so that, with regard to live weight performance and feed expenditure the group with the highest energy supply showed the best results. The level of energy supply had a remarkable influence on the composition of weight gain; thus the amount of fat in the carcass of the animals of groups 3 was by 1.8 kg and 2.5 kg resp. lower than of the animals in groups 2 and 1.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 8. The effect of various protein levels on the performance and feed expenditure of fattening pigs

Live weight development and feed expenditure were investigated on 3 levels of protein supply and isocaloric rations in scientific feeding experiments with 10 castrated male pigs each of the genetic origin land race pig X large white fed individually in the live weight range between 30 and 100 kg with a subdivision at 60 kg. In the air-dried matter the crude protein content of the feed mixtures used in the first fattening period was 17.6; 15.7 and 13.7% resp. and in the second fattening period from 60 kg live weight onwards 14.9; 12.8 and 11.4% resp. for the 3 test groups. In both fattening periods the digestibility of the rations and the N-balance were determined at 3 representative animals from each of the 3 groups. The following average live weight gains were achieved in the 3 test groups: 1st fattening period: 662; 592 and 539 g resp.; 2nd X fattening period: 709; 676 and 644 g resp. Feed expenditure over the complete fattening period was 4.2; 4.5 and 5.2 kg air-dried matter per kg live weight gain. The highest protein supply resulted in the best live weight gain performance and the lowest expenditure.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 5. The effect of the crude protein concentration in the isocaloric diet on the fattening performance of swine of the Bulgarian Landrace

Live weight development and feed expenditure on 3 levels of crude protein supply and with isocaloric rations were investigated in scientific feeding experiments with 7 castrated male pigs each of the Bulgarian land race in the live weight range between 30 and 100 kg with a subdivision at 60 kg. The crude protein concentrations in the rations for the 3 groups were 17%, 15% and 13% in the first fattening period and 15% 13% and 11% in the second fattening period. In the two fattening periods the digestibility of the feed mixtures used was ascertained in experiments. The daily live weight gain in the three groups over the whole fattening period reached a high level of performance (836 g, 778 g and 757 g). The feed expenditure values were 3.3, 3.7 and 3.7 kg mixed feed (88% dry matter) per kg live weight gain. The highest protein supply resulted in the best weight gain performance and the lowest feed expenditure.     

Studies on the performance-related lysine requirement in fattening pigs. 1. Influence of energy and aminoacid intake on fattening

A total of 110 barrows fed varying levels of energy and amino acids in 8 treatments, were tested. The weight gains per fattening day and energy expenditure were found to be mainly determined by energy intake. Up to a liveweight of 100 kg both low and high levels of amino acid supply produced the same fattening performance results as amino acid supply to standard. In the 100-120 kg liveweight range, the animals fed higher levels of protein proved slightly superior. As to energy expenditure, animals subjected to restricted feeding up to 70 kg liveweight and fed full rations later, consumed 2.22 kEFs (2.22 kilo energetic feed equivalents/swine) per kg gain and proved significantly superior to those animals that were very intensively fed at the beginning and put to restricted feeding beyond 70 kg liveweight (2.53 kEFs per kg gain) as well as to those receiving high levels of energy all the time (2.39 kEFs/kg gain). In the latter case, 23 g of lysine were required per kg gain.     

Lysine requirement of fattening boars in respect to their performance. 1. Influence of the consumption of energy and amino acids on the fattening performance

With a total number of 157 boars 9 feeding variants with different levels of energy and amino acids were checked. The weight increase per fattening day and the energy and lysine expenditure per kg live weight increase were determined. The insufficient supply with lysine had negative effects on the live weight increase and the energy expenditure during the whole fattening period. Between the variantes with a high supply with amino acids (120%) and the supply according to standard (100%) no significant differences concerning the live weight increase could be ascertained up to 90 kg live weight. Between 90 and 120 kg live weight the animals in the variant with medium energy level and 120% lysine supply achieved significantly higher increases than those in the standard variant. Up to 90 kg live weight the energy expenditure for all groups amounted to 2,08 kEFs (energetic feed units for pigs) per kg live weight increase. The most suitable results were achieved by the animals which received the variants rich in energy (1,760 resp. 1,770 kEFs per kg live weight increase). Above the 90 kg live weight limit the energy expenditure rose considerably, remained however under 2,000 kEFs per kg live weight increase for the boars of the variant with medium energy level and 120% lysine supply as well as for the variant rich in energy and 100% lysine supply. The lysine expenditure in the first variant amounted to 25.1 g per kg live weight increase and for the variant rich in energy to 20.6 g lysine per kEFs.     

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.     

Effect of the polyether antibiotic "monensin" on fattening and slaughtering performance as well as protein and energy retention in bulls

In an individual feeding experiment (150-500 kg live weight) the influence of the polyether antibiotic Monensin on the fattening, slaughtering and retention performances of crossbreeding dairy bulls (genotype 31) and fattening hybrids (genotype 61) was ascertained. The supplementation of the polyether antibiotic on average resulted in a decrease by approximately equal to 11% of the dry matter and energy expenditure per kg weight gain due to a lower feed intake and a higher live weight gain. The slaughtering parameter investigated and the chemical composition of the empty body remained uninfluenced. The daily nutrient retention values were positively influenced by the Monensin supplementation since the fattening bulls of the test group required 30 days less to achieve the attempted fattening weight. The additional retention of protein, fat and energy per animal and day in the dairy bulls approximately equal to 10.9; 13.5 and 16.4% and in the fattening hybrids 1.9; 3.2 and 2.6%. Due to a higher energy retention at a lower level of feed and energy intake after Monensin supplementation an average of approximately equal to 11.3 and 15.4% resp. more of the consumed digestible protein and the digestible energy resp. were retained in the empty bodies. One can conclude that Monensin improved the utilisation of feed energy; obviously the effect of the polyether antibiotic is due to its influence on processes in the rumen or directly or indirectly on metabolism.     

Nutrient and energy retention in growing lambs. 1. Results of growth experiments

The results of a growth experiment are explained which was carried out as basis for the control slaughtering method and for N-balance experiments with hybrid fattening lambs of both sexes and of three different genetic constructions in comparison with male merino mutton lambs. The animals were kept individually on perforated floor and received pelleted fattening feed for lambs ad libitum. In the live weight range between 15 and 30 kg the male hybrid lambs reached significantly higher live weight gains than the merino mutton sheep, the former tending towards higher feed intake and lower energy expenditure. The male hybrid lambs showed a significantly higher live weight gain and a significantly lower energy expenditure than the female animals of equal live weight whereas there were no differences between the sexes in feed intake.     

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.     

Vitamin A requirement of growing swine. 1. Effect of vitamin A supply on growth of piglets and fattening swine

For the purpose of ascertaining the vitamin A requirement seven experiments with 303 pigs in the live weight range between 6.5 and 114 kg were made. In three experiments under in practice conditions we checked the standard vitamin A supplement to the mixed feed with 1,732 pigs (live weight range between 8.5 and 110 kg). The supplement to vitamin-A-free rations and to those poor in or free of carotene amounted to between 0 and 8,000 IU/kg feed. Above that, between 0 and 16 mg beta-carotene and 1,000 mg nitrite/kg feed were supplemented. As long as the vitamin A store in the liver during weaning amounted to greater than 50 IU and greater than 100 IU/g at the beginning of fattening, feed intake, live weight growth and feed expenditure were not influenced by the supplement of vitamin and provitamin resp. The supplement of 250 IU resulted in the same weight growth from weaning to the end of fattening as that of 4,000 IU. Nitrite supplement had a negative effect at 250 IU, at 500 IU vitamin A consumption and weight growth tended to be only insignificantly lower. The methaemoglobin content decreasing in the course of the experiment reflects the adaptation of the pigs to the nitrite load. The consumption and growth depression caused by vitamin A deficiency could be observed from the 7th week of the experiment when casein-swelling starch rations were fed, but from the 13th week of the experiment only when cereal-soybean oilmeal rations were fed. The weight of liver, spleen, kidneys, heart and brain was not influenced by vitamin A supply. The same applies to the body composition and retention with the exception of two deficiency piglets, which contained less fat in the empty body than the control animals.     

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

The gain in structural matter had a linear course with a corresponding feeding intensity and depending on the period of fattening. However, the animals given high-energy diets deposited 130 g protein per day during the first fattening period, this deposition being compensated in the course of further growth by a considerably lower deposition in the sense of aequifinality. Up to a live weight of 70 kg, animals subjected first to restricted feeding and then to fully balanced feeding revealed the highest protein deposition during the last period of fattening, this fact emphasizing the leanmeat character of the animal material used. The daily fat deposition was found clearly determined by energy intake and independent of amino acid supply. Lysine conversion was influenced by the intake of lysine and energy. Under feeding to norm it reached some 40 and 30% during the first and second periods of fattening, respectively.     

Effect of iodine, copper and zinc supplements to rations with a high quota of rapeseed extract meal on the growth and thyroid function of fattening swine. 2. The effect of the iodine supplement on nutrient digestibility and on protein and energy retention

Three groups of six pigs each (live weight at the beginning of the experiment 20 kg) were given a cereal ration with 8% rape seed meal. Group I did not receive a J supplement and was fed ad libitum. The rations of groups II and III were supplemented with 1 mg J/kg feed. The feed intake of group II was limited to the amount consumed by group I (pair fed); group III received the feed ad libitum. The daily weight gains of the 3 groups were 327, 377 and 613 g, feed expenditure 3.79, 3.68 and 3.47 kg/kg gain. In an N balance experiment carried out with 3 animals each from groups I and II, 41.4% of the N taken in group I and 43.8% in group II were retained (p greater than 0.05). Liver, intestinal fat and leaf were heavier in group I (p less than 0.01), the protein content of the empty body, the bones and bristles significantly lower than in group II. Protein retention in group II was 14% higher than in group I. In case of iodine deficiency protein retention is lower, energy retention, however, is largely unchanged.     

Comparative growth performance of pigs immunised with a gonadotrophin releasing factor vaccine with surgically castrated pigs and entire boars raised under conventionally managed conditions

The objective of this study was to determine the effect of using a gonadotrophin releasing factor (GnRF) vaccine on growth performance of male pigs. Vaccinated pigs were compared with surgically castrated pigs and entire males under conventionally managed farm conditions. Male pigs were randomly assigned to three treatment groups: pigs surgically castrated during the first week of life (group "C", n=274), pigs immunised twice during the fattening period with a GnRF vaccine, the first when 13-14 weeks of age and the second when 20-21 weeks of age (group "V" n=280) and entire males (group "E", n=56). Average daily weight gain (ADG) was measured during the study. Additionally, feed conversion ratio (FCR) as defined by feed intake/weight gain and feed consumption was assessed during the fattening period. No difference in the ADG during the fattening period could be determined between "C" and "V". From the start of the study until slaughter at study day 160/173 the ADG in group "E" was lower (625 g/day; P) than in group "C" (681 g/day; P < 0.001) and group "V" (675 g/day; P < 0.01). The FCR during the fattening period until study day 160, three days before the first batch of pigs were slaughtered at 24-25 weeks of age, was higher in group"C" (2.72 kg feed intake/kg weight gain) compared with group "V" (2.44 kg feed intake/kg weight gain; P < 0.001) and group "E" (2.44 kg feed intake/kg weight gain; P <0.01). Pigs in group "V" performed similarly to those in group "E" until the second vaccination (day 135) after which time they showed a substantial increase in feed intake and ADG, while retaining an FCR advantage over group C.     

Lysine requirement of fattening sows depending on their performance. 2. Relations between energy consumption and live weight increase

105 growing sows in the live weight range were fed with 7 test rations with graduated energy and amino acid levels. The growth intensity was very much influenced by the daily energy consumption. On the basis of regression analysis the following linear relation between daily weight increase (y in g per kg live weight0,75) and the daily energy consumption (x in energetic feed units for pigs per kg live weight0,75) was calculated: y = -13,79 + 0,7037 x (r = 0,84, sb -0,0295). The interpolation with regard to live weight balance resulted in a maintenance requirement of 19,8 energetic feed units for pigs resp. 70 kcal net energy fat for pigs per kg live weight0,75. The methods of assessment chosen showed an increase of the energy requirement per 100 g additional live weight increase per day of a constant amount, independent of the live weight, of 142 energetic feed units for pigs resp. 497 kcal net energy fat for pigs.     

Initial research on the use of mixed corn grain and stalk silage in broiler fattening

The suitability of a corn and cob maize silage (CCM) as a component rich in energy in the fattening ration was investigated in a growth experiment with male broilers. The CCM silage with a dry matter content of 60.2% contained the following substances determining its value (per 1 kg dry matter of the feed): 102 g crude protein, 61 g crude fibre and 682 energetic feed units for chickens (EFUc). CCM silage was either fed as a component of a feed mixture consisting of 70.5% CCM silage and 29.5% protein concentrate (all values of original substance) or both components of the ration were fed to broilers separately. The protein concentrate was composed as follows (values per kg): 650 g soybean oilmeal, 110 g fishmeal, 85 g tankage from rendering plants, 55 g torula yeast, 70 g mineral mixture and 30 g of a mixture of biologically active substances. The broilers of the control group received commercial fattening feed for broilers with coarse maize meal as cereal component. The feed mixture with CCM silage and separate CCM silage were accepted readily. When CCM silage and protein concentrate were offered alternatively, the same amount of CCM silage was consumed but 8% less protein concentrate. The broilers fed with CCM silage plus protein concentrate reached 96-97% of the live weight of the control animals (1.952 g/animal, 49th day), which received conventional feed, although their net energy intake was 10% lower. This proves a more favourable net energy expenditure for the test groups fed with CCM silage.     

甜菜碱对育肥猪生长性能和PRKAG3基因相对表达量的影响

为了研究甜菜碱对育肥猪生长性能和PRKAG3基因表达量的影响,试验采用单因子试验设计,选用80 kg左右的健康杜长大三元杂交猪60头,随机分成4组,每组3个重复,每个重复5头猪,在日粮中添加甜菜碱0,500,1 000,1 500 mg/kg,试验期为41 d,试验结束后随机选择(每组随机选择3头)12头猪进行屠宰测定。结果表明:与对照组相比,日粮中添加甜菜碱对育肥猪的日增重、日采食量、料重比均有明显影响,可以不同程度地提高日增重和采食量,降低料重比,其中以添加1 500 mg/kg甜菜碱(4组)的效果最为明显;日粮中添加甜菜碱可以不同程度地提高育肥猪PRKAG3基因的表达量,其中以1 500 mg/kg甜菜碱(4组)的效果最为明显。说明甜菜碱可以提供甲基供体,节约蛋氨酸和胆碱,从而提高育肥猪的生长性能。     

Effectiveness of the use of momensin for cattle fattening

Two groups of fattened bulls (125 bulls in each group) were investigated for the effect of monensin (125-175 mg per head/day) on live weight gains and for the effectiveness of monensin administration. After 160 days of fattening, the average daily weight gain was 713 g in the control group and 800 g in the monensin-treated group (an increase by 12.2%). After 11 months of fattening the daily weight gain was 702 g in the control group and 768 g in the monensin-treated group (an increase by 9.4%). Besides the control and experimental groups, monensin was administered to 1500 head of fattened cattle on the whole. Greater differences in the daily live weight gains (higher gains in the monensin-treated animals) were recorded mainly in the period when the feed ration contained high-quality bulk feeds. When the bulls were given feeds of lower quality (mainly late in winter), the differences in the average daily live weight gains decrease and the effect of monensin treatment is not so great. Throughout the fattening period, monensin had a favourable influence on the live weight gains and its use was economically advantageous.     

Joint research on the precise determination of the energy and protein requirements of fattening pigs. 3. The energy requirement of hybrid swine

The energy requirement for hybrid pigs ((large white X land race pig) X line 150) in the live weight range between 35 and 120 kg is derived from 242 measurings of the total metabolism as the sum of energy requirement for maintenance and energy requirement for live weight gain. Energy requirement is estimated by means of the following equation: (Formula: see text). Energy maintenance requirement, energy content per 1 kg live weightgain in dependence of the daily gain and the derived energy requirement for growth and fattening are compared with corresponding results from investigations with pigs of the species large white and land race pig. Essential differences concerning parameters of energy metabolism determining the requirement could not be detected.     

The effect of rank order on feed intake and growth of fattening pigs

On the basis of 120 fattening pigs, classified in 6 groups of 20 animals each, the rank order was determined and its influence on the feed intake behaviour as well as on the fattening progress was studied. The results show that with respect to the total length of stay at the trough and to the time per visit to the feeding station the dominant barrows stayed significantly longer at the feeding place than their subordinate pen mates. Additionally, they showed a higher weight at the end of the fattening period and a higher weight gain per day of fattening. As to the frequency of the visits to the feeding station there was no significant difference between high-ranking and low-ranking animals during the period of observation.     

Urea utilization of growing lambs. 2. Growth experiments

In two growth experiments with 30 lambs per group the influence of urea (1-2% of the ration) and straw (20-30% of the ration) on the performance was studied under conditions of intensive fattening. The content of native crude protein in the rations varied between 10.1 and 18.4% of the DM. In experiment 1 the lambs of the two groups which received mixed feed for fattening lambs without urea on average consumed with 1.02 and 1.11 kg DM resp., 696 and 757 EFUcattle resp. and 173 and 189 g crude protein resp. per animal and day. The groups with wheat or barley and urea consumed 1.06 and 0.96 kg DM resp., 714 and 627 EFUcattle resp. and 209 and 155 g crude protein resp. Their weight gain of 247 g/animal and day was 24% and that of 230 g resp. 26% higher than that in the control groups without urea. The lowest dry matter intake (0.91 and 0.82 kg resp.) was shown by the animals of the groups which received wheat or barley without urea. In the second experiment the control group achieved an average daily weight gain of 327 g at an expenditure of 2.24 kEFUcattle/kg weight gain. Despite a partly higher dry matter intake, the daily EFUcattle intake was between 12.2 and 24.5% lower in the straw groups and energy expenditure increased between 12.0 and 27.8%. Urea supplements of between 1 and 2% improved dry matter, EFUcattle and crude protein intake and thus weight gain.