生长肥育猪胴体品质和瘦肉生长指数的研究

为验证NRC( 1998)生长猪营养需要模型 ,进而建立我国生长猪营养需要模型 ,本试验在较高营养水平下研究测定了生长肥育猪生产性能、胴体品质和瘦肉生长指数。全期试验结果表明 ,在一定营养水平和环境条件下 ,公、母猪日增重、采食量、饲料转化率差异不显著 (P >0 .0 5) ,但公猪日增重有高于母猪日增重的趋势。胴体品质上 ,公、母猪热胴体重、瘦肉重、背脂、瘦肉脂肪含量差异不显著 (P >0 .0 5)。通过测定热胴体重、最后肋背脂得到瘦肉生长指数为 :去势公猪 2 78g/d ,母猪 2 82g/d ,公母平均 2 81g/d。通过测定热胴体重 ,第 10肋背脂、第 10肋眼肌面积得到的瘦肉生长指数为 :去势公猪 2 56g/d ;母猪 2 72g/d ;公母平均 2 64g/d。将瘦肉生长指数、温度、饲养密度等参数输入NRC( 1998)模型得到的营养需要量估测值有一定实际意义 ,但在实践中的应用情况有待进一步评估验证     

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 × 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease (P =0.10) as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased (P <0.01) when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased (P <0.01). The digestible energy and metabolizable energy content of diets decreased (P <0.01) as the total dietary fiber increased.     

The effects of dietary fiber level on nutrient digestibility in growing pigs

The objective of this study was to investigate the effects of total dietary fiber level on nutrient digestibility and the relationship between apparent total tract digestibility of total dietary fiber, and soluble dietary fiber, insoluble dietary fiber and available energy. Sugar beet pulp was as the only fiber source. The experiment was designed as a 6 x 6 Latin square with an adaptation period of 7 d followed by a 5-d total collection of feces and urine. Feed intake tended to decrease （P =0.] O） as total dietary fiber level increased. The apparent total tract digestibility of dry matter, crude protein and gross energy decreased （P 〈0.0]） when total dietary fiber increased but the digestibility of soluble dietary fiber and insoluble dietary fiber increased （P 〈0.01）. The digestible energy and metabolizable energy content of diets decreased （P 〈0.01） as the total dietary fiber increased.     

Thoughts on fiber utilization in swine

There is continued incentive for the development of alternative feed resources for use in swine production. The availability of distillery by-products may be expected to increase as the use of corn and cereal grains for ethanol production expands. The acceptability of distillery by-products, milling by-products, forages and other fibrous feeds as energy sources for swine depends on such factors as cell wall content of the plant, degree of microbial fermentation in the large intestine, and extent of absorption and utilization of the volatile fatty acids produced. Physiological effects of dietary fiber, including effects on gastric emptying, rate of transit of digesta, gut motility, digestive secretions, and absorption and utilization of breakdown products need quantification. Limited evidence suggests that there are genetic differences in the response of pigs to dietary fiber and in their ability to utilize it as an energy source. Recombinant DNA technology offers the possibility of cloning cellulase genes from microorganisms for application in swine feeding programs. The extent to which biotechnology will be applied in swine feeding will depend ultimately on the economic incentive for developmental effort and on unknown biological limitations of the pig and its gastrointestinal microbial ecosystem.     

Use of refined potato (Solanum tuberosum L. cv. Gogu valley) protein as an alternative to antibiotics in weanling pigs

This study investigates the use of refined potato protein (RPP) obtained from the potato (Solanum tuberosum) tubers of “Gogu valley” for their antimicrobial properties and its effects on growth performance, apparent nutrient digestibility and microbial populations in feces and large intestine of weanling pigs. Pigs (n = 280; Landrace × Yorkshire × Duroc; average initial body weight of 5.96 ± 0.66 kg; 23 ± 3 d of age) were allotted on the basis of their body weight and sex to five dietary treatments (each treatment comprised of 4 replicate pens with 14 pigs in each) in a randomized complete block design. The dietary treatments were: PC (positive control; basal diet + 150 ppm apramycin sulfate and 10 ppm colistin sulfate), and RPP (basal diet added with 0, 200, 400 and 600 ppm RPP). The RPP showed in vitro antimicrobial activity and at the concentration of 150 ppm inhibited the growth of tested microbes (Staphylococcus aureus, Salmonella choleraesuis, Salmonella gallinarum and Escherichia coli). Pigs fed with antibiotic diet showed better growth performance and had lower populations of total bacteria, coliforms and Staphylococcus spp. in the feces and large intestine when compared with pigs fed RPP diets. Increasing the levels of RPP in diets linearly improved performance and reduced the populations of total bacteria, coliforms and Staphylococcus spp. in feces and contents of colon and rectum. The apparent fecal digestibility of DM, CP and apparent ileal digestibility of amino acids did not differ among pigs fed antibiotic and RPP diets. These results suggest that antibiotics were more effective in improving the performance of pigs, while feeding of RPP also improved the performance and reduced the harmful microbes being more effective at higher levels. Thus at higher levels RPP obtained from the potato tubers of Gogu valley can be a potential replacement of antibiotics in the feed of weanling pigs.     

Effect of oat particle size on energy and nutrient utilization in growing pigs

An experiment was conducted to determine the energy content of oats and to investigate the effects of oat particle size on nutrient and energy balance in growing pigs. Eighteen barrows (23.56 ± 0.94 kg initial body weight) were randomly assigned to one of the three dietary treatments with six replicates per treatment. Whole oats were ground with a hammermill fitted with 4.8- and 3.2-mm screens to make coarse and medium particle size oats, respectively. Medium oats were further ground with a rotary steel cutting grinder fitted with a 2.0-mm screen, and the further ground oats were mixed with medium oats in a 1:3 ratio to make fine oats. Three experimental diets consisted of 96.3% of the coarse, medium, or fine oats as a sole source of energy were used. Pigs were fed diets for 16 d, including 10 d for adaptation and 6 d for total fecal and urine collection. Pigs were then moved into indirect calorimetry chambers to determine 24-h heat production and 12-h fasting heat production. All data were analyzed using the MIXED procedure of SAS with the individual pig as the experimental unit. The geometric mean particle sizes for coarse, medium, and fine oats were 765, 619, and 569 μm, respectively. Pigs fed the medium oats diet tended to have (P < 0.10) greater apparent total tract digestibility (ATTD) of starch, neutral detergent fiber, and gross energy than those fed coarse oats diet. The medium oats diet contained greater (P < 0.05) digestible energy (DE), metabolizable energy (ME), and net energy (NE) than the coarse oats diet. Pigs fed the fine oats diet had lower (P < 0.05) ATTD of Ca and P than those fed the coarse oats diet. The DE, ME, and NE contents of fine oats were comparable with those of coarse oats. The determined NE contents for coarse, medium, and fine oats were 2,335, 2,615, and 2,521 kcal/kg on a dry matter basis, respectively. The NE content in medium oats was greater (P < 0.05) than the NE values predicted using published equations. In conclusion, it was suggested to grind whole oats for 619 μm concerning energy utilization. Further grinding to 569 μm reduces Ca and P digestibility.     

Effects of Xylanase and Protease Supplementation on Nutrient Digestibility in Diets Based on Peas and Wheat Fed to Weaned Pigs

This experiment was conducted to determine the effects of a commercial enzyme mixture providing xylanase and protease activities on the di gesfibility of dietary nutrients when added to diets based on peas and wheat and fed to 9.5 to 15 kg pigs.Pigs were weaned at 18 to 21 days of age and fitted with a simple T-cannula at the distal ileum,6 to 7 days after weaning.After 5 to 7 days for adaptation to their diets,ileal digesta,and feces were collected.Enzyme supplementation had no effect on the apparent ileal or fecal digestibility of any dietary nutrient.There Was a numerical improvement(P＞0.05)in the ileal digestibility of fiber.In conclusion.xylanase and protease appeared to be ineffective in improving nutrient digestibility when supplemented in diets based on peas and wheat fed to weaned pigs.     

在含粗小麦粉的生长育成期猪日粮中添加植酸酶的效果

试验采用 5 4头杂交猪 (初始体重为 2 8.4± 0 .98kg)来评估在含粗小麦粉的生长育成日粮中添加植酸酶的效果。试验猪被随机分成 2组 :对照组和试验组。试验组日粮除了以每千克 5 0 0单位的植酸酶取代相应的无机磷以外 ,其它成分与对照组日粮相同。试验期分 3个日粮阶段 ,采用 Cr2 O3 为外源指示剂来测定营养成分的消化率 ,每 2周测定 1次猪的体重和采食量并计算饲料效率。在第 2和第 3个日粮阶段分别为 7d的 2个采样期中 ,每天随机采取猪的粪样并按栏混合 ,然后对粪样的干重以及 Ca、P、Cu、Zn的含量分别进行测定。试验结果表明 ,试验组和对照组之间无论是平均日增重还是平均日采食量均没有显著差异。 5～ 8周间对照组的料肉比高于试验组 ( P<0 .0 5 ) ,但在其它各阶段均无显著差异。干物质消化率在第 2日粮阶段中无显著差别 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。 Ca的消化率也同样是在第 2阶段中 2组相似 ,但在第 3阶段中试验组高于对照组 ( P<0 .0 1 )。磷 ( P)的消化率则无论在第 2阶段 ( P<0 .0 5 )还是第 3阶段 ( P<0 .0 1 ) ,均是试验组高于对照组。试验结果表明 ,在含粗小麦粉的生长育成猪日粮中添加植酸酶可以达到同直接添加无机磷一样的效果。添加植酸酶可以促进含粗小麦粉日粮中钙     

Nutritional value of a new source of fermented soybean meal fed to growing pigs

Three experiments were conducted to test the hypothesis that the standardized ileal digestibility (SID) of amino acids (AA), concentrations of digestible energy (DE) and metabolizable energy (ME), and the standardized total tract digestibility (STTD) of P in a new source of fermented soybean meal (Fermex 200) are greater than in conventional soybean meal (SBM-CV). In experiment 1, 9 barrows (initial body weight: 9.17 ± 1.03 kg) were surgically fitted with a T-cannula in the distal ileum and allotted to a triplicated 3 × 3 Latin square design. A nitrogen-free diet and 2 diets that contained cornstarch and SBM-CV or Fermex 200 as the sole source of crude protein (CP), and AA were formulated. Results indicated that there were no difference between SBM-CV and Fermex 200 for SID of CP and AA. In experiment 2, 24 growing pigs (initial body weight: 14.19 ± 1.18 kg) were housed individually in metabolism crates. Pigs were allotted to a corn-based diet or 2 diets that contained corn and SBM-CV or corn and Fermex 200. Feces and urine samples were collected using the marker-to-marker approach with 5-d adaptation and 4-d collection periods. Results indicated that the concentration of DE and ME in Fermex 200 were not different from DE and ME in SBM-CV. In experiment 3, 40 barrows (initial body weight: 11.01 ± 1.38 kg) were allotted to 1 of 4 diets with 10 replicate pigs per diet. Four diets were formulated to contain Fermex 200 or SBM-CV and either 0 or 1,000 units/kg of microbial phytase. Pigs were housed individually in metabolism crates. Fecal samples were collected as explained for experiment 2. Results indicated that the STTD of P in Fermex 200 was greater (P < 0.01) than in SBM-CV, but the addition of microbial phytase to the diets increased the ATTD and STTD of P in SBM-CV, but not in Fermex 200 (interaction; P < 0.01). In conclusion, the SID of AA and concentrations of DE and ME in Fermex 200 were not different from values determined for SBM-CV, but the STTD of P was greater in Fermex 200 than in SBM-CV if microbial phytase was not added to the diet.     

Apparent and standardized ileal digestibility of amino acids in diverse barley cultivars fed to growing pigs

The objectives of this study were to determine the chemical composition, ileal amino acid (AA) digestibility of barley varieties and to develop equations to predict the AA digestibility based on the chemical characteristics of individual barley. A wide selection of nine barley varieties in the main growing regions of China was used in the experiment. Ten crossbred pigs (30.9 ± 1.8 kg) were allotted to a 6 × 10 Youden Square. The treatments included a nitrogen‐free diet and nine barley test diets. Considerable variation was observed in the content of neutral detergent fiber, acid detergent fiber, crude protein (CP) and all AAs among the barley samples. The standardized ileal digestibility (SID) of indispensable AAs with the exception of arginine, phenylalanine and threonine were different (P < 0.05) among the nine barley sources tested. With R² values exceeding 0.50, significant linear regression equations for CP and threonine were obtained. In conclusion, significant differences existed in the ileal digestibility of CP and AAs among barley varieties. It is difficult to predict the SID of most of the amino acids in barely based upon chemical characteristics.     

The influence of lupin seed germination on the chemical composition and standardized ileal digestibility of protein and amino acids in pigs

The germination process can modify the chemical composition of nutrients in seeds, which can influence the digestibility and utilization of sprouts in animal diets compared to raw seeds. The aims of research were to provide controlled germination process of lupin seeds, monitor the changes in seed composition and determine the influence of the germination on the coefficients of standardized ileal digestibility (SID) of crude protein and amino acids in growing pigs, compared to raw lupin seeds. The seeds of two lupin species were used: yellow (RYL) (Lupinus luteus, cv. Lord) and blue (RBL) (Lupinus angustifolius, cv. Graf). Germination was provided in the dark at 24 °C for 4 days. Nutritional and antinutritional compositions of raw and germinated seeds (GYL and GBL, respectively) were analysed. Digestibility study was performed on pigs with an average body weight of 25 kg, and the pigs were surgically fitted with a T‐cannula in the distal ileum, with chromic oxide as an indicator. Seed germination increased the crude protein and fibre concentrations, but reduced the levels of the ether extract, nitrogen‐free extracts and all amino acids in protein. The content of alkaloids and raffinose family oligosaccharides decreased in both lupin species. Germination had no positive impact (p > 0.05) on the SID of crude protein and amino acids. Germination of lupin seeds negatively influenced the SID of lysine and methionine (p < 0.05). The results of the research revealed a decrease in the concentrations of antinutritional factors in the sprouts of yellow and blue lupins compared to raw seeds; however, no positive effect was observed on the coefficients of the standardized ileal apparent digestibility of protein and amino acids.     

北方冬季应用塑料棚舍对肥育猪增重的影响

本试验选择杜洛克×长白杂交肥育猪２４头，在相同营养水平条件下进行试验，探索不同环境温度对肥育猪增重的影响。试验结果，试验Ⅰ、Ⅱ组舍内温度（１４．５℃、１０．５℃）均高，与最适温度（１５℃－２３℃）的基本接近。分别比对照组提高２８．９℃和２４．９℃（Ｐ＜０．０１）；日增重分别比对照组高出５８．５５％和４４．６５％（Ｐ＜０．０１）；每ｋｇ增重消耗饵饲料量分别比对照组减少３６．９％和３０．８％（Ｐ＜０．０１）。     

浅谈日粮纤维在猪的生产中的应用

概括了粮纤维在猪生产中的重要实践意义，以及积极的和消极的影响，并提出了实际生产中应注意的问题。     

Immunological characterization of peripheral blood leukocytes using vaccine for mycoplasmal pneumonia of swine (MPS) in swine line selected for resistance to MPS

This study was conducted to evaluate immunological changes in peripheral blood leukocytes in pigs that were genetically selected for their improved resistance to mycoplasmal pneumonia of swine (MPS), using MPS vaccine as an antigen. Twelve castrated MPS‐selected Landrace pigs were compared with the same number of pigs from a nonselected line by using a time‐course analysis at the hematological level. After the second sensitization with MPS vaccine, the percentages of B cells, CD4⁺ T cells, and natural killer (NK) cells in total leukocytes were lower in the selected line than in the nonselected line, whereas the percentage of granulocytes in total leukocytes increased in the MPS‐selected line. We also assessed the proliferative ability of peripheral blood mononuclear cells (PBMCs) stimulated with Mycoplasma hyopneumoniae, lipopolysaccharide or concanavalin A, and found that although the proliferative ability of the PBMC was not different between the two lines at a steady state, the nonselected line showed a significantly higher proliferative ability after sensitization with MPS vaccine than the selected line regardless of antigens used. These results thus indicate that the selection of pigs on the basis of MPS resistance changes their immunophenotype, and would give us beneficial information for the prevention of MPS infection.     

Adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization in swine

Adipic acid, upon catabolism, results in intermediates that bear a structural similarity to lysine degradation products. The objectives of this research were to determine whether adipic acid affects lysine concentrations in plasma and to evaluate whether adipic acid improves the efficiency of lysine utilization in pigs. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on plasma amino acid concentrations (plasma collected on d 7). In Exp. 2, nursery pigs (n = 56) were fed (for a period of 15 d) either a control diet or the same diet but deficient in either lysine, threonine, or tryptophan with or without supplemental adipic acid to assess the effects of adipic acid on the efficiency of amino acid utilization. The results from Exp. 1 showed that adipic acid increased plasma lysine (by 18%) but not alpha-amino adipic acid, an intermediate in lysine degradation. Experiment 2 demonstrated that adipic acid did not increase the efficiency of utilization of lysine, threonine, or tryptophan. The lack of effects on alpha-amino adipic acid in Exp. 1 and the lack of a positive effect on the efficiency of utilization of lysine, threonine, and tryptophan suggest that adipic acid does not inhibit the mitochondrial uptake of lysine and(or) its degradation in the mitochondrion. It is concluded that feeding adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization.     

猪日粮有效磷水平对氮磷排放的影响

本研究采用4×4拉丁方设计,选用4头52kg左右的健康三元杂交阉公猪(杜×长×大),以玉米-豆粕型基础日粮(不添加磷酸氢钙,日粮1)为对照,试验日粮分别添加磷酸氢钙0.12%(日粮2)、0.24%(日粮3)和0.36%(日粮4),相应的日粮有效磷(AP)水平分别为0.13%、0.15%、0.17%和0.19%.每期试验12d,预饲期5d,正试期3d,每期试验结束后有4d的恢复期.通过氮、磷平衡试验研究猪对磷、氮的利用率及其对环境的影响.结果表明:日粮1、日粮2、日粮3和日粮4的磷真消化率分别为53.00%、53.78%、65.19%和68.09%;粪磷的排泄量随食入磷量的减少而降低,氮的排泄量与氮表观消化率受日粮磷水平的影响不显著(P＞0.05);综合评价,磷酸氢钙的添加水平为0.12%～0.24%的效果较好,即AP在0.15%～0.17%之间,在不影响猪氮、磷营养需要的条件下,能有效的改善猪排泄物中氮、磷对环境的污染.     

Feeding brittle culm1 whole crop rice replacing wheat by-products to growing-finishing pigs

Abstract

The effect of feeding brittle culm1 whole crop rice (WCR) replacing wheat by-products on performance, digestibility and carcass quality was evaluated in growing-finishing pigs. Fifty-four pigs (Duroc) were randomly assigned to three dietary treatments: WCR at levels of 0 (control), 10 or 20%, respectively. Pigs were fed from about 29 to 85 kg. A digestion trial was conducted with all pigs at about 60 kg live weight. When the feeding trial was completed, six pigs from each treatment were slaughtered to determine carcass quality. In the growing period, pigs receiving the 10 or 20% WCR diet were not significantly different in daily feed intake, daily weight gain and feed conversion from the control pigs (p>0.05). In the finishing period, daily feed intake and daily weight gain of pigs fed the 20% WCR diet were significantly lower than control pigs or 10% WCR diet (p<0.05). However, the feed conversion was not significantly different among the pigs on three different diets. No significant (p>0.05) difference was shown in the apparent nutrient digestibility with the WCR substituting for wheat by-products. The dressing percentage and mean backfat thickness tended to be lower in pigs fed the 10 or 20% WCR diet than in control pigs. The meat from pigs on the 20% WCR diet showed a higher pH value at 24 h post mortem, and higher protein and lower fat content in longissimus muscles than control pigs (p<0.05). This study indicated that WCR could be an alternative feed source to replace wheat by-products in growing-finishing pig diets, but a high proportion of the WCR may result in an adverse effect on the performance traits.     

猪日粮有效磷水平对氮磷排放的影响

本研究采用4×4拉丁方设计,选用4头52kg左右的健康三元杂交阉公猪(杜×长×大),以玉米—豆粕型基础日粮(不添加磷酸氢钙,日粮1)为对照,试验日粮分别添加磷酸氢钙0.12%(日粮2)、0.24%(日粮3)和0.36%(日粮4),相应的日粮有效磷(AP)水平分别为0.13%、0.15%、0.17%和0.19%。每期试验12d,预饲期5d,正试期3d,每期试验结束后有4d的恢复期。通过氮、磷平衡试验研究猪对磷、氮的利用率及其对环境的影响。结果表明:日粮1、日粮2、日粮3和日粮4的磷真消化率分别为53.00%、53.78%、65.19%和68.09%;粪磷的排泄量随食入磷量的减少而降低,氮的排泄量与氮表观消化率受日粮磷水平的影响不显著(P>0.05);综合评价,磷酸氢钙的添加水平为0.12%～0.24%的效果较好,即AP在0.15%～0.17%之间,在不影响猪氮、磷营养需要的条件下,能有效的改善猪排泄物中氮、磷对环境的污染。