生长猪植物性饲料中可消化磷的评定

采用4×4拉丁方设计 ,用玉米淀粉—豆粕作为基础饲粮 ,运用替代基础饲粮的方法测定了生长猪对一些植物性饲料中磷的消化吸收情况 ,并分析了饲料的总磷、植酸磷含量和饲料植酸酶(E.C.3.1.3.26)活性的高低与饲料表观可消化磷的关系。试验结果表明 ,生长猪对以下几种饲料磷的表观消化率如下 :次粉 ,(54.43±3.41) % ;麦麸 ,(50.67±3.96) % ;小麦 ,(49.11±3.37) % ;大麦 ,(42.06±2.12) % ;豆粕 ,(30.83±3.66) % ;玉米 ,(18.99±4.11) % ;细米糠 ,(14.22±2.00) % ;统糠 ,(10.60±3.28) %。试验结果的分析表明 :饲料的总磷含量(X,g/kgDM)、植酸磷含量(Y,g/kgDM)、饲料天然植酸酶活性(Z,PU/g DM)对饲料的表观可消化磷含量(ADP ,g/kgDM)的影响极显著(P<0.01) ,并有极显著的回归关系 :ADP= -0.4155+0.7972X -0.7802Y +0.0013Z(R2=0.9767,P=0.001)。     

猪饲料磷生物学价值的评定

磷是猪必需的常量矿物元素,在猪体内具有重要的营养生理功能,是现代养猪生产过程中必须添加的矿物元素之一。本文综述了猪饲料磷生物学价值评定的研究进展。     

猪饲料表观可消化氨基酸和真可消化氨基酸

目前许多饲料厂家用总氨基酸含量设制日粮配方。因为氨基酸尤其是几种限制性氨基酸的消化率差异大,用总氨基酸含量配制日粮可能过高或过低估计了氨基酸的营养价值,导致氨基酸营养不平衡。许多研究认为,用可消化氨基酸配制日粮比总氨基酸日粮更精确,在选用氨基酸含量低或消化率变异大的饲料原料时更是如此。用可消化氨基酸配制日粮可以更准确地预测猪的生产性能并降低生产成本。 　　1氨基酸消化率的测定方法 　　现在已普遍用回肠分析法测定猪饲料氨基酸消化率,粪分析法较少采用。在过去二十年间曾测定了许多种饲料的猪回肠表观氨基…     

猪用3种饲料级磷酸盐磷沉积率的评定

运用平衡试验法 ,以去势生长公猪为试验动物 ,采用 4× 4拉丁方设计 ,用玉米淀粉、葡萄糖玉米蛋白粉、血粉等原料配置低磷的基础饲粮。用待测矿物质磷源替代基础饲粮中玉米淀粉的方法配置试验饲粮 ,通过平衡试验 ,测定了生长猪对 3种常用饲料级磷酸盐中磷的沉积率。试验结果表明 ,生长猪对以下 3种饲料级磷酸盐磷的沉积率分别为 :磷酸一钙 (磷酸二氢钙MCP) ,85 70 % ;磷酸二钙 (磷酸氢钙DCP) ,77 76 % ;骨粉 ,73 92 %。     

饲料级无机磷酸盐和饲料原料中磷的生物学效价的评定

磷(P)是日粮中不可缺少的重要营养元素。无论无机还是有机磷,他们的生物学效价都会不同。因此,了解生物学效价的知识和评定方法对选择饲料磷的来源,最大限度地发挥动物和家禽的生产性能,避免粪便过量的磷排泄具有极为重要的意义。本文的目的是对一些评定无机磷酸盐和有机饲料原料磷的生物学效价的常规方法做一介绍,并对他们的物理和化学特性加以描述。 磷是动物所必需的主要矿物元素之一。磷、钙,对于动物骨骼系统的生长和发育具有重要作     

生长猪高油玉米、玉米蛋白粉、棉粕可消化磷的评定

磷是动物生长发育所必需的常量矿物元素之一。植物性饲料中的磷60％-80％都以植酸磷形式存在，由于猪体内缺乏内源性植酸酶系统．所以难以利用饲料中的植酸态磷。在养猪生产中，往往向饲粮中添加大量的无机磷酸盐，从而造成磷资源的浪费、无机磷价格的迅速上升以及严重的环境污染等问题。所以很有必要从动物采食的磷源人手，准确评定各种饲料中磷的利用率，避免生产中磷的过量添加，达到既满足动物营养需要叉控制粪磷排出的目的。     

生长猪植物性饲料可消化磷预测模型的研究

本文旨在通过测定常用植物性饲料中总磷、植酸磷和天然植酸酶的含量,并结合动物试验的结果,探讨建立猪植物性饲料可消化磷预测模型的可行性,为磷资源的有效合理利用、降低养殖业排泄物对环境的磷污染提供简便方法。选用19种植物性饲料原料和2种配合饲料,在分析测定其总磷、植酸磷和天然植酸酶酶活的基础上,以25 kg左右三元杂交生长瘦肉型猪为试验动物,采用6×6(2个)、4×4(3个)拉丁方设计,以玉米淀粉-豆粕为基础日粮,分别按替代法和回归法,测得了单一饲料原料中磷的表观消化率和真消化率,并建立了可消化磷的预测模型。所建立的预测模型分别为:表观可消化磷(g/kg)Y=-0.411 0.405X1-0.227X2 0.003 15X3(R2=0.822,RSD=0.272,P<0.001),其中X1=总磷(g/kg),X2=植酸磷(g/kg),X3=植酸酶活(FTU/kg),下同;真可消化磷(g/kg)二元模型Y=0.062 9 0.655X1-0.412X2(R2=0.859,RSD=0.386,P<0.001),三元模型Y=-0.220 0.589X1-0.304X2 0.003X3(R2=0.882,RSD=0.244,P<0.001)。可以用饲料总磷、植酸磷和天然植酸酶酶活指标来预测植物性饲料可消化磷的含量,比较而言,对真可消化磷预测结果的准确性更高。     

生长猪用豆饼、菜粕、高赖氨酸玉米中可消化磷的评定

磷是动物机体必需的常量矿物质元素之一,对动物骨骼系统的发育及维持有着非常重要的作用。同时,磷是许多器官的有机组成部分,在机体的生化反应中发挥着关键作用。现代研究表明,磷还是畜禽营养中功能最多的营养成分之一,磷化合物几乎参与了动物机体内各种物质的合成过程,它还是对畜禽肉品质有影响的唯一矿物质元素(周顺伍,2000;杨文正,1996),并对能量代谢及维持组织细胞正常生理状态具有重要作用。动物机体缺磷会导致生长缓慢,生产力下降,饲料利用率降低等,严重时还会导致骨质软化症及佝偻病;饲粮中磷过量时,也会使骨组织发生病变,营养学上称…     

猪用植物性饲料中可消化磷的评定及植酸酶的作用

运用平衡试验法,以去势生长公猪为试验材料,采用4×4拉丁方设计。先后评定了生长猪用12种常规饲料中可消化磷的含量,同时评定了3种常规饲料在添加500FTU/千克微生物植酸酶的条件下,磷的表观消化率。试验结果表明,生长猪对普通玉米、豆粕、麦麸中磷的表观消化率分别为20.14％、31.42％、49.83％;DDGS(玉米干酒糟及其可溶物)、玉米胚茅粕、米糠中磷的表观消化率分别为54.64％,26.75％、10.85％;豆饼、菜籽粕、高赖氨酸玉米中磷的表观消化率分别为24.95％、29.25％、21.86％;小麦、稻谷、高梁中磷的表观消化率分别为50.00％、52.42％、16.51％;在添加500FTU/千克微生物植酸酶的条件下,小麦、稻谷、高梁中磷的表观消化率分别为77.64％、74.26％、64.38％。     

ORIGINAL ARTICLE: Fish bones – a highly available calcium source for growing pigs

In general, there is a lack of scientific documentation of nutritional value of marine by‐products. The bone fraction from fish has been regarded as waste. Due to the high mineral content of fish bones, this material can be well suitable as a natural calcium source. In the present study, apparent calcium absorption of different fish bone sources was tested using growing pigs. The experimental diets consisted of boiled salmon frames, or salmon, saithe or cod bones treated with enzymes. Calcium carbonate (CaCO₃) was used as control. The experimental diets were formulated to contain 0.7% total calcium of which the added calcium source to be tested contributed about 71% (study 1) and 86% (study 2). Except for the calcium and phosphorus sources, the animals received similar basal diets. Apparent calcium digestibility coefficient was calculated using yttrium as indicator (both studies) and was based on complete collection of faeces and urine (study 2). The experimental design was parallel and cross‐over in study 1 and study 2, respectively. In study 1, piglets getting salmon bone treated with enzymes had significantly higher calcium absorption than piglets getting boiled fish bone or calcium carbonate. Therefore, in the second study only enzymatically treated fish bones were included. The higher calcium absorption from enzymatically treated salmon bone was also found in study 2, but this time not significant. Calcium from boiled salmon bones in study I, and from enzymatically treated saithe and cod bones in study II were absorbed as well as the calcium carbonate control. The results indicate that fish bones may be a useful and well absorbed calcium source. Due to the high mineral content of the bone fraction, salmon bones can be well suitable as a natural calcium and phosphorus source in, for example, food, feed or as supplement.     

Lysine requirement for maintenance in growing pigs

Probably due to methodological problems the knowledge about the AA requirement for maintenance in pigs is rather scarce. In the present study an alternative experimental approach was applied and its underlying hypothesis was tested, whether protein retention decreases with body weight (BW), when daily lysine intake remains constant and acts as the limiting factor for protein retention, and whether this decrease reflects the increasing requirement of lysine for maintenance. If this hypothesis can be confirmed, lysine requirement for maintenance can be calculated when assuming a certain value for lysine concentration in body protein, since marginal efficiency of dietary lysine utilisation for protein retention is not affected by its level of intake (when being below the level necessary for maximum response), BW, protein retention capacity of the animal nor by energy intake. A series of N balances experiments using twelve castrated male pigs were performed at approximately 35, 55, 80, 110, and 140 kg of BW and body composition was determined by the D₂O dilution technique. Two lysine intake levels were tested to prove that the animals on the lower level respond to additional lysine and, therefore, have received a lysine-limiting diet, the prerequisite for the alternative. Based on the extent of the decrease in protein retention with BW the following estimates for the maintenance lysine requirement were derived: 18 mg/kg BW, 71 mg/kg BW^0.75, 29 mg/kg fat free substance, and 121 mg/kg body protein. These estimates are higher than values reported in the literature, which might be caused by methodological differences or by the higher feed intake of the animals in the present study.     

生长猪对饲料原料中磷的消化率

磷是生长猪的一种重要营养素,但它总是不能被猪完全利用,因为其经常与植酸结合在一起。使用标准全肠道消化率（Standard Total Tract Digestibility,STTD）概念,可以更好地测定饲料原料中磷的准确营养价值。豆粕是猪饲料中一种优质蛋白质原料,由于全球猪鸡的饲养规模不断扩大,大豆的需求量快速增加,大大超过了其供应量。因此,一些其它来源的蛋白质原料有时会用于饲料中,以向动物提供一些必需氨基酸。     

Influence of dietary phosphorus concentration on the digestibility of phosphorus in monocalcium phosphate by growing pigs

An experiment was conducted to test the hypothesis that the dietary inclusion rate of P does not influence the digestibility of P. The experiment was conducted at 4 experiment stations where the same protocol was followed. A total of 60 growing pigs (initial BW: 22.22 +/- 2.13 kg) were allotted to 6 dietary treatments with 10 replications per treatment. All pigs were placed in metabolism cages that allowed for the total, but separate, collection of urine and fecal materials. Six diets were formulated. The basal diet was based on corn (54.2%), soybean meal (20%), and cornstarch. No inorganic P was used, and the total concentration of P in the basal diet was calculated to be 0.29%. Five additional diets were formulated by adding monocalcium phosphate (MCP) in increments of 0.34% to the basal diet and thereby creating diets that were calculated to contain 0.36, 0.43, 0.50, 0.57, and 0.64% total P, respectively. Ground limestone was also added to these diets to maintain a calculated Ca:P ratio of 1.2:1. The balances of Ca and P and the apparent total tract digestibility (ATTD) of Ca and P were calculated for each diet. The contribution of P from the basal diet was then subtracted from the MCP-containing diets to calculate the balance and ATTD for P in MCP. Results of the experiment showed that the absorption and retention of both Ca and P increased (linear, P < 0.001) with increasing concentrations of Ca and P in the diet. The ATTD for Ca ranged from 62.3 to 66.8% and was not influenced by the dietary concentration of Ca. However, the ATTD for P increased from 38.4 to 65.2% as increasing levels of MCP were added to the diet (linear, P < 0.001). Increasing P intake from MCP increased (linear, P < 0.001) the excretion of P in the feces, but the quantity of P that was absorbed and retained also increased (linear, P < 0.001) as more P from MCP was added to the diet. When measured as a percentage of P intake, P retention was not influenced by the dietary P concentration. The ATTD for P in MCP ranged from 79.5 to 88.5% and was not affected by the concentration of P in the diet. Results of this experiment demonstrated that the digestibility and absorption of P from MCP are not influenced by the dietary concentration of P.     

提高猪磷利用率的分子生物学方法

本文从分子生物学方法的3个方面来论述提高猪对磷的利用率:1)通过添加经分子生物学改造的植酸酶来提高饲料磷的消化率;2)通过遗传方法改进大豆、玉米磷的水平来减少猪粪磷的含量;3)通过基因编码植酸酶来提高动物的代谢潜能(转植酸酶基因猪)。     

Influence of the amount of dietary fiber on the available energy from hindgut fermentation in growing pigs: use of cannulated pigs and in vitro fermentation

Available energy from hindgut fermentation to pigs fed various amounts of dietary fiber was investigated using an in vivo-in vitro methodology. Six growing pigs fitted with a simple T-shaped cannula at the terminal ileum, and following a Latin-square design, were fed 3 diets differing in the content of non-starch polysaccharides (NSP): a low fiber diet (LFD, 77 g/kg of DM), a standard fiber diet (SFD, 160 g/kg of DM), and a high fiber diet (HFD, 240 g/kg of DM). After adaptation to the diet for 10 d, samples from feces and ileum were collected and analyzed for DM, energy, NSP, and chromic oxide; feces were also analyzed for short chain fatty acids (SCFA). Freeze-dried ileal samples (10 g/L) were fermented in vitro in a fecal slurry consisting of an anaerobic mineral salt medium and feces (50 g/L) from cannulated pigs fed the same diets. Available energy was calculated from the amount of SCFA produced in vitro after 48 h of incubation. Nonstarch polysaccharide content in the fermented material was measured to assess the in vitro degradation of this fraction. Increasing dietary NSP from 77 to 240 g/kg of feed DM increased (P < 0.001) ileal flow from 199 to 468 g/kg of feed, leading to a reduction in the energy digested at the terminal ileum, from 15 to 11 MJ/kg of feed DM and an increment in energy digested in the hindgut, from 1.6 to 3.5 MJ/kg of feed DM. Total in vitro production of SCFA/kg of feed DM was dependent on the amount of ileal substrate available for fermentation; that is, increased concentrations of NSP in the diet led to an increase in the SCFA that may be available to the animal (P < 0.001). The molar ratio of SCFA produced in vitro was affected by diet; the high fiber diet showed the greatest (P = 0.004) proportion of acetic acid, and the low fiber diet showed a tendency (P = 0.081) to an increased butyric acid proportion compared with the other 2 diets. Net disappearance of NSP during fermentation in vivo and in vitro were compared and showed a close relationship (P < 0.001, slope = 0.906, r = 0.960). In our experimental conditions, available energy as SCFA to the animal from hindgut fermentation increased with the concentration of dietary NSP (P < 0.001) and provided between 7.1 and 17.6% of the total available energy.     

磷缺乏日粮添加米糠和植酸酶对生长猪养分利用率及氮磷代谢的影响

文章旨在研究日粮添加不同水平米糠及植酸酶对生长猪养分消化率及钙磷代谢的影响。试验选择48头平均体重为(87.0±2.45)kg的生长猪,随机分为6组,每组4个重复,每个重复2头猪。对照组饲喂玉米-豆粕型基础日粮,处理组用7.5%、15%、30%的米糠替代基础日粮,同时另外两组在对照组和30%米糠组分别添加750IU/kg植酸酶,试验共进行2周,包括1周适应期和1周试验期。结果显示:随着日粮米糠添加水平的升高,干物质、能量、氮、纤维、钙表观消化率显著线性升高(P<0.05),而磷表观消化率显著线性降低(P<0.05)。随着日粮米糠添加水平的升高钙沉积率显著升高(P<0.05),对磷代谢平衡其他指标均具有显著升高的影响(P<0.05),粪氮量显著升高(P<0.05),其他氮平衡指标显著降低(P<0.05)。日粮添加植酸酶显著提了磷、脂肪和钙表观消化率(P<0.05),而米糠添加水平显著提高了养分表观消化率(P<0.05)。米糠替代基础日粮添加植酸酶显著提高了钙沉积率(P<0.05),显著提高了磷的吸收和沉积量(P<0.05)。结论:猪日粮中添加米糠较玉米-豆粕型日粮降低了磷表观消化率,添加植酸酶后可以改善氮、磷代谢。