降低生长肥育猪饲料中磷酸氢钙水平的研究

分30-60kgBW、60～100kgBW和30～100kgBW三个阶段研究了降低饲料中磷酸氢钙水平及降低磷酸氲钙的同时添加植酸酶对猪生长性能的影响。结果表明：磷酸氢钙添加水平在生长猪（30～60kgBW）饲料中由对照组的0．920％降低到0．552％、肥育猪（60-100kgBW）饲料中由对照组的0．760％降低到0．380％时都没有显著降低猪的生长性能（P〉0．05），降低磷酸氢钙的同时添加植酸酶虽没有显著提高猪的生长速度（P〉0．05），但能降低料肉比，其中在全阶段（30～100kgBW）的作用显著（P〈0．05）。     

微生物植酸酶对猪钙、磷利用率及骨骼发育的影响

本试验旨在研究从断奶到肥育结束,在饲粮中添加微生物植酸酶对猪钙、磷代谢及骨骼发育的影响。试验采用完全随机设计,将72头35日龄断奶的仔猪分为4组,每组3个重复,每个重复6头。试验在相同钙水平基础上设4个组,分别为:1)玉米-豆粕基础日粮(对照组);2)基础日粮 植酸酶-50%磷酸氢钙(处理1);3)基础日粮 植酸酶-75%磷酸氢钙(处理2);4)基础日粮 植酸酶-100%磷酸氢钙(处理3)。试验期按体重分3个阶段:8~20 kg、20~50 kg、50~90 kg,3个阶段植酸酶的添加量分别为750、500和250 U/kg。试验结果表明:(1)在8~20 kg和20~50 kg阶段,添加植酸酶的3个处理,钙、磷消化率显著高于对照组(P<0.05);血钙和血磷浓度,处理1和处理2与对照组无显著差异(P>0.05),处理3显著低于对照组(P<0.05)。在50~90 kg阶段,添加250 U/kg植酸酶代替100%磷酸氢钙,血磷、血钙浓度显著低于对照组(P<0.05);(2)在试验的3个阶段添加植酸酶同时降低饲粮无机磷水平,对血清碱性磷酸酶活性均无显著影响(P>0.05);(3)添加植酸酶使胃中植酸磷消化率显著提高(P<0.0 1),粪中磷排出量显著降低(8~2 0 kg、2 0~5 0 kg阶段,P<0.0 1;5 0~9 0 kg阶段,P<0.0 5);(4)添加植酸酶代替50%或75%磷酸氢钙,猪的掌骨灰分与采食正常磷日粮的对照组无显著差异,但代替100%磷酸氢钙组,猪的掌骨灰分和蹠骨强度则显著低于对照组(P<0.05);添加植酸酶代替50%磷酸氢钙组,猪的蹠骨强度显著高于对照组(P<0.05),代替75%磷酸氢钙组与对照组差异不显著(P>0.05)。总之,在断奶和生长阶段,在猪玉米-豆粕日粮中添加植酸酶可代替部分磷酸氢钙,促进了钙、磷消化利用,促进了骨骼生长,也促进了植酸磷的利用,降低了粪磷排出。     

植酸酶和磷酸氢钙对生长猪生长性能和养分消化率的影响

选择体重(35.92±4.84)kg的长白X大约克二元杂种阉公猪56头,随机分为4个处理,分别饲喂常磷不加植酸酶饲粮、低磷不加植酸酶饲粮、常磷加植酸酶饲粮和低磷加植酸酶饲粮,每个处理14个重复,每个重复1头猪,研究饲粮添加植酸酶(750 IU/kg饲料)和不添加磷酸氢钙对生长猪的生长性能和养分代谢的影响.结果表明:低磷不加植酸酶组与常磷不加植酸酶组相比,采食量降低1.23%(P>0.05),料重比增加13.82%(P<0.01),日增重降低18.52%(P<0.01),单位增重饲料成本增加13.50%(P<0.01),磷表观消化率降低13.83%(P<0.01),钙表观消化率降低4.21%(P>0.05).粗蛋白质表观消化率降低2.55%(P>0.05);常磷加植酸酶组与常磷不加植酸酶组相比,采食量增加2.06%(P>0.05),料重比降低4.73%(P<0.01),日增重增加7.33%(P<0.01),单位增重饲料成本降低4.70%(P<0.01),磷表观消化率提高12.45%(P<0.05),钙表观消化率提高5.63%(P<0.05),粗蛋白质表观消化率提高4.00%(P>0.05);低磷加植酸酶组与低磷不加植酸酶组相比,采食量增加5.00%(P>0.05),料重比降低12.14%(P<0.01),日增重增加27.67%(P<0.01),单位增重饲料成本降低12.07%(P<0.01),磷表观消化率提高39.59%(P<0.01),钙表观消化率提高7.94%(P<0.01),粗蛋白质表观消化率无显著变化(P>0.05);低磷加植酸酶组与常磷不加植酸酶组相比采食量、日增重、料重比和单位增重饲料成本均差异不显著,磷表观消化率提高20.28%(P<0.01),钙表观消化率提高3.39%(P<0.05),粗蛋白质表观消化率无显著变化(P>0.05).结论:1)添加植酸酶(常磷加植酸酶组与常磷不加植酸酶组比,低磷加植酸酶组与低磷不加植酸酶组比)能够提高生长猪生长性能和钙、磷的表观消化率,降低生产成本,对粗蛋白质表观消化率无显著影响;2)不添加磷酸氢钙(低磷加植酸酶组与常磷加植酸酶组比,低磷不加植酸酶组与常磷不加植酸酶组比)会降低生长猪生长性能,但对钙和粗蛋白质的表观消化率无显著影响;3)低磷加植酸酶组与常磷加植酸酶组相比,猪的生长性能和钙、粗蛋白质的表观消化率无显著差异,但磷的消化率大大提高了,有利于环境保护;4)低磷加植酸酶饲粮有利于猪的生长、降低生产成本和环境保护,为最佳饲粮.     

不同磷酸氢钙水平大麦型饲粮对生长猪生长性能及粪磷排放的影响

试验研究了不同磷酸氢钙添加水平的大麦型饲粮在添加植酸酶及非淀粉多糖酶类条件下,对生长猪生长性能及粪磷排泄量的影响.选择(33.4±2.33) kg的杜长大杂种仔猪108头,随机分成3组,分别饲喂如下3种磷水平饲粮:总磷0.39％(磷酸氢钙6 kg/t)；总磷0.33％(磷酸氢钙3 kg/t)；总磷0.29％(不添加磷酸氢钙).每组3个重复,每个重复12头猪.结果表明,本试验条件下,植酸磷含量较高的大麦型生长猪饲粮,添加植酸酶等酶制剂后,少量添加或完全不添加磷酸氢钙对生长猪的生长性能没有显著影响(P＞0.05),试验猪采食每千克低磷酸氢钙水平饲粮或不添加磷酸氢钙饲粮之粪磷排泄量减少13.25％～22.29％.     

饲粮中添加微生物植酸酶和有机酸对断奶仔猪生产性能的影响

试验通过测定断奶仔猪的生长性能,研究断奶仔猪日粮中添加微生物植酸酶和有机酸的效果。试验采用完全随机设计,将72头体重相近、遗传基础相似的35日龄断奶的杜×长×大三元杂交仔猪分为4组,每组3个重复,每个重复6头猪。试验日粮在相同钙水平基础上,分别设为:玉米—豆粕型基础日粮(正对照组)、基础日粮-50%磷酸氢钙(负对照组)、基础日粮+植酸酶(500U/kg)-50%磷酸氢钙(处理1组)、基础日粮+植酸酶(500U/kg)+有机酸(0.35%柠檬酸)-50%磷酸氢钙(处理2组)。试验结果表明:①与负对照组相比,处理1组和处理2组平均日增重(ADG)和增重与饲料比(G/F)显著提高(P<0.05),处理1组和处理2组之间无显著差异(P>0.05),但ADG和G/F均以处理2组较高;各处理组间仔猪的平均日采食量(ADFI)无显著差异(P>0.05)。②添加植酸酶或植酸酶和有机酸不影响粗蛋白(CP)的表观消化率和血清尿素氮(SUN)浓度(P>0.05)。总之,仔猪断奶阶段,在玉米—豆粕型基础日粮中添加植酸酶或植酸酶和有机酸代替部分磷酸氢钙,仔猪的生长性能与含正常无机磷水平的正对照组相比无显著差异,500U/kg植酸酶或500U/kg植酸酶和0.35%柠檬酸足以代替仔猪日粮中50%磷酸氢钙,但植酸酶和有机酸对于提高仔猪生长性能不存在显著的协同效应。     

转植酸酶基因玉米对肉仔鸡生长性能及钙磷代谢的影响

选择480只AA商品代肉仔鸡,随机分为4组,每组3个重复,对照组添加磷酸氢钙,试验各组磷酸氢钙减半,分别添加500 U/kg的外源植酸酶和500、750 U/kg转植酸酶基因玉米来源的植酸酶。试验结果表明:肉仔鸡试验期间健康状况正常,各组平均日增重、饲料转化率均无显著差异(P>0.05);各组间血清和胫骨中钙、磷、氮水平无显著差异(P>0.05);试验组21和42日龄时粪中磷的存留量分别比对照组降低49.43%、55.17%、54.02%和31.50%、32.28%、14.96%,差异极显著(P<0.01);转植酸酶基因玉米组与微生物植酸酶组相比差异不显著(P>0.05)。转植酸酶基因玉米可以替代外源植酸酶作为一种植酸酶来源在肉仔鸡日粮中使用,不仅不影响生产性能,而且减少磷酸氢钙的使用和氮磷的排放。     

植酸酶替代磷酸氢钙对肉鸡生长性能、胴体性状、骨矿化及经济效益的影响

文章旨在评估日粮添加不同水平植酸酶替代磷酸氢钙对肉鸡生长性能、胴体性状、骨矿化的影响。试验将平均体重为（55.11±1.08）g的672只1日龄商品肉鸡随机分为3组,每组4个重复,每个重复56只。对照组肉鸡饲喂无植酸酶的日粮,T1和T2组分别饲喂植酸酶（20000 FYT/g）添加水平为50和100 mg/kg的日粮,同时磷酸氢钙添加量从对照组的15.8 g/kg减少到7.5g/kg和5.5 g/kg,试验分为1～21 d和22～42 d。结果：与对照组相比,100 mg/kg植酸酶组42 d肉鸡的体重显著提高2.99%（P＜0.05）,同时,22～42 d和1～42 d饲料报酬分别显著提高7.02%和4.76%（P＜0.05）。50和100 mg/kg植酸酶组小肠相对重量较对照组分别显著提高40.13%和38.16%（P＜0.05）,而100 mg/kg植酸酶组心脏相对重量显著提高19.08%（P＜0.05）。日粮添加植酸酶对大部分胴体性状无显著影响（P＞0.05）,但与对照组相比,100 mg/kg植酸酶组肉鸡的腹脂相对重量显著提高12.15%（P＜0.05）。结论：在本研究条件下,粮添加50～100 mg/kg植酸酶对肉鸡胴体性状和骨矿化程度无负面影响,但用100 mg/kg植酸酶替代10.3 g/kg磷酸氢钙可以提高肉鸡的饲料报酬,降低增重成本。 [关键词]植酸酶|磷酸氢钙|肉鸡|生长性能|胴体性状|骨矿化     

植酸酶对断奶仔猪的生产性能和有关生化指标的影响

选择28日龄体重相近的断奶仔猪30头,随机分成3组,即2个试验组、1个对照组,饲喂玉米-豆粕型日粮。试验Ⅰ组以200g/t料的植酸酶取代50%磷酸氢钙,试验Ⅱ组以200g/t料的植酸酶取代75%磷酸氢钙,对照组饲喂基础日粮。试验结果表明:用植酸酶(200g/t料)取代50%的磷酸氢钙(试验Ⅰ组),生长猪的日增重和饲料报酬均优于对照组(P<0.05)。但用200g/t植酸酶取代75%的磷酸氢钙(试验Ⅱ组)则上述指标下降。添加植酸酶后,粪中磷含量分别下降24.19%和38.7%(P<0.05),对环境的污染明显下降,血液中的磷的含量与对照组没有显著差异(P>0.05)。     

植酸酶和磷酸氢钙对育肥猪生长性能和养分消化率的影响

采用体重75 kg的长白×大约克二元杂交阉公猪56头,随机分为4个处理,分别饲喂常磷日粮、低磷日粮、常磷加植酸酶日粮和低磷加植酸酶日粮。每个处理14个重复,每个重复1头,研究杂粕型日粮添加植酸酶(750 U/kg)和不添加磷酸氢钙对育肥猪的生产性能和养分消化率的影响。结果表明:低磷组比常磷组的采食量降低了5.04%(P<0.05),料重比增加了17.94%(P<0.01),日增重降低了19.80%(P<0.01),单位增重饲料成本增加了17.20%(P<0.01),磷表观消化率降低了10.16%(P<0.01),钙表观消化率降低了8.56%(P<0.05),粗蛋白表观消化率无显著变化(P>0.05);常磷加酶组比常磷组的采食量增加了2.97%(P>0.05),料重比增加了3.53%(P>0.05),日增重降低了1.70%(P>0.05),单位增重饲料成本增加了4.12%(P>0.05),磷表观消化率降低了3.46%(P>0.05),钙表观消化率降低了4.40%(P>0.05),粗蛋白表观消化率无显著变化(P>0.05);低磷加酶组比低磷组的采食量增加了7.50%(P<0.01),料重比降低了13.47%(P<0.01),日增重增加了24.30%(P<0.01),单位增重饲料成本降低了13.60%(P<0.01),磷表观消化率提高了42.09%(P<0.01),钙表观消化率提高了11.18%(P<0.01),粗蛋白表观消化率无显著变化(P>0.05);低磷加酶组(即无磷酸氢钙日粮加酶组)与常磷组相比采食量、日增重、料重比和单位增重饲料成本均差异不显著(P>0.05),磷表观消化率提高了27.66%(P<0.05),钙表观消化率提高了1.68%(P>0.05),粗蛋白表观消化率无显著变化(P>0.05)。结论:低磷日粮添加植酸酶可以提高猪生长性能,提高钙磷表观消化率,但对粗蛋白表观消化率无显著影响;常磷日粮添加植酸酶对猪的生长性能和养分表观消化率均无显著影响;不添加磷酸氢钙会降低猪的生长性能和钙磷的表观消化率。     

不同无机磷水平日粮添加植酸酶对保育猪生长性能、血清生化指标及养分表观消化率的影响

本试验旨在研究不同无机磷水平日粮添加植酸酶对保育猪生长性能、血清生化指标及养分表观消化率的影响。选择(40±2)日龄保育猪224头,随机分为7个处理,每个处理4个重复,每个重复8头猪。处理Ⅰ为对照组,饲喂基础日粮(参照NRC(1998)配制,通过加入磷酸氢钙满足磷需要量),处理Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ组磷酸氢钙水平分别为对照组的100%,75%、50%、25%、0%,并添加750FTU·kg-1的植酸酶,处理Ⅶ为阴性对照组,不添加磷酸氢钙和植酸酶,预试期7d,试验期35d。试验结果表明,100%、75%、50%磷酸氢钙加酶组的平均日采食量、平均日增重和料重比均与对照组无显著差异(P0.05),无磷酸氢钙组添加植酸酶可以显著改善料重比(P0.05)。随日粮无机磷水平的降低,加酶组的平均日增重、平均日采食量及血清磷浓度呈线性和二次曲线降低(P0.01),血清碱性磷酸酶(ALP)活性及钙、磷、粗蛋白、干物质的表观消化率呈线性和二次曲线升高(P0.01)。无磷酸氢钙加酶组钙和磷的表观消化率显著高于阴性对照组(P0.05)。综上所述,本试验条件下,在日粮中添加植酸酶降低无机磷添加量能提高保育猪对日粮中养分的表观消化率,改善生长性能;并且,植酸酶在低磷日粮中的效果更为明显。综合各项指标,在保育猪日粮中添加750FTU·kg-1的植酸酶可以降低25%~50%的磷酸氢钙添加量。     

Water-soluble phosphorus excretion in pigs fed diets supplemented with microbial phytase

Three experiments were conducted to compare the excretion of water-soluble phosphorus (P) of starter, grower, and finisher pigs fed corn-soybean meal-based P-deficient basal diet containing no added inorganic P (B), P-adequate diet (the basal diet with added dicalcium phosphate; B + P), the basal diet plus 500 units of microbial phytase/kg (B + 500), or the basal diet plus 1000 units of microbial phytase/kg (B + 1000). There were 6 barrows per diet, in a randomized complete block design, with an average initial body weight of 10.4, 20.0, or 51.1 kg for each of starter, grower, and finisher pigs in the three phosphorus balance experiments, respectively. In the experiments, the addition of dicalcium phosphate or phytase to the basal diet increased ( P  < 0.05) the digestibility and retention of P, and there were linear reductions ( P  < 0.05) in water-soluble P excretion as a result of supplementing the basal diet with phytase. In the starter pig experiment, phytase addition at 500 or 1000 units/kg reduced ( P  < 0.05) water-soluble P excretion by 28 or 42%, respectively when compared with the B + P diet. In the grower pig experiment, adding phytase at 500 or 1000 units/kg reduced ( P  < 0.05) water-soluble P excretion by 24 or 34%, respectively when compared with the B + P diet. The use of phytase at 500 or 1000 units/kg reduced ( P  < 0.05) water-soluble P excretion by 11 or 30%, respectively in the finisher pig experiment. The proportion of water-soluble phosphorus in total phosphorus was not affected by dietary treatment in any of the three experiments. In conclusion, adding phytase at 1000 units/kg to a corn-soybean meal-based P-deficient diet basal diet containing no added inorganic P compared with B + P diet reduced the daily excretion of water-soluble P in starter, grower, and finisher pigs by 42, 34, and 30%, respectively.     

Distribution of supplemental Escherichia coli AppA2 phytase activity in digesta of various gastrointestinal segments of young pigs

The objective of this study was to determine the functional location and disappearance of activity of a supplemental Escherichia coli AppA2 phytase and its impact on digesta P and Ca concentrations in the gastrointestinal tract of pigs. In Exp. 1, 18 pigs (8.3 +/- 0.2 kg of BW) were allotted to 3 groups (n = 6 each) and fed a low-P (0.4%) corn-soybean meal, basal diet (BD), BD + phytase [500 units (U)/kg of feed], or BD + inorganic P (iP, 0.1%) for 4 wk. In Exp. 2, 30 pigs (14.5 +/- 0.2 kg of BW) were allotted to 3 groups (n = 10 each) and fed BD, BD + 500 U of phytase/kg of feed, or BD + 2,000 U of phytase/kg of feed for 2 wk. Five or six pigs from each treatment group were killed at the end of both experiments to assay for digesta phytase activity and soluble P concentration in 6 segments of the digestive tract and digesta total P and Ca concentrations in stomach and colon. Compared with pigs fed BD, pigs fed BD + 500 U of phytase/kg of feed in Exp. 1 and BD + 2,000 U of phytase/kg of feed in Exp. 2 had greater (P < 0.05) phytase activities in the digesta of the stomach and upper jejunum (2 m aborally from the duodenum). No phytase activity was detected in the digesta of the lower jejunum (2.12 m cranial to the ileocecal junction) or ileum from any of the treatment groups in either trial. Concentrations of digesta-soluble P peaked in the upper jejunum of pigs fed BD in Exp. 1 and 2, but showed gradual decreases between the stomach and the upper jejunum of pigs fed BD + phytase or BD + iP. In both experiments, pigs fed only BD had greater (P < 0.05) colonic digesta phytase activity and soluble P concentrations than those fed phytase. In Exp. 2, total colonic digesta P or Ca concentrations, or both, of pigs displayed a phytase-dose-dependent reduction (P < 0.05). In conclusion, supplemental dietary AppA2 mainly functioned in the stomach and was associated with a reduced phytase activity in colonic digesta of weanling pigs.     

Effect of phytase addition and dietary calcium and phosphorus levels on plasma metabolites and ileal and total-tract nutrient digestibility in pigs

Two experiments were conducted to determine the effect of phytase on plasma metabolites and AA and energy digestibility in swine. In Exp. 1, eight barrows (surgery BW = 52 kg) were fitted with steered ileocecal cannulas. The experiment was a Latin rectangle and the treatments were 1) corn-soybean meal diet adequate in Ca and P (0.5% Ca, 0.19% available P [aP]), 2) corn-soybean meal diet with reduced Ca and P (0.4% Ca, 0.09% aP), 3) Diet 1 with 500 phytase units/kg, or 4) Diet 2 with 500 phytase units/kg. Pigs were fed twice daily to a total daily energy intake of 2.6 x maintenance (106 kcal of ME/kg of BW(0.75)). For each ileal digesta sample, digesta samples were collected for two 24-h periods and combined for each pig. The combination of supplementing with phytase and decreasing the concentration of dietary Ca and P increased average ileal AA (P < 0.02), starch (P < 0.02), GE (P < 0.04), and DM (P < 0.03) digestibilities. In Exp. 2, a feeding challenge was conducted with barrows (eight per treatment; average BW of 53 kg). The treatments consisted of a corn-soybean meal diet or corn-soybean meal diet + 500 phytase units per kilogram of diet. In the diet with no phytase, Ca and aP were at 0.50% and 0.19%, respectively, and, in the diet with phytase, Ca and aP were each decreased by 0.12%. A catheter was surgically inserted into the anterior vena cava of each pig 6 d before the start of the feeding challenge. The barrows were penned individually, and the diets were fed for 3 d before the challenge. The pigs were held without feed for 16 h, and blood samples were obtained at -60, -30, and 0 min before the pigs were fed (2% of BW). Blood samples were then collected at 10, 20, 30, 40, 50, 60, 75, 90, 105, 120, 150, 180, 210, 240, 270, and 300 min after feeding. Glucose area under the response curve and plasma glucose, insulin, urea N, and total alpha-amino N concentrations were increased (P < 0.05) in pigs fed the diet with reduced Ca and P and the phytase addition. Area under the response curve for insulin, urea N, and total alpha-amino N; insulin:glucose; and plasma NEFA concentration, clearance, and half-life were not affected by diet. In conclusion, the combination of Ca and P reduction and phytase addition increased nutrient and energy digestibility in diets for pigs and increased plasma concentrations of glucose, insulin, urea N, and alpha-amino N.     

猪的生长阶段对饲料磷的全肠道消化率的影响

本试验旨在研究猪的生长阶段对饲料磷的全肠道消化率的影响。选用初始平均体重分别为27.2、59.1、103.1kg的生长育肥猪各16头,根据体重随机分为低磷饲粮组和高磷饲粮组,每组8个重复,每个重复1头猪。低磷饲粮为无磷酸氢钙(DCP)的玉米-豆粕型饲粮,饲粮总磷浓度为3.3 g/kg,在低磷饲粮中添加14.5g/kgDCP构成总磷浓度为5.9 g/kg的高磷饲粮。采用全收粪法测定总磷的表观全肠道消化率(ATTD),采用差量法计算DCP中磷的全肠道真消化率(TTTD)。试验共12 d,包括5 d适应期和7 d粪样收集期。结果表明:高磷饲粮组的可消化磷含量和总磷的ATTD均显著高于低磷饲粮组(P<0.05);饲喂高磷饲粮时,不同生长阶段猪磷的ATTD无显著差异(P>0.1);饲喂低磷饲粮时,育肥猪磷的ATTD显著高于生长猪和生长育肥猪(P<0.05);虽然饲粮总磷的ATTD受生长阶段影响(P<0.05),但生长阶段对DCP中磷的TTTD无显著影响(P>0.1)。由此可见,猪的生长阶段显著影响植物性饲料原料中磷的消化利用率,但对DCP中磷的消化利用率无显著影响。     

Effectiveness of an experimental consensus phytase in improving dietary phytate-phosphorus utilization by weanling pigs

Consensus phytase is a new biosynthetic, heat-stable enzyme derived from the sequences of multiple homologous phytases. Two experiments were conducted to determine its effectiveness, relative to inorganic P and a mutant enzyme of Escherichia coli phytase (Mutant-EP), in improving dietary phytate-P availability to pigs. In Exp. 1, 36 pigs (3 wk old, 7.00 +/- 0.24 kg of BW) were fed a low-P corn-soybean meal basal diet plus consensus phytase at 0, 250, 500, 750, 1,000, or 1,250 U/kg of feed for 5 wk. Plasma inorganic P concentration, plasma alkaline phosphatase activity, bone strength, and overall ADG and gain:feed ratio of pigs were improved (P < 0.05) by consensus phytase in both linear (R2 = 0.20 to 0.70) and quadratic (R2 = 0.30 to 0.70) dose-dependent fashions. In Exp. 2, 36 pigs (4 wk old, 9.61 +/- 0.52 kg BW) were fed the basal diet + inorganic P at 0.1 or 0.2%, consensus phytase at 750 or 450 U/kg of feed, Mutant-EP at 450 U/kg of feed, or 225 U consensus + 225 U Mutant-EP/kg of feed. Pigs fed 750 U of consensus phytase or 450 U of Mutant-EP/kg feed had plasma inorganic concentrations and bone strength that fell between those of pigs fed 0.1 or 0.2% inorganic P. These two measures were 16 to 29% lower (P < 0.05) in pigs fed 450 U of consensus phytase/kg of feed than those of pigs fed 0.2% inorganic P. Plasma inorganic P concentrations were 14 to 29% higher (P < 0.05) in pigs fed Mutant-EP vs. consensus phytase at 450 U/kg at wk 2 and 3. In conclusion, the experimental consensus phytase effectively releases phytate P from the corn-soy diet for weanling pigs. The inorganic P equivalent of 750 U of consensus phytase/kg of feed may fall between 0.1 and 0.2%, but this requires further determination.     

低聚木糖对生长肥育猪生长性能、胴体性状和肉品质的影响

为了研究低聚木糖(XOS)对生长肥育猪生长性能、胴体性状和肉品质的影响,试验选取平均体重为30 kg左右的三元杂交猪80头,随机分为8组,每组10头,公、母各占1/2,单栏饲养。试验设对照组、抗生素组,3065 kg阶段100、250和500 g/t XOS组,以及30100 kg阶段100、250和500 g/t XOS组。分别于试验开始和结束时记录每头猪的空腹体重及采食量,计算平均日采食量(ADFI)、平均日增重(ADG)和料重比(F/G);于试猪平均体重达100 kg时屠宰采样,测定胴体性状、肉品质和肌肉化学成分。结果表明:与对照组或抗生素组相比,饲粮添加不同剂量的XOS对生长肥育猪的ADFI、ADG、F/G、胴体性状和肉品质均无显著影响(P0.05);3065 kg阶段添加250 g/t XOS可显著增加脾脏指数以及背最长肌粗蛋白质含量(P0.05);30100 kg阶段添加500 g/t XOS可显著增加脾脏指数及背最长肌粗蛋白质含量(P0.05)。综上所述,饲粮添加不同剂量的XOS虽对生长肥育猪的ADFI、ADG、F/G、胴体性状和肉品质等指标影响不显著,但可通过增加肌肉粗蛋白质含量而改善猪肉营养价值;以30100 kg阶段添加500 g/t XOS效果较佳。     

冬季可拆迁式猪舍对生长育肥猪生长性能及舍内温湿度的影响

试验通过可拆迁式猪舍与传统(固定)猪舍的饲养对比试验,研究了冬季可拆迁式猪舍对生长肥育猪的生长性能及舍内温度和相对湿度的影响。选取同期转群、体重30 kg左右杜大长生长猪216头,随机分成可拆迁式猪舍组和传统猪舍组,每组3个重复,每个重复36头。试验至猪体重达到100 kg左右出栏结束。结果表明:可拆迁式猪舍组试猪的平均日增重和平均日采食量分别比传统猪舍组提高17.28%(P0.01)和12.13%(P0.01),饲料料增重比降低7.00%(P0.05);可拆迁式猪舍的舍内平均温度为20.33℃,比固定猪舍的16.86℃高3.47℃,比室外的15.15℃高5.18℃,差异均极显著(P0.01)。试验结果表明,可拆迁式猪舍对生长育肥的生长性能和室内环境控制优于传统猪舍。     

高粱替代玉米对育肥猪生长性能、血液生化指标、抗氧化性能和免疫力的影响

本试验旨在研究高粱替代不同水平的玉米对育肥猪生长性能和血液生化指标的影响。选择体重为(48.93±3.01)kg、健康的杜×长×大三元育肥猪160头,随机分为4组,每组4个重复,每个重复10头猪。基础日粮为玉米-豆粕型,根据NRC(2012)配制,对照组饲喂基础日粮,试验组分别用高粱替代30%、65%和100%的玉米,预试期7d,试验期60d。结果表明:与对照组相比,高粱替代部分玉米后对育肥猪的耗料增重比、平均日采食量无显著影响,高粱全部替代玉米后育肥猪平均日增重降低3.4%(P<0.05);用高粱替代65%和100%的玉米对育肥猪血清免疫指标和血液生化指标无显著影响,但抗氧化酶活性提高了32.4%和38.7%(P<0.05),同时还能够降低丙二醛浓度(P<0.05)。综上所述,在本试验条件下,高粱替代玉米可以提高育肥猪血清抗氧化功能,可替代日粮中30%～65%的玉米进行猪育肥生产。     

Genetic Parameters for Average Daily Gain,Area of M. Longissimus Dorsi,Feed Efficiency and Feed Intake Capacity in Young Bulls of Dairy Populations

Abstract

Effects of phytase and xylanase supplementation to a wheat-based pig diet were studied. The diet was fed without or with supplementation of dicalcium phosphate (diet A), phytase (diet BP), xylanase (diet BX) and phytase + xylanase (diet BPX). Apparent digestibility of P and Ca were higher in diets BP and BPX. Apparent digestibility of crude protein (CP) was higher in pigs which were fed the BPX diet than pigs which were fed the BP and BX diets. Pigs given diet BPX, had highest daily weight gain and had higher daily feed consumption, except for pigs given diet BP. In conclusion, phytase improved the utilisation of P and Ca, while xylanase alone had no positive effects on OM, CP and NDF digestibility. The combination of the two enzymes had some benefits in terms of CP digestibility and resulted in an improved feed intake and daily weight gain, while feed conversion ratio was unaffected.