植物性植酸酶对蛋鸡生长性能的影响和营养物质的利用情况

实验以2～10周龄的海兰褐蛋鸡为研究对象,以玉米-豆粕为基础日粮,设1个对照组和6个处理组。通过对比各组饲粮,研究麦麸中植物性植酸酶对蛋鸡生长性能的影响及其蛋白质、钙和磷的利用率状况。研究结果表明:饲粮中添加5%的麦麸作为植物性植酸酶的来源时,蛋鸡表现出较好的生长性能,每1只日采食量、日增重分别比对照组提高16.3%和17.4%,且差异显著(P<0.05)。而在蛋白质、钙、磷的利用率上,各处理组与对照组相比分别提高了22.25%、94.5%和40.59%,且差异显著(P<0.05)。而试验组添加5%的麦麸和在此基础上添加商品植酸酶(300FTU/kg),蛋白质、钙和磷的利用率没有明显差异。     

植酸酶对肉鸡生产性能及钙、磷代谢影响的研究

试验研究AA肉鸡在低磷日粮中添加植酸酶对生产性能及磷、钙代谢的影响。试验分5个处理组,每个处理组180只肉鸡,每个处理组3个重复,每个重复60只肉鸡,试验分0～21、22～42、43～49d3个饲养阶段,分别饲喂处理1(对照组)、处理2、处理3、处理4和处理5日粮。研究结果表明:(1)各处理组平均日增重、料增重比和采食量差异不显著(P>0.05);各组腿病发生率差异不显著(P>0.05)。(2)与对照组比较,采食1kg日粮的肉鸡磷的排泄量处理2、3、4、5组分别降低26.67%(P<0.05)、24.35%(P<0.05)、20.58%(P>0.05)和25.80%(P<0.05)。(3)各处理组胫骨长度、灰分含量、灰中钙含量、灰中磷含量差异不显著(P>0.05);但胫骨重量、胫骨强度处理2与对照组差异显著(P<0.05)。(4)各处理组血清钙、磷、碱性磷酸酶差异不显著(P>0.05)。     

植酸酶对蛋鸭锌、铜、镁生物学利用率影响的研究

研究植酸酶对蛋鸭锌、铜、镁生物学利用率的影响.选取200日龄产蛋期金定鸭1 000只,随机分为5个处理,每个处理4个重复,每个重复50只.处理A为对照组,有效磷水平为0.45%;处理B、C、D、E有效磷水平依次为0.38%、0.32%、0.25%、0.18%,同时添加植酸酶500 FTU/kg.结果表明:日粮有效磷水平从0.45%降低到0.25%,同时添加500 FTU/kg植酸酶,不会影响蛋鸭对Ca、P、Cu、Zn的表观利用率及其在蛋鸭血清和胫骨中的含量(P>0.05).当日粮中有效磷水平为0.18%时,即使添加了植酸酶,Ca、P、Cu、Zn的表观利用率及其在蛋鸭血清和胫骨中的含量都会显著降低(P<0.05).降低有效磷水平和添加植酸酶与否不会影响Mg的生物学利用率.添加植酸酶可以降低蛋鸭日粮中的有效磷水平,对Zn、Mg、Cu的生物学利用率无影响,日粮中有效磷水平的适宜范围为0.25%～0.45%.     

低磷日粮高剂量添加植酸酶对清远麻肉鸡生长性能、屠宰性能及胫骨灰分含量的影响

研究低磷日粮中,添加高剂量植酸酶对优质清远麻肉鸡生长性能、屠宰性能及胫骨灰分含量影响,以期得到植酸酶高剂量添加情况下肉鸡饲料中适宜的非植酸磷水平。结果表明,综合肉鸡的生长性能、屠宰性能及胫骨灰分含量的数据来看,对于上市天龄120日龄的清远麻肉鸡,在植酸酶高剂量的添加情况下(2 000 IU/kg)可大幅下调不同生长阶段的日粮非植酸磷水平,0～30、31～60、61～90、91～120日龄阶段非植酸磷水平分别为0.20%、0.16%、0.16%、0.15%,即能满足肉鸡生长及胫骨发育等的需要,在当前的配方结构下只要确保总磷水平,60日龄后日粮中可不添加磷酸氢钙等无机磷源。     

不同植酸酶理化性能及肉鸡应用效果研究

本研究选用七种不同植酸酶产品,通过粒度分布、水分、灰分、容重、耐热性、体外对植酸磷的释放效应等方面进行不同植酸酶物理特性的评估,同时在零无机磷的极端饲料配方下,观察不同植酸酶对肉鸡生长性能和胫骨发育的影响,以综合评估不同植酸酶的功效。结果表明:不同植酸酶的几何平均粒径无差异(P0.05),但算术平均粒径和粒度模数差异显著(P0.001),植酸酶A、B、F和G颗粒可能更细更集中;水分、灰分含量和容重差异显著(P0.05),植酸酶A和F更有益于在配合饲料中的混合和均匀分布;不同植酸酶耐热性能不同(P0.001),A和G表现更好;体外酶解释放磷的效果差异极显著(P0.01),植酸酶A的体外磷释放率较高;相比于其他植酸酶,肉鸡饲粮中添加植酸酶A,能够极显著提高肉鸡采食量(P0.01),且有提高期末体重和平均日增重的趋势(P=0.083)。此外,处理A表现出了更大的肉鸡胫骨重(P0.05)。不同植酸酶产品理化特性比较及在肉鸡上的实际饲喂效果存在差异,可见,对植酸酶的评估不能从单一方面(如耐热性)考虑,应综合植酸酶的粒度分布和均匀度、耐热性能、肉鸡生长性能和养分释放效应以及胫骨发育等指标科学系统评估。     

耐高温植酸酶替代磷酸二氢钙对异育银鲫生长及机体成分的影响

研究了耐高温植酸酶替代磷酸二氢钙对异育银鲫生长性能、鱼体成分和机体磷含量的影响.对照组投喂不加植酸酶的基础日粮,试验1、2组在基础日粮基础上用1000 U/kg植酸酶分别替代基础日粮中0.3和0.6个百分点的磷酸二氢钙.结果表明:与对照组比较,试验1组鱼增重率提高了3.28％ (P＞0.05),试验2组异育银鲫的肥满度显著提高(P＜0.05),对肝体比和脏体比影响不显著(P＞0.05);添加耐高温植酸酶使肌肉粗灰分含量显著降低(P＜0.05),但对粗蛋白质、粗脂肪和磷含量影响不显著(P＞0.05);而试验1组血浆中磷的含量降低显著(P＜0.05).     

低有效磷饲粮添加植酸酶对肉仔鸡矿物质代谢的影响

100只艾维因肉仔鸡随机分为5组,每个组设4个重复。第1组喂标准饲粮;第2,3,4,5组喂低有效磷（0．20％）饲粮,分别加植酸酶0,350,500,650FTU／kg,饲养试验分两个阶段：0－3周,4－6周。试验期为5周,观察各组肉鸡的营养物质表观利用率、胫骨质量、血清化学指标的变化,研究低有效磷饲粮中添加植酸酶对矿物质代谢的影响及作用机制。试验结果表明：在低有效磷饲粮中添加植酸酶对矿物代谢有一定积极影响,以植酸酶最大添加量650FTU／kg组的效果为最佳。     

饲料添加小麦秸秆生物质炭对肉鸡生长、屠宰性能和脂质代谢的影响

旨在研究小麦秸秆生物质炭对肉鸡生产性能、屠宰性能和脂质代谢的影响。试验选用100只22日龄、健康状况良好、体重670 g左右的罗斯308肉鸡,随机分成4组。对照组饲喂基础日粮,试验组分别饲喂添加1%、5%和10%小麦秸秆生物质炭的基础日粮,试验期33 d。结果表明:1)与对照组相比,添加5%的小麦秸秆生物质炭肉鸡的平均日增重增加10.12%(P0.05);胸肌率提高23.42%(P0.05);添加5%和10%的小麦秸秆生物质炭肉鸡的腹脂率分别降低31.44%和23.02%(P0.05);试验组肉鸡的料重比均在一定程度上低于对照组,但无显著差异(P0.05);2)与对照组相比,添加5%的小麦秸秆生物质炭显著降低肉鸡血清总胆固醇含量(P0.05);试验组显著降低肉鸡血清三酰甘油含量(P0.05),但对肉鸡血清葡萄糖、低密度脂蛋白胆固醇和高密度脂蛋白胆固醇含量没有显著影响(P0.05);3)虽然添加小麦秸秆生物质炭增加了单位饲料成本,但添加1%和5%小麦秸秆生物质炭试验组每千克肉鸡增重饲料成本分别比对照组降低8%和6%。因此,饲料添加一定量的小麦秸秆生物质炭可以减少肉鸡腹脂沉积,降低血清总胆固醇和三酰甘油含量,在一定程度上有助于改善肉鸡的屠宰性能和生产性能。     

壳聚糖对黄羽肉鸡平均日增重和血清生化指标的影响

对照组饲喂基础日粮,试验组在基础日粮基础上分别饲喂添加0.1%、0.3%和0.5%壳聚糖的饲粮,试验21 d.结果表明,在49日龄的黄羽肉鸡日粮添加0.1%的壳聚糖能明显提高试验期内平均日增重(P＜0.05),而添加0.3%和0.5%的壳聚糖有降低平均日增重的趋势;添加0.1%、0.3%和0.5%的壳聚糖能显著降低血清总胆固醇含量(P＜0.05),有提高血清高密度脂蛋白胆固醇含量和降低血清低密度脂蛋白胆固醇含量的趋势,显著提高血清高密度脂蛋白胆固醇与低密度脂蛋白胆固醇的比值(P＜0.05),但对血清中的总蛋白和尿酸含量无明显的影响(P＞0.05).     

饲粮中添加腐殖酸钠对黄羽肉鸡生长性能的影响

试验旨在研究日粮添加腐殖酸钠对黄羽肉鸡生长性能的影响。将1 200只1日龄黄羽肉鸡随机分为2个组(对照组,试验组在对照组基础上添加2 kg/t腐殖酸钠),每组8个重复,每个重复75只鸡。进行63 d的试验。结果表明：在日粮中添加2 kg/t腐殖酸钠能显著(P<0.05)改善肉鸡的耗料增重和,但对日均采食量、日均增重比无显著改善(P>0.05)。综上所述,日粮添加腐殖酸钠对于提升肉鸡肠道健康水平,改善耗料增重比有一定作用。     

The degradation of phytate by microbial and wheat phytases is dependent on the phytate matrix and the phytase origin

BACKGROUND: Phytases increase utilization of phytate phosphorus in feed. Since wheat is rich in endogenous phytase activity it was examined whether wheat phytases could improve phytate degradation compared to microbial phytases. Moreover, it was investigated whether enzymatic degradation of phytate is influenced by the matrix surrounding it. Phytate degradation was defined as the decrease in the sum of InsP₆ + InsP₅. RESULTS: Endogenous wheat phytase effectively degraded wheat InsP₆ + InsP₅ at pH 4 and pH 5, while this was not true for a recombinant wheat phytase or phytase extracted from wheat bran. Only microbial phytases were able to degrade InsP₆ + InsP₅ in the entire pH range from 3 to 5, which is relevant for feed applications. A microbial phytase was efficient towards InsP₆ + InsP₅ in different phytate samples, whereas the ability to degrade InsP₆ + InsP₅ in the different phytate samples ranged from 12% to 70% for the recombinant wheat phytase. CONCLUSION: Wheat phytase appeared to have an interesting potential. However, the wheat phytases studied could not improve phytate degradation compared to microbial phytases. The ability to degrade phytate in different phytate samples varied greatly for some phytases, indicating that phytase efficacy may be affected by the phytate matrix. Copyright © 2011 Society of Chemical Industry     

Effects of freeze-dried Mitsuokella jalaludinii culture and Natuphos(®) phytase supplementation on the performance and nutrient utilisation of broiler chickens

BACKGROUND: Phytate‐bound phosphorus (P) in poultry diets is poorly available to chickens. Hence exogenous phytase is often added to their diets. Mitsuokella jalaludinii is a rumen bacterial species that produces high phytase activity. In this study the effects of freeze‐dried active M. jalaludinii culture (FD‐AMJC) and Natuphos^® phytase (phytase N) supplementations on the growth performance and nutrient utilisation of broiler chickens fed a low‐available P (aP) diet were evaluated. RESULTS: Supplementation of FD‐AMJC or phytase N to the low‐aP diet improved the feed intake, feed conversion rate, body weight gain, dry matter (DM) digestibility and P, Ca and Mn retention, increased the tibia bone ash content, Ca and P concentrations in tibia DM and P and Zn concentrations in plasma and reduced the P excretion of broiler chickens. However, the feed conversion rate, P and Ca retention, DM digestibility and reduction of P excretion were better with FD‐AMJC than phytase N supplementation. Supplementation of FD‐AMJC to the low‐aP diet also improved the apparent metabolisable energy value of the diet, Cu and Zn retention and crude protein digestibility, but phytase N supplementation did not. CONCLUSION: FD‐AMJC supplementation was more efficient in improving nutrient utilisation and reducing P excretion in chickens than phytase N supplementation. Copyright © 2011 Society of Chemical Industry     

乳酸菌发酵饲料对生长猪生产性能的影响

研究了乳酸菌发酵饲料对规模化猪场生长猪生产性能和健康的影响。对照组直接饲喂基础日粮,1组饲喂"基础日粮+20%乳酸菌发酵饲料(风干)",2组饲喂"基础日粮+30%乳酸菌发酵饲料(风干)",3组饲喂"基础日粮+50%乳酸菌发酵饲料(风干)"。结果表明:1、2和3组平均日增重比对照组分别提高了9.67%、11.47%和13.68%,3组与对照组相比差异极显著,1、2组与对照组相比差异显著;1、2和3组头平均日采食量比对照组分别提高了3.47%、4.16%和4.88%,3组与对照组相比差异极显著,1、2组与对照组相比差异显著。1、2和3组料肉比比对照组分别下降了5.16%、6.35%和7.54%,发病率比对照组分别降低了38.46%、46.15%和69.23%;1、2和3组比对照组多盈利22.7%、26.8%和31.6%。     

Bioavailability of Calcium Citrate Malate Added to Microbial Phytase-Treated, Hydrothermally Cooked Soymilk

Effects of microbial phytase on bioavailability of calcium added to corn/soy diets were investigated in chickens. No effect (P > 0.17) of phytase was found for weight gain, feed intake, tibia/body weight, ash%, and ash Ca% when calcium citrate malate (CCM) was added to corn/soybean meal and corn/hydrothermally cooked (HTC) soymilk diets. Using calcium carbonate in corn/HTC soymilk diets, means for weight gain, feed intake, tibia/body weight, and ash% were less (P < 0.05) without phytase. We hypothesize that CCM is less amenable to the formation of calcium phytate complexes than are other calcium salts and, therefore, should be more effective for fortification of soymilk products.     

响应面法优化麦麸发酵产植酸酶条件的研究

以纳豆芽孢杆菌JSU-2为供试菌株,麦麸皮为唯一固体发酵基质,运用响应面法对其产植酸酶的条件进行优化.首先用24-1部分因子试验设计对影响植酸酶活性的主要变量进行了评价,发现主要影响因子为麸皮与水的比例和培养时间.然后用中心组合试验设计确定主要变量的最佳水平.最佳产酶发酵条件为:粒径为3 mm、麸皮与水的比例为1:9.6、接种量为3 mL和培养时间为25 h.在最佳产酶条件下进行发酵,得到的植酸酶活性为595 U/g麦麸.     

The effects of population densities and diet on Tribolium castaneum (Herbst) life parameters

The effects of population densities (10, 25, 50 and 100 adults/50 g) and three diet types (protein-rich, carbohydrates-rich and compound feed) on life parameters (first emergence, development rate, number of progeny and body weight) of T. castaneum progeny were assessed. For each diet type and population density unsexed adults were allowed to feed and oviposit for 7 days before removal.No progeny developed on protein-rich diets (sunflower meal, soybean concentrate, and corn gluten). In carbohydrates-rich diets (corn feed flour, wheat bran, coarse wheat) and compound feed for pigs and laying hens, first adults required the least time to emerge in wheat bran and control diet (wheat flour + 5% yeast) (15.2–16.5 days), and the longest in corn feed flour (23.1–24.5 days). In wheat bran and control diets, the adult emergence period was the shortest (15.7 and 15.2 days) at the initial population densities of 100 and 50 adults/50 g, and significantly longest (16.5 and 16 days) at the lowest density. Conversely, adults fed on feed for hens diet emerged the latest, after 22.5 days, at the population density of 100 adults/50 g, and the earliest, after 18.6 days, at 25 adults/50 g. The shortest period of adult emergence at all population densities was found in the control (15.9–20.2 days) and wheat bran (18–29.7 days), and the longest in feed for hens (56.2 days) and pigs (59.5 days) at the highest population density. Considering all densities, number of progeny were the highest in control diet (498-1226 adults) and wheat bran (354-1344 adults), and lowest in coarse wheat (220-300 adults). With increasing population density, progeny body weight decreased, and the highest weight was found in control diet and wheat bran (1.7 and 1.6 mg) at the lowest population density, and the lowest weight (1.0 mg) in hen and pig feeds at the highest density.     

Dietary supplementation with nonconventional feeds from the Middle East: assessing the effects on physicochemical and organoleptic properties of Awassi sheep milk and yogurt

Increased feed costs affect the livelihoods of dairy sheep farmers in the Middle East. Farmers endure high risks with large fluctuations in the price of grain used as animal feed, which is further affected by drought and declining range productivity. Using agricultural by-products and treated straw or vetch grazing for supplementing sheep diets would provide resource-poor dairy farmers with increased options to reduce feed costs, but the effects of such feeds on the quality of yogurt (the main product) need to be better understood. Two experiments were conducted to evaluate these effects. The first trial evaluated alternative diets using locally available feedstuffs, including agricultural by-products, compared with traditional diets used by dairy sheep farmers, and was conducted on-station at the International Center for Agricultural Research in Dry Areas (ICARDA, Tel Hadya, Aleppo, Syria). Milking Awassi ewes (n = 56) were used to test 6 alternative diets against a traditional control diet containing barley, wheat bran, and barley straw. The 6 alternative diets contained 4 or more of the following ingredients: barley, sugar beet pulp, molasses, cotton seed cake, wheat bran, urea-treated wheat straw, and barley straw. Ewes on one of the alternative diets grazed vetch pasture, whereas ewes on the control diet and the 5 alternative diets grazed native range pasture. The milk fat content was higher in diets containing urea-treated straw. Yogurt firmness and adhesiveness were significantly lower in energy-rich diets (e.g., the control diet) and in the diets rich in soluble sugar (molasses). The effects of diet on yogurt color and on citric and succinic acid contents were significant. A yogurt produced from the milk of the group grazing on vetch was the most yellowish in color, which is appealing to Syrian consumers. The content of citric acid tended to be higher in yogurts produced from diets containing molasses. The second trial was conducted on 3 farms in northern Syria to assess an alternative diet (1 of the 6 tested in the first trial) on 15 milking ewes compared with the farmer's traditional diet (control). The alternative diet increased yogurt firmness and adhesiveness by 7 to 9% and 10 to 16%, respectively. The use of nonconventional feeds available in the region enhances yogurt quality, may reduce requirements for expensive grains, and thus, increase farmers’ livelihoods by targeting expanding markets with better quality products.     

Production of phytase in a low phosphate medium by a novel yeast Candida krusei

A yeast strain producing high levels of phytase was isolated from soil and identified as Candida krusei. The phytase was located on the yeast cell wall and was a glucanase-extractable protein. The phytase production was controlled by the phosphate concentration in the medium used. The maximum production of phytase occurred in a medium containing 0.5 mg of phosphorus per 100 ml, and most of the cells were ellipsoid-shaped and did not exhibit budding. Increasing the concentration of phosphorus in the medium to more than 5 mg of phosphorus per 100 ml caused inhibition of phytase production and 90% of the cells exhibited budding. On the other hand, transferring cells grown in the high-phosphate medium into a phosphate-free one derepressed the phytase production. For example, transferring cells grown in 2 mg of phosphorus per 100 ml into the phosphate-free medium, enhanced the total phytase activity up to 5.5-fold that in the medium containing 0.5 mg of phosphorus per 100 ml. The phytase showed two optimum pHs of 2.5 and 5.5, an optimum temperature of 40 degrees C and the K(m) value for Na-phytate was 0.03 mM. Using in vitro experiments that simulated the conditions of the digestive tract, 50-80% phosphorus was liberated from different plant samples (wheat bran, rice bran and feeds) by the strain.     

Comparative evaluation of the efficacy of cereal and microbial phytases in growing pigs fed diets with marginal phosphorus supply

Two experiments with a total of 76 growing pigs (average initial body weight 16.6 kg) were conducted to compare the efficacy of cereal phytases (wheat and rye) and supplemented microbial phytase (Natuphos®). Using the slope ratio technique, the dose–response relationship between five levels of phytase (0, 50, 100, 150 and 200 U kg^?1) and the apparent absorption of phosphorus (P) within each source of phytase was calculated. Graded phytase levels in the diets were obtained by adding increasing amounts of microbial phytase or phytase‐containing wheat (Exp 1) or rye (Exp 2) to phytase‐inactivated basal diets at the expense of phytase‐inactivated wheat (Exp 1) or rye (Exp 2). Except for wheat phytase, addition of phytase to the basal diets increased (P < 0.05) apparent P absorption, with microbial phytase being more efficient (P < 0.05) than cereal phytase. There were no significant differences in apparent P absorption between the wheat‐ or rye‐based diets when either microbial or cereal phytases were supplemented from 0 to 200 U kg^?1. It could be derived from the results of this study, by means of regression analysis, that the efficacy of cereal phytases was 40% compared to microbial phytase. © 2002 Society of Chemical Industry