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Charmaine D Espinosa Maryane S F Oliveira Deepak E Velayudhan Yueming Dersjant-Li Hans H Stein 《Journal of animal science》2021,99(8)
A 20-d experiment was conducted to test the hypothesis that phytase increases nutrient digestibility, bone ash, and growth performance of pigs fed diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. Within each level of phytate, five diets were formulated to contain 0, 500, 1,000, 2,000, or 4,000 phytase units (FTU)/kg of a novel phytase (PhyG). Three reference diets were formulated by adding a commercial Buttiauxella phytase (PhyB) at 1,000 FTU/kg to diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. A randomized complete block design with 144 individually housed pigs (12.70 ± 4.01 kg), 18 diets, and 8 replicate pigs per diet was used. Pigs were adapted to diets for 15 d followed by 4 d of fecal collection. Femurs were collected on the last day of the experiment. Results indicated that diets containing 0.35% phytate-bound P had reduced (P < 0.01) digestibility of Ca, P, Mg, and K compared with diets containing less phytate-bound P. Due to increased concentration of total P in diets with high phytate, apparent total tract digestible P and bone ash were increased by PhyG to a greater extent in diets with 0.29% or 0.35% phytate-bound P than in diets with 0.23% phytate-bound P (interaction, P < 0.05). At 1,000 FTU/kg, PhyG increased P digestibility and bone P more (P < 0.05) than PhyB. The PhyG increased (P < 0.01) pig growth performance, and pigs fed diets containing 0.35% or 0.29% phytate-bound P performed better (P < 0.01) than pigs fed the 0.23% phytate-bound P diets. In conclusion, the novel phytase (i.e., PhyG) is effective in increasing bone ash, mineral digestibility, and growth performance of pigs regardless of dietary phytate level. 相似文献
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The objective was to determine correlations between individual bones and total body bone ash to identify the bone that is most representative of total body bone ash in growing pigs. Twenty growing pigs were allotted to 1 of 2 diets that were formulated to contain 60% or 100% of the requirement for standardized total tract digestible (STTD) P. Both diets had an STTD Ca to STTD P ratio of 1.90:1. Growth performance and carcass weights were determined. Metacarpals, metatarsals, femur, tibia, fibula, 3rd and 4th ribs, and 10th and 11th ribs, and all other bones from the left half of the carcass were collected separately. Each bone was defatted and ashed. Pigs fed the diet containing 100% of required Ca and P had greater (P < 0.05) average daily gain, gain to feed, and ash concentration (%) in total and all individual bones except femur and fibula compared with pigs fed the diet containing 60% of required Ca and P. Calcium and P concentrations in bone ash were not affected by dietary treatments. Weights (g) of bone ash, bone Ca, and bone P were greater (P < 0.05) or tended to be greater (P < 0.10) for pigs fed the diet containing 100% of required Ca and P. Correlation coefficients between the weight of ashed metacarpals, metatarsals, and tibia and the weight of total bone ash were >0.95. In conclusion, metacarpals, metatarsals, and tibia were more representative of total body bone ash compared with other bones. 相似文献
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An experiment was conducted to test the hypothesis that formulating diets for pigs based on a ratio between standardized total tract digestible (STTD) Ca and STTD P instead of total Ca and STTD P does not decrease Ca retention, but increases P utilization. Forty barrows (59.4 ± 3.8 kg) were individually housed in metabolism crates and allotted to four corn-soybean meal-based diets in a randomized complete block design with two blocks and five pigs per diet in each block. Diets were formulated using a 2 × 2 factorial design with two diet formulation principles (total Ca or STTD Ca) and two inclusion levels of microbial phytase (0 or 500 units per kg of feed). Phytase was assumed to release 0.11% STTD P and 0.16% total Ca. Diets were formulated based on requirements for total Ca and STTD P or a ratio between STTD Ca and STTD P of 1.25:1. Diets were fed for 11 d and fecal and urine samples were collected from feed provided from day 6 to day 10. Interactions (P < 0.05) between diet formulation principle and phytase level were observed for Ca intake, Ca in feces, Ca absorbed, Ca retained, P digestibility, P absorbed, and P in urine. Phytase increased (P < 0.05) the digestibility of Ca in both total Ca and STTD Ca diets. Without phytase, Ca intake, Ca in feces, and Ca absorbed was greater (P < 0.05) from pigs fed total Ca diets than from pigs fed STTD Ca diets, but P absorbed, P digestibility, and P in urine was greater (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. However, in the presence of phytase, no differences between diet formulation principles were observed in these variables. Regardless of phytase, Ca in urine was lower (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. There were no differences in Ca retention between pigs fed STTD Ca diets and total Ca diets, but pigs fed total Ca diets retained less (P < 0.05) Ca if diets contained phytase. No differences in P retention were observed between diet formulation principles, but pigs fed non-phytase diets retained more (P < 0.05) P than pigs fed diets with phytase. In conclusion, because diets formulated based on STTD Ca contain less Ca than total Ca diets, pigs fed STTD Ca diets excreted less Ca in urine, but retention of Ca was not affected. Formulating non-phytase diets based on STTD Ca instead of total Ca increased P absorption, which confirms the detrimental effect of excess Ca on P digestibility. However, P retention was not improved if pigs were fed STTD Ca diets. 相似文献
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试验研究肉仔鸡低有效磷日粮中添加植酸酶对生产性能及钙、磷利用率的影响。选取960只1日龄AA肉仔鸡,随机分为8个处理,每个处理6个重复,每个重复20只仔鸡（公母各半）,试验分为前期（1-21 d）和后期（22-42 d）两个阶段。第I组为正对照组PC（试验基础日粮,前、后期有效磷水平分别为0.47%、0.43%）,第II组为负对照组NC（前、后期分别降低有效磷水平0.06%、0.1%）,第Ⅲ-第Ⅴ组分别为NC＋500 U/kg包衣植酸酶、NC＋1 000U/kg包衣植酸酶,NC＋1 0000 U/kg包衣植酸酶,第Ⅵ组为NC＋500 U/kg粉状植酸酶,第Ⅶ组为NC＋500 U/kg微丸植酸酶,第Ⅷ组为NC＋500 U/kg进口粉状植酸酶。结果表明：（1）除Ⅶ组后期采食量较正对照组有显著提高外,各处理组平均日采食量、平均日增重差异均不显著（P〉0.05）,Ⅶ组前期料重比较正、负对照组均有显著降低（P〈0.05）,且正对照组全期料重比显著低于负对照组（P〈0.05）,所有酶处理组后期和全期料重比均较负对照组有所降低,但差异不显著（P〉0.05）。（2）Ⅵ组前期DM和EE消化率显著高于正对照组,除Ⅲ组外所有酶处理组前期能量和P消化率均显著高于正、负对照组（P〈0.05）;Ⅶ和Ⅷ组后期DM消化率显著高于正对照组（P〈0.05）,Ⅳ组后期EE消化率显著高于正、负对照组,除Ⅲ组外所有酶处理组以及负对照组后期P消化率均显著高于正对照组（P〈0.05）。（3）Ⅲ组前期胫骨长度显著高于正、负对照组,Ⅳ和Ⅴ组及负对照组后期胫骨长度均显著大于正对照组（P〈0.05）;Ⅴ组后期胫骨Ca含量显著高于正、负对照组,所有酶处理组前、后期胫骨P含量均较负对照组有所升高,但差异不显著（P〉0.05）。试验结果表明低有效磷日粮中添加植酸酶对饲料利用率有一定的改善作用,有效提高饲料代谢能以及磷的消化和沉积。 相似文献
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研究了3个不同品牌的微生物植酸酶在两个不同磷酸氢钙添加水平（0.44%和0.77%）下对肉仔鸡生产性能和钙磷消化率的影响。试验结果表明：与正常磷酸氢钙添加水平（1.1%）的对照组相比,降低磷酸氢钙用量并添加植酸酶后肉仔鸡的采食量和日增重与对照组接近,饲料转化率有一定提高,死淘率和腿病发生率与对照组差异不显著。降低磷酸氢钙用量并添加植酸酶能够一定程度的提高肉仔鸡对灰分的消化利用率（P＞0.05）,显著提高磷的消化利用率（P＜0.05）,并大幅提高24日龄肉仔鸡的钙表观消化率（P＜0.01）,小幅提高42日龄肉仔鸡的钙表观消化率（P＞0.05）, 不同品牌植酸酶的作用效果存在一定差异。 相似文献
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植酸酶对肉仔鸡生产性能及钙、磷利用率影响的研究 总被引：16，自引：2，他引：16
本试验研究肉仔鸡低磷日粮中添加植酸酶对生产性能、钙、磷利用率的影响。试验分4个处理 ,每个处理6个重复 ,每个重复15只鸡。试验分0～3、4～6、7～8周三个饲养阶段 ,分别饲喂处理1(含总磷为0.59 %、0.56 %、0.52 %) ,处理2(含总磷0.45 %、0.40 %、0.35 %加植酸酶500FTU/kg)、处理3(含总磷0.55 %、0.50 %、0.45 %加植酸酶500FTU/kg)、处理4(含总磷0.55 %、0.50 %、0.45 %加植酸酶250FTU/kg)。结果表明 :(1)各处理组平均日增重、饲料增重比差异不显著(P>0.05) ,各组腿病鸡数差异不显著(P>0.05)。处理2平均日采食量降低显著 ,为8.46 %(P≤0.05)。(2)采食每千克日粮磷的排泄量处理2、3、4比对照组分别降低24.15 %(P<0.05)、18.90 %(P>0.05)、24.93 %(P<0.05)。(3)各处理胫骨长度、灰分含量、钙含量差异不显著(P>0.05))。胫骨重量处理2显著低于对照组(P≤0.05) ,胫骨灰分中磷含量处理4显著低于对照组(P≤0.05) ,胫骨强度处理2显著低于其它处理(P≤0.05)。(4)各处理血清钙、血清磷、血清碱性磷酸酶差异不显著(P>0.05)。 相似文献
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《The Journal of Applied Poultry Research》2014,23(2):181-187
Phytate is an antinutrient in animal feeds, reducing the availability and increasing the excretion of nutrients. Phytases are widely used to mitigate the negative influences of phytate. This trial was designed to compare the efficacy of 2 Escherichia coli-derived phytases on broiler performance and bone ash as influenced by dietary phytate level. A total of 1,024 Arbor Acres male broilers were used with 8 replicate pens of 16 birds/pen. Experimental diets were based on low available phosphorus (avP; 1.8 g/kg) with low (6.40 g/kg) or high (10.65 g/kg) phytate. The low-avP diets were then supplemented with mono-dicalcium phosphate to increase the avP level to 4.5 g/kg, 500 phytase units/kg of phytase A, or 500 phytase units/kg of phytase B to create 8 experimental diets. Feed intake, BW gain, FCR, and livability were influenced by a P source × phytase interaction. Feed intake, BW gain, and livability were reduced and FCR was higher in broilers fed low-avP diets, particularly in the presence of high phytate. Phytase A or phytase B improved feed intake, BW gain, and FCR, particularly in the high-phytate diet. However, broilers fed phytase A ate more and were heavier than broilers fed phytase B. Tibia ash was lowest in broilers fed the low-avP diet and highest in broilers fed the diet supplemented with mono-dicalcium phosphate. Phytase increased tibia ash, and broilers fed phytase A had an increase in tibia ash compared with broilers fed phytase B. In conclusion, high dietary phytate reduced broiler performance. Phytase A and phytase B improved bone ash and growth performance, especially in the high-phytate diets. However, phytase A was more efficacious than phytase B, regardless of the level of phytate. 相似文献
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We conduct this study to investigate the effects of corn-wheat-soybean meal (SBM)-based diet supplemented with high-dosing Trichoderma reesei phytase on the growth performance, nutrient digestibility, carcass traits, faecal gas emission and meat quality in growing-finishing pigs (29.71–110.58 kg live weight; 70-day-old to 166-day-old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were used in 96-day experiment with a completely randomized block design. The growing period was from day 0 to 42, and the finishing period was from day 43 to 96. Pigs were randomly allocated to one of two treatments with seven replicate pens and four pigs (two barrows and two gilts) per pen and fed corn-wheat-SBM-based nutrient adequate basal diet or the basal diet supplemented with 1500 FTU/kg diet Trichoderma reesei phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate per minute at 37°C and pH 5.5. Dietary supplement with Trichoderma reesei phytase had increased body weight on day 96 and average daily gain in days 0–96. Moreover, high apparent total tract digestibility (ATTD) of phosphorus (P) was observed in pigs fed with Trichoderma reesei phytase. However, the carcass traits, faecal gas emission and meat quality of pigs were unaffected by Trichoderma reesei phytase supplementation. In conclusion, supplementation of high-dosing Trichoderma reesei phytase (1500 FTU/kg diet) in the corn-wheat-SBM-based nutrient adequate basal diet increased body weight and the ATTD of P, while no adverse effects were observed on the production characteristics. 相似文献
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《The Journal of Applied Poultry Research》2015,24(2):115-126
Concerns about the environment, nutrition, and farm profits all point to the increasing importance of the phosphorus (P) content of a diet. Animals must now be fed near their P requirements. However, it is very difficult to know the exact P requirements of broilers. The objective of this study was to provide efficacy data of a 6-phytase for use in broilers at different Ca levels and Ca/P ratios. Broilers were randomly assigned to 6 treatments, each with 6 replicates. The treatments comprised diets differing in Ca and P level: 1) normal Ca and total normal phosphorus (Pt) level, 2) normal Ca and low Pt level, 3) low Ca and Pt level, and differing in phytase level (no, normal or high phytase supplementation). During the entire study, lowest BW was obtained when broilers were given the imbalanced (normal Ca and low Pt level) diet with low phytase supplementation. Among the balanced dietary treatments no significant effects on performance were observed. A higher Ca/Pt ratio decreased feed intake, whereas addition of phytase increased feed intake. For the starter period, the most favorable feed conversion was obtained when broilers were fed the imbalanced diet with a high dosage of phytase or the low Ca, low Pt diet supplemented with phytase. For the grower and finisher period, broilers with the highest weight gain had the highest feed intake resulting in comparable feed conversions between treatments. Litter quality was not affected by dietary treatments but prevalence of foot pad lesions and hock burn was significantly influenced by treatments. The highest percentage of both was seen when broilers were given the imbalanced diets. The overall results of this study emphasises the relevance of the Ca/P ratio in modern broiler feeding and P studies. It can be concluded from this study that dietary Ca and P concentrations can be reduced by 20% if done in a balanced way. If done in combination with phytase supplementation, performance results improve even more. 相似文献
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本试验旨在研究饲粮钙水平对猪生长性能、胫骨性能及血清生化指标的影响,探讨30～60kg生长猪的适宜钙需要量.试验采用单因子完全随机试验设计,将30头初重(34.2±2.1)kg的“杜×长×大”生长猪随机分为5个组,每组6个重复,每个重复l头猪.各组分别饲喂钙水平为0.45％(对照组)、0.50％、0.55％、0.60％和0.65％的玉米-豆粕型试验饲粮.预试期5d,正试期28d.结果表明:1)饲粮钙水平对料重比影响不显著(P＞0.05).0.55％、0.60％钙水平组平均日采食量显著高于对照组(P＜0.05),0.50％、0.55％钙水平组平均日增重显著高于对照组(P＜0.05).2)饲粮钙水平对试验猪的胫骨长度、胫骨鲜重、胫骨相对重量影响不显著(P＞0.05).0.55％、0.60％、0.65％钙水平组脱脂胫骨灰分含量显著高于对照组(P＜0.05),0.55％和0.60％钙水平组胫骨灰分钙含量显著高于对照组(P＜0.05),0.55％、0.60％、0.65％钙水平组胫骨灰分磷含量显著高于对照组(P＜0.05).3)饲粮钙水平对血清钙、磷含量无显著影响(P＞0.05),0.45％、0.50％和0.65％钙水平组血清碱性磷酸酶活性显著高于0.55％和0.60％钙水平组(P＜0.05).综上所述,饲粮钙水平为0.55％时,30～60kg生长猪获得较好的生长性能;饲粮钙水平为0.60％时,30～60kg生长猪获得较好的胫骨性能. 相似文献
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《The Journal of Applied Poultry Research》2006,15(1):72-81
Three experiments were conducted to study the effects of broiler strain and phytase supplementation on chick nonphytate P (NPP) requirements for growth, feed intake, and tibia ash. The first experiment compared the NPP requirements for 8- to 22-d-old chicks from 2 broiler strains, Ross 308 and 708, that have been selected for differences in early weight gain and performance. The second experiment utilized similar 8- to 22-d-old Ross 308 and 708 chicks but also compared the effects of dietary fungal phytase supplementation (600 U/kg) on broiler NPP requirements. The third experiment utilized a younger starting age, 5 to 23 d old, for Ross 308 and 708 chicks with and without phytase supplementation. Minor differences in chick growth did not affect chick NPP requirements in Experiments 1 and 3, but a substantial and unexplained reduction of growth of the Ross 708 chicks in Experiment 2 resulted in a lower NPP requirement for chick growth and feed intake but not for tibia ash. As expected, supplementation of diets with fungal phytase did result in decreased NPP requirements for growth, feed intake, and tibia ash in both strains used in Experiment 3. 相似文献
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Adewale EMIOLA Oluwole AKINREMI Bogdan SLOMINSKI C. Martin NYACHOTI 《Animal Science Journal》2009,80(1):19-26
The effect of high levels of microbial phytase supplementation in diets for growing pigs was studied in a 2‐week performance and nutrient digestibility trial involving 28 growing pigs weighing 16.4 ± 1.06 (mean ± SD) kg. Seven corn‐barley‐soybean meal‐based diets consisting of a positive control (PC) formulated to meet or exceed NRC nutrient requirements; a negative control (NC) with non‐phytate P reduced by 0.1% unit from NRC requirement and fed without or with 500 or 1000 U/kg; a doubled negative control (DNC) with no added inorganic P and fed without or with 2000 or 4000 U/kg. Chromic oxide was added as an indigestible marker and all diets were fed as mash. Pigs fed the PC diet had a higher P digestibility compared with those fed the NC (P < 0.02) and the DNC (P < 0.001) diets. Supplementing the NC diet with pyhtase tended to improve P digestibility (P < 0.10). However, addition of phytase to the DNC diet resulted in linear (P < 0.001) and quadratic (P < 0.03) increases in P digestibility with an overall improvement of 8% and 121% at 4000 phytase U/kg of diet, respectively, compared with the PC and DNC diets. Apparent total tract digestibility of N, OM and DM were higher (P < 0.05) in the PC diet compared with the DNC diet, but not the NC diet (P < 0.10). No effect of phytase addition to NC was observed on Ca, N, DM and OM digestibility. Phytase addition to the DNC diet resulted in a linear increase (P < 0.05) in N, DM and OM digestibility but not Ca. Increasing the levels of phytase supplementation in the NC and the DNC diets linearly decreased fecal P (P < 0.05) content by 45 and 42%, respectively. Adding phytase at 1000 or 4000 U/kg increased P retention (P < 0.05) by 14.3 or 15.6% units, respectively, compared with the PC diet. Urinary P excretion was higher in the group fed the PC diet compared with those fed the NC and DNC diets (P < 0.05). The results of this study show that complete removal of inorganic P from growing pig diets coupled with phytase supplementation improves digestibility and retention of P and N, thus reducing manure P excretion without any negative effect on pig performance. 相似文献
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Yueming Dersjant-Li M Reza Abdollahi Abiodun Bello Katie Waller Leon Marchal V Ravindran 《Journal of animal science》2022,100(2)
The effect of a novel consensus bacterial 6-phytase variant (PhyG) on apparent ileal digestibility (AID) of amino acids (AA) and phosphorus (P) utilization in young broilers when added to diets with high phytate-P (PP) content without added inorganic phosphate (Pi) and deficient in digestible (dig) AA and metabolizable energy (ME) was investigated. A total of 256 Ross 308 male broilers were assigned to 4 treatments (8 birds/cage, 8 cages/treatment) in a completely randomized design. Treatments comprised a positive control (PC, 2,975 kcal/kg ME, 3.7 g/kg dig P, 2.83 g/kg PP, 8.4 g/kg Ca, 10.6 g/kg dig lysine), a negative control (NC) without added Pi (ME −68 kcal/kg, crude protein −10 g/kg, dig AA −0.1 to −0.4 g/kg, Ca −2.0 g/kg, dig P −2.2 g/kg, Na −0.4 g/kg vs. PC), and NC plus 500 or 1,000 FTU/kg of PhyG. Test diets were corn/soy/rapeseed-meal/rice-bran-based and fed from 5 to 15 d of age. Ileal digesta and tibias were collected on day 15. Excreta was collected during days 12 to 15 to determine P retention. The NC (vs. PC) reduced (P < 0.05) P retention (−10.4% units), tibia ash (−14.3% units), weight gain (−109 g), feed intake (−82 g) and increased FCR (from 1.199 to 1.504), confirming that the NC was extremely deficient in nutrients and energy. Phytase addition to the NC linearly (P < 0.001) improved performance, but did not fully recover it to the level of the PC due to the severe nutrients/energy reduction in NC. Phytase linearly increased P retention (P < 0.001), tibia ash (P < 0.001), AID of dry matter (P < 0.05), nitrogen (P < 0.01), gross energy (P < 0.05), and all 17 individual AA (P < 0.01). At 1,000 FTU/kg, phytase increased (P < 0.05) P retention vs. PC and NC (+14.5 and +24.9% units, respectively) and increased tibia ash vs. NC (+13.8% units), equivalent to PC. The NC decreased AID of Cys, Gly, Thr, and Met vs. PC (P < 0.05). At 1,000 FTU/kg, phytase increased AID of all 17 AA vs. NC (P < 0.01), equivalent to PC. At 1,000 FTU/kg, AID AA responses (above NC) ranged from +4.5% (Met) to +15.0% (Cys), being maximal for essential Thr (+10.4%) and Val (+8.2%) and non-essential Cys (+15.0%) and Gly (+10.4%). The results highlight the efficacy of PhyG at a dose level of 500 to 1,000 FTU/kg in young broilers for improving the ileal digestibility of nitrogen, AA, and energy alongside P retention and tibia ash. The performance data emphasize the need to consider digestible nutrient intake as a response variable in exogenous enzyme studies. 相似文献
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The objective of this study was to eval- uate the effects of inorganic phosphorus source and phytase addition on performance, nutrient digestibility and bone mineralization in broiler chickens. In Exp. 1,150 two-day old, male broiler chicks were fed a corn-soybean meal basal diet supplemented with phos- phorus provided by dicalcium phosphate, tricalcium phosphate or defluorinated rock phosphate. Five cages containing 10 birds were allotted to each of the three treatments. In Exp. 2,120 three-day old, male broiler chicks were fed the basal diet from Exp. 1 supplemen- ted with 0,250,500 ,or 1,000 P-＇rU phytase per kg of diet. Six cages containing five chicks were allotted to each of the four treatments. In Exp. 1, there was no difference in weight gain, feed intake or feed conver- sion as a result of feeding the different sources of in- organic phosphorus. The digestibility of phosphorus was significantly lower （P =0.01 ） for chicks fed di- ets supplemented with tricalcium phosphate than for chicks fed the other two diets. However, despite the lower digestibility, serum phosphorus levels did not differ among the three treatments. For Exp. 2, feedconversion showed a linear improvement （P = 0.03 ） with increasing levels of phytase inclusion （ days 0 to 33 ）. Phytase supplementation resulted in linear increa- ses in the digestibility of dry matter （P = 0.02 ）, crude protein （ P --- 0.04 ） and energy （ P 〈 0.01 ）. Chicks fed 1,000 FTU/kg phytase had significantly higher bone calcium （ P = 0.05 ） and bone breaking strength （P = 0.04 ） than chicks fed the basal diet on day 33. In conclusion, the results of the current study indicated that the performance of birds fed diets sup- plemented with dicalcium phosphate, tricalcium phos- phate or defluorinated phosphate was similar and therefore production costs could be lowered by choo- sing the cheapest inorganic phosphorus source when formulating diets for poultry. When diets were formu- lated to meet dietary phosphorus requirements, the growth of broilers was not enhanced with phytase sup- plementation. However, increases in feed conversion and bone breaking strength and its potential to impact culling and mortality in broiler operations may be suf- ficient justification for the routine inclusion of phytase in diets fed to broilers. 相似文献
19.
The objective of this study was to evaluate the effects of inorganic phosphorus source and phytase addition on performance, nutrient digestibility and bone mineralization in broiler chickens. In Exp. 1, 150 two-day old, male broiler chicks were fed a corn-soybean meal basal diet supplemented with phosphorus provided by dicalcium phosphate, tricalcium phosphate or defluorinated rock phosphate. Five cages containing 10 birds were allotted to each of the three treatments. In Exp. 2, 120 three-day old, male broiler chicks were fed the basal diet from Exp. 1 supplemented with 0, 250, 500, or 1,000 FTU phytase per kg of diet. Six cages containing five chicks were allotted to each of the four treatments. In Exp. 1, there was no difference in weight gain, feed intake or feed conversion as a result of feeding the different sources of inorganic phosphorus. The digestibility of phosphorus was significantly lower (P = 0.01) for chicks fed diets supplemented with tricalcium phosphate than for chicks fed the other two diets. However, despite the lower digestibility, serum phosphorus levels did not differ among the three treatments. For Exp. 2, feed conversion showed a linear improvement (P = 0.03) with increasing levels of phytase inclusion (days 0 to 33). Phytase supplementation resulted in linear increases in the digestibility of dry matter (P = 0.02), crude protein (P = 0.04) and energy (P < 0.01). Chicks fed 1,000 FTU/kg phytase had significantly higher bone calcium (P = 0.05) and bone breaking strength (P = 0.04) than chicks fed the basal diet on day 33. In conclusion, the results of the current study indicated that the performance of birds fed diets supplemented with dicalcium phosphate, tricalcium phosphate or defluorinated phosphate was similar and therefore production costs could be lowered by choosing the cheapest inorganic phosphorus source when formulating diets for poultry. When diets were formulated to meet dietary phosphorus requirements, the growth of broilers was not enhanced with phytase supplementation. However, increases in feed conversion and bone breaking strength and its potential to impact culling and mortality in broiler operations may be sufficient justification for the routine inclusion of phytase in diets fed to broilers. 相似文献
20.
Sarah K. Duffy Alan K. Kelly Gaurav Rajauria Louise C. Clarke Vivian Gath Frank J. Monahan John V. O'Doherty 《Journal of animal physiology and animal nutrition》2018,102(5):1296-1305
The objective of this study was to investigate the effects of supplementing both phytase and 25‐hydroxyvitamin D3 (25‐OH ‐D?) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25‐OH ‐D? (T3) and low P diet + phytase + 25‐OH ‐D? (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI ) (2.45 kg vs. 2.59 kg; p < 0.05) and lower feed conversion ratio (FCR ) (2.74 kg/kg vs. 2.85 kg/kg; p < 0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p < 0.05) coefficient of apparent total tract digestibility (CATTD ) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25‐OH ‐D3 diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p < 0.05) bone DM , ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p < 0.05) between phytase and 25‐OH ‐D3 on cook loss. Pigs offered 25‐OH ‐D3 had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25‐OH ‐D3 were offered in combination compared to the phytase only diet. Pigs offered 25‐OH ‐D3 exhibited higher (p < 0.05) Warner Bratzler shear force values and lower (p < 0.05) pork lightness (L *) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25‐OH ‐D3 on pig performance, bone parameters or pork quality. 相似文献