低蛋白低磷饲粮添加氨基酸和植酸酶对肥育猪粪氮磷排泄量的影响

选择体重为(60±1.5)kg的去势杜长大公猪12头,随机分为3组,每组4个重复,每个重复1头猪.处理1组日粮粗蛋白为16％、总磷为0.5％;处理2组日粮粗蛋白为14.5％、总磷为0.4％;处理3组日粮粗蛋白为13％、总磷为0.4％.根据主要氨基酸比例(Lys∶ Met+Cys∶ Thr∶ Trp=100∶ 60∶ 65∶ 20)添加合成氨基酸,3个处理组的赖氨酸含量为0.8％,处理2组和处理3组日粮中添加植酸酶.结果表明:3个处理间的日增重和料重比差异不显著,处理2组的粪氮排出量比处理1组降低17.03％ (P＜0.05);处理3组的粪氮排出量分别比处理1组和处理2组降低28.33％、13.62％ (P＜0.05),处理2组和处理3组的粪磷排出量比处理1组分别降低23.23％、21.10％ (P＜0.05).     

低蛋白日粮添加氨基酸对猪粪氮磷排泄的影响

本试验通过在低蛋白日粮中添加赖氨酸、蛋氨酸、生物菌制剂,研究对猪粪氮磷排泄量的影响。试验分为3组,每组12头,第1组为对照组,第2组为自配低蛋白日粮中添加赖氨酸、蛋氨酸组,第3组为自配低蛋白日粮中添加赖氨酸、蛋氨酸、生物菌制剂组。结果表明,在低蛋白饲料日粮中添加赖氨酸、蛋氨酸、生物菌制剂对猪的生产性能有一定提高,各组间有差别,但差异不显著;可显著地减少猪粪中氮磷的排出,猪粪中粗蛋白含量分别减少11%和9%,猪粪中氮含量分别减少49%和48%,猪粪中磷含量分别减少23%和25%。第2组与第3组间差异不显著,但对生长肥猪的日增重、粪中氮磷的排出量仍有影响。     

低蛋白低磷加酶日粮对生长猪生产性能及减排效果的影响

选择30头24.4kg左右的健康杜×长×大杂交猪,将其随机分成2组,每组3个重复,每个重复5头猪,分别饲喂两种日粮：对照组日粮（18.4%CP＋0.37%有效磷,高蛋白高磷组日粮）和试验组日粮（16.0%CP＋0.28%有效磷＋100g/t植酸酶,低蛋白低磷加酶组日粮）,研究低蛋白低磷加酶日粮对生长猪生产性能及减排效果的影响。结果表明,低蛋白低磷加酶日粮对生长猪生产性能没有显著影响,但是可显著提高氮、磷的利用率,从而减少氮、磷排放。     

蛋用鸡连续饲喂低蛋白低有效磷饲粮的安全性和添加植酸酶效果的评价

对蛋用鸡连续饲喂低蛋白低有效磷饲粮的安全性及添加植酸酶的效果进行了探讨。结果表明,2～36周龄蛋用鸡在2～8、9～15、16～18和19～36周龄连续饲喂粗蛋白为17．0％、13．5％、13．0％、15．0％和有效磷为0．35％、0．3％、0．3％、0．3％的低蛋白中磷饲粮,除蛋重降低外,其他生产性能指标与粗蛋白为19．0％、15．0％、14．5％、16．5％和有效磷为0．45％、0．4％、0．4％、0．4％的高蛋白高磷饲粮无显著差异,并使8、15、36周龄鸡的氮、磷排泄量分别减少9．50％（P〈0．01）、18．81％（P〈0．01）、13．42（P〈0．05）和15．93％（P〈0．01）、16．18％（P〈O．01）、19．21％（P〈0．01）。连续饲喂粗蛋白为17．0％、13．5％、13．0％、15．0％和有效磷为0．25％、0．2％、0．2％、0．2％的低蛋白低磷饲粮,可显著降低2～18周龄生长鸡平均日增重和饲料利用率,但添加300IU／kg植酸酶后可达到高蛋白高磷的饲养效果,并使8、15、36周龄鸡的总磷和粗蛋白表观利用率分别提高12．55％（P〉0．05）、7．24％（P〉0．05）、32．66％（P〈0．01）和26．23％（P〉0．05）、15．70％（P〈0．01）、7．77％（P〈0．05）,而氮、磷排泄分别减少17．70％（P〈0．01）、25．19％（P〈0．01）、17．63（P〈0．05）和37．41％（P〈0．01）、36．71％（P〈0．01）、43．17％（P〈0．01）。     

饲用添加复合酶制剂的低磷、低蛋白日粮对生长猪生产性能和氮、磷代谢的影响

为了探讨饲用添加复合酶制剂的低磷、低蛋白日粮对生长猪生产性能和氮、磷代谢的影响,试验将初始体重为(32.19±1.33)kg、健康的“杜×长×大”三元杂交生长猪48头均分为2组(对照组和试验组),每组3个重复,每个重复8头(公母各半),对照组饲喂玉米-豆粕型基础日粮,试验组饲喂用8%的双低菜粕和9%的黄酒糟替代基础日粮中18%的豆粕、同时添加氨基酸和复合酶制剂的试验日粮(饲料粗蛋白含量降低2%,有效磷含量降低0.1%),预试期7 d,饲养试验时间为46 d,代谢试验时间为7 d,比较两组的生产性能(始重、末重、平均日增重、平均日采食量、料重比),氮、磷代谢情况[食入氮(磷)、粪氮(磷)、尿氮(磷)、总排氮(磷)、沉积氮(磷)、氮(磷)表观消化率、氮(磷)利用率]。结果表明：对照组和试验组的生产性能各指标均差异不显著(P>0.05),但试验组的平均日增重和平均日采食量较对照组均略有提高;与对照组比,试验组的尿氮降低了58.36%,总排氮量降低了44.35%,均差异显著(P<0.05);氮利用率有所提高,但差异不显著(P>0.05);试验组的粪磷和总排磷量均降低了40.1...     

植酸酶和蛋白酶在肉鸡低蛋白、低磷日粮中的应用

选用健康无残、体重无差异的艾维茵肉鸡（18 d）96只,随机分为3个处理组,每个处理4个重复,每个重复8只。分为对照组（基础日粮1）、处理1组（基础日粮2+200 g/kg 植酸酶）、处理2组（基础日粮3+200 g/kg 植酸酶+200 g/kg 蛋白酶）,有效磷水平分别设定为0.35%、0.30%、0.25%,粗蛋白水平分别设定为18%、16.5%、16.5%。研究了添加植酸酶和蛋白酶对肉鸡生长性能、胫骨性能、血液生化指标以及氮、磷排泄的影响。结果表明：与单一添加植酸酶相比,植酸酶和蛋白酶有较好的协同作用,日粮蛋白水平可以降低1.5个质量百分含量,可替代60%的磷酸氢钙,氮、磷的排放分别下降了45.68%、44.79%。     

无氮日粮和酪蛋白对猪回肠内源氨基酸排出量的影响

采用平均体重为 65± 1.85 kg的瘘管猪 6头，研究酪蛋白日粮和无氮日粮对猪回肠内源氨基酸排出量的影响。试验结果表明，酪蛋白组中，除 Met、 Phe、 Pro外，几乎所有的内源氨基酸排出量均高于无氮日粮组。其中， His、 Ile、 Lys、 Thr、 Val、 Asp、 Glu、 Gly、 Ser差异显著 (P< 0.05)。酪蛋白组的内源氮排出量、内源总必需氨基酸、总非必需氨基酸和总氨基酸的排出量均显著高于无氮日粮组 (P< 0.05)，提高的百分比分别为 94.1％、 73.0％、 76.4％和 74.8％。由本次试验结果可以得出，无氮日粮法低估了猪的回肠内源氨基酸损失，而在无氮日粮中添加肽类物质（本试验中添加量为 5％）对内源氨基酸的排出有刺激作用。     

猪和鸡的低蛋白日粮

1研究与推广低蛋白质日粮的必要性1.1低蛋白质日粮与环境保护在中国,猪禽年产粪5~8亿t,粪水60亿t。每头成年猪的生化需氧量(BOD)是人的13倍。如此大量需氧腐败有机物不经处理进入水体,会造成严重的水体污染,水中氧含量下降,硝酸根离子增加,并随畜禽粪便排出大量金属元素、细菌病毒和有害气体(甲烷、硫化氢、甲醇等)。表1猪氮、磷的摄入量、排出量和存留量*仔猪(9~25kg)生长猪(25~106kg)种母猪(年产19.6头仔猪)氮摄入/kg0.946.3227.78排出/kg0.564.2422.42存留/%403319磷摄入/kg0.211.226.55排出/kg0.130.825.42存留/%393317*Jongbloed等(1…     

低蛋白补充合成氨基酸日粮对仔猪氦排泄的影响

试验选用32头断奶仔猪，初始体重为6．8kg，共进行14d，其中适应期9d，正式收粪尿期为5d。试验全面研究了不同蛋白水平补充合成氨基酸对仔猪氨排泄的影响。研究发现，降低蛋白水平并按照理想蛋白模式补充合成氨基酸，显著降低了粪尿排放量（P=0．01），线性降低了氮排泄（P〈0．001），同时日氮沉积绝对量也呈现线性下降（P〈0．001）；平均每降低一个百分点的仔猪日粮蛋白水平．可减少8．4％的氮排泄量。     

The effect of short-term phytase supplementation on the apparent total tract digestibility of calcium and phosphorus and the reproductive performance of late gestation and lactating sows fed diets without mineral phosphorus

The objective of this study was to measure apparent total tract digestibility (ATTD) of Ca and P as well as reproductive performance in late gestation and lactating sows supplemented with a novel phytase and to compare the response to phytase supplementation between late gestation and lactating sows. A total of 45 late gestation sows and 45 lactating sows were used in experiments 1 and 2, respectively, in a completely randomized design. The sows were provided with a control diet or the control diet supplemented with 187.5 or 375 FYT phytase/kg feed for 10 days. The diets were prepared according to the formulas in use for production but without any inorganic P supplement. Titanium dioxide was included at 3 g/kg feed as an indigestible marker. Each dietary treatment was replicated with 15 sows individually housed in farrowing stalls. The sows were allowed to adapt to the experimental diets for 5 days before a 5-d fecal collection by grab sampling, and the performance of the sows and their litters were measured until weaning. The results showed that the ATTD of Ca increased linearly (P < 0.001), while the ATTD of P increased both linearly and quadratically (P < 0.01) with increasing supplementation of phytase in both late gestation and lactating sows. There was no significant effect of phytase on the ATTD of dry matter, crude protein, and gross energy, and the performance of the sows and their progenies. The phytase added at 187.5 and 375 FYT/kg feed released 0.07% and 0.10% digested P, respectively, in late gestation sows, which compared with 0.09% and 0.12% digested P in lactating sows. In conclusion, a novel phytase at 187.5–375 FYT/kg feed could release 0.07–0.12% digestible P for sows. It appeared that using the P digestibility values of feed ingredients listed by NRC to formulate a diet for sows might overestimate dietary P supply and a greater response to phytase supplementation could be expected in lactating sows than in late gestation sows.     

Effect of dietary phosphorus content on milk production and phosphorus excretion in dairy cows

Background：Phosphorus（P） supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.Method：Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield,and assigned randomly to one of the three dietary treatments：0.37,0.47,and 0.57%P（DM basis）;these P levels represent the NRC recommendations,Chinese recommendations,and the amount of dietary P commonly fed by Chinese dairy farmers,respectively.Average daily feed intake was calculated from monthly data on feed offered and refused.Milk yields of individual cows were recorded weekly,and milk samples were taken for analysis of protein,fat,solids-not-fat,lactose,and somatic cell count.Blood samples were collected on days-6,-3,0,3,6 relative to calving,and then monthly throughout lactation,and analyzed for P and Ca concentrations.Spot samples of feces and urine were collected for 3 consecutive d during weeks 12,24,and 36,and P concentrations were analyzed.Reproduction and health data were recorded.Results：Dietary P did not affect dry matter intake or milk yield（P〉 0.10）.Milk fat content was slightly higher in cows fed 0.37%P than in cows fed 0.47%P（P = 0.05）.Serum concentrations of P and Ca did not reflect dietary P content（P〉 0.10）.Fecal and urinary P both declined linearly（P〈 0.05） as dietary P decreased from 0.57 to0.37%.Fecal P content was 25%less when dietary P was 0.37%compared to 0.57%.Health events and reproductive performance were not associated with dietary P content（P〉 0.05）.Conclusions：Lowering dietary P from 0.57 to 0.37%did not negatively affect milk production,but did significantly reduce P excretion into environment.     

Effects of low protein diet and low protein diet supplemented with synthetic essential amino acids on meat quality of broiler chickens

We investigated the effects of a low crude protein (CP) diet and a low CP diet supplemented with synthetic essential amino acids (EAA) on the meat quality of broiler chickens. Twenty‐one‐day‐old chickens were assigned to one of three diets: control, low CP (LCP), or low CP supplemented with EAA (ELCP). The chickens received these diets for 10 days. The shear force value (SFV) and free glutamate content of the Pectoralis major muscle were measured as indicators of the meat toughness and taste. The collagen and crude fat content of the muscle and the cross‐sectional area of myofibers were measured to evaluate the effects of the LCP and ELCP diets on meat toughness. The SFV of the ELCP group was 47% lower than that of the control group (P < 0.01). However, the LCP diet did not affect the SFV. The collagen and crude fat content were not affected by the dietary treatment. The cross‐sectional area was lower in the LCP and ELCP groups (P < 0.05) than the control group. The free glutamate content of muscle was not affected by the dietary treatment. Thus, a low CP diet supplemented with EAA is an effective means of producing tender meat.     

Effect of floor cooling on performance of lactating sows during summer

Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17 °C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8 °C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8 °C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P < 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P < 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P < 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P < 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.     

低蛋白猪日粮添加氨基酸的研究

以密码子使用频率为指导进行低蛋白日粮氨基酸生物配比。低蛋白日粮中添加氨基酸能显著改善猪的生产性能。对照组与试验组Ⅰ、Ⅱ、Ⅲ的日增重分别为 5 6 1 0 7g± 4 8 0 2g ,389 2 7g±2 7 31g ,5 2 6 79g± 33 72 g和 4 76 71g± 39 5 9g。结果表明 ,密码子的使用频率可以作为指导氨基酸生物配比的参考依据。     

蛋白质水平和氨基酸模型对蛋鸡生产性能及氮磷利用与排泄的影响

本试验研究了按理想蛋白氨基酸模式配制日粮对蛋鸡生产性能及营养素氮和磷利用与排泄的影响。试验结果表明:试验组比对照组的产蛋率、产蛋量、蛋重及饲料转化率均有所提高,但差异不显著(P>0.05);而氮和磷的表观利用率分别提高了6.46%和9.31%,差异显著(P<0.05);氮排泄量降低了11.93%,差异显著(P<0.05);总磷排泄量降低了2.20%,差异不显著(P<0.05)。结果表明,按理想蛋白氨基酸模式配制日粮,通过合理的营养调控技术,可以降低蛋鸡氮磷排泄量。     

Effect of dietary phosphorus content on milk production and phosphorus excretion in dairy cows

Background

Phosphorus (P) supplementation is costly and can result in excess P excretion. This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.

Method

Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield, and assigned randomly to one of the three dietary treatments: 0.37, 0.47, and 0.57% P (DM basis); these P levels represent the NRC recommendations, Chinese recommendations, and the amount of dietary P commonly fed by Chinese dairy farmers, respectively. Average daily feed intake was calculated from monthly data on feed offered and refused. Milk yields of individual cows were recorded weekly, and milk samples were taken for analysis of protein, fat, solids-not-fat, lactose, and somatic cell count. Blood samples were collected on days −6, −3, 0, 3, 6 relative to calving, and then monthly throughout lactation, and analyzed for P and Ca concentrations. Spot samples of feces and urine were collected for 3 consecutive d during weeks 12, 24, and 36, and P concentrations were analyzed. Reproduction and health data were recorded.

Results

Dietary P did not affect dry matter intake or milk yield (P > 0.10). Milk fat content was slightly higher in cows fed 0.37% P than in cows fed 0.47% P (P = 0.05). Serum concentrations of P and Ca did not reflect dietary P content (P > 0.10). Fecal and urinary P both declined linearly (P < 0.05) as dietary P decreased from 0.57 to 0.37%. Fecal P content was 25% less when dietary P was 0.37% compared to 0.57%. Health events and reproductive performance were not associated with dietary P content (P > 0.05).

Conclusions

Lowering dietary P from 0.57 to 0.37% did not negatively affect milk production, but did significantly reduce P excretion into environment.     

在不同有效磷日粮中添加植酸酶对仔猪生产性能的影响

将体重相近的60头15kg左右的杜长大仔猪分为5个处理（对照组、AP降低0．1％、AP降低0．12％、AP降低0．1％＋酶、AP降低0．12％＋酶），每个处理3个重复，每重复4头仔猪。研究结果表明：曰粮有效磷水平和植酸酶对仔猪生长、料重比都有显著的影响（P〈0．05），与对照组相比，当日粮有效磷水平降低0．1％，仔猪体重、日增重会显著降低，而料重比显著上升；当有效磷降低0．1％添加植酸酶时，仔猪体重、日增重会显著增加，而料重比显著下降；当日粮有效磷降低0．12％时，不论加酶与否，其体重、日增重都会显著下降，而料重比会显著增加。