肉鸡饲粮钙磷比对豆粕中磷真消化率的影响

本试验旨在使用线性回归法和差量法研究肉鸡饲粮钙磷比对豆粕中磷真消化率的影响。选用576只15日龄罗氏肉鸡,根据3×3因子完全随机区组设计分为9个处理,每个处理8个重复,每个重复8只鸡。通过添加3个水平的豆粕(30.00%、43.00%和56.00%),研究饲粮钙磷比(1.0、1.5和2.0)对豆粕中磷真消化率测定值的影响。试验期7 d。结果表明:肉鸡体增重、饲料转化效率、回肠食糜磷排泄量和可消化磷均随豆粕水平提高呈线性增加(P0.01),而干物质消化率和磷的表观消化率呈线性降低(P0.01)。提高饲粮钙磷比可显著增加回肠食糜磷排泄量,从而降低可消化磷和磷的表观消化率(P0.01)。使用线性回归法和差量法在钙磷比为2.0时测得豆粕中磷的真消化率分别为40.79%和39.84%,显著低于钙磷比在1.0(53.36%和55.59%)和1.5(56.81%和56.36%)时测得磷的真消化率(P0.05)。由此可见,肉鸡饲粮钙磷比显著影响豆粕中磷真消化率的测定,但真消化率计算方法(线性回归法和差量法)对测定结果无显著影响。     

肉鸡基础饲粮组成对豆粕中磷真消化率评定的影响

本试验旨在比较肉鸡基础饲粮组成对线性回归法测得豆粕中磷的真回肠消化率(TID)的影响。试验选用432只雄性15日龄罗氏肉鸡,根据初始体重按照3×3因子完全随机区组设计分为9个处理,每个处理8个重复,每个重复6只鸡。9个日粮处理组包含3种基础饲粮(玉米淀粉组、酪蛋白组和玉米组)和3个豆粕水平(13.0%、26.0%和39.0%),试验期7 d。结果表明:酪蛋白组和玉米组肉鸡体增重和饲料转化效率高于玉米淀粉组(P<0.05),而玉米组的采食量高于玉米淀粉组和酪蛋白组(P<0.01);玉米组干物质表观回肠消化率低于玉米淀粉组和酪蛋白组(P<0.01);玉米组回肠食糜中磷的排泄量高于玉米淀粉组和酪蛋白组(P<0.01);酪蛋白组可消化磷含量大于玉米组,而玉米组可消化磷含量大于玉米淀粉组(P<0.01);酪蛋白组磷的表观回肠消化率大于玉米淀粉组(P<0.05),而玉米淀粉组大于玉米组(P<0.01);饲喂不同日粮肉鸡的回肠食糜磷排泄量和可消化磷含量随豆粕水平提高线性增加(P<0.01)。线性回归法测得玉米组豆粕中磷的TID(61.85%)低于玉米淀粉组(75.08%)和酪蛋白组(71.77%)豆粕中磷的TID(P<0.05)。由此可见,肉鸡基础饲粮类型显著影响豆粕中磷的TID的评定。     

线性回归法测定生长猪内源磷排泄量及鱼粉磷真消化率

本研究采用线性回归法测定生长猪内源磷排泄量及鱼粉磷的真消化率.选用5头健康大白×长白阉公猪为试验动物,平均体重为(27.17±0.28)kg.采用5×5拉丁方设计,设5个磷水平(0.08%、0.12%、0.17%、0.21%和0.25%),日粮以葡萄糖和玉米淀粉等为基础原料,鱼粉为磷唯一来源.日粮中添加0.1%TiO2作为外源指示剂.试验分5个试验期,每期6 d,4 d适应期,2 d收粪期.结果表明,生长猪粪磷的排出量与日粮磷的摄入量呈线性关系(y=0.292 7x-0.052 8,R2=0.99,P<0.01),回归法测得生长猪内源磷的排泄量为0.798 5 g/kg,鱼粉磷的真消化率为71.12%.分析粪磷来源发现,内源磷排泄量基本不变(P>0.05),而粪磷随日粮磷含量的增加而增加(P<0.01).由结果可知,线性回归法可用于测定猪内源磷排泄量及鱼粉磷真消化率.     

多重线性回归法测定猪内源磷排泄量及饲料磷真消化率的研究

本研究采用多重线性回归法测定生长猪内源磷排泄量及花生粕和豆粕磷的真消化率。选用6头健康大白×长白阉公猪为试验动物,平均体重为(24.8±1.42)kg。采用6×6拉丁方设计,设6个磷水平(0.09%、0.17%、0.26%、0.35%、0.43%、0.53%),以豆粕、葡萄糖、玉米淀粉等为基础,以花生粕为待测植物性饲料,配制半纯合试验日粮,花生粕和豆粕为磷唯一来源。日粮中添加0.35%Cr2O3作为外源指示剂。试验分6个试验期,每期8 d,6d适应期,2 d收粪期。结果表明,在以g/kg DMI为计量单位条件下,生长猪粪磷的排出量与日粮磷的摄入量呈线性关系(P=0.000 1),回归法测得生长猪内源磷的排泄量为0.526 6 g/kg DMI,花生粕磷的真消化率为28.00%,豆粕磷的真消化率为38.87%。分析粪磷来源发现,内源磷排泄量基本不变(P=0.13),而日粮来源粪磷随日粮含量的增加而增加(P=0.000 1),说明多重线性回归法可用于测定猪内源磷排泄量及非常规植物性饲料磷的真消化率;比较真消化率和表观消化率值说明,真消化率比表观消化率具有较好的重复性。     

生长猪基础饲粮组成对磷酸氢钙和磷酸二氢钙中磷的全肠道真消化率的影响

本试验旨在研究生长猪基础饲粮组成对磷酸氢钙(DCP)和磷酸二氢钙(MCP)中磷的全肠道真消化率(TTTD)的影响。试验1选用10头平均体重为(30.4±1.8)kg的生长猪,按照10×8不完全拉丁方设计,分别饲喂含有5个DCP添加水平的玉米-豆粕型和含有5个DCP添加水平的小麦-豆粕型饲粮,进行8期消化试验;试验2选用10头平均体重为(30.9±1.5)kg的生长猪,按照10×8不完全拉丁方设计,分别饲喂含有5个M CP添加水平的玉米-豆粕型和含有5个MCP添加水平的小麦-豆粕型饲粮,进行8期消化试验。每期消化试验包括5 d的饲粮适应期和2 d的粪便收集期。结果表明:1)玉米-豆粕型饲粮的总粪磷排泄量极显著高于小麦-豆粕型饲粮(P0.01),小麦-豆粕型饲粮的全肠道可消化磷含量和磷的表观全肠道消化率(ATTD)极显著高于玉米-豆粕型饲粮(P0.01)。饲粮添加DCP和MCP线性增加总粪磷排泄量、全肠道可消化磷含量及磷的ATTD(P0.01)。2)通过使用线性回归法,测得生长猪采食玉米-豆粕型和小麦-豆粕型饲粮对DCP中磷的TTTD分别为82.33%和82.88%,生长猪采食玉米-豆粕型和小麦-豆粕型饲粮对MCP中磷的TTTD分别为85.88%和84.62%。由此可见,生长猪基础饲粮组成对DCP和MCP中磷的TTTD无显著影响。     

日粮磷水平对线性回归法测定磷真消化率的影响

本试验旨在研究日粮磷水平对线性回归法测定豆粕中磷真消化率的影响。选用48头平均体重为(36.0±0.1)kg生长公猪,采用2×3因子完全随机区组设计,随机分为6个处理,每个处理8个重复,每个重复1头猪。通过在半纯合日粮(低磷日粮,无玉米添加)和常规日粮(高磷日粮,含50.0%玉米)上添加3个水平豆粕(13.0%、26.0%和39.0%),研究日粮类型(低磷日粮和高磷日粮)对线性回归法测定豆粕中磷真消化率的影响。结果表明:随日粮豆粕水平增加,生长公猪的总磷摄入量、粪磷排泄量、可消化磷和存留磷量呈线性增加(P<0.01)。与低磷日粮相比,采食高磷日粮显著增加日粮总磷摄入量、粪磷排泄量、尿磷排泄量、可消化磷和存留磷(P<0.05)。通过使用线性回归法,生长猪采食高磷日粮测得豆粕中磷的真消化率为36.11%,显著低于采食低磷日粮测得结果 43.38%(P<0.05)。由此可见,由半纯合日粮(低磷日粮)测定得出的豆粕中磷的真消化率显著高于常规日粮(高磷日粮)的测定值,因此在使用半纯合日粮测得饲料原料中磷真消化率的数据用于日粮配置时应考虑上述因素。     

二元线性回归法测定生长猪内源磷排泄量及麦麸和豆粕磷的真消化率

本研究采用二元线性回归法测定生长猪内源磷排泄量及麦麸和豆粕磷的真消化率.选用6头健康大白×长白阉公猪为试验动物,平均体重为(34.42±0.64)kg.采用6×6拉丁方设计,设6个总磷水平(0.12%、0.25%、0.28%、0.35%、0.47%和0.54%),日粮以豆粕、葡萄糖、玉米淀粉等为基础原料,麦麸和豆粕为磷来源.日粮中添加0.1%TiO2作为外源指示剂.试验分6个试验期,每期6 d,4 d适应期,2 d收粪期.结果表明,生长猪粪磷的排出量与日粮磷的摄入量呈线性关系(y=0.515 7x-0.0133,R2=0.97,P<0.01),回归法测得生长猪内源磷的排泄量为0.933 0g/kg,麦麸和豆粕磷的真消化率分别为48.07%和47.50%.分析粪磷来源发现,内源磷排泄量基本不变(P>0.05),而粪磷随日粮磷含量的增加而极显著增加(P<0.01).由结果可知,线性回归法可用于测定猪内源磷排泄量及麦麸和豆粕磷的真消化率.     

酪蛋白对线性回归法测定磷真消化率的影响

本试验旨在使用线性回归法研究肉鸡饲粮添加酪蛋白对豆粕中磷真消化率测定的影响。采用2×3因子完全随机区组设计将384只15日龄罗斯肉鸡随机分为6个处理,每个处理8个重复,每个重复8只鸡。试验因子包含2种饲粮类型(无酪蛋白添加和添加酪蛋白)和3个磷水平(0.22%、0.30%和0.38%),选择三氧化二铬作为指示剂测定肉鸡对豆粕中磷的利用效率。结果表明:随饲粮总磷水平增加,肉鸡采食量、体增重和饲料转化率显著线性增加,而磷表观消化率和存留率以及干物质消化率和存留率显著线性降低(P0.01);饲粮添加酪蛋白显著减少肉鸡食糜和排泄物中总磷排泄量(P0.01);使用线性回归法测得酪蛋白添加组豆粕中磷的真消化率71.26%和存留率60.58%显著高于无酪蛋白添加组的61.84%和48.68%(P0.05)。由此可见,饲粮添加酪蛋白影响线性回归法对豆粕中磷真消化率的测定。     

多重线性回归法测定猪内源磷排泄量及饲料磷真消化率的研究

本研究旨在采用多重线性回归法测定生长猪内源磷排泄量及高粱和豆粕中磷的真消化率。试验选用6头健康大白×长白阉公猪为消化试验动物,平均体重为(23.6±1.23)kg。采用6×6拉丁方设计,设6个磷水平(0.08%、0.15%、0.23%、0.30%、0.38%、0.53%),以豆粕、葡萄糖、玉米淀粉等为基础,以高粱和豆粕为磷唯一来源,配制半纯合试验饲粮。饲粮中添加0.35%Cr2O3作为外源指示剂。试验分6个试验期,每期8d,其中6d适应期,2d收粪期。饲粮中磷表观消化率受饲粮中磷水平的影响(P<0.05),并随饲粮中磷水平的提高由14.88%增大至34.88%。在以g/kgDMI为计量单位条件下,生长猪粪磷的排出量与饲粮磷的摄入量呈线性关系(P=0.0001)。结果表明,多重线性回归法可用于生长猪内源磷排泄量和植物性饲料磷真消化率的测定;以豆粕-高粱型模型饲粮测定出生长猪内源磷排泄量为0.2940g/kgDMI,高粱中磷的真消化率为56.05%,豆粕中磷的真消化率为39.41%。     

多元线性回归法测定生长猪小麦和豆粕磷真消化率的研究

<正>磷由于其独具的消化-吸收-代谢过程以及它在动物营养中不可取代性及其在配合饲料中的重要经济地位,100多年来人们对它的研究从未间断过(霍启光,2002)。以有效磷来确定饲料中磷的含量和动物磷的需要量,是时代发展的必然趋势。     

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。     

差量法测定鸭饲料氨基酸真消化率和内源氨基酸排泄量的研究

为了考察差量法测定氨基酸真消化率及内源氨基酸排泄量的可行性,用平均体重(3.0±0.1)kg、7周龄的天府肉公鸭(樱桃谷×建昌鸭)96只进行试验,设计6个试验日粮,蛋白质水平分别为0、5%、10%、15%、20%和25%。采用Sibbald的强饲法测定氨基酸的消化率,并同时用无氮日粮法、梯度回归法及饥饿法测定内源氨基酸的排泄量,计算各蛋白质水平日粮氨基酸的真消化率。试验结果表明,差量法测得各蛋白质水平段日粮氨基酸真消化率为(90.54±2.70)%、(90.62±1.88)%、(92.52±1.73)%、(92.73±1.77)%、(93.44±1.59)%和(92.37±1.09)%,在10%～20%的日粮蛋白质水平范围基本稳定。差量法、无氮日粮法、回归法和饥饿法测得日粮氨基酸真消化率平均值分别为(92.37±1.09)%、(92.65±0.56)%、(92.53±0.48)%和(89.15±2.02)%,其内源氨基酸排泄总量分别为0.233±0.015(6个蛋白质水平日粮平均值)、0.228、0.230和0.184g/(4只.h)。由此得知,差量法可用于测定饲料氨基酸的真消化率及内源氨基酸排泄量。     

差量法和酶解酪蛋白法测定鸭饲料氨基酸真消化率及内源排泄量的比较研究

本试验研究了差量法和酶解酪蛋白法测定动物在采食正常含氮日粮条件下的内源氨基酸排泄量及饲料氨基酸真消化率的差异,并同时与无氮日粮法作比较。差量法以豆粕为唯一蛋白源,配制成15%和20%2种粗蛋白质水平的试粮;酶解酪蛋白法以酶解酪蛋白作为蛋白质来源,配制成17.5%粗蛋白质水平的试粮;无氮日粮用淀粉和纸纤维进行配制。每种方法选用7周龄、平均体重(2.77±0.16)kg天府肉公鸭64只,分为4组,分别饲喂4种不同日粮,每组4个重复,每重复4只鸭,采用Sibbald的强饲法进行代谢试验,测定各试粮氨基酸表观消化率、内源氨基酸排泄量及真消化率。结果显示:差量法、酶解酪蛋白法和无氮日粮法测定的内源氨基酸排泄量分别为0.9946、1.2243和0.9297mg/gDMI;差量法测定的氨基酸真消化率(%)为88.93±4.43,用酶解酪蛋白法和无氮日粮法测定的内源氨基酸排泄量计算的15%和20%2个粗蛋白质水平日粮氨基酸真消化率(%)分别为91.15±4.33和91.97±4.16、88.55±4.29和88.82±4.61。以上结果表明,在15%～20%的日粮蛋白质水平范围,差量法测定的氨基酸真消化率和内源氨基酸排泄量较酶解酪蛋白法准确,酶解酪蛋白法可能高估了内源氨基酸排泄量和氨基酸真消化率。     

Effects of corn gluten feed inclusion at graded levels in a corn-soybean diet on the ileal and fecal digestibility of growing pigs

Background

This study aimed to determine the effect of the inclusion of corn gluten feed (CGF) on the apparent and standardized ileal digestibility of protein and amino acids and the apparent ileal and total tract digestibility of energy in growing pigs. The study was performed using 16 barrows (weight, 45.3 ± 4.5 kg) that were fitted with a T cannula at the terminal ileum. There were four treatments: a corn-soybean diet without CGF and three corn-soybean diets containing increasing levels of CGF (65, 130, and 195 g/kg). Data were analyzed according to a randomized complete block design, four blocks with four pigs each (one pig per treatment). The trend of the response (linear or quadratic) was determined using orthogonal contrasts, and when a linear effect was determined, a linear equation was obtained.

Results

The results showed that the inclusion up to 195 g/kg of CGF in the corn-soybean diet did not diminish the ileal digestibility (apparent and standardized) of protein and amino acids (P > 0.05), except that of phenylalanine, cystine, and proline. A linear decrease (P < 0.05) per gram of CGF added to the diet in the apparent and standardized ileal digestibility of phenylalanine (0.011 and 0.015 percentage units, respectively), cystine (0.048 and 0.043 percentage units, respectively), and proline (0.045 and 0.047 percentage units, respectively) was noted. Similarly, ileal digestibility of dry matter and energy were adversely affected (reduced by 0.028 and 0.025 percentage units, respectively, per gram of CGF increment in the diet). A significant (P < 0.05) linear reduction in total tract digestibility with increase in CGF amount in the diet was observed for energy (0.027 percentage units), dry matter (0.027 percentage units), crude protein (0.020 percentage units), and neutral detergent fiber (0.041 percentage units) per gram of CGF added to the diet.

Conclusion

CGF did not affect the ileal digestibility of protein and most amino acids but reduced the ileal and total tract digestibility of energy.     

Evaluation of in vitro methods to estimate the in vivo nutrient digestibility of barley in pigs

Two experiments were conducted for the comparison of the in vivo and the in vitro nutrient digestibility of barley in pigs. The first experiment studied the in vivo and in vitro apparent ileal digestibilities (AID) of protein (CP) and amino acids (AA) of seven barleys. The second experiment studied a further eleven samples of barley to compare the in vivo and in vitro values of AID of CP and AA and of apparent faecal digestibility (AFD) of dry matter (DM) and organic matter (OM). The in vitro digestibilities of the different barley samples were determined using the multi-enzymatic methods described by Boisen and Fernández [Boisen, S., Fernández, J.A. (1995). Prediction of the apparent ileal digestibility of protein and amino acids in feedstuffs and feed mixtures for pigs by in vitro analysis. Anim. Feed Sci. Technol. 51, 29–43. Boisen, S., Fernández, J.A. (1997). Prediction of the total tract digestibility of energy in feedstuffs and pigs diets by in vitro analyses. Anim. Feed Sci. Technol. 68, 277–286.]. A good fit to the linear regression equation between the in vivo and in vitro values was found for all the parameters (P < 0.05). When comparing the equation to the bisectrix (i.e. intercept = 0 and slope = 1), a good agreement was found in both experiments between the in vitro and in vivo AID values for CP, Leu, Phe, His and Lys, the values for Met, Cys, Val and Ile were in good agreement in only one of the two experiments and those for Thr did not agree for any of them. Finally, in the second experiment, while a good agreement between the OM AFD coefficients was observed, AFD for DM was underestimated with the in vitro method.     

Phosphorus availability in feed phosphates determined by regression

Due to environmental concern a lot of effort has been dedicated to improve the utilisation of phytate phosphorus (P) in cereals and seeds. Consequently, microbial phytases are added to pig diets at the expense of feed phosphates. However, there is still a need for inclusion of feed phosphate, especially in diets for young piglets and lactating sows in order to meet their P requirement. This creates a demand for feed phosphates with a high P availability. Fourteen feed phosphates, including two newly developed monocalcium phosphates (MCP), were tested in this experiment. For each source, a series of 5 diets was prepared by inclusion of increasing amounts of either MCP or MSP. These diets were offered to pigs kept in metabolism crates (6 pigs on each of the 5 diets). After 5 days adaptation, total collection of faeces and urine was performed for 7 days. P availability in each source was determined by regression of the net absorption of P on P-intake. The experiment revealed that MSP had the highest availability (79%) and the availability of all the tested phosphates varied between 50 and 79%. The new MCPs proved to be 71 and 75% available.     

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。