Low crude protein formulation with supplemental amino acids for its impacts on intestinal health and growth performance of growing-finishing pigs

Background Low crude protein(CP)formulations with supplemental amino acids(AA)are used to enhance intestinal health,reduce costs,minimize environmental impact,and maintain growth performance of pigs.However,extensive reduction of dietary CP can compromise growth performance due to limited synthesis of non-essential AA and limited availability of bioactive compounds from protein supplements even when AA requirements are met.Moreover,implementing a low CP formulation can increase the net energy(NE)content in feeds causing excessive fat deposition.Additional supplementation of functional AA,coupled with low CP formulation could further enhance intestinal health and glucose metabolism,improving nitrogen utilization,and growth performance.Three experiments were conducted to evaluate the effects of low CP formulations with supplemental AA on the intestinal health and growth performance of growing-finishing pigs.Methods In Exp.1,90 pigs(19.7±1.1 kg,45 barrows and 45 gilts)were assigned to 3 treatments:CON(18.0%CP,supplementing Lys,Met,and Thr),LCP(16.0%CP,supplementing Lys,Met,Thr,Trp,and Val),and LCPT(16.1%CP,LCP+0.05%SID Trp).In Exp.2,72 pigs(34.2±4.2 kg BW)were assigned to 3 treatments:CON(17.7%CP,meeting the requirements of Lys,Met,Thr,and Trp);LCP(15.0%CP,meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and VLCP(12.8%CP,meeting Lys,Thr,Trp,Met,Val,Ile,Phe,His,and Leu).In Exp.3,72 pigs(54.1±5.9 kg BW)were assigned to 3 treatments and fed experimental diets for 3 phases(grower 2,finishing 1,and finishing 2).Treatments were CON(18.0%,13.8%,12.7%CP for 3 phases;meeting Lys,Met,Thr,and Trp);LCP(13.5%,11.4%,10.4%CP for 3 phases;meeting Lys,Thr,Trp,Met,Val,Ile,and Phe);and LCPG(14.1%,12.8%,11.1%CP for 3 phases;LCP+Glu to match SID Glu with CON).All diets had 2.6 Mcal/kg NE.Results In Exp.1,overall,the growth performance did not differ among treatments.The LCPT increased(P<0.05)Claudin-1 expression in the duodenum and jejunum.The LCP and LCPT increased(P<0.05)CAT-1,4F2hc,and B0AT expressions in the jejunum.In Exp.2,overall,the VLCP reduced(P<0.05)G:F and BUN.The LCP and VLCP increased(P<0.05)the backfat thickness(BFT).In Exp.3,overall,growth performance and BFT did not differ among treatments.The LCPG reduced(P<0.05)BUN,whereas increased the insulin in plasma.The LCP and LCPG reduced(P<0.05)the abundance of Streptococcaceae,whereas the LCP reduced(P<0.05)Erysipelotrichaceae,and the alpha diversity.Conclusions When implementing low CP formulation,CP can be reduced by supplementation of Lys,Thr,Met,Trp,Val,and Ile without affecting the growth performance of growing-finishing pigs when NE is adjusted to avoid increased fat deposition.Supplementation of Trp above the requirement or supplementation of Glu in low CP formulation seems to benefit intestinal health as well as improved nitrogen utilization and glucose metabolism.

Effects of Powdery Mildew on 1 000-Kernel Weight, Crude Protein Content and Yield of Winter Wheat in Three Consecutive Growing Seasons

In order to clarify the impact posed by wheat powdery mildew （Blumeria graminis f. sp. tritici） on the yield and yield components in different epidemic seasons, field trials were conducted in three growing seasons, 2009-2010, 2010-2011 and 2011-2012, in Langfang City, Hebei Province, China. The relationships between 1000-kernel weight, crude protein content of grain and yield and disease index （DI）, as well as area under disease progress curve （AUDPC） were studied. The models of the percentage of loss of 1000-kernel weight, crude protein content and yield were constructed using DI at critical point （CP） of growth stages （GS） and AUDPC in the three growing seasons, respectively. The CPs for estimating 1 000-kernel weight, crude protein content of grain and yield of wheat caused by powdery mildew were GS 11.1, GS 10.5.3 and GS l 0.5.3, respectively. Models based on DI at CP to estimate the percentage of loss of 1000-kernel weight, crude protein content of grain and yield were better than models based on AUDPC. And models of the percentage of loss of 1000-kernel weight, crude protein content and yield for 2011-2012 season were significant different from these for 2009-2010 and 2010-2011 seasons. These results indicated that besides powdery mildew, weather conditions also had influence on 1 000-kernel weight, crude protein content of grain and yield loss of wheat when powdery mildew occurred.

Effects of Different Dietary Crude Protein Levels on Reproductive Performance in Breeder Roosters

[Objective] To investigate effects of different dietary crude protein levels on reproductive performance and find out the optimal additive proportion of crude protein. [Method] A total of 45 New Yangzhou breeder roosters at 21 weeks old were sampled and divided into three groups, namely, low-protein diet group, medium-protein diet group and high-protein diet group. They were fed with diets respectively at crude protein levels of 17.23%, 13.04% and 11.32%. The sperm volume, testicular traits and levels of reproductive hormones were analyzed during the whole repro- ductive period. [Result] The sperm volume, sperm motility and sperm density of the medium-protein diet group were higher than that of the other two groups, and the sperm deformity rate of the medium-protein diet group was lowest. The rooster＇s testicular traits including weight, volume and testis indexes were not significantly affected by different protein levels, but the testis shrank slowly with aging （ P 〈 0.05）. The levels of testosterone （T）, luteinizing hormone （LH） and follicule stimulating hormone （FSH） in plasma were respectively 6.34%, 19.64% and 3.88% higher in the lowprotein diet group than in the medium-protein diet group, and these indexes were respectively 7.20%, 17.54% and 9.84% higher in the low-protein diet group than in the high-protein diet group. But all these differences were not significant. [ Conclusion] The breeder roosters fed with the diet at the crude protein level of 13.04% show better reproductive performance and economic efficiency.

Predicting Levels of Crude Protein, Digestibility, Lignin and Cellulose in Temperate Pastures Using Hyperspectral Image Data

Hyperspectral sensors provide the potential for direct estimation of pasture feed quality attributes. However, remote sensing retrieval of digestibility and fibre (lignin and cellulose) content of vegetation has proven to be challenging since tissue optical properties may not be propagated to the canopy level in mixed cover types. In this study, partial least squares regression on spectra from HyMap and Hyperion imagery were used to construct predictive models for estimation of crude protein, digestibility, lignin and cellulose concentration in temperate pastures. HyMap and Hyperion imagery and field spectra were collected over four pasture sites in southern Victoria, Australia. Co-incident field samples were analyzed with wet chemistry methods for crude protein, lignin and cellulose concentration, and digestibility was calculated from fiber determinations. Spectral data were subset based on sites and time of year of collection. Reflectance spectra were extracted from the hyperspectral imagery and collated for analysis. Six different transformations including derivatives and continuum removal were applied to the spectra to enhance absorption features sensitive to the quality attributes. The transformed reflectance spectra were then subjected to partial least squares regression, with full cross-validation “leave-one-out” technique, against the quality attributes to assess effects of the spectral transformations and post-atmospheric smoothing techniques to construct predictive models. Model performance between spectrometers, subsets and attributes were assessed using a coefficient of variation (CV), —the interquantile (IQ) range of the attribute values divided by the root mean square error of prediction (RMSEP) from the models. The predictive models with the highest CVs were obtained for digestibility for all spectra types, with HyMap the highest. However, models with slightly lower CVs were obtained for crude protein, lignin and cellulose. The spectral regions for diagnostic wavelengths fell within the chlorophyll well, red edge, and 2000-2300 nm ligno-cellulose-protein regions, with some wavelengths selected between the 1600 and 1800 nm region sensitive to nitrogen, protein, lignin and cellulose. The digestibility models with the highest CV’s had confidence intervals corresponding to ±5% digestibility, which constitutes approximately 30% of the measured range. The cellulose and lignin models with the highest CV’s also had similar confidence intervals but the slopes of the prediction lines were substantially less than 1:1 indicating reduced sensitivity. The predictive relationships established here could be applied to categorizing pasture quality into range classes and to determine whether pastures are above or below for example threshold values for livestock productivity benchmarks.

The Effect of Varied Dietary Crude Protein Levels with Balanced Amino Acids on Performance and Egg Quality Characteristics of Layers at First Laying Phase

Four diets were formulated to study the influence of varying crude protein levels on the performance, egg quality, serum and haematological characteristics at the first phase of laying cycle of sixty Bovan Nera laying birds that were randomly allotted to dietary treatments. The four experimental diets had five replicates each and three birds per repli-cate. Diet 1 contained 14% crude protein (CP), while diet 2 contained 15% CP, diets 3 and 4 contained 16% and 17% CP respectively. The experimental birds were fed for 10 weeks and the data collected were statistically analysed. Apparent variations recorded for all the performance characteristics such as Egg number, Hen-day production, Feed Conversion Ratio (FCR) and weight gain were significantly different (p < 0.05). The best FCR value were recorded by birds fed 17% CP (3.45), while the highest weight gain mean value were also recorded by birds fed 17% CP value. Findings indicated a direct relationship between dietary crude protein values and performance.

Rumen Degradation Regularity of Dry Matter and Crude Protein of Common Roughage in Beef Cattle

Three individuals of Horqin yellow cattle equipped with permanent fistula, weighed （548 ±21） kg, were sdected as the experimental animals. The ru- men degradation characteristics of dry matter （DM） and crude protein （CP） of roughage at 6, 12, 24, 48 and 72 h were measured by nylon bag method. The re- suits showed that the effective degradation rates of DM and CP of alfalfa hay were the highest, while higher contents of rapid degradation part and potential degrada- tion part of DM and CP also resulted in higher degradation rates of DM and CP. The effective degradation rates of CP and DM of roughage presented strong positive correlation with CP, but showed strong negative correlation with neutral detergent fiber （NDF）. The effective degradation rates of CP of five roughages successively were alfalfa hay 〉 alfalfa block 〉 ryegrass 〉 silage corn 〉 straw.

The influence of phytase, pre-pellet cracked maize and dietary crude protein level on broiler performance via response surface methodology

Background:The reduction of crude protein levels in diets for broiler chickens may generate economic,environmental and flock welfare and health benefits;however,performance is usually compromised.Whole grain feeding and phytase may improve the utilization of reduced crude protein diets.Results:The effects of pre-pellet cracked maize(0,15%and 30%)and phytase(0,750 and 1500 FTU/kg)in isoenergetic maize-soy diets with three levels of crude protein(22%,19.5%and 17%)were evaluated via a BoxBehnken response surface design.Each of 13 dietary treatments were offered to 6 replicate cages(6 birds/cage)of male Ross 308 broiler chicks from 7 to 28 d post-hatch.Model prediction and response surface plots were generated from experimental data via polynomial regression in R and only significant coefficients were included and discussed in the predicted models.Weight gain,feed intake and FCR were all influenced by pre-pellet cracked maize,phytase and crude protein level,where crude protein level had the greatest influence.Consequently,the reduction from 22%to 17%dietary crude protein in non-supplemented diets reduced weight gain,feed intake,relative gizzard weight,relative gizzard content and relative pancreas weight but improved FCR.However,the inclusion of 30%cracked maize to 17%crude protein diets restored gizzard weight and 1500 FTU phytase inclusion to 17%crude protein diets increased relative gizzard contents and pancreas weights.Cracked maize and phytase inclusion in tandem to 17%crude protein diets increased weight gain,feed intake and FCR;however,this FCR was still more efficient than broilers offered the non-supplemented 22%crude protein diet.Broilers offered the prepellet cracked maize and phytase inclusions reduced AME in 22%crude protein diets but improved AME by 2.92 MJ(14.16 versus 11.24 MJ;P<0.001)in diets containing 17%crude protein.Ileal N digestibility was greater in broilers offered diets with 17%crude protein than those offered the 22%crude protein diet;irrespective of phytase and pre-pellet cracked maize.Conclusion:Pre-pellet cracked maize and phytase inclusions will improve the performance of broilers offered reduced crude protein diets.

Influence of Varying Crude Protein Levels and Balanced Amino Acids on the Performance and Haematological Characteristics of Laying Hens at the Second Phase of Production

Varying levels of dietary crude proteins and balanced amino acids were fed to layers for a period of eight weeks starting from the twenty-sixth week of age of birds and six weeks into egg production. Effects on performance and haematological characteristics were investigated at this second phase of production. Sixty Black Nera hens were randomly allotted into four (4) dietary treatments, containing the following levels of crude protein 14%, 15%, 16%, 17% and the metabolizable energy was iso-caloric for each treatment. The results showed that there were no significant differences (P > 0.05) observed for lymphocyte, Haemoglobin (Hb), Packed Cell Volume (PCV), Red Blood Cell (RBC) and White Blood Cell (WBC), these haematological parameters were within the range for healthy birds. Thus crude protein level of 14% can be used in diets of layers at the second phase of production provided that adequate amino acids are given, without adverse effect on egg laying, feed intake and measured blood parameters.

Effects of Dietary Metabolizable Energy and Crude Protein Levels on Reproductive Performance of Magang Geese

[ Objective] To investigate the effects of different levels of metabolizable energy and crude protein on egg laying performance and hatch- ing efficiency in Magang geese. [Method] The healthy Magang geese at 2 years old were randomly assigned into four groups, group Ⅰ, group Ⅱ, group Ⅲ and control group. They were fed with diets at different levels of metabolizable energy and crude protein, and then their eggs were collect- ed and hatched. During the test, their health was observed, and the egg weight, egg yield and hatching rate were recorded. [ Result] The average egg laying rates and average egg weight were significantly higher in the group Ⅰ, group Ⅱ and group Ⅲ than in the control group. The hatchable egg rates and egg fertilization rates of the group Ⅰ, group Ⅱ and group Ⅲ were also increased, and significance was found between the group Ⅲ and the other group （P 〈 0.05）. The feed costs of the three test groups were lower than that of the control group, and the feed cost was higher in the group Ⅲ than that in the group Ⅰ and Ⅱ. [ Conclusion] The levels of metabolizable energy and crude protein in diet have significant effects on laying performance and hatching efficiency in Magang geese.

Effects of NaOH Treatment on Fiber, Crude Protein and Soluble Sugar Content of Corn Straw

[Objective] The paper was to study the effects of different levels of NaOH on fiber, crude protein and soluble sugar content of cornstraw. [Method] Four treatments were designed in the test, namely control group, group 1, group2 and group 3, which were added with 0, 2%, 3%and 4% NaOH according to the dry weight of corn straw, and the moisture of corn straw after treatment was 45%. After being treated at room tem-perature for 48 h, sensory evaluation and nutrient composition analysis were performed for each group, and the contents of neutral detergent fiber（NDF）, acid detergent fiber （ADF）, crude protein （CP） and soluble sugar （SS） were measured. [Result] With the increasing addition level of NaOH,the content of NDF and ADF decreased gradually, and significant differences were observed between group 3 （adding 4% NaOH） and control group（P〈0.05）. There was no significant difference in CP content among treatment groups（P〉0.05）; the SS content gradually increased, and there weresignificant differences between treatment groups and control group （P〈0.05）. [Conclusion] 4% NaOH reduced the fiber content and increased thesoluble sugar content of corn straw.

不同粗蛋白质水平对白王种鸽繁殖性能和乳鸽生长性能的影响

试验旨在探究“2+2”生产模式下不同粗蛋白质水平对白王种鸽繁殖性能和乳鸽生长性能的影响。试验选取产蛋性能相近的300日龄健康种鸽168对,随机分为4组,每组7个重复,每个重复6对种鸽,每对种鸽哺育2只乳鸽。试验Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组分别饲喂粗蛋白质水平为13.43%、15.04%、16.64%和18.25%的饲粮。试验期46 d,其中孵化期18 d (1~18 d),哺乳期28 d (19~46 d)。结果显示,试验Ⅱ组、Ⅲ组产蛋间隔显著低于试验Ⅰ组(P<0.05),试验Ⅲ组种蛋受精率显著高于试验Ⅰ组、Ⅳ组(P<0.05),试验Ⅲ组入孵蛋孵化率极显著高于试验Ⅰ组、Ⅱ组、Ⅳ组(P<0.01)。试验Ⅲ组乳鸽28日龄体重显著高于试验Ⅰ组(P<0.05),乳鸽屠宰率极显著高于试验Ⅰ组(P<0.01),乳鸽胸肌率显著高于试验Ⅰ组、Ⅱ组、Ⅳ组(P<0.05)。试验Ⅱ组、Ⅲ组、Ⅳ组窝料重比1极显著低于试验Ⅰ组(P<0.01)。研究表明,不同粗蛋白质水平影响了种鸽的繁殖性能、乳鸽的生长性能以及窝料重比,在“2+2”生产模式下,建议白王种鸽饲粮适宜粗蛋白质水平为16.64%。

近红外光谱法快速检测花生籽仁主要品质指标定量模型的研究

建立花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的近红外光谱快速测定方法。利用波通DA7200型近红外分析仪采集近红外光谱,采用凯氏定氮法、索氏提取法分别测定粗蛋白、粗脂肪的含量,采用气相色谱法测定油酸、亚油酸的相对含量,采用偏最小二乘法,构建花生籽仁主要品质指标含量的近红外预测模型。结果表明,模型对花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的决定系数分为0.9270、0.9647、0.9915、0.9915,均方根误差分别为0.8702、0.5631、1.6671、1.4040。经外部验证,独立测试集决定系数分别为0.9608、0.9460、0.9605、0.9492。该模型对花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的预测准确,可实现花生籽仁主要品质指标的快速、无损测定,提升高品质花生新品种的育种效率。

交配前后雌雄桑蚕蛾营养价值评价

为深入了解桑蚕蛾的营养物质成分,检测了交配前后9芙雌雄蚕蛾蛋白质、脂肪酸和氨基酸的组成和含量。通过粗蛋白、粗脂肪、不饱和脂肪酸含量、动脉粥样硬化指数(indices of atherogenicity,IA)、血栓形成指数(thrombogenicity,IT)以及氨基酸评分、化学评分、必需氨基酸指数(essential amino acid index,EAAI)、营养指数(nutrition index,NI)和生物价(biological value,BV)等指标评价了蚕蛾的营养价值。结果表明,蚕蛾氨基酸和不饱和脂肪酸含量丰富,交配前雌蛾蛋白质(21.6%,鲜重)、总氨基酸(46.94 g/100 g)、必需氨基酸含量(15.86%)以及EAAI(99.33)、NI(21.45)和BV(96.57)最高,同时含有丰富的甜味、药效和支链氨基酸,粗脂肪含量(7.11%,鲜重)低,多不饱和脂肪酸占比(78.18%)高,IA(0.21)和IT(0.14)低,是理想的蛋白源。交配后的雄蛾粗脂肪(24.46%,鲜重)、不饱和脂肪酸(44.31 g/100 g)、亚麻酸含量(19.37 g/100 g)最高,IA(0.28)和IT(0.22)指数较低,是提取不饱和脂肪酸的优质原料。该研究为桑蚕蛾在食品领域的开发应用提供了理论依据。

饲粮代谢能和粗蛋白水平对产蛋后期双莲鸡生产性能、蛋品质和肝脏脂代谢的影响

试验旨在研究饲粮不同代谢能和粗蛋白水平对产蛋后期双莲鸡配套系生产性能、蛋品质、肝脏脂代谢的影响。试验选取240只健康、体重及产蛋率接近的40周龄双莲鸡产蛋母鸡,随机分为6组,每组4个重复,每个重复10只鸡。试验采取2×3双因素设计,代谢能(ME)设定为11.30和10.88 MJ/kg两个水平,粗蛋白(CP)设定为16.2%、15.2%和14.2%三个水平,预试期2周,正试期12周。结果显示:(1)粗蛋白水平对产蛋率、料蛋比、平均蛋重无显著影响(P>0.05),但11.30 MJ/kg代谢能水平可显著降低51~54周龄双莲鸡产蛋率和平均日产蛋量(P<0.05),并显著增加平均蛋重(P<0.05)。(2)饲粮代谢能和粗蛋白互作极显著影响46周龄鸡蛋蛋白高度和哈氏单位(P<0.01),并显著影响50周龄鸡蛋蛋黄颜色(P<0.05);10.88 MJ/kg代谢能水平54周龄鸡蛋哈氏单位、蛋黄比例显著高于11.30 MJ/kg代谢能水平(P<0.05),而46、54周龄鸡蛋蛋黄颜色和46、54周龄鸡蛋蛋壳厚度极显著低于11.30 MJ/kg代谢能水平(P<0.01),50周龄蛋壳厚度显著低于11.30 MJ/kg代谢能水平(P<0.05);16.2%粗蛋白水平46周龄鸡蛋哈氏单位显著高于14.2%粗蛋白水平(P<0.05),而54周龄鸡蛋蛋黄比例极显著低于15.2%和14.2%粗蛋白水平(P<0.01)。(3)10.88 MJ/kg代谢能水平双莲鸡血清、肝脏甘油三酯水平,肝脏相对重量和腹脂相对重量以及肝脏脂肪酸合成相关基因如SREBP-1c、ACACA、FAS、SCD1表达量均显著低于11.30 MJ/kg代谢能水平(P<0.01)。综合分析,本试验条件下双莲鸡配套系蛋鸡产蛋后期(42~54周龄)代谢能和粗蛋白水平分别以10.88 MJ/kg和16.2%为宜。

新疆畜禽饲料资源中粗蛋白含量的调查研究

试验旨在研究新疆不同地州间各种常规饲料原料的粗蛋白含量和分布情况,为各地州饲粮合理配制提供科学依据。对新疆全区14个地州的13种115个主要畜禽饲料原料在科学采样的基础上进行粗蛋白含量测定。对同类不同种饲料样品和不同饲料样品的粗蛋白含量进行单因素方差分析,比较不同饲料原料中粗蛋白含量的差异及不同地区之间的差异。结果表明:不同原料除青贮玉米外,干物质含量都在92%以上;粮油加工副产物的粗蛋白含量最高,粮食作物秸秆粗蛋白含量最低。8个地州采集玉米样品中喀什的粗蛋白含量最高。全疆各地州的各种类饲料原料中粗蛋白含量相互之间变化非常大,因此,实际应用中要充分考虑到不同区域饲粮中粗蛋白含量,为精准配方、精准营养提供技术支撑。

饲粮蛋白水平和酿酒酵母对秦川肉牛血常规指标和氮磷代谢的影响

【目的】研究不同蛋白水平饲粮及酿酒酵母(SC)对秦川肉牛血液生理生化指标和氮磷代谢的影响。【方法】选择18头14月龄初始体质量为(298±9.78)kg/头、健康的秦川肉牛(母牛)作为试验动物,采用2种蛋白水平(13.23%(A1)和(10.59%(A2))饲粮和3种酿酒酵母添加水平(0(B1),4×10^(8) CFU/kg(B2),8×10^(8) CFU/kg(B3))作为两因素进行饲喂试验。采用全收粪(尿)法测定各处理秦川肉牛粪便和尿液中的氮磷含量,试验结束时于晨饲前采用颈静脉穿刺法采血,测定血常规指标和酶活性,试验期55 d。【结果】①试验期11~55 d,饲粮中添加8×10^(8) CFU/kg SC显著提高了秦川肉牛的采食量(P<0.05),A1B3组秦川肉牛采食量最高,显著高于A1B1组(P<0.05)。②B3组秦川肉牛血清中甘油三酯含量显著低于B1组(P<0.05),A2B3组秦川肉牛血清中总蛋白、白蛋白、球蛋白、免疫球蛋白G和免疫球蛋白M含量均显著高于A2B1组(P<0.05)。③B3组秦川肉牛粗蛋白(CP)和中性洗涤纤维(NDF)的表观消化率较B1组分别显著提高了8.44%和16.90%(P<0.05),A2B3组秦川肉牛的粗蛋白、有机物和酸性洗涤纤维表观消化率最高。④与A2B1组相比,A2B3组秦川肉牛粪氮排放减少了31.28%,尿氮排放减少了19.67%,氮消化率提高了7.66%,氮沉积率提高了62.57%。⑤B2和B3组秦川肉牛的粪磷含量显著低于B1组,A2B3组秦川肉牛磷消化率、磷沉积率相较于A2B1组显著升高了35.96%和45.94%(P<0.05)。【结论】本试验条件下,添加8×10^(8) CFU/kg酿酒酵母能够提高秦川肉牛的采食量、免疫水平和营养成分消化率,减少氮磷排放。在10.59%粗蛋白水平下,饲粮添加8×10^(8) CFU/kg酿酒酵母饲喂秦川肉牛效果最好。

稻米加工副产品营养指标的近红外预测模型的建立

为实现对稻米加工副产品营养物质的快速检测,按需进行饲料加工和加工副产品分级,研究选用302份稻米加工副产品样品(碎米107份、腹白米77份及异色粒118份),经过标准方法理化数据检测、样品前处理、近红外光谱采集、光谱数据预处理、筛选特征波长和建立模型等步骤,最终建立了针对碎米、腹白米及异色粒3种稻米加工副产品总体的水分、粗蛋白、粗脂肪以及粗纤维营养指标的总定量预测模型。结果显示:所建立的模型决定系数R^(2)均大于0.85,相对分析误差(RPD)均大于2.5,具有较好的准确性、稳定性。研究表明,此检测方法快速、高效、准确,提高了稻米加工副产品的综合利用率。

饲粮代谢能和粗蛋白质水平对27~80周龄京粉6号商品代蛋鸡生产性能和蛋品质的影响

试验旨在研究饲粮代谢能和粗蛋白质水平对27~80周龄京粉6号商品代蛋鸡生产性能和蛋品质的影响。试验选用768只产蛋率、体重相近的27周龄京粉6号商品代蛋鸡,随机分为4组,每组192只,每组8个重复,每个重复24只。试验采用2×2代谢能、粗蛋白质双因子设计(代谢能分为高、低水平,粗蛋白质分为高、低水平),组成4个试验饲粮,试验分4个阶段(27~40周龄、41~50周龄、51~72周龄和73~80周龄)进行。结果显示:(1)饲粮粗蛋白质水平对京粉6号商品代蛋鸡51~72周龄产蛋率、蛋重、产蛋总重和41~50周龄蛋重有显著影响,其中16.2%粗蛋白质水平41~50周龄蛋重显著高于15.8%粗蛋白质水平,15.8%粗蛋白质水平51~72周龄产蛋率、蛋重、产蛋总重显著高于15.4%粗蛋白质水平(P<0.05)。(2)粗蛋白质水平由15.8%降低至15.5%以及由15.6%降低至15.1%分别显著加深62、72周龄和80周龄鸡蛋的蛋黄颜色(P<0.05);饲粮代谢能和粗蛋白质水平对蛋黄颜色、蛋黄比率表现出显著的交互作用(P<0.05),其中,高能高蛋白组蛋黄颜色显著低于低能低蛋白组(P<0.05),高能低蛋白组蛋黄比率较低能高蛋白组提高2.1%~3.2%(P<0.05),11.18 MJ/kg、11.13 MJ/kg代谢能水平蛋黄比率均显著高于11.05 MJ/kg代谢能水平(P<0.05)。研究表明,本试验条件下,综合产蛋性能和经济效益,推荐低能低蛋白组,27~40周龄、41~50周龄、51~72周龄和73~80周龄,饲粮代谢能和粗蛋白质水平分别为11.22MJ/kg和16.0%、11.18MJ/kg和15.8%、11.05MJ/kg和15.4%、11.05MJ/kg和15.1%;以获得最佳产蛋性能和蛋品质为目标,推荐高能高蛋白组,饲粮代谢能、粗蛋白质水平分别为11.34 MJ/kg和16.5%、11.30 MJ/kg和15.8%、11.18 MJ/kg和15.4%、11.13 MJ/kg和15.6%。

青檀叶片饲用营养价值分析与优良无性系筛选

【目的】全面分析与评价青檀叶片的饲用营养价值,为青檀用作木本饲料提供数据支撑。【方法】对10个青檀无性系进行叶片营养成分、抗氧化活性、次生代谢产物组分和含量、氨基酸成分和含量的测定,并采用质量评价指标综合评价其饲用特性。【结果】1)不同青檀无性系叶片各营养成分指标均达到极显著差异,粗蛋白含量介于10.15%~24.36%,平均为17.60%,其中‘福缘’(24.36%)和‘WT’(24.33%)含量最高;粗脂肪含量介于7.98%~11.45%,平均为9.31%;粗纤维含量较低,平均为4.08%;无氮浸出物含量平均为49.69%;中性洗涤纤维含量的品种间差异最大,介于17.76%~67.67%,平均为45.51%;酸洗洗涤纤维含量的差异较小,平均为24.07%;全磷和钙含量平均值分别为0.1733%和5.8633%;单宁含量远低于拒食标准,平均为2.9260 g·kg^(-1)。2)饲用质量评价指标无性系间均有极显著差异,10个无性系中有4个达到美国牧草和草地协会(AFGC)干草1级标准,分别为‘WT’、‘金玉缘’、‘慧光’和‘巨龙’。3)抗氧化活性综合指数法(APC)评价认为,‘大叶’、‘巨龙’和‘青龙’叶片抗氧化能力强,‘无量’、‘金玉缘’和‘慧光’叶片抗氧化能力弱。4)青檀叶片总类黄酮和5个黄酮类物质含量在无性系间均有极显著差异,具有筛选高生物活性物质的基础;总类黄酮含量平均为9.92 mg·g^(-1),5种物质中绿原酸含量最高(710.96μg·g^(-1)),其次是异鼠李素(27.12μg·g^(-1)),儿茶素(16.53μg·g^(-1))、槲皮素(9.09μg·g^(-1)),咖啡酸含量极低,仅为1.73μg·g^(-1)。5)检测到18种游离氨基酸和19种水解氨基酸,平均总量分别为47.87 mg·g^(-1)和108.20 mg·g^(-1),且总含量在无性系间均有极显著差异;两类氨基酸组分中均以异亮氨酸、亮氨酸含量最高。【结论】青檀叶片具有粗蛋白、粗脂肪、钙含量高,粗纤维、中性洗涤纤维、酸性洗涤纤维、单宁含量低的特点,饲用评价指标综合等级达到1级标准,具备发展成为优良木本饲料树种的物质基础;初步筛选出‘WT’、‘福缘’和‘巨龙’3个优异无性系。

育成期雪山鸡种母鸡饲粮代谢能和粗蛋白质适宜水平研究

本试验旨在研究饲粮代谢能和粗蛋白质水平对育成期雪山鸡种母鸡生长性能、体尺性状、屠宰性能、卵巢指数、开产日龄和蛋重以及肠道微生物的影响,以明确其育成期饲粮代谢能和粗蛋白质适宜水平。试验采用3×3双因素完全随机试验设计,设置3种代谢能水平(10.88、11.30、11.72 MJ/kg)和3种粗蛋白质水平(12.50%、14.00%、15.50%),同时选取6周龄末健康状态良好、体重相近的雪山鸡种母鸡1458只,随机分为9组,每组9个重复,每个重复18只鸡。试验期10周,16周龄末进行生长性能测定及屠宰采样,20周龄开始跟踪开产日龄和蛋重。结果表明:1)随着饲粮代谢能和粗蛋白质水平的升高,育成期雪山鸡种母鸡末重和平均日增重显著升高(P<0.05),料重比显著下降(P<0.05)。饲粮代谢能与粗蛋白质水平对末重和平均日增重有显著互作效应(P<0.05)。2)中代谢能组和高代谢能组体斜长、龙骨长和屠宰率显著高于低代谢能组(P<0.05);高蛋白质组体斜长和龙骨长显著高于低蛋白质组(P<0.05),全净膛率显著高于中蛋白质组和低蛋白质组(P<0.05)。3)中代谢能组开产蛋重显著高于高代谢能组(P<0.05);高蛋白质组卵巢指数显著高于低蛋白质组和中蛋白质组(P<0.05)。4)中代谢能组和高蛋白质组盲肠厚壁菌门(Firmicutes)和乳杆菌属(Lactobacillus)相对丰度较高,盲肠变形菌门(Proteobacteria)相对丰度较低。综合考虑各项指标,推荐育成期雪山鸡种母鸡饲粮适宜代谢能水平为11.30 MJ/kg、粗蛋白质水平为15.50%。