Nutritional requirement of digestible tryptophan for white-egg layers of 60 to 76 weeks of age

The objective of this study was to determine the nutritional requirement of digestible Trp for white egg layers in the period from 60 to 76 wk of age. A total of 180 Dekalb White layers with an average weight of 1,345 kg were distributed in a completely randomized design with 5 increasing levels of digestible Trp (0.167, 0.175, 0.183, 0.191, and 0.199%), 6 replicates, and 6 birds per experimental unit. The diets of the treatments contained 0.759% of digestible Lys, which was obtained using the prediction equation of the Brazilian Tables for Poultry and Swine, and each treatment consisted of a digestible Trp-to-Lys ratio of 22, 23, 24, 25, or 26%. The digestible Trp levels in the diet had a quadratic effect on egg production, egg mass, and conversion per mass and per dozen eggs, and a linear effect on egg weight. In conclusion, a diet with 0.192% digestible Trp, in a 25.33% ratio with digestible Lys or 212 mg/bird per day, can be recommended for white egg layers of 60 to 76 wk of age.     

30～38周龄产蛋鸡理想氨基酸模式的研究

本试验旨在通过4个剂量-反应试验,研究30～38周龄产蛋鸡对赖氨酸(Lys)、蛋氨酸(Met)、色氨酸(Trp)和苏氨酸(Thr)4种必需氨基酸(AA)的需要量及其比例.每个试验均采用360只海兰灰产蛋鸡,设5个处理,分别采食5个AA梯度水平的试验饲粮,每个处理6个重复,每个重复12只鸡.采用蛋公鸡回肠食糜法测定饲料原料的标准回肠可消化(SID)值.试验预试期14 d,正试期56 d.结果表明:海兰灰产蛋鸡的产蛋率、蛋重、日产蛋量和料蛋比与SIDLys、SID Met、SID Trp和SID Thr的摄入水平均有较好的折线回归关系;以日产蛋量为自变量(x),AA摄入水平为依变量(Y)分别建立的回归方程为:YSID Lys=51.60-0.041 6(682.5-x),R2=0.96;YsID Met=51.43-0.085(314.1-x),R2 =0.95;YSID Trp =51.17-0.155 4(163.0-x),R2=0.97;YsID Thr=52.85-0.057 6(499.5-x),R2=0.93.在饲粮粗蛋白质12.8％的条件下,以日产蛋量为参照指标确定的30 ～ 38周龄产蛋鸡的SID Lys、SID Met、SID Trp和SID Thr需要量分别为684、313、171和506 mg/(只·d).以日产蛋量为指标建立的30～38周龄产蛋鸡理想SID AA模式为:Lys:Met:Trp:Thr=100∶46∶24∶73.     

Growth performance and carcass characteristics of male broilers fed diets varying in digestible threonine to lysine ratio from 21 to 49 days of age

Two experiments were conducted to ascertain digestible Thr to Lys ratio of male broilers from 21 to 35 d of age (experiment 1) and 35 to 49 d of age (experiment 2) based on growth performance and processing yields. In both experiments, 2 diets (dilution and summit; 3,108 kcal ME/kg and 18.2% CP in experiment 1; 3,163 kcal ME/kg and 17.2% CP in experiment 2) consisting of corn, soybean meal, poultry by-product meal, and peanut meal formulated to be surfeit in limiting amino acids with exception of digestible Lys and Thr were mixed at various proportions to create 8 titration dose-response diets. Digestible Lys was formulated to contain 95% of the requirements from 21 to 35 and 35 to 49 d of age. In each experiment, gradient treatment structure was arranged in a randomized complete block design. Calculated digestible Thr to Lys ratios ranged from 0.512 to 0.806 in approximately increments of 0.040 (1,600 Hubbard × Cobb 500 broilers; experiment 1) and 0.552 to 0.793 in approximately increments of 0.035 (3,000 Ross × Ross 708 broilers; experiment 2). In experiment 1, digestible Thr to Lys ratio for male Hubbard × Cobb 500 broilers was estimated at 0.68 and 0.67 for BW gain and feed conversion from 21 to 35 d of age. In experiment 2, digestible Thr to Lys ratio of Ross × Ross 708 was determined at 0.68 and 0.63 for feed conversion ratio with quadratic and linear broken-line models, respectively. Meat weights and yields were not affected by the dietary treatments in either experiment. These data indicate that a digestible Thr to Lys ratio of 0.68 can optimize growth performance of broilers from 21 to 35 and 35 to 49 d of age.     

饲粮添加生姜粉对蛋鸡生产性能和蛋品质的影响

试验旨在探讨饲粮添加不同水平的生姜粉对蛋鸡生产性能和蛋品质的影响。选取27周龄罗曼褐壳蛋鸡120只,随机分为4组,每组设3个重复,每个重复10只。对照组饲喂基础饲粮,试验组分别添加0.5%、1.0%、1.5%的生姜粉。预饲期7 d,试验期4周。结果表明:饲粮中添加适量的生姜粉可以提高蛋鸡的平均日产蛋量和试验3~4周的产蛋率以及试验1~2周的平均蛋重(P<0.05)。饲粮中添加适量生姜粉能够提高鸡蛋的哈夫单位和蛋比重(P<0.05)。结果提示,饲粮中添加生姜粉可提高罗曼褐壳蛋鸡的生产性能和蛋品质,以1.0%生姜粉为最适添加量。     

用杂粕代替部分豆粕配制日粮对蛋种鸡生产性能及蛋品质的影响

试验研究了氨基酸平衡的低蛋白质和杂粕日粮对蛋种鸡产蛋性能和蛋品质的影响,结果表明:当棉籽粕、菜籽粕、棉菜粕分别代替5.5%、5%、10%的豆粕时,对蛋鸡产蛋率、日产蛋重和料蛋比无显著影响,也不影响蛋的品质(P>0.05),同时每产1kg蛋消耗的饲料成本玉米-棉粕和玉米-棉菜粕组,显著低于对照组(P<0.05);但当日粮粗蛋白质水平降低2个百分点时,蛋种鸡的日平均产蛋重显著低于正常蛋白质水平的玉米-豆粕日粮(P<0.05),而与正常蛋白质水平的杂粕日粮相比,差异不显著(P>0.05)。     

桑叶粉对蛋鸡生产性能和蛋品质的影响

本试验旨在研究桑叶粉对蛋鸡生产性能和蛋品质的影响。选取163只412日龄的罗曼粉蛋鸡,随机分成4组,每组12个重复,每个重复3～4只。分别饲以桑叶粉添加量为0、5%、8%和11%的试验日粮。试验期为40 d。试验结果表明:(1)桑叶粉添加组的产蛋率显著低于对照组(不添加组)(P<0.01);5%桑叶粉组的料蛋比显著高于对照组(P<0.05),8%、11%桑叶粉组的料蛋比与对照组的差异不显著(P>0.05);各组间平均日采食量差异不显著(P>0.05)。(2)桑叶粉添加组的蛋黄颜色显著深于对照组(P<0.01),且随着桑叶粉添加量的增加,蛋黄颜色加深;除蛋黄颜色外,各组间其他的鸡蛋物理指标均无显著差异(P>0.05)。(3)各组的蛋黄粗脂肪、粗蛋白质及胆固醇含量差异不显著(P>0.05);各桑叶粉添加组的蛋黄多不饱和脂肪酸(PUFA)、ω-6系脂肪酸的含量显著高于对照组(P<0.05),8%、11%桑叶粉组的蛋黄ω-3系脂肪酸含量显著低于对照组(P<0.01),而各组饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)含量差异不显著(P>0.05)。以上结果表明,从开发饲料资源、提高蛋黄色泽和蛋黄中PUFA、ω-6...     

低豆粕日粮对产蛋鸡生产性能及蛋品质的影响

试验选用1 600只生产性能相同、体况良好的33周龄罗曼蛋种鸡,随机分为4组,在总蛋白质含量相同和满足必需氨基酸需要量的情况下,用价格较低的蛋白饲料取代蛋鸡日粮中豆粕,研究氨基酸平衡的低豆粕日粮对蛋种鸡生产性能和蛋品质的影响。结果表明:氨基酸平衡的低豆粕日粮对蛋鸡产蛋率、种蛋合格率、健雏率、蛋形指数、蛋比重、蛋壳厚度、哈氏单位等指标无显著影响(P>0.05),但当日粮中的豆粕含量降低8～15个百分点时,蛋种鸡的日平均蛋重、日采食量、受精率、孵化率等显著低于正常豆粕日粮(P<0.05),而考虑综合因素日粮中的豆粕含量降低8个百分点的第1组,与正常豆粕日粮相比,差异不显著(P>0.05),而且能降低饲料成本,可以提高蛋鸡养殖效益,具有实际意义。     

Comparison of spray‐dried egg and albumen powder with conventional animal protein sources as feed ingredients in diets fed to weaned pigs

We evaluated the apparent (AID) and standardized ileal digestibility (SID) of amino acids (AA) in spray‐dried egg (SPE) and albumen powder (AP) compared with spray‐dried porcine plasma (SDPP), dried porcine solubles (DPS) and fish meal (FM). Additionally, the effects of these egg byproducts as a replacement for conventional animal proteins on the performance and nutrient digestibility of piglets were studied. In Exp. 1, six barrows fitted with ileal T‐cannulas were allotted to a 6 × 6 Latin Square design and fed six diets. The AID and SID of AA were generally higher in AP and FM (P < 0.01) than in the other protein sources. In Exp. 2, 150 piglets weaned at 21 days, were fed diets containing the five protein sources for 3 weeks. Weight gain of piglets fed SDPP was the highest among the treatments. Dry matter and protein digestibility for pigs offered SDPP were higher (P < 0.01) than those offered FM and DPS. AP decreased (P < 0.05) Escherichia coli counts in the cecum. DPS decreased (P < 0.05) serum diamine oxidase compared with SPE. In conclusion, AP and SPE are competitive with traditional animal protein sources and can be successfully fed to piglets without compromising performance.     

苜蓿草粉饲粮添加纤维素酶对蛋鸡生产性能、蛋品质及养分利用率的影响

本研究的目的是探讨在蛋鸡饲粮中添加不同比例的苜蓿草粉和在高水平苜蓿草粉饲粮中添加纤维素酶对其生产性能、蛋品质及养分利用率的影响。试验选用40周龄健康海兰褐蛋鸡210只,采用单因子完全随机设计,分为7个组,每组3个重复,每个重复10只鸡,分别在饲粮中添加不同比例的苜蓿草粉和纤维素酶,依次为:0(对照组)、3％苜蓿草粉(试验I组)、5％苜蓿草粉(试验II组)、7％苜蓿草粉(试验Ⅲ组)、7％苜蓿草粉+0.1%纤维素酶(试验IV组)、7％苜蓿草粉+0.2%纤维素酶(试验V组)、7％苜蓿草粉+0.3%纤维素酶(试验VI组)。结果表明,1)添加苜蓿草粉和纤维素酶对蛋鸡的产蛋率、蛋重均无显著影响(P＞0.05),但试验Ⅲ组的采食量和试验Ⅴ组的料/蛋比对照组显著下降。2)在饲粮中添加不同水平的苜蓿草粉及纤维素酶后,对蛋黄相对重、蛋壳厚度、蛋黄pH和蛋白pH指标无改进,但高水平苜蓿草粉饲粮中添加纤维素酶提高了蛋重和蛋形指数,尽管和对照组及低用量的苜蓿草粉组相比差异不显著(P＞0.05);各试验组的蛋壳强度、哈夫单位和蛋黄颜色都得到提高,其中试验V组、VI组蛋壳强度较对照组差异显著(P＜0.05),均提高了39％,添加苜蓿草粉后,蛋黄颜色均显著改善(P＜0.05),且随着苜蓿草粉添加量的增加,蛋黄颜色呈上升趋势;高苜蓿草粉饲粮同时添加不同水平纤维素酶组,对蛋黄颜色提高有加强作用。 3)在鸡蛋保存期的7,14,21,28 d,饲粮中添加苜蓿草粉和纤维素酶均能显著降低蛋黄中丙二醛(MDA)含量,从而延长鸡蛋的货架期。4)在饲粮中添加不同水平的苜蓿草粉和纤维素酶,对粗蛋白质、钙和粗纤维的消化率有改进作用,其中试验Ⅴ组较试验Ⅲ组粗蛋白质、粗脂肪、粗纤维、酸性洗涤纤维消化率分别增加了14.79%(P＞0.05),8.48%(P＞0.05),15.91%(P＞0.05)和4.17%(P＞0.05)。总的来说,在蛋鸡饲粮中添加苜蓿草粉后对生产性能、蛋品质无显著影响,但能在一定程度上改善蛋品质,蛋黄颜色得到极显著提高,高水平的苜蓿草粉组添加纤维素酶后,对粗蛋白质、钙和粗纤维的消化率有改进。     

Effect of dietary digestible lysine concentration on performance,egg quality,and blood metabolites in laying hens

An experiment was conducted to evaluate the effect of dietary digestible lysine concentration on productive performance, egg quality, and blood metabolites in laying hens. A completely randomized block design was performed with 5 treatments and 6 replicates of 8 Hy-line W-36 hens each, from 32 to 44 wk of age. The treatments were 5 digestible lysine concentrations (0.657, 0.707, 0.757, 0.807, and 0.857% of diet). Feed intake was significantly increased with each increment in dietary digestible lysine concentration. Significant improvement in egg production, egg weight, egg mass, Haugh unit, and FCR were observed by an increase in lysine intake. Dietary lysine concentration did not have a significant impact on percentage of egg components, specific gravity, eggshell thickness, DM, and protein constituents of eggs. Dietary digestible lysine concentration did not have a significant effect on triglyceride, cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), uric acid, and total protein in plasma. The digestible lysine requirements for optimal egg production, egg mass, and egg weight (32 to 44 wk of age), based on the linear broken-line regression analysis, were 814, 810 and 778 (mg/b/d), respectively. Whereas, these values were 4, 3.9, and 6 percent less than those estimated by the quadratic broken-line model, respectively.     

安全环保型蛋鸡饲料配方的筛选与应用

在优化出海兰灰蛋鸡氨基酸模型的基础上,确立了日粮低蛋白水平15%、14%的试验;集成和优化了蛋鸡安全环保型日粮的配方和添加剂组合(包括复合酶、植酸酶、益生素、果寡糖、除臭灵等),开发出了产蛋鸡安全环保1%预混合饲料,使用该环保添加剂,在生产性能不降低的前提下,可使蛋鸡粪便氮、磷排出量分别降低;同时蛋壳质量和鸡蛋品质得到改善。     

日粮氨基酸对犊牛生长和健康影响的研究进展

犊牛在断奶前免疫系统发育不成熟,体质敏感,而在断奶后生长发育迅速。这两个阶段的犊牛都需要提供含有优质蛋白质的日粮以保证其生长发育。结合中国蛋白质资源紧缺的现状,做好犊牛阶段的氨基酸营养在促进犊牛健康生长和提高蛋白质利用率上都具有重要作用。此外,氨基酸在提高犊牛免疫力方面有不可替代的作用,近年来的研究还发现,氨基酸对犊牛消化道易感细菌和病毒有特殊的抑制功能。针对犊牛生长速度快、免疫功能不完善、死亡率高、断奶前后生理结构和营养需要变化迅速的生理特点,作者重点介绍了单一氨基酸不同水平及多种氨基酸不同比例对犊牛断奶前后生长性能的影响,并从氨基酸提高犊牛自身免疫力和抑制微生物繁殖两方面来阐述氨基酸对犊牛健康的影响机制,以期为推进氨基酸在犊牛生产中的应用提供理论依据。