Evaluation of laying-hen feed with varied vitamin E and antioxidant supplementation

In two experiments with 1,250 laying hybrids the influence of the elimination of vitamin E and antioxidant supplements to the laying hen feed was tested. With mixed feed according to official quality requirements but without vitamin E and antioxidant supplements laying hens achieved the same laying performance and individual weight as the control group. There was no influence on feed consumption, feed expenditure per 100 g egg, mortality, development of body weight, the tensile strength of the eggs and the fat quality of the body either. Vitamin E content in the yolk increases with the growing vitamin E content in the feed. The vitamin E requirement norm of laying hens for consumer egg production is achieved at a native vitamin E content of 7 mg/kg laying hen feed. The supplement of synthetic antioxidant is unnecessary.     

Relation between vitamin E supply and the fertility of laying hens

In 4 experiments with a total of 1296 laying hens it was ascertained that a laying hen requires 1 mg vitamin E/kg feed for egg production if the ration contains sufficient selenium and is not rich in multiply unsaturated fatty acids. For the fertilization of the eggs little more of this vitamin is required. There were close relations, however, between the amount of vitamin E supplement to the feed and the number of hatched chickens in % of the fertilized eggs. With the help of the experiments carried out so far the exact requirement could not yet be ascertained. Based on the results of our experiments we recommend 20 mg vitamin E/kg feed for breeding hens of the laying variant. There is a close relation between the vitamin E content of the feed and that of the yolk. A supplement of 7 or 14% resp. of vitamin-free sunflower oil decreases -in dependence on the vitamin E supplement-hatching in particular without diminishing the vitamin E content of the yolk. The vitamin E content of the yolk sac, however, was drastically reduced. The influence of polyene fatty acids in hatching is smaller when sunflower oil rich in vitamin E is supplemented. Vitamin-free sunflower oil has an influence on the vitamin content of the yolk, but it diminishes drastically the vitamin content of the yolk sac and, provided that vitamin E supply is low, prevents hatching.     

Vitamin E requirement of chicks and young hens

In 4 experiments young chickens of the species White Leghorn received semisynthetic rations with a vitamin E content less than 1 mg/kg basal ration. Sunflower oil heated with FeCl3 supplement was used as a factor increasing requirement. Feed intake, live weight gain and feed expenditure with semisynthetic rations without oil supplements did not depend on vitamin E supplements. After the feeding of rations without vitamin E animal losses were higher. The losses were normalized by 1 mg vitamin E supplement per kg feed. Rations containing sunflower oil without vitamin E supplementation resulted in encephalomalacia of the young chickens. Vitamin deficiency increased triiodine thyronine content in the blood plasma. Antibody formation after the application of human gamma globulin did not depend on the vitamin E supply studied. A vitamin E requirement of young chickens and young hens of the laying species of less than 1 mg/kg mixed feed is derived from the results.     

Dietary selenium increases vitamin E contents of egg yolk and chicken meat

1. The influence of different forms of dietary selenium (Se) on vitamin E (alpha-tocopherol) and Se contents of egg yolk and chicken meat was investigated. 2. Eggs were collected from laying hens subjected to 4 different dietary treatments after 24 weeks of age. Treatments compared the effects of inorganic Se supplementation (selenite) to those of organic (Se-enriched yeast, Se-enriched alga Chlorella) supplements. In a second experiment the effect of the above organic dietary Se supplementation on the alpha-tocopherol contents of meat from broiler chickens was evaluated. 3. Dietary Se supplementation increased the alpha-tocopherol content of egg yolks from 297 mg/kg dry matter in treatment without supplementation to 311 mg/kg when selenium was supplemented as selenite, and to 370-375 mg/kg when organic supplements were used. The Se and alpha-tocopherol contents of breast and thigh meat in broilers were significantly increased by organic dietary Se supplementation. 4. The inclusion of organic dietary Se sources in the diets of laying hens and broilers would enhance the nutritional value (vitamin E and Se contents) of products (eggs and meat) for human consumption.     

Vitamin E hypervitaminosis in laying hens.

The aim of this investigation was to contribute to the problem of overdosing vitamin E. A total of 80 laying hens, divided into 5 groups, were fed diets supplemented with 0, 100, 1000, 10,000 and 20,000 mg/kg vitamin E over a period of 20 weeks within two brooding tests. Laying performance and hatching parameters were registered. All vitamin E doses did not significantly influence health and performances of hens. Vitamin E content of eggs increased from 1 to 4, 21, 46 and 51 mg per egg with vitamin E supplementation. High doses decreased oxidative stability of abdominal fat, vitamin A concentration of liver and egg yolk colour. In both tests vitamin E supplements of 10,000 and 20,000 mg/kg feed resulted in a decrease of living hatched chicken, which demonstrated an adverse effect. Further studies seem to be necessary to explain the effect.     

维生素E对免疫抑制产蛋鸡生产性能和蛋品质的调控效应

试验探讨维生素E对免疫抑制蛋鸡生产性能和蛋品质的调控效应,选取健康的尼克褐产蛋鸡270只,随机等分为5组,每组3个重复,每重复18只。第Ⅰ组为对照组,第Ⅱ~Ⅴ组为免疫抑制组,对第Ⅱ~Ⅴ组鸡在试验第5、6、7 d进行腿部肌肉注射80 mg/kgBW环磷酰胺(CTX),第Ⅰ组注射等量生理盐水。Ⅰ、Ⅱ组饲喂基础日粮(维生素E含量44.59 mg/kg),Ⅲ、Ⅳ、Ⅴ组在基础日粮中分别添加50、100、200 mg/kg维生素E。结果显示:①免疫抑制产蛋鸡的产蛋率、平均蛋重和平均日采食量显著降低(P<0.05),破蛋率显著升高(P<0.05)。基础日粮中添加50 mg/kg维生素E显著提高免疫抑制产蛋鸡的产蛋率、平均蛋重和平均日采食量(P<0.05),但仍低于对照组Ⅰ(P<0.05);显著降低料蛋比和破蛋率(P<0.05)。②免疫抑制产蛋鸡的蛋壳厚度、蛋壳强度和哈氏单位显著降低(P<0.05),蛋形指数和蛋黄颜色无显著改变(P>0.05);50 mg/kg维生素E添加量显著提高免疫抑制产蛋鸡的蛋壳厚度、蛋壳强度和哈氏单位(P<0.05),与对照组Ⅰ无显著差异(P>0.05)。因此,免疫抑制显著降低产蛋鸡的生产性能和蛋品质;基础日粮中添加维生素E对免疫抑制蛋鸡的生产性能和蛋品质具有明显的调控效应,且以50 mg/kg添加量效果较好。     

饲粮添加维生素E和酵母硒对黄羽肉种鸡产蛋性能、孵化性能及蛋中维生素E和硒沉积量的影响

本试验旨在研究饲粮添加维生素E和酵母硒对黄羽肉种鸡产蛋性能、孵化性能及蛋中维生素E和硒(Se)沉积量的影响。试验采用3×3双因子设计,设3个维生素E添加水平(0、20、40 IU/kg)和3个Se添加水平(0、0.15、0.30 mg/kg)。选用32周龄快大型岭南黄羽肉鸡父母代种母鸡864只,根据产蛋率和体重一致性原则随机分成9个组,分别为VE_0Se_0组、VE_0Se_(0.15)组、VE_0Se_(0.30)组、VE_(20)Se_0组、VE_(20)Se_(0.15)组、VE_(20)Se_(0.30)组、VE_(40)Se_0组、VE_(40)Se_0.15组和VE_(40)Se_0.30组,每组6个重复,每个重复16只鸡。试验期8周。结果表明:1)饲粮中维生素E和Se添加水平对黄羽肉种鸡的体增重、平均日产蛋量、料蛋比、平均蛋重、产蛋率、破蛋率和不合格蛋率均无显著影响(P0.05)。2)饲粮中维生素E和Se添加水平对黄羽肉种鸡的蛋长径、蛋短径、蛋白高度、蛋黄颜色、哈氏单位、蛋黄重、蛋壳重和蛋壳厚度均无显著影响(P0.05)。3)饲粮中维生素E和Se添加水平对黄羽肉种鸡的健雏出壳重、孵化率、弱雏率和受精率均无显著影响(P0.05)。4)饲粮中维生素E添加水平对黄羽肉种鸡血浆MDA含量有显著影响(P0.05),随饲粮中维生素E添加水平的升高血浆MDA含量呈降低趋势,其中维生素E添加水平为40 IU/kg时血浆MDA含量显著低于0 IU/kg时(P0.05);饲粮中维生素E和Se添加水平对血浆MDA含量有显著交互作用(P0.05),其中VE_(40)Se_0组的血浆MDA含量显著低于VE_0Se_(0.15)和VE_0Se_(0.30)组(P0.05)。5)随饲粮中维生素E和Se添加水平的升高,黄羽肉种鸡蛋中维生素E和Se含量显著增加(P0.05);饲粮中维生素E和Se添加水平对蛋中维生素E和Se含量有显著交互作用(P0.05)。结果提示,维生素E可以提高黄羽肉种鸡的抗氧化水平,饲粮中维生素E和Se添加水平可以显著影响蛋中维生素E和Se的含量;建议在无任何应激因素刺激和不使用Se缺乏地区饲料原料的情况下,黄羽肉种鸡玉米-豆粕型饲粮可以不用额外添加维生素E和Se。     

Influence of high vitamin E dosages on retinol and carotinoid concentration in body tissues and eggs of laying hens.

The aim of the study was to contribute to the discussion of overdosing vitamin E in laying hens. A total of 45 laying hens, divided into 5 groups were fed diets supplemented with either 0; 100; 1000; 10,000 or 20,000 mg dl-alpha-tocopheryl acetate/kg diet over a period of 10 weeks. Concentrations of vitamins A and E were measured in plasma, various tissues and egg yolk. Furthermore egg yolk colour and some carotinoids were measured in egg yolks. None of the vitamin E doses significantly influenced performance of the hens. As expected, vitamin E concentration in plasma, all tissue samples and egg yolk was significantly increased with increasing tocopherol content in the diet. The egg yolk showed the highest vitamin E concentration, followed by liver and muscles. Feeding 1000 mg alpha-tocopheryl acetate per kg diet resulted in an increase of vitamin A concentration in the liver. Very high doses (10,000 and 20,000 mg/kg diet) significantly decreased retinol concentration in the liver and egg yolk, as well as carotinoid concentration in the egg yolk. The lower carotinoid concentration in egg yolk resulted in a decreased intensity of egg yolk colour. A prooxidative and/or competitive effect of very high doses of vitamin E with other fat soluble substances has been discussed.     

硒和铬对蛋鸡脂质代谢及鸡蛋硒含量的影响

本试验旨在研究在蛋鸡日粮中添加酵母硒和吡啶羧酸铬及其互作对蛋鸡生产性能、脂质代谢及鸡蛋品质的影响.选用320只45周龄海赛克斯蛋鸡随机分为4组,每组4个重复,每个重复20只鸡,在基础口粮中分别添加0 mg/kg吡啶羧酸铬(Ⅰ组)、0.4 mg/kg吡啶羧酸铬(Ⅱ组)、0.5 mg/kg酵母硒(Ⅲ组)、0.4 mg/kg吡啶羧酸铬+0.5 mg/kg酵母硒(Ⅳ组),预饲1周,试验从46周龄持续到50周龄,试验期5周(35 d).结果表明,Ⅲ、Ⅳ组产蛋率极显著提高,料蛋比极显著降低(P<0.01).Ⅱ、Ⅳ组血清总胆固醇含量极显著降低(P<0.01),Ⅲ、Ⅳ组血清高密度胆固醇含量极显著升高(P<0.01).Ⅱ、Ⅲ、Ⅳ组蛋黄中的胆固醇含量与Ⅰ组差异极显著(P<0.01).Ⅲ、Ⅳ组与Ⅰ、Ⅱ组相比,鸡蛋硒含量极显著升高(P<0.01).Ⅲ、Ⅳ组在试验开始到第2周末鸡蛋硒含量极显著升高(P<0.01),从第2周末到第5周末,硒含量基本稳定,4个组均进入平台期.结果显示,吡啶羧酸铬极显著降低了血清及蛋黄中的胆固醇含量.酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了蛋黄中胆固醇含量,提高了鸡蛋中的硒含量.同时添加吡啶羧酸铬和酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了血清及蛋黄中的胆固醇含量,提高了血清中高密度胆同醇含量和鸡蛋中的硒含量.     

In vivo antioxidant properties of vitamin E and chromium in cold-stressed Japanese quails.

An experiment was conducted to determine if vitamin E (alpha-tocopherol-acetate) and chromium (chromium picolinate, Cr Pic) supplementation attenuate the negative effects of cold stress on egg production, egg quality, serum metabolites, and antioxidant status in Japanese quails (Corurnix coturnix japonica). One hundred and fifty laying Japanese quails (50-day-old) were divided into five groups, 30 birds per group. The laying quails kept at 6 degrees C for 12 h/d (08.00 p.m. to 08.00 a.m.) were fed either a basal diet (low temperature-basal diet, CS group) or the basal diet supplemented with either 400 microg of Cr/kg of diet (Cr group), 250 mg of alpha-tocopherol-acetate per kg of diet (Vit. E group) or 400 microg of Cr plus 250 mg of alpha-tocopherol-acetate per kg of diet (Vit. E + Cr group) while quails kept at 18 degrees C were fed a basal diet (thermo-neutral-basal diet, TN group). Performance and egg quality were significantly reduced in CS group compared with TN group. Supplemental chromium and vitamin E significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed laying hens compared with the group fed the basal diet at 6 degrees C. Egg production and egg weight were also greater (P < 0.05) in each supplemental group compared with the CS group. However, a combination of vitamin E and chromium, rather than each separately, provided the greatest performance. Supplemental vitamin E and chromium also increased serum vitamin C and E but, decreased malondialdehyde (MDA) concentrations (P < 0.05); the combination of vitamin E and chromium resulted in the highest levels of serum vitamin C and E within the cold-stressed quails. Results of the present study indicate that combined antioxidant supplements increased performance, egg quality and serum antioxidant levels while lowering MDA in cold-stressed quails.     

The vitamin A supply of laying hens including during rearing. 2. Effect of varied vitamin A supplementation of mixed feed in rearing on production in the laying period

In six experiments with laying hybrids the influence of a varied nutritive beta-carotene and vitamin A supply during rearing on the performance in the laying period was tested. Basal rations poor in carotene without vitamin A supplementation in the rearing period diminished feed intake and laying performance in the laying period, retarded the beginning of intensive laying and increased feed expenditure per 100 g egg if the feed for laying hens contained less than 5000 IU vitamin A per kg. Relations between varied vitamin A supply and the performance parameters of the laying performance could not be proved if chick and young hen feed with maize even without vitamin A supplement or if rearing feed with approximately 2500 IU vitamin A or laying hen feed greater than 5000 IU vitamin A supply were used.     

Glutathione Peroxidase Activity and Erythrocyte Lipid Peroxidation as Indices of Selenium and Vitamin E Status in Young Pigs

A randomized, blocked 2³ factorial experiment was conducted with 48 pigs from sows fed a diet low in selenium and vitamin E. From 3 to 12 weeks of age the piglets were kept in single pens and fed a basic diet consisting mostly of barley, dried skim milk, soybean meal and dried yeast, and containing 55 µg selenium and 3 mg vitamin E per kg. The treatment factors — i.e. feed supplements — were 2 levels of Se (nil, 60 µg/kg), 2 levels of vitamin E (nil, 50 mg/kg), and 2 levels of the feed antioxidant ethoxyquin (nil, 150 mg/kg). Blood samples, collected at termination of the experiment, were examined for glutathione peroxidase activity (GSH-Px) and resistance against erythrocyte lipid peroxidation (ELP) to evaluate Se and vitamin E status, respectively. Analysis of variance showed the GSH-Px activity to be litter-dependent (P < 0.001) and influenced by selenium supplementation (P < 0.001) but not by the other supplements or by interactions between supplements. Resistance against ELP was influenced only by vitamin E supplementation (P < 0.001). GSH-Px and ELP thus seem to be valuable and simple methods for evaluating, respectively, Se status and vitamin E status in growing pigs.     

Tomato powder in laying hen diets: effects on concentrations of yolk carotenoids and lipid peroxidation

1. The effects of tomato powder supplementation on performance, egg quality, serum and egg yolk carotenoids, vitamins and malondialdehyde (MDA) concentrations in were investigated in laying hens in mid-lay.

2. A total of 90 laying hens, 49 weeks old, were divided into 3 groups consisting of 6 replicate cages, 5 birds per cage. Birds were randomly fed on one of three diets: basal diet and basal diet added with 5 or 10?g tomato powder per kg diet.

3. As tomato powder concentration increased, there were linear increases in feed intake, egg production, egg weight and yolk colour and a linear decrease in feed conversion. Shell weight, shell thickness and Haugh unit remained unchanged in response to dietary treatments.

4. Concentrations of serum and egg yolk lycopene, β-carotene, lutein and vitamin A increased for both diets including tomato powder, whereas MDA decreased linearly with increasing supplemental tomato powder concentration.

5. Tomato powder supplementation increased egg production persistency and increased carotenoids and vitamin A contents in egg yolk, accompanied by reduced yolk lipid peroxidation.     

Vitamin E supplementation can alleviate negative effects of heat stress on egg production,egg quality,digestibility of nutrients and egg yolk mineral concentrations of Japanese quails

The aim of this study was to determine if the negative effects of high ambient temperature (34 degrees C) on egg production, egg quality, digestibility of nutrients, and mineral content of egg yolk could be alleviated by dietary vitamin E (dl-alpha-tocopheryl acetate) supplementation in laying Japanese quails (Coturnix coturnix japanica). Japanese quails (n=240; 7-week-old) were divided into eight groups, 30 birds per group. The quails were fed either a basal diet or the basal diet supplemented with either 125, 250 or 500 mg of dl-alpha-tocopheryl acetate/kg of diet. Birds were kept at 22 degrees C and 55% relative humidity (RH). At 14 weeks of age, the thermo-neutral (TN) group remained in the same temperature as at the beginning of the experiment, whereas the heat stress (HS) group was kept at an environment-controlled room at 34 degrees C and 44% RH for 3 weeks. Heat exposure decreased performance when basal diet was fed (P=0.001). With 250 and 500 mg/kg of diet, an increase in body weight (P=0.01), feed intake (P=0.01), egg production (P=0.001), and improvement in feed efficiency (P=0.01) was found with vitamin E supplementation in quails reared under heat stress conditions (HS). Similarly, egg weight (P=0.01), egg specific gravity (P=0.01), egg shell thickness (P=0.05) and Haugh unit (P=0.01) were positively influenced by vitamin E supplementation. Heat exposure decreased digestibility of dry matter (DM) (P=0.03), organic matter (OM) (P=0.05), crude protein (CP) (P=0.02), ether extract (EE) (P=0.05) and were elevated by supplemental vitamin E (P相似文献   

维生素E对蛋鸡产蛋后期产蛋性能和蛋品质的影响

文章旨在研究日粮中不同梯度维生素E添加水平对蛋鸡产蛋后期产蛋性能和蛋品质的影响.试验选择60周龄罗曼白壳商品蛋鸡300羽,试验随机分为5组,添加水平分别为0(对照组),30、60、120、240 mg/kg,每组6个重复,每个重复10羽鸡,预试期1周,正试期8周.结果表明:与对照组相比,蛋鸡产蛋后期日粮中添加120 m...     

茶多酚对蛋鸡生产性能、蛋品质和抗氧化能力的影响

本试验旨在研究茶多酚(TP)对蛋鸡生产性能、蛋品质和抗氧化能力的影响。试验选用450只24周龄的健康海兰灰产蛋鸡,分为5个组,每组6个重复,每个重复15只鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加40、80、200和400 mg/kg TP。试验期63 d,其中预试期7 d、正试期56 d。结果表明,与对照组相比:1)400 mg/kg TP显著降低了试验期前4周的平均蛋重(P0.05);200 mg/kg TP显著改善试验期后4周的料蛋比(P0.05);TP未显著影响产蛋率和平均日采食量(P0.05)。2)饲粮中添加TP未显著影响蛋形指数、蛋壳强度、蛋壳厚度、蛋白高度、哈夫单位和蛋黄颜色(P0.05)。3)TP显著提高了血浆总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GPx)活性(P0.05);显著提高试验期第8周时血浆总抗氧化能力(T-AOC)(P0.05)。4)TP显著提高了肝脏和蛋黄T-AOC和T-SOD活性(P0.05);显著降低肝脏和蛋黄中丙二醛(MDA)含量(P0.05)。由此可见,饲粮中添加TP未显著影响蛋鸡蛋品质;400 mg/kg TP降低了平均蛋重,200 mg/kg TP改善了料蛋比,两者均提高了蛋鸡的抗氧化能力,其中以200 mg/kg组效果最佳。     

饲粮中添加维生素E和有机硒对攸县麻鸭产蛋性能、蛋品质、血清生化指标及咸蛋蛋黄品质的影响

本试验旨在研究饲粮中添加维生素E和有机硒对攸县麻鸭产蛋性能、蛋品质、血清生化指标及咸蛋蛋黄品质的影响。选用200只健康的处于产蛋高峰期的攸县麻鸭,随机分为4个组,每组5个重复,每个重复10只鸭。对照组(Ⅰ组)饲喂基础饲粮,3个试验组(Ⅱ、Ⅲ、Ⅳ组)分别在基础饲粮中添加50 IU/kg维生素E、0.2 mg/kg硒、0.2 mg/kg硒+50 IU/kg维生素E。试验期为63 d。结果表明：1)Ⅱ、Ⅲ和Ⅳ组的产蛋率和日产蛋重均显著高于对照组(P<0.05)。Ⅱ、Ⅲ和Ⅳ组的料蛋比均显著低于对照组(P<0.05)。2)Ⅲ和Ⅳ组的蛋黄硒含量显著高于对照组(P<0.05)。Ⅱ和Ⅳ组的蛋黄维生素E含量显著高于对照组(P<0.05)。3)Ⅱ、Ⅲ和Ⅳ组的咸蛋蛋黄硬心率显著低于对照组(P<0.05),Ⅳ组硬心率显著低于Ⅱ和Ⅲ组(P<0.05)。4)Ⅱ、Ⅲ和Ⅳ组的血清中丙二醛(MDA)含量显著低于对照组(P<0.05)。Ⅱ、Ⅲ和Ⅳ组的血清中谷胱甘肽(GSH)含量和谷胱甘肽过氧化物酶(GSH-Px)活性均显著高于对照组(P<0.05)。由此可见,饲粮中添加维生...     

凝结芽孢杆菌对蛋鸭产蛋性能、蛋品质及血清生化指标的影响

 试验旨在研究饲粮中添加不同水平凝结芽孢杆菌对蛋鸭产蛋性能、蛋品质及血清生化指标的影响。选取200日龄,产蛋率约80%的临武鸭240羽,随机分成4组,每组6个重复,每个重复10羽鸭,对照组饲喂基础饲粮,试验组在基础饲粮中分别添加100 mg/kg、150 mg/kg和200 mg/kg凝结芽孢杆菌,预试期7 d,正试期28 d。结果表明：（1）饲粮添加凝结芽孢杆菌可提高蛋鸭产蛋率、平均日产蛋量、平均蛋重和饲料转化率,但未达显著水平（P>0.05）;添加100 mg/kg和150 mg/kg凝结芽孢杆菌可显著降低产蛋鸭采食量（P<0.05）,添加200 mg/kg与各组间均无显著差异（P>0.05）;(2）饲粮添加凝结芽孢杆菌可显著降低鸭蛋蛋壳厚度（P<0.05）,当添加150 mg/kg和200 mg/kg时,差异达极显著水平（P<0.01）,凝结芽孢杆菌还可显著提高鸭蛋蛋黄颜色,蛋白高度和哈氏单位（P<0.05）;（3）芽孢杆菌对产蛋鸭血清中血糖、总蛋白、总胆固醇、甘油三脂等血清生化指标均无显著影响（P>0.05）。由此可知,饲粮中添加凝结芽孢杆菌能在一定程度上提高蛋鸭饲料转化率和产蛋性能,虽会引起蛋壳厚度降低,但不影响合格蛋率,还可提高蛋黄颜色和哈氏单位,对蛋品质有一定改善。综合考虑,蛋鸭饲粮中凝结芽孢杆菌的添加量以150 mg/kg较为适宜。     

日粮添加甜菜碱对夏季高温蛋鸡生产性能、蛋品质及血液理化特征的影响

本研究旨在评估夏季高温时日粮添加甜菜碱对蛋鸡生产性能、蛋品质及骨骼和血液理化特性的影响.试验将480只产蛋性能一致的罗曼粉壳蛋鸡随机分为2组,每组240只,每组10个重复(24只/重复).对照组饲喂基础试验日粮,处理组蛋鸡饲喂基础试验日粮+150?mg/kg甜菜碱,试验为期8周.结果:日粮添加150?mg/kg甜菜碱对...