桑叶黄酮对49～56周龄蛋鸡生产性能、器官指数和生殖激素的影响

试验旨在研究桑叶黄酮对蛋鸡生产性能、器官指数及繁殖激素水平的影响，并初步探讨日粮中桑叶黄酮的适宜添加量。选取49～56周龄海兰褐蛋鸡240只，随机分为5组（每组4个重复，每个重复12只），各组间产蛋率差异不显著，对照组饲喂基础日粮，试验组在日粮中分别添加10、50、100、200 mg/kg桑叶黄酮提取物。预试期1周，正试期8周。试验期间测定产蛋性能、饲料转化率，试验第8周屠宰测定器官指数和生殖激素水平。结果表明：与对照组相比，日粮中添加桑叶黄酮后对产蛋率、蛋重、料蛋比和平均日耗料均无显著影响，但可以提高产蛋率，以10 mg/kg添加水平产蛋率最高；添加桑叶黄酮对内脏器官无显著影响，但均可降低腹脂率；添加10、50 mg/kg桑叶黄酮均可增加十二指肠长度（P<0.05）；添加10、50 mg/kg桑叶黄酮可提高排卵后卵泡数量，添加50 mg/kg桑叶黄酮可增加输卵管重量，而添加10、50 mg/kg桑叶黄酮均可增加血液中孕酮和雌二醇含量。由此可见，日粮中添加10～100 mg/kg桑叶黄酮能提高海兰褐蛋鸡产蛋率、降低腹脂率；而添加10、50 mg/kg桑叶黄酮均可显著增加十二指肠...     

大豆黄酮对产蛋后期蛋鸡生产性能、血液指标和经济效益的影响

本试验旨在探讨饲粮中添加大豆黄酮对产蛋后期蛋鸡生产性能、血液指标、经济效益的影响。选取体重、产蛋率相近的56周龄海兰褐蛋鸡640只,随机分为4组(每组8个重复,每个重复20只),对照组饲喂基础饲粮,试验组饲喂在基础饲粮中分别添加10、50、100 mg/kg大豆黄酮的试验饲粮,试验期12周。结果表明:添加10 mg/kg大豆黄酮能极显著提高蛋重(P<0.01);添加50 mg/kg大豆黄酮能极显著提高产蛋率、降低料蛋比(P<0.01)。添加大豆黄酮显著提高了蛋鸡血清总蛋白、磷、钙、总胆固醇含量(P<0.05),对采食量、血液常规指标及血清白蛋白含量、谷草转氨酶活性、甘油三酯含量、葡萄糖含量、碱性磷酸酶活性、雌二醇水平和孕酮水平影响均不显著(P>0.05)。从经济效益上看,添加50 mg/kg大豆黄酮最好。由此可知,在蛋鸡产蛋后期饲粮中添加50 mg/kg大豆黄酮可以改善生产性能,且能够获得较佳的经济效益。     

大豆黄酮在蛋鸡饲料中的安全性评价:生产性能、蛋品质和繁殖器官发育

本试验旨在研究高剂量大豆黄酮对产蛋后期蛋鸡生产性能、蛋品质和繁殖器官发育安全性的影响。选取体重、产蛋率相近的56周龄海兰褐蛋鸡640只,随机分为4组,每组8个重复,每个重复20只鸡。对照组饲喂基础饲粮,试验组饲喂在基础饲粮中分别添加10、50、100mg/kg大豆黄酮的试验饲粮。预试期3周,试验期12周。结果表明:大豆黄酮添加量显著影响了蛋鸡死亡率、产蛋率、产蛋量和料蛋比(P<0.05),其中产蛋率(P=0.029)、产蛋量(P=0.003)和料蛋比(P=0.019)均与大豆黄酮添加量呈显著二次曲线关系,达到最佳产蛋率、产蛋量和料蛋比时,饲粮中大豆黄酮添加量分别为72.50、46.50和59.52mg/kg。3个与钙代谢相关的蛋品质指标(蛋壳厚度、蛋壳比例和蛋壳强度)受大豆黄酮添加量影响显著(P<0.05)。大豆黄酮添加量也显著影响了输卵管指数(P<0.05)。由此可见,产蛋后期饲喂高剂量大豆黄酮对蛋鸡采食量、蛋品质和繁殖器官发育没有负面影响,对产蛋率、产蛋量和料蛋比的最高限量建议值为72.50、46.50和59.52mg/kg。     

大豆黄酮对产蛋后期地方蛋鸡生产性能、蛋品质和血浆激素指标的影响

本试验旨在研究饲粮中添加大豆黄酮对产蛋后期地方蛋鸡生产性能、蛋品质和血浆激素指标的影响。试验选用体重及产蛋率相近的55周龄如皋黄鸡蛋鸡192只,随机分为2组,每组6个重复,每个重复16只鸡。对照组饲喂基础饲粮,试验组饲喂在基础饲粮中添加60 mg/kg大豆黄酮的试验饲粮。预试期2周,正试期14周。结果表明:1)试验组产蛋率显著高于对照组(P0.05),试验组死亡率、平均蛋重、平均日采食量和料蛋比与对照组相比较差异不显著(P0.05)。2)试验组鸡蛋哈氏单位显著高于对照组(P0.05),试验组其他蛋品质指标与对照组相比较差异不显著(P0.05)。3)试验组血浆雌二醇(E2)含量显著高于对照组(P0.05),试验组血浆卵泡刺激素(FSH)含量显著低于对照组(P0.05),试验组其他血浆激素指标与对照组相比较差异不显著(P0.05)。综上所述,饲粮添加60 mg/kg大豆黄酮能改善产蛋后期地方蛋鸡生产性能、蛋品质以及血浆激素指标。     

大豆黄酮对白羽番鸭繁殖性能及相关激素水平的影响

在基础日粮中分别添加6mg/kg和12mg/kg大豆黄酮饲喂44周龄的白羽番鸭。结果发现：6mg/kg大豆黄酮组番鸭产蛋率显著提高（P〈0.01）,血清孕酮和T3水平上升（P〈0.01）,而12mg/kg大豆黄酮组番鸭产蛋率呈下降趋势;两试验组种蛋受精率和孵化率均明显下降。试验结果表明：大豆黄酮可通过调节体内激素分泌,进而影响番鸭的生殖功能。     

大豆黄酮对白羽番鸭繁殖性能及相关激素水平的影响

在基础日粮中分别添加6mg/kg和12mg/kg大豆黄酮饲喂44周龄的白羽番鸭.结果发现:6mg/kg大豆黄酮组番鸭产蛋率显著提高(P＜0.01),血清孕硐和T3水平上升(P＜0.01),而12mg/kg大豆黄酮组番鸭产蛋率呈下降趋势;两试验组种蛋受精率和孵化率均明显下降.试验结果表明:大豆黄酮可通过调节体内激素分泌,进而影响番鸭的生殖功能.     

日粮中添加大豆黄酮对鹌鹑生产性能和血液中激素水平的影响

本试验采用了 3个生产阶段的蛋用鹌鹑。 35日龄开产期蛋用鹌鹑日粮中添加 3mg/kg大豆黄酮 ,鹌鹑的产蛋率和血液中T3 水平均发生显著性提高 (P <0 0 5 )。 7月龄蛋用鹌鹑日粮中添加 3mg/kg大豆黄酮 ,可显著提高鹌鹑的产蛋率 (P <0 0 5 )和血液中T3 水平 (P <0 0 5 ) ;而日粮中添加 6mg/kg大豆黄酮则使鹌鹑的产蛋率显著下降 (P <0 0 5 )。 12月龄蛋用鹌鹑日粮中添加 6mg/kg大豆黄酮 ,鹌鹑的产蛋率提高 10 3% (P <0 0 1) ;血液中T3 、T4和IGF 1水平分别提高 34 8% (P <0 0 1)、2 7 6 % (P <0 0 5 )和 30 8% (P <0 0 5 )。本次研究结果表明 ,日粮中添加一定剂量大豆黄酮能显著增加开产期、高峰期和后期蛋用鹌鹑的产蛋率 ,并影响其内分泌机能     

大豆黄酮对肉种鸡产蛋和繁殖性能的影响

本试验旨在探索添加大豆黄酮后对肉种鸡产蛋和繁殖性能的影响。选取43周龄体况接近一致(体重、产蛋率)的肉种鸡S2系母鸡240只,随机分成4组,每组6个重复,每个重复10只:选取1组作为对照组,饲喂无大豆黄酮的基础饲粮,其余3组分别在基础饲粮基础上添加5、10、20 mg/kg大豆黄酮。再挑选20只强健的S2系公鸡采集精液,混精对试验鸡进行人工授精,试验期为15周。结果表明:与对照组相比,1)添加大豆黄酮对S2系母鸡体增重、采食量及死亡率无显著影响(P0.05)。2)添加大豆黄酮后能显著提高产蛋率(P0.05),其中10 mg/kg组产蛋率提高了4.1%(P0.05),日产蛋量提高了3.5%(P0.05),为3组最佳。5、10 mg/kg组料蛋比分别降低了8.0%和11.2%(P0.05)。3)10 mg/kg组受精率、孵化率和健雏率分别提高了13.1%、20.5%和5.8%(P0.05)。由此可见,饲粮中添加大豆黄酮能显著影响肉种鸡产蛋和繁殖性能,其中10 mg/kg组综合效果最佳。     

类黄酮对蛋鸡生产性能、蛋品质和血液生化特性的影响

试验选用864只39周龄海兰褐蛋鸡,随机分为3个处理,每个处理3个重复,每个重复96只鸡,采用单因素随机试验设计,分别饲喂添加0、30 mg/kg蜂胶黄酮（PF）和6 mg/kg大豆黄酮（DA）的玉米-豆粕型日粮8周。结果表明,日粮中添加PF和DA对蛋鸡产蛋率、破软壳率、料蛋比有改善的趋势;日粮中添加PF和DA能够显著降低蛋黄胆固醇的含量,在蛋保存的第7和14天两者均能不同程度降低蛋黄丙二醛的含量;在试验第4、8周,日粮中添加DA和PF能够显著提高血清HDL水平（P<0.05）,在试验第8周,DA显著降低血清TC和TG水平,而PF显著降低血清TC水平并显著提高血清胰岛素水平（P<0.05）;此外,日粮中添加DA和PF能够显著提高第4周时T、B淋巴细胞转化率（P<0.05）,且添加PF显著提高第8周时T淋巴细胞转化率（P<0.05）。     

日粮硫酸铜水平对蛋鸡生产水平、壳蛋质量及淋巴组织的影响

选择体重及产蛋率相近的海兰褐23周龄蛋鸡216只，随机分成6个处理组，每组4个重复，每个重复9只，以玉米－杂粕型日粮为基础日粮，硫酸铜（以铜计）添加水平分别为0、6、15、30、60、125mg/kg。试验结果表明：所有硫酸铜添加组的产蛋率及料蛋比均高于对照组，添加6、15、60mg/kg硫酸铜各组产蛋率与对照组差异显著（P＜0．05）；添加60mg/kg铜组料蛋比最佳；30mg/kg铜处理组的蛋壳强度和蛋壳厚度最佳，盲肠淋巴小结平均直径以15mg/kg铜处理组最大，60mg/kg铜处理组最小，且各处理组差异极显著（P＜0．01）。     

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。     

葡萄原花青素对产蛋后期蛋鸡生产性能和抗氧化能力的影响

本试验旨在研究葡萄原花青素(grape procyanidins,GPC)对产蛋后期蛋鸡生产性能、蛋品质及血浆、肝脏和蛋黄抗氧化能力的影响。选取产蛋率、体重相近,健康状态良好的64周龄罗曼蛋鸡288只,随机分为4组,每组6个重复,每个重复12只鸡。对照组:饲喂基础饲粮;GPC50组和GPC100组:分别在基础饲粮中添加50和100 mg/kg的GPC;抗氧化剂特丁基对苯二酚(tert-butyl hydroquinone,TBHQ)组:基础饲粮+200 mg/kg TBHQ。预试期7 d,正试期56 d。结果表明:1)GPC显著抑制了产蛋后期蛋鸡产蛋率和鸡蛋哈夫单位下降(P0.05),显著增加了蛋壳厚度(P0.05)。2)GPC50组蛋鸡血浆和肝脏总超氧化物歧化酶(T-SOD)活性和总抗氧化能力(T-AOC)均显著提高(P0.05),血浆和肝脏丙二醛(MDA)含量显著降低(P0.05);TBHQ显著提高了蛋鸡血浆T-SOD活性(P0.05),显著降低了肝脏M DA含量(P0.05)。3)GPC显著提高了蛋黄T-SOD活性(P0.05),显著降低了蛋黄M DA和胆固醇含量(P0.05);TBHQ显著降低了蛋黄M DA含量(P0.05)。综上,饲粮添加GPC可改善产蛋后期蛋鸡产蛋率和哈夫单位,增加蛋壳厚度,改善机体抗氧化能力,其中以50 mg/kg GPC添加效果较好,优于200 mg/kg TBHQ。     

苜草素对产蛋后期蛋鸡抗氧化能力、脂质代谢及相关基因表达的影响

本试验旨在研究不同水平苜草素对产蛋后期蛋鸡抗氧化能力、脂质代谢及相关基因表达的影响。选用69周龄、健康海兰褐蛋鸡324只,随机分为3组,每组6个重复,每个重复18只鸡。对照组饲喂基础饲粮,试验组在基础饲粮的基础上添加500和1 000 mg/kg苜草素。试验预试期2周,正试期8周。结果表明,与对照组相比:1)试验组蛋鸡产蛋率显著升高(P0.05),料蛋比显著降低(P0.05)。2)500 mg/kg苜草素显著增加了蛋壳强度(P0.05),极显著降低了肝脏甘油三酯含量(P0.01),显著降低了肝脏总胆固醇含量(P0.05)。3)1 000mg/kg苜草素极显著提高了血浆谷胱甘肽过氧化物酶(GSH-Px)、总超氧化物歧化酶(T-SOD)及肝脏GSH-Px活性(P0.01),显著提高了血浆总抗氧化能力(T-AOC)、降低了丙二醛(MDA)的含量(P0.05),极显著降低了肝脏与蛋黄总胆固醇和甘油三酯含量(P0.01),极显著提高了肝脏硫氧还蛋白还原酶1(Trx R1)、胆固醇-7α羟化酶(CYP7A1)、固醇调节元件结合蛋白-1c(SREBP-1c)mRNA表达量(P0.01),极显著降低了3-羟基-3-甲基戊二酸单酰辅酶A还原酶(HMGCR)mRNA表达量(P0.01),而对GSH-Px mRNA表达量无显著影响(P0.05)。由此可见,饲粮中添加苜草素可降低产蛋后期蛋鸡蛋黄胆固醇和甘油三酯含量,提高生产性能、蛋壳强度、机体抗氧化和胆固醇代谢能力,且以添加1 000 mg/kg苜草素效果较好。     

产蛋种鸡日粮中不同水平维生素E与有机和无机硒的效果研究

在３×５的两因子试验中,研究了不同添加水平维生素Ｅ（４、１４和２４ｍｇ／ｋｇ）与有机和无机硒（亚硒酸钠０．２０、０．３５和０．５０ｍｇ／ｋｇ,酵母硒０．３５和０．５０ｍｇ／ｋｇ）对褐壳蛋种母鸡在２０～４０周龄阶段生产繁殖性能和有关血液指标的影响。结果表明,产蛋母鸡的采食量、产蛋率、蛋重、产蛋量、饲料转化率和死淘率在３个维生素Ｅ添加水平间无差异;除了添加酵母硒０．５０ｍｇ／ｋｇ组蛋鸡的蛋重和产蛋量显著低于酵母硒０．３５ｍｇ／ｋｇ组以外,其它各项生产性能指标在各硒处理组间差异不明显。维生素Ｅ和硒可增加彼此在血液中的存留;当日粮中只补加维生素Ｅ４ｍｇ／ｋｇ时,将日粮亚硒酸钠硒添加水平由０．２０ｍｇ／ｋｇ提高到０．３５～０．５０ｍｇ／ｋｇ可使血浆α－生育酚含量由０．５０μｇ／ｍｌ上升到接近１．０μｇ／ｍｌ左右。     

甜菜碱促进猪生长的机理

９６ 头“杜长大”生长猪按饲养试验要求分成 ４ 组（每组 ３ 个重复）,分别饲 以添加 ０、１ ０００、１ ５００、２ ０００ ｍ ｇ／ｋｇ甜菜碱的基础日粮,试验期 ６２ ｄ。结果表明,１ ０００ ｍ ｇ／ｋｇ 剂量组试验猪生长性能最佳,日增重较对照组提高了 １３２０％ （ Ｐ ＜ ００１）, 料重比降低了 ７９３％ （ Ｐ ＜ ００１）。该组猪血清 Ｇ Ｈ、 Ｉ Ｇ Ｆ Ｉ、 Ｔ３ 、 Ｔ４ 水平分别升高了 １０１７６％ （ Ｐ＜ ００１）, ４４７５％ （ Ｐ ＜ ００１）, ２６５３％ （ Ｐ＜ ００１） 和 １６８３％ （ Ｐ＜ ００５）; 血清游离丝氨酸含量提高了 １４２８％ （ Ｐ ＜ ００５）; 血清总蛋白上升了 ２１６９％ （ Ｐ ＜ ００１）, 血清尿素氮含量降低 了 ４７６７％ （ Ｐ ＜ ００１）; 背最 长肌 和 肝脏 中 Ｒ Ｎ Ａ 含量 及 背最 长肌 Ｒ Ｎ Ａ／ Ｄ Ｎ Ａ 比 率分 别升 高了１２６０％ （ Ｐ ＜ ００５）, １７８０％ （ Ｐ ＜ ００２） 和 １９７９％ （ Ｐ ＜ ００２）; 肝脏 和腺 垂体 ｃ Ａ Ｍ Ｐ 含 量提 高了４７５３％ （ Ｐ ＜ ００１） 和 ６５２１％ （ Ｐ ＜ ００１）。研究结果提示,甜菜碱似作用     

Vitamin E requirement of mink with special reference to tocopherol composition in plasma, liver, and adipose tissue

Tissue responses of 4 different tocopherols found in a basal diet (BD) and the effect of 2 physiologic levels of dl-alpha-tocopheryl acetate (25 and 150 mg/kg) on tissue tocopherol content were studied in the mink. The BD contained a total of 7.1 mg vitamin E/kg, with alpha-, beta-, gamma-, and delta-tocopherol in a ratio of 1:0.07:0.55:0.10, respectively. The corresponding ratios in the tissues were: liver, 1:0.04:0.12:0; plasma, 1:0:0.13:0; and adipose tissue, 1:0:0.19:0. After mink were fed diets containing vitamin E, alpha- and gamma-tocopherol were distributed in similar proportions in plasma and liver, but gamma-tocopherol was in a slightly higher proportion in adipose tissue. Addition of 25 or 150 mg/kg of alpha-tocopheryl acetate to the BD decreased the gamma-tocopherol levels in all 3 tissues; this was considered to be a dilution effect of other tocopherols in BD with added alpha-tocopheryl acetate. The beta-tocopherol content in the liver remained unchanged, irrespective of the dietary amount of alpha-tocopheryl acetate. Plasma alpha-tocopherol had a linear relationship to log dietary dose, with an apparent half-saturation of the vitamin E binding capacity at 13 mg vitamin E/kg diet. At the given dietary levels, liver and adipose continued to accumulate alpha-tocopherol. The correlation between total plasma lipids and plasma alpha-tocopherol was significant (P less than 0.001) only in the group fed the BD. Vitamin E analysis of plasma could be used as a routine method for controlling the vitamin E status of mink.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary iron on performance and mineral utilization in lambs fed a forage-based diet

Twenty-four lambs, averaging 29 kg, were used to determine the effect of supplemental dietary Fe on performance and Cu, P, Zn and Mn utilization. Treatments consisted of supplemental Fe at 0, 300, 600 or 1,200 mg/kg diet as ferrous carbonate. The basal diet contained 154 mg Fe/kg diet and consisted of 90% Coastal bermudagrass pellets, 9.45% group corn, .5% sodium chloride and .05% vitamin mix. Lambs were slaughtered after having ad libitum access to diets for 98 to 121 d. Dietary Fe did not affect lamb gain or feed intake. Supplemental Fe increased Fe concentrations in liver (P less than .01), spleen (P less than .01) and bone (P less than .10), but not in kidney and muscle. Serum Fe concentrations and percentage transferrin saturation in serum were increased (P less than .01) by supplemental Fe at 28 and 84 d, but not at the termination of the study. Plasma Cu was decreased (P less than .01) at 56 d, whereas serum ceruloplasmin activity was reduced (P less than .01) at 28 d in lambs fed 1,200 mg Fe/kg diet compared with lambs fed 600 mg Fe/kg diet. Lower levels of Fe (300 and 600) reduced (P less than .01) ceruloplasmin by 56 d and plasma Cu by 84 d compared with controls. Liver Cu also was decreased (P less than .05) by supplemental Fe. Plasma P was decreased slightly (P less than .10) by 28 d and significantly (P less than .01) at the other sampling dates by supplemental Fe.(ABSTRACT TRUNCATED AT 250 WORDS)     

Supplemental defatted microalgae affects egg and tissue fatty acid composition differently in laying hens fed diets containing corn and flaxseed oil

Effects of defatted microalgae (DFA) on fatty acid composition of eggs and tissues of hens have not been well studied. This experiment was to determine how low concentrations of supplemental DFA in the presence or absence of flaxseed oil (FO) altered fatty acid profiles of egg yolk, liver, adipose tissue, and plasma of layers. A total of 60 Shaver Leghorn layer hens (individually caged, 20-wk old) were allotted into 6 groups (n = 10) and fed a corn/soybean meal basal diet containing 0, 3, or 5% DFA and 0 (1.5% corn oil, CO) or 1.5% FO for 6 wk. BW, ADFI, egg production rate, and egg component weights were not affected by any of the dietary treatments at various time points, but egg yolk color was changed (P < 0.05) with increasing concentrations of DFA. The concentration of n-3 fatty acids in egg yolk and plasma were elevated by FO up to 9-fold (P < 0.05) starting at wk 1 or 2, and 39 to 83% (P < 0.05) by DFA. Supplemental DFA improved (P < 0.05) n-6/n-3 fatty acid ratios in egg yolk and plasma from 13 to 23 and 7 to 13, respectively, only in hens fed diets without FO. Fatty acid profiles of liver and adipose tissue (at wk 6) displayed responses to supplemental DFA and FO similar to those of egg yolk or plasma. In conclusion, supplemental 3 or 5% DFA caused moderate enrichments of n-3 fatty acids and decreased the n6/n3 fatty acid ratios of egg yolk and tissues in hens fed diets without FO.     

Yolk and serum cholesterol and production traits,as affected by incorporatinga supraoptimal amount of copper in the diet of the leghorn hen

1. An experiment was conducted to investigate the possibility of lowering the yolk cholesterol of the egg by supplementing the diet with supraoptimal amounts of copper (50, 150 or 250 mg/kg) as sulphate or acetate. 2. A significant reduction in egg production and a negative effect on food conversion was found when 250 mg/kg of copper was added compared to the control (no added copper). Acetate seemed significantly less harmful in both cases. 3. A significant linear reduction was found in plasma and yolk cholesterol (20% and 14%) and in plasma and yolk triglycerides (24% and 30%) as the dietary copper content was increased from 0 to 250 mg/kg. 4. Regardless of type or quantity of copper, cholesterol and lipids were decreased linearly as birds remained longer on the treatments. A significant interaction between quantity and period showed a greater reduction at a later time. 5. If slightly lower egg production can be accepted, the addition of 250 mg/kg copper might be beneficial in reducing the cholesterol content of the yolk.     

饲粮锌添加水平对蛋鸡生产性能及组织锌含量的影响

试验选用66只18周龄商品代伊莎褐育成母鸡。随机分为3组,每组22只,对照组饲喂基础饲粮,试验1、2组在基础饲粮中分别添加60、180mg/kg的锌。研究不同锌添加水平对蛋鸡生产性能和组织器官重量及锌含量的影响。结果表明,在蛋鸡饲粮中添加锌对产蛋量、耗料量和料蛋比无显著影响(P>0.05),但破蛋率略下降,蛋重显著降低(P<0.05);除输卵管重有显著升高外(P<0.05),蛋鸡体重及其它组织器官重均无显著变化(P>0.05);肝脏中锌含量极显著提高(P<0.01);胫骨和蛋中含量显著提高(P<0.05),血清和羽毛锌有升高趋势。