乳牛口服大量β-胡萝卜素对维生素A的吸收及钙磷代谢的影响

从北京西郊某农场选取６头健康成年黑白花乳牛,随机分成试验和对照两组。整个试验周期共８周,分为前期,中期和后期。试验结果表明,试验组乳牛血清β－胡萝卜素水平与血清ＡＫＰ活性的变化规律相一致,均于中期时最高,血清ＡＫＰ同工酶酶谱中骨带染色变宽变深;血清维生素Ａ水平呈现逐渐升高趋势;血清钙水平呈下降趋势;血清无机磷水平逐渐下降。据此可以表明,β－胡萝卜素进入机体后,其转化为维生素Ａ的效率在不同的吸收阶段     

环磷酰胺预处理制备兔抗Ⅰ型鸭肝炎病毒高免血清

以正常鸡胚尿囊液和环磷酰胺预处理试验兔, 再以Ⅰ型鸭肝炎病毒（Ｄｕｃｋ Ｈｅｐａｔｉｔｉｓ Ｖｉｒｕｓ Ｔｙｐｅ Ⅰ, ＤＨＶ Ⅰ） 标准强毒（ＡＴＣＣ, Ｃ９／Ｄ２） 接种后致死鸡胚的尿囊液, 经灭活、乳化制成油佐剂抗原多次免疫试验兔, 获得了鸡胚中和效价（ＥＰＤ５０） 达１∶３２ 以上的兔抗Ⅰ型鸭肝炎病毒高免血清（ＤＨＶ ⅠＳ） 。     

Replacing fish oil and astaxanthin by microalgal sources produced different metabolic responses in juvenile rainbow trout fed 2 types of practical diets

Dietary fish oil supplementation provides n-3 long-chained polyunsaturated fatty acids for supporting fish growth and metabolism and enriching fillet with eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; c22:6n-3). Two experiments were performed as a 3 × 2 factorial arrangement of dietary treatments for 16 wk to determine effects and mechanisms of replacing 0%, 50%, and 100% fish oil with DHA-rich microalgae in combination with synthetic vs. microalgal source of astaxanthin in plant protein meal (PM)- or fishmeal (FM)- based diets for juvenile rainbow trout (Oncorhynchus mykiss). Fish (22 ± 0.26 g) were stocked at 17/tank and 3 tanks/diet. The 100% fish oil replacement impaired (P < 0.0001) growth performance, dietary protein and energy utilization, body indices, and tissue accumulation of DHA and EPA in both diet series. The impairments were associated (P < 0.05) with upregulation of hepatic gene expression related to growth (ghr1and igf1) and biosynthesis of DHA and EPA (fads6 and evol5) that was more dramatic in the FM than PM diet-fed fish, and more pronounced on tissue EPA than DHA concentrations. The source of astaxanthin exerted interaction effects with the fish oil replacement on several measures including muscle total cholesterol concentrations. In conclusion, replacing fish oil by the DHA-rich microalgae produced more negative metabolic responses than the substitution of synthetic astaxanthin by the microalgal source in juvenile rainbow trout fed 2 types of practical diets.     

Regulation of fibroblast growth factor 9 on the differentiation of goat intramuscular adipocytes

It has been found that fibroblast growth factor receptor (FGF-FGFR) signaling can regulate the expression of adipocyte differentiation genes. FGF9 is one of the members of FGFs that mainly binds receptors FGFR2 and FGFR3. FGF9 is highly expressed in the adipose tissue of humans and mice, but there are few reports on the role of FGF9 in goat intramuscular adipocyte differentiation. Therefore, this study explored the effect of FGF9 on adipocyte differentiation through cell culture, interference, and overexpression. The expression of receptors FGFR1–FGFR4 in adipocyte differentiation and their effects on differentiation were detected to screen receptor gene of FGF9. Finally, the interaction between FGF9 and the receptor was tested by cotransfection. Our results showed that FGF9 interacts with FGFR2 to inhibit goat intramuscular adipocyte differentiation by regulating peroxisome proliferator-activated receptor gamma (PPARγ) and preadipocyte factor 1 (Pref1), which is a data support for subsequent pathway research.     

近年全球禽业发展趋势概述（1）

1全球禽肉产量增长降至3％以下随着养殖业对能源依赖性的日益提高．以及饲料成本的快速上涨．油价的上涨越来越受到关注。然而．根据经济合作与发展组织（OECD）和联合国世界粮农组织（FAO）的最新报告显示．粮食的供应最终会超过食品、饲料以及工业用粮（主要是生物燃料）的需求。因此,饲料价格预计将从当前的最高点回落．但仍会比平均值高。     

贵州天然豆科牧草——窄叶野豌豆的引种与驯化

对采自贵州省册亨县、三都县的窄叶野豌豆野生种进行了引种驯化。结果表明：其产草量中等，鲜草３７．５～４５ｔ／ｈｍ２，草质优良；生育期短，早熟；种子产量高，收纯净种子５００～６００ｋｇ／ｈｍ２。适合在我国南方中亚热带地区同水稻、玉米轮作，也可作为农田填闲作物栽培     

新太湖猪选育过程中近交技术的应用及效应分析

利用新太湖猪选育过程中（１９８６～１９９４）６个世代母猪的分娩产仔记录,后备猪生长发育测定资料,分析了近交对繁殖性能和生长发育性状的影响。相关分析表明,近交与产仔数、产活仔数的相关系数分别为－０．１６２５、－０．１５４６。与１８０日龄活重、体高、胸围、及８０ｋｇ时背膘厚度的相关系数分别为－０．１３５,－０．２１１,－０．２１８,－０．２０４。回归分析表明,近交系数每上升１０％,产仔数下降０．３９头,１８０日龄活重下降１．５ｋｇ,背膘厚下降０．０７４８ｃｍ。产仔记录分析表明,母猪近交系数在２０％以下时,产仔数比非近交组下降０．２７头,差异不显著（Ｐ＞０．０５）;近交系数在２０％以上时,下降１．３５头,差异不显著（Ｐ＞０．０５）。生长发育性状表明,近交系数在３０％以上时,１２０日龄活重、１８０日龄活重等性状都显著下降。８０ｋｇ活体背膘厚当个体近交系数上升到２０％以上时,与非近交组相比下降０．１６ｃｍ,差异显著（Ｐ＜０．０５）。     

体细胞数对发酵乳品质的影响研究

为确定用于生产发酵乳的原料乳质量标准,以提高发酵乳产品品质,选用蒙牛自有牧场30头不同健康状况、不同泌乳期的荷斯坦牛原料乳,按体细胞数分为低于20万个/mL组、20万-80万个/mL组及大于80万个/mL组,在发酵乳制备的当天及样品冷藏后的第1、7、14、21天分别测定发酵的产酸曲线、发酵乳的质构特性。结果表明,随着原料乳中体细胞数的增加,产品黏度下降,弹性降低,硬度增加,pH值降低,品质下降。     

兔组织中阿维菌素残留的高效液相色谱法测定研究

阿维菌素是一种新型大环内酯类广谱抗寄生虫药物。本试验采用乙腈提取,然后通过氧化铝柱净化组织样本,经Ｎ－甲基咪唑与三氟醋酸酐衍生化后,用高效液相色谱－荧光检测器在激发波长为３６５ｎｍ,发射波长为４７０ｎｍ处,对衍生化产物进行测定。     

不同投喂方式对革胡子鲶消化酶的影响

在（25±1）℃水温、自然光照条件下,设3种投喂方式饲养革胡子鲶（clarias leath-er）：第1种连续投喂整个试验期间不间断,第2和3种分别连续投喂3、7 d 后饥饿1 d,3种方式分别以R0（对照组）、R1/3、R1/7表示,试验周期共45 d。结果显示：R0、R1/3和R1/7组胃、后肠和肝脏中蛋白酶活性影响差异不显著,但前肠和中肠内蛋白酶活性影响存在差异(P<0.05)。R0、R1/3、R1/7组的胃、前肠、中肠、后肠和肝脏中淀粉酶影响不显著,R0、R1/3、R1/7的胃、前肠和肝脏内脂肪酶活性影响差异显著(P<0.05),而R0、R1/3、R1/7组中肠和后肠中脂肪酶活性影响差异不显著(P>0.05)。