IGF-I、TGF-α、bFGF对猪卵母细胞体外成熟和卵裂的影响

 研究了IGF-I、bFGF、TGF-α 3种细胞因子单独或者联合作用对猪卵母细胞体外成熟和孤雌激活后卵裂的影响,以确立猪卵母细胞体外成熟的最佳条件。结果表明，3种细胞因子对卵母细胞的成熟和激活后卵裂呈现双重效应（1）20 ng·ml-1的IGF-I的成熟率和卵裂率显著的高于对照组和10、30、40、50、100 ng·ml-1组[（85.3 ±2.11) %，（85.4±2.81）%；（71.1 ±1.91）%，（62.5 ±0.98）%；（77.5 ±2.5）%，（59.1 ±3.93）%；（61.9 ±1.72）%，（54.3 ±3.48）%；（58.6 ±4.26）%，（53.1 ±1.23）%；（44.4 ±5.10）%，（49.8 ±3.55）%；（33.9 ±3.48）%，（46.1 ±3.59）%，P <0.05)，当IGF-I的浓度达到100 ng·ml-1时,成熟率（33.9±3.48）%和卵裂率（46.1±3.59）% 降低，与其它各组相比差异显著（P < 0. 05）。（2）20 ng·ml-1的bFGF的成熟率（85.0 ±1.70）%和卵裂率（85.0±2.82）%最高,和其它各组相比,差异显著（P < 0.05）。（3）15 ng·ml-1的TGF-α的成熟率（86.9±0.46）%和卵裂率（86.3±2.01）%最高,和其它各组相比,差异显著（P < 0.05）。（4）15 ng·ml-1TGF-α和20 ng·ml-1bFGF联用组，卵母细胞成熟率和分裂率显著高于20 ng·ml-1 bFGF和20 ng·ml-1 IGF-I联合组；15 ng·ml-1TGF-α和20 ng·ml-1 IGF-I联合组；与20 ng·ml-1 bFGF、20 ng·ml-1 IGF-I和15 ng·ml-1 TGF-α三者联用组。[（89.2±1.44）%和（88.8±0.17）%.（75.6±0.98）%和（78.3±1.65）%；（77.2±2.54）%和（80.2±2.26）%；（76.4±1.28）%和（77.4±3.73）%，P <0.05]。     

Effects of dietary forage to concentrate ratio and wildrye length on nutrient intake,digestibility, plasma metabolites,ruminal fermentation and fecal microflora of male Chinese Holstein calves

Twenty-eight male, weaned Chinese Holstein calves((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio(F:C) and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement: whole-length forage(WL) with low F:C(50:50); WL with high F:C(65:35); short-length forage(SL) with high F:C(65:35); and SL with low F:C(50:50). Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size(~50% particles 19 mm). Dry matter intake(DMI) and organic matter(OM) intake was increased by increasing both F:C(P0.01) and forage length(FL)(P0.05), while acid detergent fiber(ADF) and neutral detergent fiber(NDF) intakes were only increased by increasing the F:C(P0.01). The digestibility of NDF was increased as the FL increased(P0.01), and it was also affected by interaction between F:C and FL(P0.05). Cholesterol(CHO)(P0.01), leptin(LP)(P0.05), and growth hormone(GH)(P0.01) concentrations in plasma were increased as dietary F:C increased. A significant increase in plasma triglyceride(TG)(P0.01), insulin(INS)(P0.05), and GH(P0.01) levels was observed with decreasing dietary FL. Ruminal p H values of calves fed with low F:C diets were significantly lower than those in high F:C treatment(P0.05). Increasing the F:C enhanced ruminal acetic acid(P0.05) and acetic acid/propionic acid(P0.01). Fecal Lactobacillus content was significantly higher, while Escherichia coli and Salmonella contents were significantly lower in WL and high F:C groups(P0.05). Lower fecal scores(higher diarrhea rate) were observed in calves fed with SL hay compared to WL hay(P0.05). Denatured gradient gel electrophoresis(DGGE) bands and richness index(S) were significantly affected by the interaction between F:C and FL(P0.05), under high F:C, band numbers and richness index from WL group were higher than that from SL group(P0.05), whereas there were no differences between WL andSL groups under low F:C(P0.05). Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F:C(65:35) diet is suitable for weaned calves.     

Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings' corticosterone metabolites of broilers

The present study aimed to investigate the effect of relative humidity(RH) at either acute or chronic moderate ambient temperature(Ta) on growth performance and droppings' corticosterone metabolites of broilers.Two experiments were conducted: effect of RH(35,60 or 85%) on average daily feed intake(ADFI) and droppings' corticosterone metabolites at acute(1 d: 20–26 or 31–20°C,26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta(experiment 1) and effect of RH(35,60 or 85%) on growth performance and droppings' corticosterone metabolites at chronic(step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta(experiment 2).Droppings were collected at the 2,4,6,8,and 22 h after Ta-RH controlled in experiment 1 and at the 2,4,6,and 22 h after Ta controlled to 32°C in experiment 2.The results showed that: 1) In experiment 1,85% RH increased(P0.05) the droppings' corticosterone metabolites at the 2,6,8,and 22 h and 35% RH increased(P0.05) it at the 2 and 22 h compared to the 60% RH.Moreover,85% RH further increased(P0.05) it compared to the 35% RH,however,no difference(P0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased(P0.05) droppings' corticosterone metabolites at the 2,6,8 and 22 h and decreased(P0.05) ADFI compared to the 60% RH,moreover,85% RH further increased(P0.05) droppings' corticosterone metabolites and further decreased(P0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings' corticosterone metabolites in the whole period had a negative correlation(P0.02) with the ADFI.2) In experiment 2,85% RH increased(P0.01) droppings' corticosterone metabolites only at the 2 h and decreased(P0.02) ADFI and average daily gain(ADG) compared to the 60% RH,no difference(P0.05) in droppings' corticosterone metabolites was found between the 35 and 60% RH,however,35% RH decreased(P0.01) ADG compared to the 60% RH,and the average of droppings' corticosterone metabolites in the whole period also had a negative correlation(P0.02) with ADFI and ADG.In conclusion,droppings' corticosterone metabolites could be used as a RH stress index and low and high RH,especially high RH,reduced growth performance possibly through inducing RH stress at moderate temperature.     

不同蛋白水平下添加抗菌肽对赤点石斑鱼影响的研究

评估了不同饲料蛋白水平(44%,48%,52%)和抗菌肽浓度(0.01%,0.02%)对赤点石斑鱼生长性能、血清生化、消化酶和抗氧化能力的影响。实验组分别为:D1(44%,0.01%),D2(48%,0.01%),D3(52%,0.01%),D4(44%,0.02%),D5(48%,0.02%),D6(52%,0.02%)。每组3个平行,养殖8周结果如下:一定范围内,增重率、特定生长率和饲料转化率随蛋白水平和抗菌肽浓度增加,D5组显著高于D1组(P0.05)。形态学指标,D6组肝体比(HSI)、脏体比(VSI)和肠系膜脂肪(IPF)显著低于D5组(P0.05)。同一蛋白水平下增加抗菌肽浓度可降低肌肉粗脂肪含量,D4组显著低于D1组(P0.05)。血清总蛋白、白蛋白含量随蛋白水平和抗菌肽浓度的增加而升高(P0.05),D3和D5组谷丙转氨酶、谷草转氨酶和血糖显著低于其他组(P0.05)。D5组胰蛋白酶高于其他组(P0.05),D1组过氧化物酶显著低于其他组(P0.05)。随着抗菌肽浓度增加,胃蛋白酶、过氧化物酶、过氧化氢酶活性增加,且丙二醛含量降低(P0.05)。实验结果表明,48%蛋白水平下添加0.02%抗菌肽可以提高赤点石斑鱼生长性能,增强消化酶活性和抗氧化能力,降低饲料系数。     

Effect of breed, sex and birth parity on growth, carcass and meat quality in pigs

The effects of breed, sex and birth parity on the traits of growth, carcass and meat quality were investigated in three different breeds including Swedish Landrace, British Large White and an indigenous Chinese breed — Tongcheng pigs. The results indicated that the Swedish Landrace and the British Large White had advantages over the Tongcheng pigs in growth rate, feed conversion rate (FCR) and carcass traits, but had disadvantages in meat quality. In contrast to the British Large White, the Swedish Landrace had higher average daily gain during the trial (ADG2) (877.04 g·day⁻¹ vs. 813.95 g·day⁻¹, P < 0.05), and marbling score (MS) (2.48 vs. 2.02, P < 0.01), larger eye muscle area (EMA) (41.80 cm² vs. 35.14 cm, P < 0.01) and more efficient feed conversion rate (FCR) (3.06 vs. 3.29, P < 0.05), lower muscle shear force (MSF) (4.20 kgf (1 kgf = 9.80665 N) vs. 4.93 kgf, P < 0.05) and backfat thickness (BF) (all P < 0.01) including live backfat thickness (LBF), average backfat thickness at 3 points in the carcass (ABF), backfat thickness between 6th and 7th ribs (6–7 th BF) and backfat thickness at 10th rib (10 th BF). There was a difference (P < 0.05) only inMS between castrated females (CF) and castrated males (CM). Birth parity affected ADG2 (P < 0.05), some carcass characteristics and meat quality, including CL₁ (P < 0.001), CL₂ (P < 0.05), BF (ABF, 6–7th BF and 10th BF, all P < 0.001), EMD (P, 0.001), EMA (P < 0.001), percentage of leaf and caul fat (PLC) (P < 0.05), proportion of lean and bone of the ham (PLBH) (P < 0.05), muscle drip loss percentage (DL) (P < 0.05) and intramuscular fat content (IMF) (P < 0.05). The breed-sex interaction only impacted the average daily gain from birth to marketing (ADG1) and DL (both P < 0.05). However, there was no significant effect of sex-parity interaction on all the traits tested.     

草炭水溶解态有机质与金属离子络合稳定常数的测定

采用离子交换平衡法测定草炭水溶解态有机质与 Cu2 +、Pb2 +、Zn2 +、Cd2 + 4种金属离子 ,在 2种 p H条件下的络合稳定常数 .结果表明 ,金属离子与草炭水溶解态有机质通常形成混合或多核络合物 ;2种 p H条件下的络合配位数和稳定常数序列均为 :Cu2 + >Pb2 + >Zn2 + >Cd2 + ,高 p H条件下 ,络合配位数和稳定常数均明显增大     

Comparison of forage yield,silage fermentative quality,anthocyanin stability,antioxidant activity,and in vitro rumen fermentation of anthocyanin-rich purple corn (Zea mays L.) stover and sticky corn stover

The objective of this study was to observe the forage yield, silage fermentative quality, anthocyanin stability, and antioxidant activity during the storage period and in vitro rumen fermentation of anthocyanin-rich purple corn (Zea mays L.) stover (PS) and sticky corn stover (SS). Forage yield of corn stover was weighed and ensiled with two treatments: (1) hybrid sticky waxy corn stover (control), and (2) hybrid purple waxy corn stover (treatment). Samples were stored in mini-silos for periods of 0, 7, 14, 21, 42, 63, 84, and 105 d. The results showed that PS had significantly higher (P<0.05) yields of dry matter (DM), organic matter (OM), gross energy (GE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total anthocyanins than that of the SS. Anthocyanin-rich purple corn stover silage (PSS) showed higher (P<0.05) levels of DM and CP relative to the sticky corn stover silage (SSS). Although anthocyanin-rich PSS displayed a lower (P<0.05) level of pelargonidin-3-glucoside (P3G), it had higher (P<0.05) levels of peonidin (Peo) and pelargonidin (Pel) compared to the control. Delphinidin (Del) and malvidin (Mal) were not detected in SSS during the ensilage period; in PSS, Del was no longer detected after 7 d of ensilage. Specifically, total anthocyanins in anthocyanin-rich PSS decreased rapidly (P<0.05) prior to 7 d of ensilage, and then remained at relatively stable (P>0.05) constants. Compared to the anthocyanin-rich PSS, SSS displayed significantly higher (P<0.05) pH value and ammonia nitrogen (NH₃-N) content. Propionic acid (PA) at 0 d and butyric acid (BA) during the entire study period were not detected, whereas anthocyanin-rich PSS showed a higher (P<0.05) level of lactic acid (LA) than that of the SSS. Compared with the SSS extract, anthocyanin-rich PSS extract showed a higher (P<0.05) level of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and displayed a lower (P<0.05) half maximal inhibitory concentration (IC₅₀) value. Moreover, anthocyanin-rich PSS reduced (P<0.05) gas production (GP), and displayed lower levels of immediately soluble fraction and ratio of acetic acid (AA) to PA at 12 h, but the other parameters were unaffected (P>0.05) relative to the control. Taken together, the results indicated that: (1) anthocyanins could be stable in silage; (2) anthocyanin-rich PSS showed better silage fermentative quality and stronger antioxidant activity; and (3) anthocyanin-rich PSS had no negative effect on rumen fermentation parameters.     

Effects of Chinese herbal formula Heat-stress-releasing on antioxidant function in dairy cows

In order to investigate the effects of a Chinese herbal formula Heat-stress-releasing on the antioxidant function in dairy cows, ten dairy cows were randomly divided into the control group and the experimental group, with five cows in each group. All the cows were fed with a basal diet. The animals in the experimental group were given with 220 g of herbs per day in addition to the basal diet. The trial was conducted for 14 days. Blood samples were taken from the vena cava at day 0, day 7, and day 15, respectively. The antioxidant statuses were examined. The results are as follows. (1) Heat-Stress-releasing formula can significantly increase the milk yield of dairy cows under heat stress. Compared with the control group, the milk yield of the herb-treated group increased by 14.01% (P<0.05), 14.32% (P<0.05) and 15.01% (P<0.05) in prophase, metaphase and anaphase of the test, respectively. (2) Heat-Stress-releasing formula can increase significantly the antioxidant status of the heat stressed dairy cows. Compared with the control group, the superoxide dismutase (SOD) activity increased by 45.93% (P<0.01) at day 7 and by 54.40% (P<0.01) at day 15. The Glutathioneperoxidase (GSH-PX) activity of the test group increased by 17.99% (P<0.05) at day 7 and 25.98% (P<0.01) at day 15. The total antioxidant capacity (T-AOC) of the test group increased by 43.64% (P<0.01) at day 7 and 46.35% (P<0.01) at day 15. The malondaldehyd (MDA) content of test group declined by 23.88% (P<0.01) at day 7 and 25.32% (P<0.01) at day 15.     

60～90日龄不同性别腾冲雪鸡血液生化指标差异研究

 采集60～90 日龄腾冲雪鸡公母各8 只的静脉血,测定了血清中的血糖(GLU)、甘油三脂(Trig)、胆固醇(CHOL)、白蛋白(ALB)、总蛋白(TP)、尿酸(UA)、肌酐(CREA)、尿素氮(UN)、谷丙转胺酶(ALT)、谷草转胺酶(AST)、钙(Ca) 和无机磷(P) 等12个指标的含量。结果发现: 除甘油三脂和无机磷(P<0.05) 及尿酸(P<0.01)性别间有显着和极显着差异外,其余9项指标公母间差异不显着(P>0.05). 因而在测定腾冲雪鸡生化指标时,除性别间差异显着的指标应分别测定才能对其是否正常作出结论外,其余指标可不考虑性别差异。合并差异不显着的指标数据后,得它们的正常值分别为: 血糖(20.41±4.82)mmol/L;胆固醇(3.64±0.41)mmol/L; 白蛋白(16.19±2.29) g/L; 总蛋白(39.88±6.41)g/L; 肌酐(136.77±10.53)μmol/L; 尿素氮(0.54±0.22)mmol/L; 谷丙转胺酶(7.31±2.87)IU/L; 谷草转胺酶(331.87±74.16) IU/L和血钙(97.13±8.69)mg/L。应考虑公母性别正常值差异的指标有:甘油三脂公鸡为(0.24±0.10)mmol/L,母鸡为(0.15±0.04)mmol/L;尿酸公鸡为(257.25±86.8)μmol/L,母鸡为(124.88±55.12)mol/L;无机磷公鸡为(63.19±4.51)mg/L,母鸡为(57.36±5.92)mg/L虽然无机磷公母性别间差异显著,但其比值间差异并小显著(P>0.05),公鸡为1.59±0.25,母鸡为1.68±0.27同时也探讨了血清日油三脂和尿酸性别间存在差异的机理。     

日本大耳白兔血常规及血气指标的正常值检测

[目的]使用新方法检测日本大耳白兔血常规及血气指标的正常值。[方法]选用健康3月龄日本大耳雄性白兔30只,用CD-1200全自动血液分析仪和i-TAT便携式血气分析仪分别系统测定白兔的静脉血WBC、RBC、HGB等15项血常规指标以及TCO2、PCO2、BEecf等10项血气指标。[结果]15项血常规指标检测结果分别为:WBC(7.20±1.49)109/L、RBC(6.20±0.41)1012/L、HGB(150.60±7.71)g/L、HCT(0.45±0.03)、MCV(71.80±4.05)fL、MCH(24.90±1.07)pg、MCHC(341.90±38.49)g/L、RDW(16.80±1.19)%、PLT(149.50±56.63)109/L、PCT(1.10±0.46)%、MPV(6.63±1.17)fL、PDW(15.40±1.33)%、LYM(4.70±1.04)109/L、MID(1.46±0.46)109/L、GRN(1.30±0.49)109/L;10项血气指标分别为:Na(143.250±2.193)mmol/L、K(3.210±0.371)mmol/L、TCO(2 17.130±2.330)mmHg、iCa(1.310±0.132)mmol/L、pH值7.280±0.035、PCO(2 31.71±3.88)mmHg、PO(2 56.92±6.75)mmHg、HCO3(-16.12±2.26)mmol/L、BEECF(-5.45±4.31)mmol/L、SO(2 82.40±5.62)%。[结论]该试验结果可作为教学参考,也可为相关研究提供参考。     

北京木本植物区系地理分析

根据对北京地区木本植物属的统计分析,结果可划分为14种土理分布类型,以温带分布为主,占区系成分属数的71.7％,其中以北温带分布类型占主导地位;与热带植物区系有一定联系,占区系成分的24.5％;与各大洲植物区系存在着广泛的联系。     

药用园林植物紫萼的化学成分

百合科玉簪属的紫萼 （Ｈｏｓｔａｖｅｎｔｒｉｃｏｓａ）常应用于园林造景、美化绿地,也是常用的室内观赏植物。作为一种药用植物,紫萼主要用于治疗吐血、崩漏、湿热带下、咽喉肿痛、胃痛、牙痛等。为全面了解和综合利用紫萼资源,笔者对其全草的化学成分进行了研究。运用 Ｄ１０１大孔树脂、ＳｅｐｈａｄｅｘＬＨ－２０和硅胶等柱层析及半制备 ＨＰＬＣ等分离手段,对其化学成分进行了分离纯化,根据波谱数据对其结构进行了鉴定。从紫萼７０％甲醇提取物中分离得到 ６个化合物,分别鉴定为 α－羟基香荚兰乙酮 （１）,７－羟基香豆素 （２）,反式对羟基桂皮酸 （３）,（２５Ｒ） －２α,３β－二羟基 －５α－螺甾 －９（１１） －烯 －１２－酮 （４）,（２５Ｒ） －２α,３β－二羟基 －５α－螺甾 －９（１１） －烯 －１２－酮 ３－Ｏ－ ｛Ｏ－β－Ｄ－吡喃葡萄糖基 － （１→２） －Ｏ－ ［β－Ｄ－吡喃木糖基 －（１→３）］ －Ｏ－β－Ｄ－吡喃葡萄糖基 － （１→４） －β－Ｄ－吡喃半乳糖苷｝ （５）和 （２５Ｒ） －３β－羟基 －５α－螺甾 －９（１１） －烯 －１２－酮 ３－Ｏ－ ｛Ｏ－β－Ｄ－吡喃葡萄糖基 － （１→２） －Ｏ－ ［β－Ｄ－吡喃木糖基 － （１→３）］ －Ｏ－β－Ｄ－吡喃葡萄糖基 － （１→４） －β－Ｄ－吡喃半乳糖苷｝ （６）。这些化合物均为首次从该种植物中分离得到。     

Effect of dioscorea opposite waste on growth performance,blood parameters,rumen fermentation and rumen bacterial community in weaned lambs

This study investigated the effects of dioscorea opposite waste(DOW) on the growth performance, blood parameters, rumen fermentation and rumen microbiota of weaned lambs. Sixty healthy weaned Small-Tailed Han lambs(male,(22.68±2.56) kg initially) were used as the experimental animals. Four levels of concentrate: 0(control, CON), 10%(DOW1), 15%(DOW2) and 20%(DOW3), were replaced with DOW in the basal diet as experimental treatments. The results showed that lambs fed the DOW2 diet had a higher(P&l...     

Effect of Wheat Middlings, Microbial Phytase, and Citric Acid on Phytate- Phosphorus, Calcium, and Protein Utilization of Broilers

A corn-soybean meal diet （CSB） （or Diet 1） containing 23% crude protein （CP） was used as the positive control, and another corn-soybean meal diet containing 21% CP and 15% wheat middlings （WM） （or Diet 2） was used as the basal diet, which was treated with four different treatments. Digestibility experiment was employed to discuss the collective effect of citric acid, and intrinsic and microbial phytase. By comparing and analyzing effects of them in the low-nutrient broiler diets, the results showed five treatments had similar effects on Tibia ash （%） （mg） （P〉0.05）. Under the supplementation of bacterial phytase or citric acid, the daily body weight gain （ADG）, gain：feed （G：F） ratio, and calcium （Ca） utilization were similar to that of standard-nutrient CSB diet （Diet 1） （P 〉 0.05）. And, fecal phosphorus （P） and CP utilization were lower than （P〈0.05） that of Diet 1. But P utilization was significantly higher than （P〈0.01） that of Diet 1. However, the ADG, G：F, and CP utilization produced by supplementation of intrinsic phytase were lower than those of Diet 1, but other aspects were similar to those produced by Diet 1 （P〉0.05）. In Diet 5, citric acid, intrinsic and bacterial phytase were added to the diet, which produced a 1.4% decrease on fecal P, a 7.2% increase on Ca utilization, which was significantly higher than （P〈0.01） those of the other four Diets, a 3.9% increase on G：F, which was similar to that of Diet 1, and a 2.3% increase on CP utilization, which was higher than （P〈0.05） that of the other three diets. In summary, the results of this study indicated that citric acid, intrinsic and bacterial phytase might have some additive or synergistic effects, and low-nutrient CSB diets with 15% wheat middlings, 750 U kg^-1 phytase, and 3% citric acid might substitute completely for standard CSB in broilers.     

Effects of Bupleurum extract on blood metabolism,antioxidant status and immune function in heat-stressed dairy cows

This experiment was conducted to evaluate the effects of Bupleurum extract(BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg–1 dry matter. Supplementation with BE decreased(P0.05) blood urea nitrogen(BUN) contents and increased blood total protein(TP) and albumin(ALB) levels compared with control cows, but it had no effects(P0.05) on blood glucose(GLU), nonesterified fatty acid(NEFA), total triglyceride(TG), low-density lipoprotein cholesterol(LDL-C), and high density lipoprotein cholesterol(HDL-C). Compared with control cows, cows fed BE had higher(P0.05) superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activity. However, supplementation with BE had no effect(P0.05) on total antioxidant capacity(T-AOC) or malondialdehyde(MDA) levels. The immunoglobulin(Ig) A and G contents increased(P0.05) in cows fed 0.25 or 0.5 g of BE kg–1. Interleukin(IL)-2 and IL-4 levels were higher(P0.05) in cows fed 0.5 and 1.0 g of BE kg–1, and IL-6 was significantly elevated(P0.05) in cows fed 0.5 g of BE kg–1. There were no treatment effects(P0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ ratio, or tumor necrosis factor-α(TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.     

中草药添加剂对生长肥育猪内分泌的影响研究

 选用20 kg左右的“杜长大”三元杂交猪120头,分成对照组、中药组、中药+西药组,每组4个重复。测定中草药添加剂对生长育肥猪血清中GH,IGF-I,T₃,T₄和cAMP含量的影响。结果表明:在20～30 kg,30～70 kg,70～110 kg阶段,中药组、中+西药组与对照组相比,血清GH的浓度分别提高了7.34%（P>0.05）和5.50%（P>0.05）,21.09%（P<0.05）和16.32%（P<0.05）,7.56%（P>0.05）和6.40%（P>0.05）;IGF-I水平分别升高了15.32%（P<0.05）和13.86%（P<0.05）,17.20%（P<0.05）和13.82%（P<0.05),6.56%（P>0.05）和4.16%（P>0.05）。在20～30 kg,30～70 kg和70～110 kg阶段,T₃含量分别增加了29.42%（P<0.05）和19.83%（P<0.05）,16.01%（P<0.05）和11.67%（P<0.05）,12.41%（P<0.05）和7.33%（P>0.05）;T₄含量分别增加了23.31%（P<0.05）和14.32%（P<0.05）,17.06%（P<0.05）和11.51%（P< 0.05）,6.81%（P>0.05）和2.03%（P>0.05）。在20～30 kg,30～70 kg和70～110 kg阶段,cAMP含量分别提高了15.88%（P<0.05）和13.97%（P<0.05）,19.88%（P<0.05）和13.14%（P<0.05）,18.33%（P<0.05）和9.86%（P<0.05）.研究结果提示,中草药添加剂对生长育肥猪的促生长、改变胴体组成作用,可能是通过影响猪内分泌系统机能而实现的。似是一种整体效应,一方面通过提高饲料养分消化率而促进生长。另一方面,是通过促进GH,IGF-I的合成和分泌,加强合成代谢;同时促进T₃,T₄和cAMP的合成和分泌,促进脂肪的动员,加速脂肪的氧化和分解、降低猪体脂的积累有关。     

寡聚糖、抗生素、益生素对仔猪生长性能和肠道菌群影响的研究

选择 12窝仔猪 ,随机分为 6组 ,每组 2窝 ,从 7日龄开始进行为期 8周的饲养试验 ,在4周末断奶 ,研究了基础日粮中添加寡聚糖、益生素、金霉素以及寡聚糖取代部分抗生素对仔猪生长性能和肠道菌群的影响。结果表明 ,与对照组相比 ,寡聚糖或其与金霉素配伍 ( 2 5mg及 12 .50mg· kg-1饲粮 )使用 ,使仔猪在 0～ 4周日增重分别提高 16.81% ( P>0 .0 5)、 15.91 ( P>0 .0 5)、 15.32 ( P>0 .0 5) ;腹泻率分别降低 7.83 ( P<0 .0 1)、 8.68 ( P<0 .0 1)、 8.35( P<0 .0 1)。在 5～ 8周 ,使仔猪日增重分别提高 9.55 ( P>0 .0 5)、 4 8.84 ( P<0 .0 5)、 38.74( P<0 .0 5) ;料肉比分别降低 0 .2 1( P<0 .0 5)、 0 .4 1( P<0 .0 1)、 0 .4 6( P<0 .0 1) ;腹泻率分别降低 12 .78 ( P<0 .0 1)、 2 2 .2 3 ( P<0 .0 1)、 2 0 .88 ( P<0 .0 1)。 0 .15益生素使 0～ 4周的仔猪腹泻率降低 4 .82 ( P<0 .0 5) ,在 5～ 8周使料肉比降低 0 .17( P<0 .0 5) ,腹泻率降低 4 .90( P<0 .0 5)。金霉素 ( 50 mg· kg-1饲粮 )组在 5～ 8周腹泻率降低 5.16% ( P<0 .0 5)。抗生素、益生素在 0～ 4及 5～ 8周对日增重的影响不大 ( P>0 .0 5)。 2 1日龄和 4 9日龄取新鲜粪样测定结果表明 :寡聚糖或寡聚糖与     

硝酸还原酶及其活力调节因子

硝酸还原酶因其在氮素同化过程中的作用,越来越引起人们的重视。许多生物工作者对此做了大量的工作。本文对硝酸还原酶的性质及其活力调节因子作了概括总结。硝酸还原酶是一种诱导酶,它的活力受内部和外部两方面因子的调节。内部因子包括:(1)机物种类和品种;(2)生育期;(3)植株部位;(4)苗龄和叶龄。外部因子包括:(1)硝态氮浓度;(2)光;(3)水分(4)温度;(5)外源激素;(6)金属离子;(7)pH值;(8)氨态氦和硝态氮;(9)某些代谢中间产物。对硝酸还原酶特性及其活力调节因子的了解,不但有助于培育优良的作物品种,而且可以通过改变外界条件。使作物的氮素代谢向人们所希望的方向发展。     

云南松林木的改良计划——二、林木改良方法

<正> 云南松的自然分布区比较大,目前仍有天然林存在,所以在进行林木改良时,可以完全利用国境内的天然林,而不使用人工林。从改良目标来看,我们需要达到的是基因型差异的改良,并能有计划地生产造林所需要的遗传优良的种子,在许多育种方法中,选择能做到人力、物力的最有效地利用,收到最大经济效果,时间短而又能生产出遗传改良的种子的方法。     

Effects of dietary yeast β-glucan on nutrient digestibility and serum profiles in pre-ruminant Holstein calves

This study aimed to investigate the effects of dietary supplementation of yeast β-glucan on the nutrient digestibility and serum profiles in pre-ruminant Holstein calves. Forty-two neonatal Holstein calves ((39.6±4.2) kg) were randomly allotted to six groups, and each was offered one of the following diets: a basal diet (control) or the basal diet supplemented with 25, 50, 75, 100 or 200 mg of yeast β-glucan kg–1 feed (dry matter basis). The basal diet consisted of a milk replacer and a starter feed. The trial lasted for 56 d. Two digestibility trials were conducted from d 14 to 20 and from d 42 to 48. Blood samples were collected on d 0, 14, 28 and 42 for serum profile analyses. On d 56, three calves from each group were slaughtered, and intestinal samples were collected to assess the villous height, crypt depth and mucosal thickness. Although feed intake was not affected by dietary treatment (P>0.05), the average daily gain (ADG) and gain-to-feed ratios were higher (P<0.05) for the calves fed 75 mg of yeast β-glucan kg–1 feed than those in the other groups. The supplementation of yeast β-glucan at 75 mg kg–1 feed increased the apparent digestibility of dry matter (DM), crude protein (CP), ether extract (EE), and phosphorus (P) (P<0.05) and the ratio of intestinal villous height to crypt depth (V/C) (P<0.05) when compared with the control group. No effects of yeast β-glucan on the serum concentrations of total protein (TP), albumin (ALB), serum urea nitrogen (SUN) and glucose (GLU) were observed (P>0.05). Compared with the control group, supplementation of yeast β-glucan decreased (P<0.05) the serum concentrations of triglycerides (TG) and total cholesterol (TC). The serum concentration of immunoglobulin G (IgG) and immunoglobulin M (IgM) increased quadratically (P<0.05), whereas the serum concentration of immunoglobulin A (IgA) was unaffected by dietary treatments (P>0.05). The supplementation of yeast β-glucan stimulated the enzymatic activity of alkaline phosphatase (ALP) (P<0.05) compared with the control group. The lysozyme (LYZ) concentration increased quadratically (P<0.05) with increasing yeast β-glucan levels. The results suggested that dietary supplementation of yeast β-glucan at 75 mg kg–1 feed improved nutrient digestibility, enhanced immunity by increasing the immunoglobulin concentration and stimulating ALP, and exerted no adverse effects on metabolism in pre-ruminant calves.