蒲草垫料对小鼠繁殖及仔鼠生长发育的影响

探讨蒲草垫料对小鼠繁殖及仔鼠生长发育的影响。小鼠连续产仔３胎,随着胎次的增加,母鼠分娩间隔及产后母体重略有增加,但各胎次实验组与对照组间无显著差异（Ｐ＞０．０５）。Ｆ１ａ、Ｆ１ｂ、Ｆ１ｃ平均产仔数、存活仔数、仔鼠初重及１－３周龄仔鼠重、仔鼠存活数实验组与对照组相近（Ｐ＞０．０５）。离乳仔鼠雄性比为１．０３－１．０８。Ｑ系数随着胎次的增加略有下降,在３８．１－２０．０之间,但实验组与对照组差异不大。Ｆ１ｂ仔鼠前１０周周增重实验组与对照组无显著差异（Ｐ＞０．０５）。Ｆ１ｂ小鼠交配繁殖２胎,Ｆ２ａ,Ｆ２ｂ各项指标实验组与对照组无显著差异（Ｐ＞０．０５）。Ｆ２ａ仔鼠前１０周周增重实验组亦与对照组相近（Ｐ＞０．０５）。说明蒲草垫料既不影响小鼠的繁殖机能,也不影响仔鼠的生长发育,是一种优质的新型实验动物垫料。     

长白猪、北京黑猪及东北民猪脂肪酸及氨基酸组成

本文测定了长白猪、北京黑猪及东北民猪背最长肌脂肪酸及氨基酸的组成。结果表明：１，长白猪总饱和脂肪酸含量显著高于北京黑猪（Ｐ＜０．０５）及民猪（Ｐ＜０．０５），北京黑猪显著高于民猪（Ｐ＜０．０５）；民猪的总不论和脂肪酸含量显著高于长白猪（Ｐ＜０．０５），与北京黑猪差异不显著（Ｐ＞０．０５）；不同性别猪各脂肪酸含量差异不显著，２，３个猪种中１５种氨基酸及衍生物含量有显著差异（Ｐ＜０．０５）。民猪和北京黑猪赖氨酸的含量显著高于长白猪，北京黑猪苏氨酸含量低于长白猪（Ｐ＜０．０５）。不同性别个体间游离氨基酸组成除丝氨酸、缬氨酸、苯丙氨酸外，没有显著差异（Ｐ＞０．０５）。     

獭兔日粮中添加酶制剂的效果

以９０只生长獭兔为试验动物,研究日粮中添加酸性蛋白酶（Ｐ）和纤维素酶（Ｃ）对日增重、屠宰性能、产品品质的影响,并对经济效益进行分析。结果表明：日粮中添加０．７５％和１．５％的纤维素酶后日增重分别比对照组提高１６．８８％（Ｐ＜０．０５）和２０．５５％（Ｐ＜０．０１）;添加０．７５％Ｐ＋０．７５％Ｃ和０．７５％Ｐ＋１．５％Ｃ后日增重分别比对照组提高１７．６２％（Ｐ＜０．０５）和２２．８２％（Ｐ＜０．０１）;各试验组间无显著差异（Ｐ＞０．０５）;单独添加纤维素酶和同时添加两种酶制剂,对屠宰性能、产品质量无明显影响（Ｐ０．０５）;经济效益以添加０．７５％Ｐ＋１．５％Ｃ为最好,每千克增重较对照组降低成本１．６８元。     

饲料中脱毒菜籽饼水平对生长猪的影响

在生长猪饲粮中加入占总量的０％、１０％、１５％、１８％和２０％的脱毒菜籽饼，并使供试五种饲粮的营养水平基本相同。经６０天试验，平均日增重，１、２、３组与５组差异极显著（Ｐ＜０．０１），４组与５组差异显著（Ｐ＜０．０５），１～４组间差异不显著（Ｐ＞０．０５）；饲料报酬，１组与５组差异显著（Ｐ＜０．０５），其他各组间差异不显著（Ｐ＞０．０５）；每千克增重需饲料成本，以４组较低，５组较高。     

葛叶粉饲喂农养肉猪试验

在山区农家饲养肉猪日粮中添加５、１０、１５、２０％的葛叶粉。结果表明：添加５％葛叶粉的不同处理的试验１、２、３组日增重分别为４８３、５１２、４９６克，与农养常规对照组４９８克之间差异均不显著（Ｐ＞０．０５）。试验２组同１０％葛叶粉的试验４组４５７克间差异明显（Ｐ＜０．０５），与１５％、２０％葛叶粉的对应试验５组４０２克、试验６组３３９克间差异均极显著（Ｐ＜０．０１）。试验４组同对照组比虽日增重低８．２％，但差异不显著（Ｐ＞０．０５）。试验５、６组与对照组、试验１、３组间差异均极显著（Ｐ＜０．０１），且该两组彼此存在明显差别（Ｐ＜０．０５）。在饲料报酬、日采食量上，对照组与试验１、２、３组间均无显著差别（Ｐ＞０．０５）。试验４组在饲料报酬上与对照组、试验２、３组间分别有明显差异（Ｐ＜０．０１），试验５组与对照组、试验１、２、３、４、６组间皆存有显著差别（Ｐ＜０．０５），试验６组同对照组、试验１、２、３组间都是差异极明显（Ｐ＜０．０１）。饲料适口性以试验２组最好，其次为对照组、试验３组，试验５、６组最差。     

家牦牛,半血野牦牛年产毛量的比较

对１７６头各龄家牦牛和半血野牦牛的年产毛量进行了测定。测定结果：家牦牛１岁０．９８±０．２９ｋｇ／头，２岁１．１２±０．２２ｋｇ／头，３一５岁１．１８±０．３８ｋｇ／头，６岁以上０．８８±０．２７ｋｇ／头；半血野牦牛相应为０．９０±０．２０ｋｇ／头，１．０５±０．２７ｋｇ／头，０．６８±０．２８ｋｇ／头，０．９０±０．３８ｋｇ／头；３一５岁家牦牛组的年产毛量极显著高于６岁以上年龄组（Ｐ＜０．０１），同１岁、２岁年龄组的年产毛量差异不显著（Ｐ＞０．０５），２岁与６岁以上年龄组之间呈显著性差异（Ｐ＜０．０５）；半血野牦牛各年龄组的年产毛量差异不显著（Ｐ＞０．０５）；１岁家牦牛公母间，２岁半血野牦牛公母间，年产毛量差异极显著（Ｐ＜０．０１）。     

日粮补锌对荷斯坦种公牛精液品质的影响

试验选用６头荷斯坦种公牛,研究了锌对性反射时间、精液品质、精清酶活性及血、精清锌与睾酮浓度的影响。结果表明：添加锌能显著提高精液的鲜精活力、精子密度、冻后精子活力和顶体完整率（Ｐ＜０．０５）;性反射时间明显减少（Ｐ＜０．０１）;鲜精精清中ＡＫＰ和ＧＯＴ活性组间差异不显著,但ＬＤＨ活性２组显著高于１组（Ｐ＜０．０５）;冻后精清ＡＫＰ、ＧＯＴ和ＬＤＨ活性组间差异不显著（Ｐ＞０．０５）。添加锌能显著提高血清锌浓度（Ｐ＜０．０１）,但对精清锌含量的影响不明显（Ｐ＞０．０５）。血清睾酮浓度１组显著高于２组（Ｐ＜０．０５）,而精清睾酮浓度组间差异不显著（Ｐ＞０．０５）。     

稀土饲料添加剂饲养绵羊的剂量选择试验

选用半舍饲的周岁龄青海细毛羊５６只，分为三组，试验１、２组各２０只，对照组１６只。在同等饲养管理条件下，试验１、２组每只羊每日分别添加０．２ｇ和０．１ｇＲＣＦ－３稀土添加剂，进行６０ｄ饲养试验。结果：试验１、２组绵羊平均日增重分别比对照组提高３０．６％（Ｐ＜０．０１）和１２．６％（Ｐ＞０．０５）；平均羊毛长度分别比对照组提高２２．１％（Ｐ＜０．０１）和５．５％（Ｐ＞０．０５）；经济效益分别比对照组提高２５．２％（Ｐ＜０．０１）和８．７％（Ｐ＞０．０５％）。试验１组平均日增重，羊毛长度和经济效益分别比２组提高１５．９％（Ｐ＜０．０５）、１５．７％（Ｐ＜０．０５）和１５．２％（Ｐ＜０．０５）以试验１组的效果为佳。     

不同形态锌对断奶仔猪补锌效果的研究

采用同窝分组法将１０头“长二”断奶仔猪按性别和体重均分为两组,分别喂含富锌真菌（有机组）和氧化锌（无机组）添加剂的日粮,补锌量均为５７．４ｍｇ／ｋｇ日粮,经１４天试验,结果表明,在日增重和料重比,有机组分别为４５０ｇ和１．５３,比无机组的４２０ｇ和１．７０分别提高７．１４％和１０．００％,但差异不显著（Ｐ＞０．０５）;有机组的血清ＡＫＰ含量为１６０．５６ｍｉｕ／ｍｌ,高于无机组的１１７．１４ｍｉｕ／ｍｌ,差异显著（Ｐ＜０．０５）;有机组和无机组的血清ＩｇＧ含量分别为２．８２ｍｇ／１００ｍｌ和２．６６ｍｇ／ｍｌ,差异不显著（Ｐ＞０．０５）;肾、脾、肝、跖骨、血清、血细胞等组织器官中锌含量差异不显著（Ｐ＞０．０５）。     

饲粮中脱毒菜籽饼水平对生长猪的影响

将长白×荣昌杂交一代仔猪（２０ｋｇ左右）７５头随机分成５组，每组１５头。在饲粮中加入占总量的０％、１０％、１５％、１８％和２０％的脱毒菜籽饼，并使供试５种饲粮的营养水平基本相同。经６０天试验，平均日增重，第１、２、３组与第５组差异极显著（Ｐ＜０．０１），第４组与第５组差异显著（Ｐ＜０．０５），第１－４组间差异不显著（Ｐ＞０．０５）。饲料报酬，第１组与第５组差异显著（Ｐ＜０．０５），其他各组间差异不显著（Ｐ＞０．０５）；每千克增重需饲料成本，以第４组最低，第５组最高。     

Open-pulled straw (OPS) vitrification of in vitro fertilised mouse embryos at various stages

The present study was designed to investigate the cryotolerance of in vitro fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3-100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8-89.5%) and hatched blastocyst rates (61.1-69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate in vivo (50.6%, 88/174), compared with that from other stages (9.3-30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.     

Vitrification of biopsied mouse embryos

Solid surface vitrification (SSV) was compared with in-straw vitrification for cryopreservation of biopsied mouse embryos. Eight-cell stage embryos were zona drilled and one blastomere was removed. Developed morulae or blastocysts were vitrified in microdrop (35% EG + 5% PVP + 0.4 M trehalose) or in straw (7.0 M EG + 0.5 M sucrose). Following recovery, embryos were cultivated in vitro or transferred into recipients. Cryopreservation had an effect not only on the survival of biopsied embryos but also on their subsequent development in vitro. Cryosurvival of biopsied morulae vitrified in straw was significantly inferior to SSV. The post-warm development of biopsied and non-biopsied morulae was delayed on Day 3.5 and 4.5 in both vitrification groups. A delay in development was observed on Day 5.5 among vitrified non-biopsied blastocysts. The percentage of pups born from biopsied morulae or blastocysts following cryopreservation did not differ from that of the control. No significant differences could be detected between methods within and between embryonic stages in terms of birth rate. The birth rate of biopsied embryos vitrified in straw was significantly lower compared to the non-biopsied embryos. The novel cryopreservation protocol of SSV proved to be effective for cryopreservation of morula- and blastocyst-stage biopsied embryos.     

生长因子EGF、bFGF对猪孤雌胚体外发育的影响

在胚胎发育的不同阶段，分别在培养基中添加EGF和bFGF，研究EGF和bFGF对猪孤雌胚体外发育的作用。结果表明：在1细胞阶段添加EGF或bFGF，添加EGF能够显著提高孤雌胚的卵裂率（P〈0．05）；2～4细胞阶段添加EGF和bFGF，添加EGF组和添加bFGF组的囊胚率都显著高于对照组（P〈0．05），而添加bFGF组的囊胚率和囊胚细胞数都略高于对照组和添加EGF组。说明EGF和bFGF有利于猪孤雌胚的体外发育，而且，bF-GF能够通过提高囊胚细胞数而提高猪孤雌胚的质量。     

Investigation into developmental potential and nuclear/mitochondrial function in early wood and plains bison hybrid embryos

Studies to date have shown that bison embryo development in vitro is compromised with few embryos developing to the blastocyst stage. The aim of this study was to use bison-cattle hybrid embryos, an interspecific cross that is known to result in live offspring in vivo, as a model for assessing species-specific differences in embryo development in vitro. Cattle oocytes fertilized with cattle, plains bison and wood bison sperm were assessed for various developmental parameters associated with embryo quality, including cell number, apoptosis and ATP content. Decreased development to the blastocyst stage was observed in hybrid wood bison embryos compared with the other treatment groups. Although both wood bison and plains bison hybrid blastocysts had significantly lower cell numbers than cattle blastocysts, only wood bison hybrid blastocysts had a greater incidence of apoptosis than cattle blastocysts. Among the treatment groups, ATP levels and expression profiles of NRF1, TFAM, MT-CYB, BAX and BCL2 were not significantly different in both 8- to 16-cell stage and blastocyst stage embryos. These data provide evidence of decreased developmental competence in the wood bison hybrid embryos, owing to inadequate culture conditions that have increased apoptotic events.     

The developmental ability of vitrified oocytes from different mouse strains assessed by parthenogenetic activation and intracytoplasmic sperm injection

Assessment of the developmental ability of oocytes following freezing and thawing is an important step for optimizing oocyte cryopreservation techniques. However, the in vitro fertilization of frozen-thawed mouse oocytes is often inefficient because of incomplete capacitation of spermatozoa in the absence of surrounding cumulus cells. This study was undertaken to determine whether the oocyte cryopreservation efficiency of different strains of mice could be assessed from the development of oocytes following parthenogenetic activation and intracytoplasmic sperm injection (ICSI). Oocytes were collected from hybrid (C57BL/6 x DBA/2) F1 or inbred (C57BL/6J, C3H/HeN, DBA/2J and BALB/cA) strains and were vitrified in a solution containing ethylene glycol, DMSO, Ficoll and sucrose. In the first series of experiments, oocytes were activated parthenogenetically by Sr(2+) treatment after warming. The oocytes from the inbred strains, but not those of the F1 hybrid, were diploidized by cytochalasin treatment to obtain a sufficient number of blastocysts. In all strains tested, parthenogenetic embryos derived from vitrified oocytes developed into blastocysts at rates between 23 and 68%. In the second series of experiments, vitrified oocytes from each strain were injected with homologous spermatozoa after warming. Normal offspring were obtained from all strains at rates between 5 and 26% per embryo transferred. Thus, the feasibility of oocyte cryopreservation protocols can be assessed easily by in vitro development of parthenogenetic embryos or by in vivo development of ICSI embryos. Moreover, the oocytes of these four major inbred strains of mice can be cryopreserved safely for production of offspring.     

Effect of culture medium and prostaglandin I(2) (PGI(2)) analogue on in vitro development of parthenogenetically activated cat oocytes

A method of reliably producing developmentally competent cat embryos in vitro is a prerequisite for study of the physiology of early development and application of assisted reproductive techniques. Oocytes were collected and then cultured in TCM-199 + 10% FBS for 4 h. The matured oocytes were activated with a 20 microsec electric pulse at 1.2 kV/mm. The activated oocytes were incubated in 2 mM of 6-dimethylaminopurine (6-DMAP) for 4 h and were then divided randomly among the treatment groups. In experiment 1, we compared the effects of three culture systems (TCM-199, CR1-aa and Tyrode's) on the in vitro development of parthenogenetically activated cat oocytes. In experiment 2, we investigated the effect of addition of Iloprost (a stable prostaglandin I(2) analogue) to Tyrode's medium on in vitro development of parthenogenetically activated oocytes. As a control, we recovered in vivo produced blastocysts and determined their average cell number. In experiment 1, the cleavage frequency of the oocytes cultured in TCM199, CR1-aa and Tyrode's media were similar (74, 72 and 83%, respectively). However, the incidence of in vitro development to the blastocyst stage was significantly higher in Tyrode's medium (20.4%) than in TCM-199 (2.4%) or CR1-aa (11.1%). Likewise, the average cell number of in vitro activated blastocysts was higher in Tyrode's than in CR1-aa or TCM-199 (106.5 +/- 45.2 vs. 68.3 +/- 25.4 and 35.0 +/- 7.7, respectively; P<0.05). In experiment 2, the percentage of parthenogenetically activated oocytes that underwent in vitro blastocyst development was significantly improved by addition of Iloprost to the culture medium (33.6 vs. 19.1%; P<0.05). The average cell number of in vivo blastocysts (909.0 +/- 226.4) was significantly higher than those of in vitro blastocysts cultured in Tyrode's medium supplemented with or without Iloprost (103.2 +/- 31.3 and 112.2 +/- 39.3, respectively; P<0.05). This result indicated that the current culture method for cat pathogenetically activated oocytes requires further improvement.     

In vitro development and postvitrification survival of cloned feline embryos derived from preadipocytes

The aim of the present study was to optimize the conditions for in vitro development and postvitrification survival of somatic cell cloned feline embryos. To determine the effects of cell cycle synchronization of the nuclear donor cells, we cultured preadipocytes under serum starvation or conventional conditions. After two days in serum starvation culture, the proportion of synchronized donor cells at the G0/G1 phase was 91.6%. This was significantly higher than the proportion of non-synchronized cells in the proliferative phase (72.6%, P<0.05). The in vitro development of somatic cell nuclear transfer (SCNT) embryos reconstructed using donor cells treated under serum starvation conditions (normal cleavage rate of 65.7%, 46/70, and blastocyst formation rate of 20.0%, 14/70) was comparable to that of the serum supplemented group (52.5%, 31/59, and 20.3%, 12/59). Use of in vitro or in vivo matured oocytes as recipient cytoplasts equally supported development of the SCNT embryos to the blastocyst stage (11.9%, 5/42, vs. 9.5%, 2/21). SCNT-derived blastocysts were vitrified using the original minimum volume cooling (MVC) or the modified (stepwise) MVC method. Although none (n=10) of the SCNT blastocysts survived following vitrification by the original MVC method, the stepwise MVC method resulted in 100% survival after rewarming (n=11). In conclusion, we demonstrated that feline somatic cell cloned embryos with a high developmental ability can be produced irrespective of cell cycle synchronization of donor cells using either in vivo or in vitro matured oocytes. Furthermore, by utilizing a stepwise vitrification method, we showed that it is possible to cryopreserve cloned feline blastocysts.     

In vitro development of mouse pronuclear embryos to blastocysts in sequential media with and without co-culture of autologous cumulus cells

The objective of this study was to use mouse embryos as a model system to investigate the effect of co-culture of cumulus cells in Sydney IVF sequential media (Cook) on embryo development, based on the hypothesis that feeder cells in co-culture with a sequential medium could work synergistically to further improve in vitro culture conditions for mammalian preimplantation embryos. The culture systems described here were evaluated by the ability to consistently produce high blastocyst formation rates and high cell number per blastocyst. The role of embryo-to-cell contact was assessed by using Transwell inserts with transparent microporous membranes. Pronuclear embryos of ICR mice were cultured to blastocysts in Cook sequential media, with and without mouse primary cultures of cumulus cells, and with or without inserts. Blastocyst formation rates and cell numbers of in vitro developing embryos in the different culture systems were compared to each other, and to in vivo derived blastocysts. Blastocyst formation rates for Cook medium only was 27.8% (without inserts) and 32.9% (with inserts), whereas Cook-Cumulus cells in identical culture systems was significantly higher at 45.8% (without inserts, P<0.05) and 55.6% (with inserts, P<0.05). When the embryos are suspended above the bottom of the well, for Cook medium significantly lower blastocyst formation rates were observed at 4.2% compared to Cook-Cumulus cells at 17.5% (P<0.05). Mean cell numbers of blastocysts obtained in all co-culture systems were significantly higher (P<0.05) compared to those developing in culture medium only. Although the putative mechanism is as yet unexplained, the improved blastocyst formation rates and cell numbers in co-culture when there is direct contact between the embryo and the cell monolayer suggest that the close proximity between the feeder cells and embryos is in part responsible for these effects.     

小鼠胚胎的玻璃化冷冻研究

用不同冷冻载体(玻璃管、塑料管和0.25 mL细管)及不同冷冻方法(程序化冷冻和玻璃化冷冻)对小鼠3.5 d~4 d桑椹胚和囊胚进行冷冻保存,并与不做任何冷冻保存处理直接培养进行对比。结果表明,使用玻璃管、塑料管和0.25 mL细管作为胚胎的承载材料进行玻璃化冷冻,效果差异不显著;采用程序化冷冻与OPS玻璃化冷冻法,对小鼠胚胎进行冷冻保存可以取得较好的结果。从而得出,用不同材质的冷冻载体进行玻璃化冷冻,可以获得与程序化冷冻相同的良好效果。     

Relationship between group II caspase activity of bovine preimplantation embryos and capacity for hatching

The occurrence of apoptosis in a fraction of blastomeres in the preimplantation embryo is well known but the consequences of this phenomenon for the developmental potential of the blastocyst has not been well established. Here we demonstrate that blastocysts with low amounts of activated group II caspase activity have increased potential for development to the hatched blastocyst stage. Bovine blastocysts produced in vitro were assayed using a non-invasive fluoregenic substrate that is cleaved by activated group II caspases (i.e., caspase-2, -3 and -7). Subsequently, blastocysts were cultured until Day 10 post-insemination and the proportion undergoing hatching determined. In Experiment 1, blastocysts were cultured without respect to stage of development (expanded or non-expanded); blastocysts classified as having low caspase activity had higher hatching rates than blastocysts with medium or high caspase activity. In Experiment 2, embryos were categorized as nonexpanded or expanded blastocysts. Caspase activity was lower and hatching rate higher for expanded blastocysts than for nonexpanded blastocysts. For nonexpanded blastocysts, embryos classified as having low caspase activity had higher hatching rates as compared to embryos with medium or high caspase activity. In conclusion, the capacity for blastocysts to undergo further development is related to degree of group II caspase activity. Conditions that enhance the incidence of apoptosis in blastocysts may reduce developmental competence. In addition, determination of caspase activity may be useful for selection of embryos for transfer into recipients.