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The aim of this study was to compare the viability of 7- and 8-day-old equine embryos cooled and stored for 6 or 24 hours in two different transport systems. Embryos (n = 97) were recovered on day 7 or 8 and assigned to 10 groups (n = 10/group). Embryos within the same age group (D7 or D8) were evaluated immediately after collection (Group-0h) or after storage in an Equitainer at 5°C for 24 hours in 5 ml Emcare Holding Solution (EHS) (Group-E-24h) or 5 ml Ham's F10 (Group-H-24h) or in a refrigerator at 5°C in 500 ml Emcare Flushing Solution (EFS) for 6 hours (Group-B-6h) or 24 hours (Group-B-24h). After collection or storage, embryos were incubated in 1 μg/ml DAPI to determine the percentage of dead cells per embryo (DAPI positive, fluorescent cells). Subsequently, embryos were fixed in 4% paraformaldehyde and re-stained with DAPI to determine the total number of cells. The percentage of dead cells in group-0h and B-6h was similar and significantly lower than for embryos stored for 24 hours in groups B-24h, E-24h, and H-24h. The percentage of dead cells was similar for embryos stored in an Equitainer (groups E-24h and H-24h) and was significantly higher for embryos stored 24 hours in EFS (Group B-24h). Within each storage system (0h, B-6h, B-24h, E-24h, and H-24h) no significant difference in the percentage of dead cells was observed between 7- and 8-day-old embryos. Storage in 500 ml EFS at 5°C for 6 hours resulted in embryos of better quality than after the traditional 24-hour storage in an Equitainer, suggesting that this simplified system offers a good alternative for short-term storage and transport.  相似文献   
3.
The aim of this study was to evaluate the effects of tree coppicing on tree-crop competition in farmed parkland and in alley farming, both in semiarid Burkina Faso.Azadirachta indica A. Juss (neem) was studied in the parklands, while neem,Albizia lebbeck (L.) Benth. (albizia) andLeucaena leucocephala (Lam.) de Wit (leucaena) were investigated in the alley farming system. The crop was sorghum (Sorghum bicolor (L.) Moench) in both cases.Under non-coppiced neem trees in the parkland, the sorghum yield at 0–3 m distance from the tree (under the tree canopy) was 82% of open field yields at 6–9 m distance, but the difference was not significant (p=0.07). Close to trees (0–3 m distance) which had been coppiced before planting, the sorghum yield was 148% of open field yields. In alley farming, early coppicing was superior; sorghum yields were highest close to trees coppiced early and lowest close to trees coppiced late.
Résumé La présente étude se propose d'évaluer les effets de la taille sur la concurrence entre arbres et cultures dans les parcs arborés et dans les cultures en couloir, en climat semiaride (Burkina Faso). Les espèces étudiées ont été:Azadirachta indica A. Juss (neem) dans les parcs et neem,Albizia lebbeck (L.) Benth. (albizia) ainsi queLeucaena leucocephala (Lam.) de Wit (leucaena) dans les cultures en couloir. Dans les deux cas la plante cultivée concerné a été le sorgho blanc (Sorghum bicolor (L.) Moench).Sous les neems non taillés des parcs, le rendement du sorgho cultivé de 0 à 3 m de l'arbre (sous le bouppier de l'arbre) a atteint 82% du rendement obtenu en plein champ, soit à une distance de 6 à 9 m de l'arbre (différence non significative,p=0.07). Une taille effectuée en début de campagne a entraîné un accroissement du rendement de 148% pour les cultures situées de 0 à 3 m de l'arbre, par rapport aux rendements en plein champ.Dans les cultures en couloir, on a constaté qu'une taille precoce est préférable, c'est à dire que les rendements de sorgho ont été supérieurs dans les lignes proches des arbres taillés tôt que dans celles proches des arbres taillés tard.
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4.
Alternate two different modes of actions of green chemicals: spinosad & methoxyfenozide to combat the lesser date moth, Batrachedra amydraula and the Almond moth, Cadra cautella Walk on dates in Dakhla Oasis, New Valley, Egypt were done in 2010 and 201 I. Based on infestation of the early insect pest B. amydraula, the three-rotation program with basic 1st spray of spinosad 24 SC at 20 mL/100 L showed insignificant difference. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozide 24 SC at 15 mL/100 L with two-week interval showed zero infestation and 1.8% at the last sample of 2010 and 2011, respectively. Based on infestation of the late insect pest, Cadra spp., tlhe same previous trend of the three-rotation results. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozid 24 SC at 15 mL/100 L with three-week interval indicated less than 1% and 1% infestation during harvest for 2010 and 201 l, respectively. The last reflected important value when storing the fruit. Both products proved to be working under dry hot high temperatures.  相似文献   
5.
Land conversion in sub‐Saharan Africa has profound biophysical, ecological, political and social consequences for human well‐being and ecosystem services. Understanding the process of land cover changes and transitions is essential for good ecosystem management policy that would lead to improved agricultural production, human well‐being and ecosystems health. This study aimed to assess land cover transitions in a typical semi‐arid degraded agro‐ecosystems environment within the Pangani river basin in northern Tanzania. Three Landsat images spanning over 30 years were used to detect random and systematic patterns of land cover transition in a landscape dominated by crop and livestock farming. Results revealed that current land cover transition is driven by a systematic process of change dominated by the following: (i) transition from degraded land to sparse bushland (10·8%); (ii) conversion from sparse bushland to dense bushland in lowland areas (6·0%); (iii) conversion from bushland to forest (4·8%); and (iv) conversion from dense bushland to cropland in the highlands (4·5%). Agricultural lands under water harvesting technology adoption show a high degree of persistence (60–80%) between time slices. This suggests that there is a trend in land‐use change towards vegetation improvement in the catchment with a continuous increase in the adoption of water harvesting technologies for crop and livestock farming. This can be interpreted as a sign of agricultural intensification and vegetation regrowth in the catchment. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
6.
Experiments, theory, and simulation were used to study glass formation in a simple model system composed of hard spheres with short-range attraction ("sticky hard spheres"). The experiments, using well-characterized colloids, revealed a reentrant glass transition line. Mode-coupling theory calculations and molecular dynamics simulations suggest that the reentrance is due to the existence of two qualitatively different glassy states: one dominated by repulsion (with structural arrest due to caging) and the other by attraction (with structural arrest due to bonding). This picture is consistent with a study of the particle dynamics in the colloid using dynamic light scattering.  相似文献   
7.
Fusidic acid known to has antibacterial, antifungal, and antimalarial activities. Fusidic acid blocks translation elongation factor G gene in Plasmodium falciparum. In the present study, the inhibitory effects of fusidic acid on the in vitro growth of bovine and equine Babesia parasites were evaluated. The inhibitory effect of fusidic acid on the in vivo growth of Babesia microti was also assessed. The in vitro growth of four Babesia species that were tested was significantly inhibited (P < 0.05) by micromolar concentrations of fusidic acid (IC50 values = 144.8, 17.3, 33.3, and 56.25 μM for Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi, respectively). Combinations of fusidic acid with diminazene aceturate synergistically potentiated its inhibitory effects in vitro on B. bovis and B. caballi. In B. microti-infected mice, fusidic acid caused significant (P < 0.05) inhibition of the growth of B. microti at the dose of 500 mg/kg BW relative to control group. These results indicate that fusidic acid might be incorporated in treatment of babesiosis.  相似文献   
8.
Antibacterial agents such as zinc bacitracin (ZB) and virginiamycin (VG) are used as growth promoting agents (GP) in broiler chicken production. The objective of this study was to evaluate the effect of the use of ZB and VG on the emergence of antibacterial resistance in a commercial broiler chicken farm. Three trials were conducted using 3 different diets: one without antibacterial agents, one containing VG, and one with ZB. Escherichia coli and Enterococcus spp. strains were isolated and tested for their susceptibility to various antibacterial agents. The occurrence of the resistance genes vatD, ermB, and bcrR in Enterococcus spp. isolates was determined by polymerase chain reaction (PCR). Comparative quantification of vatD and bcrR genes in total deoxyribonucleic acid (DNA) extracts from litter was done by SYBR Green Real-Time PCR (QPCR). Escherichia coli and Enterococcus spp. isolates from diet groups had different levels of resistance to various antibacterial agents over time. These GPs did not select for specific antibacterial agent resistance (AAR) in Enterococcus spp. The use of GPs seemed to lower the percentage of E. coli isolates resistant to some antibacterial agents. The presence of the bcrR gene could not explain all resistant phenotypes to ZB. Genes other than vatD and ermB might be involved in the resistance to VG in Enterococcus spp. Use of GPs was not associated with presence of the bcrR gene in DNA extracts from litter, but use of VG was associated with vatD presence.  相似文献   
9.
Eighteen multiparous Zebu cows in their third lactation and their calves were randomly allocated to three suckling periods, up to 3, 4 or 5 months of age of the calf. The cows were individually fed natural hay, cottonseed cake and molasses. At 2 months of age, all calves were separated from their mothers, and were offered cottonseed cake mixed with molasses and Mucuna hay individually. The calves stimulated milk ejection by suckling 30 seconds and suckled the residual milk for 45 minutes after milking. The dry matter intake of cows (3.68, 3.29 and 3.31% of body weight) and calves (2.88, 2.80 and 2.55% of body weight) for suckling up 3, 4 and 5 months of age, respectively, was not significantly affected by treatment and neither was the growth rate of the calves (178, 157 and 149 g/d for 3, 4 or 5 months suckling period, respectively). Cows suckling their calves up to 5 months had significantly higher milk yield and higher amount of saleable milk (1.97, 2.93 and 3.69 kg/cow/d for 3, 4 and 5 months suckling period, respectively). The fat content of the milk decreased with increasing length of the suckling period while the protein content was not affected. In conclusion, a suckling period of 5 months resulted in higher total milk production and higher amount of saleable milk but did not seem to have any effect on calf growth when the calves were supplemented.  相似文献   
10.
本研究旨在检测水牛二酰甘油酰基转移酶2(diacylglycerolacylt-ransferase,DGAT2)基因的单核苷酸多态性(SNP),探究摩拉水牛多态性位点的群体遗传特征。以广西水牛研究所的57头摩拉水牛为材料,PCR扩增DGAT2基因的部分序列(外显子2及内含子2、3),通过常规测序法检测其SNP,并运用遗传多样性分析软件(POPGENE)和SPSS软件对群体的多态性位点进行基因频率、基因型频率、多态信息含量(PIC)、有效等位基因数(Ne)及遗传杂合度(He)的检测。结果表明,在摩拉水牛DGAT2基因外显子2和内含子2、3上共发现了9个SNPs位点(IVS2.54 G > A、IVS2.158 A > G、EVS2.191 A > G、EVS2.228 A > G、IVS3.311 C > T、IVS3.444 A > G、IVS3.451 A > C、IVS3.466 C > T、IVS3.521 C > T),其中EVS2.191 A > G位点的突变导致氨基酸由异亮氨酸突变为缬氨酸,突变位点间存在一定程度的连锁遗传但接近连锁平衡状态。从基因频率上看,IVS2.158 A > G、EVS2.191 A > G、IVS3.311 C > T、IVS3.451 A > C、IVS3.466 C > T和IVS3.521 C > T 6个SNPs位点的两个等位基因频率有较大差异,提示等位基因频率较大的基因个体可能更适合生存。9个SNPs位点在摩拉水牛品种上多处于高度多态,杂合度在0.1744~0.4975之间,说明摩拉水牛群体中DGAT2基因遗传多态性丰富,具有较大的育种价值和性状改良潜力。  相似文献   
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