Stress and Parturition in the Pig*     

AB Lawrence  KA McLean  S Jarvis  CL Gilbert  JC Petherick 《Reproduction in domestic animals》1997,32(5):231-236

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The Effect of Season on Spermatozoa Motility,Plasma Membrane and Acrosome Integrity in Fresh and Frozen–Thawed Semen from Xinong Saanen Bucks          下载免费PDF全文

W Wang  J Luo  S Sun  L Xi  Q Gao  AB Haile  H Shi  W Zhang  H Shi 《Reproduction in domestic animals》2015,50(1):23-28

The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.  相似文献   

Fire intensity effects on seed germination of native and invasive Eastern deciduous forest understory plants     

Sarah M. Emery  Joy UwimbabaziS. Luke Flory 《Forest Ecology and Management》2011,261(8):1401-1408

Low-intensity fires were important for maintaining the structure of Eastern deciduous forests (EDFs) for thousands of years before European settlement of North America, though fire suppression became a standard management practice in the 1930s. More recently, prescribed fires have been reintroduced to EDF habitats to aid in the restoration of native plant diversity, but invasions of non-native species such as Microstegium vimineum (Japanese stiltgrass) may increase prescribed fire intensity and suppress colonization of native species. As fire becomes a more common management tool in these habitats, it is vital to predict fire temperature effects on the native and non-native species present in the system. In this study, we found that prescribed fires in areas invaded by Microstegium can be 250-300 °C hotter than fires in nearby native-dominated areas. We then compared the effects of fire on germination rates of six native and three non-native EDF understory species representing the range of functional groups common in this habitat. We manipulated both fire intensity (temperature and length of exposure) and type of fire effect (direct flame and indirect furnace heat) to generate germination curves and make predictions about potential prescribed fire effects on populations of these species. There were very different responses among species to both direct (flame) and indirect (furnace) heating. Germination of three native species, Lycopus americana (American water horehound), Verbesina alternifolia (wingstem), and Vernonia gigantea (tall ironweed), showed signs of being stimulated by heating at low temperatures, while germination of all non-native species (M. vimineum, Elaeagnus umbellata, and Schedonorus phoenix) were inhibited at these lower intensities. High fire intensity (temperatures above 300 °C) effectively killed most species, though one native species, Senna hebacarpa (American senna) and one non-native species, E. umbellata (autumn olive), were capable of tolerating 500 °C temperatures. We conclude that high-intensity prescribed fires in habitats invaded by Microstegium may reduce seed germination of some non-native species, but may also inhibit the regeneration of native understory species.  相似文献   

Assessment of smooth muscle function in Sesbania drummondii toxicosis in Gallus domesticus   总被引：1，自引：0，他引：1  

C S Venugopalan  W Flory  T A Tucker  C D Hebert  G M Strain 《American journal of veterinary research》1984,45(4):764-768

An in vitro assessment based on tissue responsiveness to 2 agonists-histamine and carbachol-was made on smooth muscle activity in chickens experimentally poisoned with sesbania. Crude extracts of Sesbania drummondii were prepared and 2 dosage levels, 0.25% and 0.5% of body weight, were used. The birds were dosed orally with the extract for 3 consecutive days, and on the 4th day segments of ileum and lung were collected from each bird. The isometric contractions of each tissue, produced by the addition of histamine or carbachol in graded concentrations, were recorded. The cumulative concentration-effect curves for the tissues to the agonists were constructed and compared with respective control curves. The results indicated the responsiveness of the tissues in the treated groups was significantly decreased, compared with that of tissues in the controls. Responses of both intestinal and parenchymal strips in the chickens given the higher dosage (0.5%) were decreased significantly, whereas in those given the smaller dosage (0.25%), only parenchyma had a significant response. This indicates that the activity of smooth muscles in general was depressed by sesbania. The effect was more evident in the lung than in the intestine. Therefore, an active principle in the extract which affects smooth muscle, rather than causing direct irritation, may exist. This assessment of smooth muscle activity is sensitive and was effective in detecting changes in tissues from sesbania-treated birds which had not shown any clinical signs. The results also support the possibility that smooth muscle involvement could be a primary cause of toxicity in sesbania poisoning.  相似文献   

RADIOGRAPHIC CHANGES IN TESTES OF BULLS INFECTED WITH BESNOITIOSIS   总被引：1，自引：0，他引：1  

Uri  Bargai  VMD AB  DVSc  Theodor  Nobel  DVM†  Shmuel  Pearl  DVM† 《Veterinary radiology & ultrasound》1984,25(5):235-239

Ten beef bulls infected with Besnoitiosis were examined radiographically and pathologically. Eight of these were slaughtered soon after diagnosis; two were left for a six-month observation period. The radiographic findings were focal and branching-tree calcification of the testes. Histopathologic examination proved these calcifications to be necrotic sections of the seminiferous tubules. Radiography of the testes as a means of evaluating the fertility status of the infected bull is recommended.  相似文献   

The Relationship Between Post‐Thaw Sperm DNA Integrity and Non‐Return Rate Among Norwegian Cross‐Bred Rams     

AB Nordstoga  A Krogens  A Ndtvedt  W Farstad  K Waterhouse 《Reproduction in domestic animals》2013,48(2):207-212

With the aim of investigating the relationship between sperm DNA integrity and non‐return rate (NRR) among Norwegian cross‐bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters % DFI, % HDS, MEAN DFI and SD DFI are all different measures of DNA denaturation and maturation. Field fertility, reported as NRR 25 days after insemination was based on all inseminations from a large‐scale breeding programme and supplied by the Norwegian Association of Sheep and Goat Farmers. From each ram, four straws from four different weeks of the breeding season were analysed, and the associations between 25‐day NRR and the mean of the four SCSA parameters were tested using a logistic regression model. The results revealed no association between fertility and % DFI or % HDS, while SD DFI and MEAN DFI showed a significant negative association with NRR. Further, the SCSA values varied significantly between ejaculates within ram among some of the rams in the study. However, no significant association was seen between these intra‐individual differences in sperm DNA integrity and NRR. In conclusion, this study suggests an association between sperm DNA integrity and NRR for rams. However, further research must be conducted to confirm these findings and determine whether sperm DNA assessments can be applied to predict ram fertility.  相似文献   

Impact of Distillery Effluent on Soil Carbon and Nitrogen Dynamics in a Vertisol of Central India     

AK Biswas  Pankaj Sharma  KM Hati  S Ramana  AB Singh 《Communications in Soil Science and Plant Analysis》2018,49(17):2189-2196

Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.  相似文献   

Organogenesis and foetal haemodynamics during the normal gestation of healthy black‐rumped agoutis (Dasyprocta prymnolopha,Wagler, 1831) bred in captivity          下载免费PDF全文

FCA Sousa  GT Pessoa  LS Moura  JR Araújo  RPS Rodrigues  MAPS Barbosa  AN Diniz  AB Souza  EG Silva  LU Lucena  MP Sanches  OF Silva‐Filho  PC Guerra  JM Sousa  WC Neves  FR Alves 《Reproduction in domestic animals》2017,52(1):60-66

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B‐mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black‐rumped agoutis via B‐mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.  相似文献   

用农业废料制成的优质刨花板和中密度纤维板     

Daproma System AB 《林产工业》2000,27(3):44-45

全球农民每年都会面对一项挑战——在不致造成生态问题或额外开支的情况下,清除农田上过量的谷物残余物。 以在农田焚烧的方式来清除麦秸稻草的惯例在许多地方均引起关注。这是由于焚烧麦秸对泥土和环境均有损害,且会导致健康和交通问题。 小麦、大麦、稻谷、玉米和蔗渣等残余物的价值基本上均微不足道。Ｄａｐｒｏｍａ可以将这些废料纤维转化成一种制造工业用优质刨花板和中密度纤维板的主要原材料。 一家装备Ｄａｐｒｏｍａ设备的工厂可将一年生植物废料加工成作家具和柜子用的板材。而由于农业废料的成本远较木纤维的成本低,农业残余…  相似文献   

Major compositional units of the moon: lunar prospector thermal and fast neutrons   总被引：2，自引：0，他引：2  

WC Feldman  BL Barraclough  S Maurice  RC Elphic  DJ Lawrence  DR Thomsen  AB Binder 《Science (New York, N.Y.)》1998,281(5382):1489-1493

Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. There appears to be a smooth transition between the most mafic and feldspathic compositions, which correspond to low and high surface altitudes, respectively. The maria show low thermal and high fast neutron fluxes, consistent with basaltic rocks.  相似文献