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A.M.H. Abdel Dayem Karima Gh. M. Mahmoud M.F. Nawito M.M. Ayoub T.H. Scholkamy 《Livestock Science》2009,122(2-3):193-198
This study aimed to develop a system of in vitro assays based on zona pellucida binding and in vitro fertilization for predicting male fertility in buffalo bulls. Frozen–thawed semen from nine bulls was tested for motility, viability index, acrosomal integrity, zona pellucida binding and in vitro fertilizing ability. Differences in post-thaw sperm motility between bulls were not significant. Differences in viability indices and percentage of spermatozoa with detached acrosome between bulls was highly significant (P < 0.001). Sperm attached per ovum, fertilization rates and polyspermy percentages varied significantly (P < 0.01) among buffalo bulls. A significant (P < 0.01) positive correlation coefficient of 0.69 was evident between normal acrosome and sperm attached per ovum, while between normal acrosome and fertilization efficiency it was 0.72. Sperm from different buffalo bulls differs in their ability to bind and fertilize oocytes. This study provides a basis to predict and maximize the in vitro fertilization performance of individual bulls. 相似文献
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The isolation of lumpy skin disease virus and bovine herpesvirus-4 from cattle in Egypt 总被引：1，自引：0，他引：1
J A House T M Wilson S el Nakashly I A Karim I Ismail N el Danaf A M Moussa N N Ayoub 《Journal of veterinary diagnostic investigation》1990,2(2):111-115
Lumpy skin disease (LSD) virus (LSDV) was isolated for the first time from cattle in Egypt in 2 disease outbreaks. Bovine herpesvirus-4 (BHV-4) and LSDV were detected in a pooled sample from the first outbreak (Suez). Only LSDV was isolated from the second outbreak (Ismalia). The capripoxviruses were identified as LSDV by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle. 相似文献
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Fatemeh Ebrahimi Mohsen Gholizadeh Ghodrat Rahimi-Mianji Ayoub Farhadi 《Tropical animal health and production》2017,49(8):1657-1662
Genome-wide association studies (GWAS) have introduced an influential tool in the search for quantitative trait loci (QTL) influencing economically important traits in sheep. To identify QTL associated with greasy fleece weight, a GWAS with 50 K single nucleotide polymorphisms (SNPs) was performed in a Baluchi sheep population. Association with greasy fleece weights was tested using the software Plink. The results of our GWAS provided three novel SNP markers and candidate genes associated with greasy fleece weight. A total of three chromosome-wide significant associations were detected for SNP on chromosomes 17 and 20 affecting greasy fleece weight across the four shearing. One of the significant SNP markers was located within ovine known genes namely FAM101A. Further investigation of these identified regions in validation studies will facilitate the identification of strong candidate genes for wool production in sheep. 相似文献
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A. T. Ayoub 《Land Degradation \u0026amp; Development》1999,10(5):489-500
The recent agricultural policies in the Sudan have focused on mechanized large-scale, rainfed agricultural ventures achieving increased grain production through expansion of the cultivated area only, not through increased per unit yield. The total harvested area increased steadily from about 4·5 million ha in 1961 to about 14 million ha in 1996, with great year-to-year variations of harvested areas, and therefore total yields, revealing a fragile balance between production and need. Per unit yields of all crops are steadily decreasing, currently reaching rates far below their genetic potential. The work reported here was intended to look into the causes of the fluctuations in yield and to propose some strategic approaches that may offer a path to sustainability of such crop production. Several factors may be contributing to these poor yields. This study shows that loss of soil fertility and rainfall variability are among such factors. Crops yields were negatively correlated at a one per cent level of significance with the cropping season indicating significant decline in soil fertility. Soil fertility management and fertilizers use could therefore be of great importance in formulating proactive strategies to enhance productivity in the rainfed agriculture in the Sudan. Rainfall in different production subregions had different levels of correlation with yields of all crops. Comparison of long-term rainfall in the four subregions of the study area showed that rainfall decline had been in the magnitude of 30–40 per cent. The western parts of the study area (Kordofan and Darfur) experienced extreme rainfall anomalies than the eastern and central parts (Gedaref and Damazin), and had suffered greater periods of desiccation than the eastern and central parts. The decadal rainfall means showed below average rainfall for the last three decades in all subregions; the western parts again showing greatest desiccation. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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Evaluation of N Fertilizer Rate and Timing and Wheat Cultivars on Soil Residual Nitrates 总被引：3，自引：0，他引：3
Nitrogen (N) fertilizer management for production of bread quality wheat may increase nitrate residues in the soil. To assess soil nitrate levels associated with bread quality wheat ( Triticum aestivum L.) production in Eastern Canada, an experiment was conducted for 2 years at each of two sites in Québec. Four cultivars (Columbus, Katepwa, Max and Hege 155-85), four N levels (0, 60, 120 and 180 kg N ha−1 ) and two N timings (all at seeding time or 60 % at seeding and 40 % at anthesis) were combined in a factorial arrangement on a Bearbrook clay and a Ste-Rosalie clay. Residual soil NO3 -N levels were measured in the 0–20 and 20– 60 cm soil layers. The cultivars used have potential as bread wheats. Cultivar effects on soil nitrate levels existed only in the Ste-Rosalie soil, suggesting that the cultivars used were better adapted to the conditions on the Bearbrook soil. Changes in soil NC3 N levels over winter indicated that mineralization had occurred. Calculated balance-sheet values were larger than measured residual NO3 -N in the autumn of each year, indicating that NO3 -N was lost from the systems, possibly due to denitrification. Potential increases in, and thus potential pollution from, residual soil NO-N existed only at the 180 kg N ha−1 level. Overwinter changes in soil NO3 -N levels were proportional to the inverse of the fall NC3 N levels. Differences between sites were large for many of the variables measured. 相似文献
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Alizadeh Fatemeh Moradian Fatemeh Farhadi Ayoub 《Tropical animal health and production》2020,52(6):3027-3034
Insulin-like growth factor-binding protein acid-labile subunit (IGFALS) encodes a protein which binds to IGF1 and IGFBP-3 to regulate the growth, differentiation, and other physiological processes. The aim of this study was the identification of allelic polymorphisms of the IGFALS gene using the PCR-RFLP technique and evaluation of their association with growth traits. For this end, 120 blood samples were randomly collected from each breed. Following amplification of an 1113-bp fragment of exon 1 and a part of intron 1 of the IGFLAS gene, genotyping was conducted by three restriction enzymes including HinfI, MscI, and PvuII. The results showed that only one allele was observed in IGFALS-PvuII site, while in IGFLAS-MscI site, three AA, AB, and BB genotypes with the frequencies of 17.5%, 32%, and 50.5% and 11%, 37.5%, and 51.5% were observed in Makouei and Ghezel sheep breeds, respectively. Additionally, in the IGFLAS-HinfI site, two AB and BB genotypes with the frequency of 34.2% and 65.8% were observed in Makouei sheep and AA, AB, and BB genotypes with the frequency of 9%, 21%, and 70% were observed in Ghezel sheep. So that, Makouei sheep with AB genotype had more chest girth (CG) compared with other genotypes. Furthermore, a significant association was observed between the genotypes of IGFLAS-HinfI with birth weight (BW) in Ghezel and BW, weaning weight (BW3), and CG in Makouei sheep. Haplotype analysis revealed an association between paternal haplotypes and BW in both Ghezel and Makouei breeds. So that, AAB and ABB haplotypes showed more BW than others in Makouei and Ghezel sheep, respectively.
相似文献18.
Impacts of the Cretaceous Terrestrial Revolution and KPg extinction on mammal diversification 总被引：1，自引：0，他引：1
Meredith RW Janečka JE Gatesy J Ryder OA Fisher CA Teeling EC Goodbla A Eizirik E Simão TL Stadler T Rabosky DL Honeycutt RL Flynn JJ Ingram CM Steiner C Williams TL Robinson TJ Burk-Herrick A Westerman M Ayoub NA Springer MS Murphy WJ 《Science (New York, N.Y.)》2011,334(6055):521-524
Previous analyses of relations, divergence times, and diversification patterns among extant mammalian families have relied on supertree methods and local molecular clocks. We constructed a molecular supermatrix for mammalian families and analyzed these data with likelihood-based methods and relaxed molecular clocks. Phylogenetic analyses resulted in a robust phylogeny with better resolution than phylogenies from supertree methods. Relaxed clock analyses support the long-fuse model of diversification and highlight the importance of including multiple fossil calibrations that are spread across the tree. Molecular time trees and diversification analyses suggest important roles for the Cretaceous Terrestrial Revolution and Cretaceous-Paleogene (KPg) mass extinction in opening up ecospace that promoted interordinal and intraordinal diversification, respectively. By contrast, diversification analyses provide no support for the hypothesis concerning the delayed rise of present-day mammals during the Eocene Period. 相似文献
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Ayoub Salari Taghi Tabarsa Abolghasem Khazaeian Ahmadreza Saraeian 《Journal of Wood Science》2012,58(6):513-524
In this study, the effect of nanoclay on some applied properties of oriented strand board (OSB) made from underutilized low quality paulownia wood was investigated. Organo-modified montmorillonite (MMT) at four levels (0, 1, 3 and 5?%) was added to urea formaldehyde (UF) resin. Some chemical properties of paulownia wood (holocellulose, cellulose, lignin and ash contents, pH value and hot and cold water solubility), mechanical [modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength, screw and nail withdrawal strengths], physical (water absorption and thickness swelling) properties and formaldehyde emission of the strand boards were evaluated. Mechanical properties of all panels complied with the general-purpose OSB minimum property requirements of European Norm. With increasing 5?% nanoclay to UF resin, mechanical and physical properties of the resulting panels improved and formaldehyde emission decreased. However, none of the panels satisfied the thickness swelling and water absorption requirement. The results of X-ray diffraction and transmission electron microscope analysis confirmed the good dispersion of nanoclay in the resulting OSBs. Using paulownia as a fast-growing underutilized species not only can sustain the forests but also can supply raw material to countries facing shortage of wood. 相似文献
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