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1.
Tropical Animal Health and Production - Avian influenza virus (AIV) H9N2 subtype is endemic in Iran and causes substantial economic loss to the growing poultry industry within the country. In this...  相似文献   
2.
Pre-conceptual sex selection is still a highly debatable process whereby X and Y chromosome bearing spermatozoa are isolated before oocyte fertilization. Recently, magnetic nanoparticles (MNP) have been used to determine X and Y chromosomes bearing spermatozoa as a result of searching for a cheap, highly efficient method using non-toxic materials. This study aimed to recover the sperm bearing X chromosomes in ram with different concentrations of MNP and then evaluate the success of this method using polymerase chain reaction (PCR). Ram sperms were divided into four groups, treated with 0 (control), 50, 100 and 200 μg/ml MNP, respectively. MNP was used to restore sperm cells bearing X chromosomes. Upon recovery, the PCR was performed to identify the X and Y sperms, Methyl ThiazoleTetrazolium (MTT), to assess MNP toxicity and sperm viability and acridine orange (AO) to evaluate sperm DNA integrity. The results of PCR revealed that the treatment of spermatozoa- bearing X chromosomes with 50 μg/ml MNP had the highest effects on the recovery of X sperm rather than the other concentrations of MNP. However, the concentrations of MNP did not have any toxic effects on spermatozoa, sperm viability and, DNA integrity, but the high concentration of MNP (200 μg/ml) significantly reduced DNA integrity. According to MTT and AO results, the concentrations of MNP used in this study had no toxic effects on spermatozoa and did not reduce the sperm viability and DNA integrity, except that 200 μg/ml MNP significantly reduced DNA integrity.  相似文献   
3.
Separation of X and Y chromosome-bearing sperm is an appropriate method for the selection of desired sex of offspring to increase the profit in livestock industries. The purpose of this study was the production of a monoclonal antibody against recombinant bovine sex-determining region Y protein for separation Y sperm. The hybridoma cells from splenocytes of immunized female's balb/C mice and Sp2/0 cells were made. The binding affinity of our monoclonal antibody (mAbSRY2) was compared with mouse monoclonal SRY-15. The Western blot method indicated that mAbSRY2 successfully detected the rbSRY protein. The specificity and sensitivity of mAbSRY2 is comparable to SRY-15 commercially ones. The SRY gene in 100% of bull semen contains the Y chromosome that had the strongest binding affinity to mAbSRY2 was synthesized. In other words, the binding affinity of semen contains the X sperms near the negative control. In general, this immunological method can help to separate X from Y sperms. However, the mAbSRY2 is bind to Y-bearing sexed sperm, but in the future; the sexed sperms need to apply in farms.  相似文献   
4.
The main objective of this study was to estimate the genetic and phenotypic relationships between calving difficulty (CD) and fertility traits, including success at first service (SF), number of inseminations to conception (INS), interval from calving to first service (CTFS), interval between first and last service (IFL) and days open (DO), in first‐parity Iranian Holsteins under standard (SMMs) and recursive (RMMs) mixed models. The data analysed in this paper included 29 950 records on CD and fertility traits, collected in the time period from 1995 to 2014 by the Animal Breeding and Improvement Center of Iran. Under all observed SMMs and RMMs, five bivariate sire‐maternal grandsire models (ten bivariate analyses in total) were used for the analyses. Recursive models were applied with a view to consider that CD influences the fertility traits in the subsequent reproductive cycle and the genetic determination of CD and fertility traits by fitting CD as covariate for any of the fertility traits studied. The existence of such cause‐and‐effect is considered in RMMs but not in SMMs. Our results implied a statistically non‐zero magnitude of the causal relationships between CD and all the fertility traits studied, with the former influencing the latter. The causal effects of CD on SF (on the observed scale, %), INS, CTFS, IFL and DO were ?2.23%, 0.10 services, 1.93 days, 3.76 days and 5.61 days, respectively. Direct genetic correlations between CD and the fertility traits under both models were not statistically different from zero (95% HPD interval included zero), except for the correlation between CD and CTFS, which were 0.197 and 0.134 under SMM and RMM, respectively, indicating that genes associated with difficult births also increase intervals between calving and the first insemination afterwards. Comparison of both models by the deviance information criterion (DIC) demonstrated the plausibility of RMMs over SMMs.  相似文献   
5.

Purpose  

The rooted zone of a soil, more precisely the rhizosphere, is a very dynamic system. Some of the key processes are water uptake and root respiration. We have developed a novel method for measuring the real-time distribution of water and oxygen concentration in the rhizosphere as a biogeochemical interface in soil. This enables understanding where and when roots are active in respect to root respiration and water uptake and how the soil responds to it.  相似文献   
6.
The objective of this study was to quantify inherent spatial variability and spatial cross-correlation of the van Genuchten retention parameters and saturated hydraulic conductivity (Ks) of surface and subsurface layers in a calcareous Inceptisols (Khuzestan province, Iran) under sugarcane cropping. Measurements were performed on 100-cm3 undisturbed soil cores collected at 94 locations along a 30-m-long transect with horizontal sampling distance intervals of 0.3 and 1 m at soil depths of 0–40 and 40–80 cm, respectively. Spatial variability was investigated using conventional statistics and geostatistical techniques. Coefficient of variation (CV) varied from 8.2% (for shape parameter, n at 40–80 cm depth) to 256.7% (for Ks at 0–40 cm depth). The n parameter and saturated water content, θs, showed a small-scale spatial heterogeneity with a maximum CV of 11.3% for the first depth and 9.2% for the second depth. Most of the hydraulic parameters at both depths showed a spatial structure and convex experimental semivariograms with dominant spherical models with the influence range of 3.2–41 m. In most cases, the extent of spatial correlation scales of cross-semivariograms for pairs of cross-correlated hydraulic variables was found to be different with reference to those relating to the direct semivariograms of correlated variables.  相似文献   
7.
The objective of this study was to evaluate the effects of organic and inorganic fertilizers on the yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore, a field trial was carried out in Peshawar, Pakistan, during the winters in 2012–2013. The field experiment was conducted in a randomized complete block design with split plots, having three replications. Fertilizer treatments (control, composted manure Higo Organic Plus at 5 t ha?1, Maxicrop Sea Gold seaweed extract at 5 L ha?1, farm yard manure at 10 t ha?1, inorganic nitrogen–phosphorus (NP) at 90:60 kg ha?1, NP at 120:90 kg ha?1 and NP at 150:120 kg ha?1) were allotted to main plots, while genotypes (Sandrina, Serenada and Kawe Terma) were allotted to the sub-plots. Plots treated with the application of NP at 120:90 kg ha?1 produced the highest beet yield (76.4 t ha?1) and sugar yield (11.1 t ha?1), and had the second highest polarizable sugar content (14.52%) and more economic return (Rs. 553,000 per hectare) as compared to control plots. Sugar beet genotype Serenada had significantly higher beet yield (55.5 t ha?1) and sugar yield (7.9 t ha?1) and a higher economic return (Rs. 380,000 per hectare) than the other genotypes. Sugar beet genotype Serenada supplied with NP at 120:90 kg ha?1is recommended for the general cultivation in the agro-climatic conditions of Peshawar valley.  相似文献   
8.
Most temperate terrestrial orchids are endangered species. Attempts to produce plantlets from plants of the genus Epipactis by asexual methods have totally failed. This study was conducted using somatic embryogenesis as a rapid vegetative propagation technique for conservation of E. veratrifolia. For these purposes, effects of different types of plant growth regulators (PGRs), different types of explants, light and dark conditions, and the effect of gibberellic acid (GA3) and Paclobutrazol (PBZ) were investigated on somatic embryogenesis induction. Abscisic acid (ABA) pre-treatment effectiveness on inducting somatic embryogenesis and increasing the number of embryos per explant were investigated. Subsequently, 16 media were tested to find the best medium for plant regeneration and shoot and root proliferation. BA (3 mg L?1) resulted in a better response than the other PGRs by supporting the development of 17 embryos per protocorm. PBZ, which resulted in 11 embryos per explant, was better than GA3. FAST medium supplemented with organic substances was recognized as the best medium for plant regeneration and shoot and root proliferation. ABA pre-treatment had positive effect on somatic embryogenesis initiation. This study, for the first time, succeeded in finding a rapid and suitable protocol for propagation and genetic resource conservation of E. veratrifolia.  相似文献   
9.
10.
This study evaluated the effect of specific calcium and magnesium ratios at two hardness values on reproductive performance and offspring quality of Macrobrachium rosenbergii brood‐females. Hatchery water containing 110.5 mg/L CaCO3 hardness was considered baseline as it has been used successfully to hatch and rear larvae and was used as the control treatment. At each hardness value of 150 and 190 mg/L CaCO3, four experimental water treatments were made in triplicate. Each treatment was adjusted using soluble salts (CaCl2·H2O, MgSO4·7H2O, and MgCl2·6H2O) to provide the hardness and calcium to magnesium ratios of 0:20, 20:80, 50:50, and 80:20 needed. Each of the experimental tanks (140 L) were stocked with six females and one male. The results indicated that both hardness and Ca:Mg ratios affect brood‐female reproductive qualitative parameters such as intermolt period, egg hatchability, egg dry weight, and egg‐clutch somatic index (ESI) parameters (P < 0.05) but not fecundity and eggs per spawn. The results revealed that brood‐females at 150 mg/L hardness showed greater reproductive performance than at 190 and 110.5 mg/L hardness. The findings also demonstrated that the treatment 50Ca50Mg at 150 mg/L hardness with 38.8 mg/L calcium and 12.9 mg/L magnesium had optimum reproductive performance and offspring quality for M. rosenbergii brood‐females.  相似文献   
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