Different Dimensionalities, Morphological Advancements and Engineering of g-C3 N4 -Based Nanomaterials for Energy Conversion and Storage.

Graphitic carbon nitride (g-C3 N4 ) has gained tremendous interest in the sector of power transformation and retention, because of its distinctive stacked composition, adjustable electronic structure, metal-free feature, superior thermodynamic durability, and simple availability. Furthermore, the restricted illumination and extensive recombination of photoexcitation electrons have inhibited the photocatalytic performance of pure g-C3 N4 . The dimensions of g-C3 N4 may impact the field of electronics confinement; as a consequence, g-C3 N4 with varying dimensions shows unique features, making it appropriate for a number of fascinating uses. Even if there are several evaluations emphasizing on the fabrication methods and deployments of g-C3 N4 , there is certainly an insufficiency of a full overview, that exhaustively depicts the synthesis and composition of diverse aspects of g-C3 N4 . Consequently, from the standpoint of numerical simulations and experimentation, several legitimate methodologies were employed to deliberately develop the photocatalyst and improve the optimal result, including elements loading, defects designing, morphological adjustment, and semiconductors interfacing. Herein, this evaluation initially discusses different dimensions, the physicochemical features, modifications and interfaces design development of g-C3 N4 . Emphasis is given to the practical design and development of g-C3 N4 for the various power transformation and inventory applications, such as photocatalytic H2 evolution, photoreduction of CO2 source, electrocatalytic H2 evolution, O2 evolution, O2 reduction, alkali-metal battery cells, lithium-ion batteries, lithium-sulfur batteries, and metal-air batteries. Ultimately, the current challenges and potential of g-C3 N4 for fuel transformation and retention activities are explored.

Photonic crystal nanostructure as a photodetector for NaCl solution monitoring: theoretical approach.

In this research, we have a theoretical simple and highly sensitive sodium chloride (NaCl) sensor based on the excitation of Tamm plasmon resonance through a one-dimensional photonic crystal structure. The configuration of the proposed design was, [prism/gold (Au)/water cavity/silicon (Si)/calcium fluoride (CaF2)10/glass substrate]. The estimations are mainly investigated based on both the optical properties of the constituent materials and the transfer matrix method as well. The suggested sensor is designed for monitoring the salinity of water by detecting the concentration of NaCl solution through near-infrared (IR) wavelengths. The reflectance numerical analysis showed the Tamm plasmon resonance. As the water cavity is filled with NaCl of concentrations ranging from 0 g l-1 to 60 g l-1, Tamm resonance is shifted towards longer wavelengths. Furthermore, the suggested sensor provides a relatively high performance compared to its photonic crystal counterparts and photonic crystal fiber designs. Meanwhile, the sensitivity and detection limit of the suggested sensor could reach the values of 24 700 nm per RIU (0.576 nm (g l)-1) and 0.217 g l-1, respectively. Therefore, the suggested design could be of interest as a promising platform for sensing and monitoring NaCl concentrations and water salinity as well.

Electro-oxidation reconstitution of aluminium copper MOF-derived metal oxyhydroxides for a robust OER process.

It is common knowledge that the O2 evolution reaction (OER) is a crucial half-reaction in the electrolysis of water. However, it is currently difficult to create inexpensive OER electrode materials in a way that is efficient, simple, and environmentally friendly. In this research, metal oxy-hydroxides with numerous oxygen defects (M-OOHv) are created at surface of Cu foam (CF) using a unique, straightforward electro-oxidation reconstitution (ER) process. Different spectroscopic and microscopy methods are used to analyse the electrode characteristics of Al2Cu-MOF@M-OOHv-ER/CF; electrochemical measurements display a lower overpotential (η) of 366 mV @ 10 mA cm-2 and a Tafel slope of 95.2 mV dec-1 in 1.0 M KOH. X-Ray diffraction (XRD), scanning electron microscopy (SEM), and Raman studies confirm the phase transition of the metal-organic framework (MOF) to the M-OOH, which acts as the active site to boost the OER activity. Through spectroscopic and microscopic investigations, it is determined that the efficiency of bimetallic electrode materials and oxygen vacancies in the M-OOHv have an impact on the electron power density. The manufactured electrode material additionally showed good durability for 50 hours. As a result, the newly developed Al2Cu-MOF@M-OOHv-ER/CF nanomaterial has greater potential for both electrolysis of water and other energy storage equipment.

Heavy metals biosensor based on defective one-dimensional phononic crystals.

In recent years, the detection of water pollution with low levels of heavy metals has attracted the great attention of many researchers as a result of the imminent danger of this type of pollution to all mankind. Meanwhile, we introduce a theoretical approach based on the one-dimensional phononic crystals (1D-PnCs) with a central defect layer as a novel platform for the highly sensitive detection of heavy metal pollution in freshwater. Therefore, the creation of a resonant peak in the transmittance spectrum related to this defect layer is highly conceivable. In this regard, the detection of cadmium chloride (CdCl2) as a dangerous, toxic, and extremely hazardous heavy metal could be investigated based on the small displacement in the position of this resonant peak with the changes in the CdCl2 concentration. Notably, any change in CdCl2 concentration has a direct impact on its acoustic properties. The theoretical framework of our research study is essentially based on the 2 × 2 transfer matrix method and the acoustic properties of the constituent materials as well. The optimization of all sensor parameters represents the mainstay of this study to get the best sensor performance. In this regard, the proposed sensor has a remarkably high sensitivity (S = 1904.25 Hz/ppm) over a concentration range of 0 - 10000 ppm. In addition, the sensor has a high quality factor (QF), and figure of merit of 1771.318, and 73529410-5 (ppm-1), respectively. Finally, we believe this sensor could be a key component of a feasible platform for detecting low concentrations of different heavy metal ions in freshwater.

Recent Advances and Future Perspectives of Metal-Based Electrocatalysts for Overall Electrochemical Water Splitting.

Recently, the growing demand for a renewable and sustainable fuel alternative is contingent on fuel cell technologies. Even though it is regarded as an environmentally sustainable method of generating fuel for immediate concerns, it must be enhanced to make it extraordinarily affordable, and environmentally sustainable. Hydrogen (H2 ) synthesis by electrochemical water splitting (ECWS) is considered one of the foremost potential prospective methods for renewable energy output and H2 society implementation. Existing massive H2 output is mostly reliant on the steaming reformation of carbon fuels that yield CO2 together with H2 and is a finite resource. ECWS is a viable, efficient, and contamination-free method for H2 evolution. Consequently, developing reliable and cost-effective technology for ECWS was a top priority for scientists around the globe. Utilizing renewable technologies to decrease total fuel utilization is crucial for H2 evolution. Capturing and transforming the fuel from the ambient through various renewable solutions for water splitting (WS) could effectively reduce the need for additional electricity. ECWS is among the foremost potential prospective methods for renewable energy output and the achievement of a H2 -based economy. For the overall water splitting (OWS), several transition-metal-based polyfunctional metal catalysts for both cathode and anode have been synthesized. Furthermore, the essential to the widespread adoption of such technology is the development of reduced-price, super functional electrocatalysts to substitute those, depending on metals. Many metal-premised electrocatalysts for both the anode and cathode have been designed for the WS process. The attributes of H2 and oxygen (O2 ) dynamics interactions on the electrodes of water electrolysis cells and the fundamental techniques for evaluating the achievement of electrocatalysts are outlined in this paper. Special emphasis is paid to their fabrication, electrocatalytic performance, durability, and measures for enhancing their efficiency. In addition, prospective ideas on metal-based WS electrocatalysts based on existing problems are presented. It is anticipated that this review will offer a straight direction toward the engineering and construction of novel polyfunctional electrocatalysts encompassing superior efficiency in a suitable WS technique.

A Targeted Review of Current Progress, Challenges and Future Perspective of g-C3 N4 based Hybrid Photocatalyst Toward Multidimensional Applications.

The increasing demand for searching highly efficient and robust technologies in the context of sustainable energy production totally rely onto the cost-effective energy efficient production technologies. Solar power technology in this regard will perceived to be extensively employed in a variety of ways in the future ahead, in terms of the combustion of petroleum-based pollutants, CO2 reduction, heterogeneous photocatalysis, as well as the formation of unlimited and sustainable hydrogen gas production. Semiconductor-based photocatalysis is regarded as potentially sustainable solution in this context. g-C3 N4 is classified as non-metallic semiconductor to overcome this energy demand and enviromental challenges, because of its superior electronic configuration, which has a median band energy of around 2.7 eV, strong photocatalytic stability, and higher light performance. The photocatalytic performance of g-C3 N4 is perceived to be inadequate, owing to its small surface area along with high rate of charge recombination. However, various synthetic strategies were applied in order to incorporate g-C3 N4 with different guest materials to increase photocatalytic performance. After these fabrication approaches, the photocatalytic activity was enhanced owing to generation of photoinduced electrons and holes, by improving light absorption ability, and boosting surface area, which provides more space for photocatalytic reaction. In this review, various metals, non-metals, metals oxide, sulfides, and ferrites have been integrated with g-C3 N4 to form mono, bimetallic, heterojunction, Z-scheme, and S-scheme-based materials for boosting performance. Also, different varieties of g-C3 N4 were utilized for different aspects of photocatalytic application i. e., water reduction, water oxidation, CO2 reduction, and photodegradation of dye pollutants, etc. As a consequence, we have assembled a summary of the latest g-C3 N4 based materials, their uses in solar energy adaption, and proper management of the environment. This research will further well explain the detail of the mechanism of all these photocatalytic processes for the next steps, as well as the age number of new insights in order to overcome the current challenges.

Hybrid Tamm plasmon resonance excitation towards a simple and efficient biomedical detector of NaI solution.

This work presents a theoretical verification for the detection of Sodium iodide (NaI) solution with different concentrations in the vicinity of Tamm plasmon (TP) resonance. The proposed sensing tool is constituted of {prism/Ag/cavity/(GaN/CaF2)15/air}. The essential foundation of this study is based on the displacement of the TP resonance by varying the concentration of an aqueous solution of sodium iodide (NaI) that fills the cavity layer. The resonant TP dip is shifted downwards the shorter wavelengths with the increment of the Ag layer thickness. Nevertheless, the resonant TP dip is shifted upwards to longer wavelengths with the increment of NaI refractive index/concentration. Also, the sensitivity of the sensing tool decreases with the increment of the NaI refractive index. However, the minimum result is not less than the value of 9913 nm RIU-1 for a concentration of 25%. Finally, the performance of our sensor in the form of the quality factor, detection limit, and figure of merit showed significant improvements in designing a high-performance liquid and biosensor.

Recent Advancement in Rational Design Modulation of MXene: A Voyage from Environmental Remediation to Energy Conversion and Storage.

Use of MXenes (Ti3 C2 Tx ), which belongs to the family of two-dimensional transition metal nitrides and carbides by encompassing unique combination of metallic conductivity and hydrophilicity, is receiving tremendous attention, since its discovery as energy material in 2011. Owing to its precursor selective chemical etching, and unique intrinsic characteristics, the MXene surface properties are further classified into highly chemically active compound, which further produced different surface functional groups i. e., oxygen, fluorine or hydroxyl groups. However, the role of surface functional groups doesn't not only have a significant impact onto its electrochemical and hydrophilic characteristics (i. e., ion adsorption/diffusion), but also imparting a noteworthy effect onto its conductivity, work function, electronic structure and properties. Henceforth, such kind of inherent chemical nature, robust electrochemistry and high hydrophilicity ultimately increasing the MXene application as a most propitious material for overall environment-remediation, electrocatalytic sensors, energy conversion and storage application. Moreover, it is well documented that the role of MXenes in all kinds of research fields is still on a progress stage for their further improvement, which is not sufficiently summarized in literature till now. The present review article is intended to critically discuss the different chemical aptitudes and the diversity of MXenes and its derivates (i. e., hybrid composites) in all aforesaid application with special emphasis onto the improvement of its surface characteristics for the multidimensional application. However, this review article is anticipated to endorse MXenes and its derivates hybrid configuration, which is discussed in detail for emerging environmental decontamination, electrochemical use, and pollutant detection via electrocatalytic sensors, photocatalysis, along with membrane distillation and the adsorption application. Finally, it is expected, that this review article will open up new window for the effective use of MXene in a broad range of environmental remediation, energy conversion and storage application as a novel, robust, multidimensional and more proficient materials.

Synergetic effect of bismuth vanadate over copolymerized carbon nitride composites for highly efficient photocatalytic H2 and O2 generation.

The development of copolymerized carbon nitride (CN)-based photocatalysts may support advances in photocatalytic overall water splitting. However, the recombination of charge carriers is the main bottleneck that reduces its overall photocatalytic activity. To overcome this problem, the construction of heterojunction technology has emerged as an effective approach to reduce the charge carrier recombination, thereby improving charge separation and transport efficiency. In this work, an innovative heterojunction was prepared between Quinolinic acid (QA) modified CN (CN-QAx) and novel nanorod-shaped bismuth vanadate (BiVO4) (BiVO4/CN-QAx) for overall water splitting through a simple in-situ solvent evaporation technique. The obtained results show that the synthesized samples have efficient and improved activities for releasing H2 (862.1 µmol/h) and O2 (31.58 µmol/h) under visible light irradiation. Furthermore, an exceptional apparent quantum yield (AQY) of 64.52 % has been recorded for BiVO4/CN-QA7.0 at 420 nm, which might be due to the substantial isolation of photoinducedcharge carriers. Therefore, this work opens up a new channel toward efficient CN-based photocatalysts in the sustainable energy production processes.

Enhanced photocatalytic overall water splitting from an assembly of donor-π-acceptor conjugated polymeric carbon nitride.

Well-organized water splitting semiconducting photocatalyst is an important concept, but stimulating aimed at decisive energy and environmental emergencies. In this context, visible light-based photocatalytic water splitting with low-dimensional semiconducting materials is proposed to produce sustainable energy. Here we optimized the sequential of organic electron-rich heterocyclic monomer namely benzothiadiazole (BTD) quenched within polymeric carbon nitride (PCN) semiconductor via copolymerization, thereby assembling a sanctum of donor-π-acceptor (D-π-A) photocatalysts. The selection of BTD is based on the benzene ring, which consequently anticipating a π cross-linker unit for hydrogen and oxygen evolution. A hydrogen evolution rates (HER) of 88.2 µmol/h for pristine PCN and 744.2 µmol/h for PCN-BTD008 (eight times higher than pure PCN) are observed. Additionally, a remarkable apparent quantum yield (AQY) of about 58.6% at 420 nm has been observed for PCN-BTD008. Likewise, the oxygen evolution rate (OER) data reflect the generation of 0.2 µmol/h1 (visible) and 1.6 µmol/h1 (non-visible) for pure PCN. Though, OER of PCN-BTD008 is found to be 2.2 µmol/h1 (visible) and 14.8 µmol/h1 (non-visible), which are economically better than pure PCN. As such, the results show an important step toward modifying the design and explain a vital part of the D-π-A scheme at a balanced theme for fruitful photocatalysts intended for future demand.

Enhancement of NLO properties of supersalt (Al(BH4)3)-doped graphene: a DFT study.

In this work, pure and supersalt-doped graphene is evaluated by the density functional theory (DFT) to explore its optical and electronic properties. The doping of supersalt Al(BH4)3 on graphene reduces the highest occupied molecular orbital and lower unoccupied molecular orbital (HOMO-LUMO) bandgap of graphene@Al(BH4)3 and graphene@2Al(BH4)3 to 3.57 and 3.55 eV from 3.61 eV. The improvement in the optoelectronic properties of the supersalt Al(BH4)3-doped graphene is determined by the upshift of UV absorption peak and dipole moment. Polarizability (α) values of graphene@Al(BH4)3, and graphene@2Al(BH4)3 increase to 14% and 26% in the comparison of pure graphene. The first hyperpolarizability (ßo) is increased from 0.44 (graphene) to 1295.4 au in graphene@2Al(BH4)3. Our findings suggest that Al(BH4)3-doped graphene could be an effective method for making graphene an efficient nonlinear optical material.

Recent Advancement of the Current Aspects of g-C3 N4 for its Photocatalytic Applications in Sustainable Energy System.

Being one of the foremost enticing and intriguing innovations, heterogeneous photocatalysis has also been used to effectively gather, transform, and conserve sustainable sun's radiation for the production of efficient and clean fossil energy as well as a wide range of ecological implications. The generation of solar fuel-based water splitting and CO2 photoreduction is excellent for generating alternative resources and reducing global warming. Developing an inexpensive photocatalyst can effectively split water into hydrogen (H2 ), oxygen (O2 ) sources, and carbon dioxide (CO2 ) into fuel sources, which is a crucial problem in photocatalysis. The metal-free g-C3 N4 photocatalyst has a high solar fuel generation potential. This review covers the most recent advancements in g-C3 N4 preparation, including innovative design concepts and new synthesis methods, and novel ideas for expanding the light absorption of pure g-C3 N4 for photocatalytic application. Similarly, the main issue concerning research and prospects in photocatalysts based g-C3 N4 was also discussed. The current dissertation provides an overview of comprehensive understanding of the exploitation of the extraordinary systemic and characteristics, as well as the fabrication processes and uses of g-C3 N4 .

Simple, efficient and accurate method toward the monitoring of ethyl butanoate traces.

We introduce in this research a simple, accurate, safe, and efficient design for the detection of ethyl butanoate that be present in the dry exhaled breath. In particular, the presence of ethyl butanoate in the dry exhaled breath could be utilized as a platform for the diagnosing of COVID 19. The main idea of this theoretical investigation is based on the inclusion of a cavity layer between a thin layer of Au and the well-known one-dimension photonic crystals. Accordingly, the cavity layer is filled with dry exhaled breath. The numerical results are investigated in the vicinity of the Drude model and transfer matrix method. The investigated results show the appearance of Tamm plasmon resonance in the reflectance spectrum of our design through the IR region. Such resonant mode provides very high sensitivity with the change in the concentration of ethyl butanoate. We have examined the performance of the proposed sensor by calculating its sensitivity, detection limit, detection accuracy, quality factor and figure of merit. The designed sensor could receive sensitivity of 0.3 nm/ppm or 260,486 nm/RIU, resolution of 7 ppm and quality factor of 969.

Effects of Trifolium alexandrinum phytoestrogens on oestrous behaviour, ovarian activity and reproductive performance of ewes during the non-breeding season.

Phytoestrogens are classified as naturally occurring endocrine disrupting chemicals that may affect reproductive performance of farm animals. To investigate the effects of Berseem clover phytoestrogens on reproductive performance of seasonal anoestrus ewes, twenty four late pregnant Rahmani ewes were fed either Berseem clover or maize silage (n = 12/treatment). Treatment started 2 months prepartum and continued until oestrous induction (week 8 postpartum), using the CIDR-eCG based protocol, and early pregnancy. Throughout the 2-8 weeks postpartum, oestrous rate and ovarian activity were not affected by treatment. After oestrous induction, ewes in both groups expressed comparable oestrous rates; however feeding Berseem clover extended (P < 0.05) interval to oestrus (57.00 compared with 42.54 h) and shortened (P < 0.05) oestrous duration (20.0 compared with 34.90 h). Feeding Berseem clover did not affect follicular activity except the number of medium follicles, which was less (P < 0.05) on day of oestrus (Day 0). Feeding maize silage increased (P < 0.05) the total number of follicles and number of small and medium follicles the day before oestrus (Day -1). On Day 0, the greater total number of follicles was due to the greater (P < 0.05) number of medium follicles that was associated with less number of small follicles. Although, the number and diameter of corpora lutea (CLs) were not affected by treatment, serum P4 concentration was greater (P < 0.05) for ewes fed maize silage than for those fed Berseem clover. Fecundity and litter size tended to be greater (about 35%; P = 0.132 and 0.085, respectively) in the maize silage fed ewes. In conclusion, feeding Berseem clover throughout seasonal anoestrus disrupted aspects of behavioural oestrus and there was less luteal P4 synthesis and fecundity of ewes.

Effectiveness of controlled internal drug release device treatment to alleviate reproductive seasonality in anestrus lactating or dry Barki and Rahmani ewes during non-breeding season.

This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non-breeding season. Forty-eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p < .05) total number of follicles, number of large follicles, serum estradiol concentration and estradiol: progesterone (E2 :P4 ) ratio compared to Rahmani ewes. Lactating ewes recorded higher (p < .05) number of small follicles and lower concentration of total antioxidant capacity (TAC) compared to dry ewes. Number and diameter of large follicles recorded the highest (p < .05) values accompanied with disappearance of corpora lutea at day of mating. Serum progesterone concentration recorded lower (p < .05) value at day of mating and the highest (p < .05) value at day 35 after mating. CIDR-eCG protocol induced 100% oestrous behaviour in both breeds, but Rahmani ewes recorded longer (p < .05) oestrous duration compared to Barki. Conception failure was higher (p < .05) in Barki compared to Rahmani ewes. In conclusion, CIDR-eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes.

Genetic screening of FecB, FecXG and FecXI mutations and their linkage with litter size in Barki and Rahmani sheep breeds.

Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR-IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) screening approach was used to detect the presence of FecB, FecXG and FecXI mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecXG and FecXI are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds.

Manipulation of reproductive seasonality using melatonin implantation in Anglo-Nubian does treated with controlled internal drug release and equine chorionic gonadotropin during the nonbreeding season.

The objective of this study was to compare the efficiency of hormonal treatments on ovarian activity and reproductive performance in anestrous Anglo-Nubian does during the nonbreeding season (February to May). A total of 48 multiparous does were divided into 2 groups (24 lactating does and 24 dry does). In each group, animals were allocated randomly into 2 equal subgroups (12 does each). In the first subgroup, does received a single 18-mg melatonin implant for 42 d followed by a controlled internal drug release (CIDR) device for 19 d in conjunction with 500 IU of equine chorionic gonadotropin (eCG) i.m. on the day of CIDR device removal. The second subgroup received CIDR combined with eCG in parallel with the first subgroup. Melatonin implantation induced a luteotrophic effect, expressed as an increasing number of corpora lutea, increased serum progesterone concentration, and reduced estradiol concentration. Regardless of treatment, dry does showed greater value of progesterone concentration. With the advancement of day of treatment, number of total follicles, small follicles, and medium follicles tended to increase to the greatest values at the day of CIDR device insertion. Furthermore, at day of mating, the numbers of large follicles reached the greatest value, which was associated with the lowest value of the number of corpora lutea. At day of mating, serum progesterone concentration achieved the lowest value, which increased until d 56 of pregnancy. The estradiol:progesterone ratio showed the opposite trend. The detrimental effect of reproductive seasonality, expressed as cessation of estrus behavior and fertile mating during the nonbreeding season, was successfully alleviated by the CIDR-eCG protocol. Furthermore, melatonin implantation in conjunction with the CIDR-eCG protocol enhanced conception rate and fecundity at d 28 of pregnancy and prolificacy at d 56 of pregnancy compared with does that were not implanted. Interestingly, does that failed to conceive did not come to heat again. In conclusion, the beneficial effect of melatonin implantation in conjunction with the CIDR-eCG protocol on the luteotrophic effect was reflected in the increasing number of corpora lutea, increasing progesterone concentration, and decreasing estradiol concentration. Furthermore, conception rate, prolificacy, and fecundity were improved compared with does that were not implanted during the nonbreeding season.

Effect of GnRH treatment on ovarian activity and reproductive performance of low-prolific Rahmani ewes.

This study was designed to evaluate the effect of GnRH treatment during different times of the reproductive cycle on ovarian activity, progesterone (P4) concentration, and subsequent fertility of low-prolific, subtropical, Rahmani ewes during breeding season. Forty-five ewes were synchronized for estrus using a double injection of 0.5 mL of PGF2α agonist (125-µg cloprostenol), 11 days apart. Ewes showing estrus (Day 0) were treated with 1 mL of GnRH agonist (4-µg buserelin) on the day of estrus (GnRH0, n = 12) or 7 days post-mating (GnRH7, n = 10) or on both days (GnRH0+7, n = 11) or not (control, n = 12). Ovarian response to the treatment and diagnosis of pregnancy were ultrasonographically monitored. Also, serum P4 concentration was determined weekly throughout 28 days post-mating. Results showed that neither total number of follicles nor their populations were changed on Day 0 or 7 days post-mating by the GnRH treatment. GnRH treatment on Day 0 or Day 7 post-mating or both days did not enhance ovulation rate compared with the control. The mean numbers of accessory CL increased (P < 0.05) in the GnRH7 group than those in the control and GnRH0 groups, whereas it was intermediate in the GnRH0+7 group. The greatest (P < 0.05) overall mean of serum P4 concentration was for the GnRH7 and GnRH0+7 groups, followed by the GnRH0 and control groups. Serum P4 concentration increased (P < 0.05) on Day 14 post-mating and continued higher (P < 0.05) until Day 28 post-mating in the GnRH7 and GnRH0+7 groups compared with the control. Regardless of the time of GnRH administration, GnRH treatment reduced (P < 0.05) pregnancy loss from Day 40 post-mating to parturition and tended to enhance (P < 0.20) lambing rate compared with the control. In conclusion, a single dose of GnRH at the time of estrus or 7 days post-mating could be used as an effective protocol to decrease pregnancy loss from Day 40 after mating to parturition in low-prolific Rahmani ewes.

Serum metabolites, milk yield, and physiological responses during the first week after kidding in Anglo-Nubian, Angora, Baladi, and Damascus goats under subtropical conditions.

This study was carried out to determine the level of certain biochemical variables reflecting the energy metabolic statuses during the first week of lactation in goats. A total of 120 Anglo-Nubian, Angora, Baladi, and Damascus does (30 does per breed) were used throughout 5 consecutive parities (30 does per parity) to investigate the effect of breed, parity, day of lactation, and their interaction on serum metabolites including total protein, albumin, globulin, glucose, total lipids, cholesterol, and transaminases. Blood samples were collected every other day during the first week of lactation. Baladi does had the greatest (P < 0.001) values in all measured biochemical variables followed by Anglo-Nubian [in total protein, globulin, and aminotransferase (AST)] and Damascus (in globulin and AST) and then Angora, which had the lowest (P < 0.001) values for all variables. Fifth parity exhibited the greatest (P < 0.001) values in all serum metabolites compared with other parities except for alanine transaminase (ALT) enzyme activity in which the greatest (P = 0.046) values were observed in the first and fourth parties. Serum concentrations of the measured variables increased gradually throughout the first day after kidding until the seventh day for total protein (P < 0.001), albumin (P = 0.013), globulin (P = 0.017), and cholesterol (P = 0.028) whereas serum glucose concentration exhibited an opposite trend. Serum concentrations of total lipids and enzyme activities of AST and ALT were not affected by day (P > 0.05) after kidding. Baladi goats had the least (P < 0.001) serum insulin concentration, which was associated (P < 0.001) with greatest serum glucose concentration. Serum triiodothyronine (T(3)) was inversely correlated (P = 0.032) with milk yield whereas greatest (P = 0.003) T(3) concentrations were associated with least (P < 0.001) milk yield recorded in Angora goats. Animal physiological responses and their indices were not affected (P > 0.05) by breed whereas both rectal temperature and coefficient of heat tolerance were affected (P < 0.001) by parity in an opposite direction. Baladi goats expressed an aspect of adaptability where their rectal temperature decreased and coefficient of heat tolerance increased with increasing parity number.