Oxidative Stress and Antioxidant Status during Transition Period in Dairy Cows

Sharma, N.,Singh, N.K.,Singh, O.P.,Pandey, V.,Verma, P.K. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.4

The study was conducted on 20 Holstein X Sahiwal cross bred dairy cows, with an average milk production of $2,752{\pm}113.79$ liters in $284{\pm}5.75$ days during a single lactation, that were divided in to two groups of 10 animals. We investigated the oxidative stress and antioxidant status during the transition period in dairy cows. In this study, plasma level of MDA was considered as an indicator of lipid peroxidation and SOD, catalase, GSH and GSHPx as antioxidants. The lipid peroxidation was significantly (p<0.001) higher in cows during early lactation as compared to the cows in advanced pregnancy. A significant positive correlation (r = +0.831, p<0.01) was determined between MDA and catalase in early lactating cows. In early lactating cows, blood glutathione was significantly lower than in advanced pregnant cows. However, early lactating cows showed non-significant negative correlation for all antioxidant enzymes with lipid peroxidation. In conclusion, dairy cows seemed to have more oxidative stress and low antioxidant defense during early lactation or just after parturition than advanced pregnant cows, and this appears to be the reason for their increased susceptibility to production diseases (e.g. mastitis, metritis, retention of fetal membranes etc.) and other health problems.

Dielectric and impedance spectroscopic behaviour of alkali oxide - containing glass ceramics in the system [SrO.TiO2]-[SiO2.B2O3]

O.P. Thakur,Lakshman Pandey,Devendra Kumar,Om Parkash 한양대학교 세라믹연구소 2004 Journal of Ceramic Processing Research Vol.5 No.2

Dielectric properties are strongly dependent on crystallization conditions, which determined the amount of SrTiO3 and secondary crystalline phases and the microstructure of the glass ceramics. Earlier reports confirm that the crystallization of the SrTiO3 phase in borosilicate (without an alkali oxide additive) as well as in aluminosilicate glassy matrix is found to be complex and difficult. Glass ceramics with varying amounts of alkali oxide (K2O) have been prepared in the strontium titanate borosilicate glass system. The glasses were crystallized in the temperature range 1073-1325 K. It is observed that the pure strontium titanate (SrTiO3) phase can be crystallized at higher temperature by choosing an optimum amount of alkali oxide (K2O). Dielectric characteristics of glass ceramic samples were measured with respect to frequency (0.1 kHz to 1 MHz) and temperature (300 to 500 K). The value of the dielectric constant is higher when Sr2B2O5 crystallizes as a primary phase while it decreases significantly when SrTiO3 crystallizes as a major crystalline phase. The temperature coefficient of the dielectric constant (TCε) becomes negative as the SrTiO3 phase crystallized out in the glass ceramics and the value of the dielectric constant increases with a higher crystallization temperature and time which finally decides the amount of the SrTiO3 phase. Attempts have also been made to correlate the observed dielectric behavior with the electrical contribution of various crystalline phases, residual glassy matrix, crystal-glass interface region and electrode contribution using the impedance spectroscopic technique.

Study on Biochemical Constituents of Caprine Ovarian Follicular Fluid after Superovulation

Mishra, O.P.,Pandey, J.N.,Gawande, P.G. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.12

The experiment was designed on 42 non pregnant Black Bengal goat. Out of which 18 were subjected to a superovulatory treatment comprising of eCG and hCG for embryo transfer study. The remaining 24 goats received no treatment and served as control for parameter studied as well as recipient for embryo transfer studies. Important biochemical constituents such as acid and alkaline phosphatase, total protein and cholesterol and inorganic phosphorus were estimated in the follicular fluid of control and treated group and the values were separately recorded for small medium and large size follicle. The results indicated a significant effect on acid phosphotase activity due to size of follicle. The value increased progressively from small to medium and from medium to large follicles. Alkaline phosphotase activity showed reverse trend. Alkaline phosphotase decreased progressively as size increased. The concentration of inorganic phosphorus did not reveal any significant difference between the control and treatment groups and also between the different size follicles. The concentration of protein decreased significantly from small to medium and from medium to large, although no difference was observed between the control and treatment groups. The concentration of Cholesterol in the follicular fluid indicated a significant increase from small to medium and to large follicle. Here also no difference was observed due to treatment. Similar in the composition of follicular fluid in the respect of above mentioned constituents indicated no of super ovulatory treatment on follicular fluid composition.

A Comparative Study on Fresh and Frozen Embryo Transfer after Superovulation in Black Bengal Goats(Capra-hircus)

Mishra, O.P.,Pandey, J.N.,Gawande, P.G. 韓國受精卵移植學會 2002 한국동물생명공학회지 Vol.17 No.2

The experiment was divided into two phases. In phase-I fresh embryos were transferred and in Phase-II frozen embryos were transferred. Embryos were collected by using Dulbecco's phosphate buffered saline. In phase-I total of 65 ova were collected out of 107 ovulation in 18 goats. Recovery of ova was 60.74%, of which 51 (78.46%) was fertilized. Sixteen embryos were transferred to 10 recipient goats and kidding was observed in 6 goats, that produced 10 kids. Thus, 62.50% embryo survival and 60% kidding were achieved in phase-I. In phase-II of the experiment, 17 regular cyclic Black Bengal goats were used. The main purpose was to study the viability of caprine embryos after cryopreservation. In this phase the embryos were collected and frozen using Bio-cool freezers. A two step addition of cryoprotectants (5% glycerol and 10% glycerol) and three-step dilution of cryoprotectants with 1mole (M) sucrose was used. Embryos were preserved for 10 to 45 days. Out of 27 embryos preserved, 18 were recovered after freezing and thawing (37 water bath) with 33.33% embryonic loss. Seventeen frozen and thawed embryos were transferred in 9 recipient goats, out of which kidding was observed in 6 goats and 7 kids were produced, giving a 66.66% kidding and embryo survival of 41.17%. The technique utilized for fresh and frozen embryo transfer can be successfully utilized to produce goats of superior genetic merits. The protocol used for addition of cryoprotectant, freezing, thawing and dilution was found suitable for caprine embryo freezing.

Equivalent circuit model of a PbZr0.6Ti0.4O3 ceramic using impedance spectroscopy

Pramod Chaitanya,O. P. Thakur,Vinod Kumar,Alok Shukla,Lakshman Pandey 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.3

The ceramic system PbZr0.6Ti0.4O3 was prepared by a solid state method and impedance measurements were carried out as a function of frequency (100 Hz-10MHz) in the temperature range 370 K-869 K. Equivalent circuit models that represent the data below and above the transition temperature were arrived at by comparing the experimental plots with the computersimulated behavior obtained for model circuits. Below the transition temperature the equivalent circuit model comprises a series LCR combination connected in series with a parallel RC network where as for higher temperatures it contains three parallel RC circuits connected in series. Variation of the values of the components as a function of temperature was also studied.

Electrical and magnetic properties of rare earth substituted strontium hexaferrites

Anterpreet Singh,S. Bindra Narang,Kulwant Singh Thind,O.P. Pandey,R.K. Kotnala 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.2

Samples of strontium ferrite (Sr-M) with different molar substitution concentrations of lanthanum, neodymium and samarium ions were prepared by a standard ceramic processing technique. AC conductivity, dielectric constant and dielectric loss tangent measurements were carried out in the frequency range of 20 Hz to 1MHz. The experimental results indicate that AC electrical conductivity increases with increasing frequency. The increase in AC conductivity with frequency can be explained on the basis of Koops model, whereas the dielectric constant and dielectric loss tangent variations have been explained with a Maxwell-Wagner type interfacial polarization in agreement with the Koops phenomenological theory. The effects of rare earth substitution on the magnetic properties such as the saturation magnetization moment (Ms), coercive field (Hc), remenance (Mr),and Curie temperature Tc (K) have been investigated. It is found that the values of the magnetization moment (Ms), and remenance (Mr) decrease with increasing rare earth ions substitution for all the series. The reason for the decrease may be both the magnetic dilution and spin canting, which promote reduction of superexchange interactions. The enhancement of Hc values may be due to higher magnetocrystalline anisotropy, where Fe2+ ion anisotropy on the 2a site could be dominant in all hexaferrites series.