Development of a novel sensitive single-tube nested PCR assay for the detection of African swine fever virus.

African swine fever (ASF) is a highly fatal and contagious viral disease caused by African swine fever virus (ASFV). It has caused significant economic losses to the swine industry and poses a serious threat to food security worldwide. Diagnostic tests with high sensitivity are essential for the effective management of ASF. Here, we describe a single-tube nested PCR (STN-PCR) assay for the detection of ASFV in which two consecutive amplification steps are carried out within a single tube. Two pairs of primers (outer and inner) were designed to target the p72 gene of ASFV. The primer concentrations, annealing temperatures, and number of amplification cycles were optimized to ensure the consecutive utilization of outer and inner primer pairs during amplification while minimizing the likelihood of amplicon contamination. In comparison with two conventional endpoint PCR assays (one of which is recommended by the World Organization for Animal Health), the newly developed STN-PCR assay demonstrated a 100-fold improvement in the limit of detection (LOD), detecting 100 copies of ASFV genomic DNA, whereas the endpoint PCR assays could detect no fewer than 10,000 copies. The clinical performance of the STN-PCR assay was validated using 95 tissue samples suspected of being positive for ASFV, and the assay showed 100% specificity. A Cohen's kappa value of 0.91 indicated perfect agreement between the assays. This new STN-PCR assay is a potentially valuable tool that will facilitate the control of ASF.

Development of a novel visual isothermal amplification assay for rapid detection of Brucella spp.

Brucellosis is an economically important livestock disease worldwide besides having a noteworthy impact on human health. In this study, a rapid, simple, and ultra-sensitive nuclei-acid diagnostic technique was developed for the detection of brucellosis harnessing saltatory rolling circle amplification (SRCA). The diagnostic method was developed using World Organization for Animal Health (WOAH) approved primers targeting the bcsp31 gene of the Brucella genome. The assay can be accomplished within 90 min at a temperature of 65 °C without the requirement of sophisticated instrumentation. The result interpretation can be done with the naked eye with the aid of SYBR green dye. The developed technique displayed 100% specificity by amplifying only 10 reference and field strains of Brucella spp. and there was no cross-reactivity with the other tested pathogens. The lower limit of detections of SRCA and end-point PCR assays were 9.7 fg/µL (2.7 genome copies of Brucella) and 970 fg/µL, respectively. Thus, the developed SRCA assay was found to be 100× more sensitive than the end-point PCR assay. To the best of our knowledge, our study is the first one to develop an SRCA-based assay for the detection of brucellosis and it can be a diagnostic tool for resource-constrained laboratories and veterinary hospitals.

Effects of integrated nutrient management on sucrose phosphate synthase enzyme activity and grain quality traits in rice.

Cropping systems and management practices can greatly affect rice crop, finally determining their grain yield and quality. In this study, we evaluated the effects of integrated nutrient management practices on sucrose phosphate synthase enzyme (SPS) activity and grain quality traits of rice. Field experiments were conducted at North Bank Plain Agro-climatic Zone of Assam, India from 2013 to 2015 on three rice ecosystems (winter, summer, and pre-monsoon). Selected fertilizer treatments were NPK as recommended inorganic fertilizer, NPK + cow dung, NPK + whole parts of the green manure Sesbania aculeata, NPK + compost of Azolla caroliniana and NPK + rice husk dust. NPK + Azolla compost application resulted in higher SPS activity compared to control. A significant relationship between panicle biomass and SPS enzyme activity was observed in the rice plants grown in different ecosystems. Integrated nutrient fertilizers in rice soil had a significant impact on the grain quality of rice. Grain nitrogen and crude protein content were higher at NPK + green manure Sesbania aculeata applied field irrespective of the ecosystems. NPK and Azolla compost were effective in improving grain productivity and grain quality parameters viz; total carbohydrates, starch, and amylose in rice crop. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01148-w.

Productive and reproductive performances of two-breed and three-breed pig crosses with Niang Megha, Hampshire and Duroc inheritance reared under subtropical Eastern Himalayan hilly climate.

The objective of the study was to evaluate the performance of different crossbreeds, viz., two-breed crosses including HN-50 (50% Hampshire × 50% Niang Megha) and HN-75 (75% Hampshire × 25% Niang Megha) and three-breed cross, HND (25% Hampshire × 25% Niang Megha × 50% Duroc) for suggesting suitable crossbred pigs with appropriate inheritance for subtropical Eastern Himalayan hilly climate. These crossbreed pigs were reared in standard management conditions in Nucleus Pig Breeding Farm of ICAR RC for NEH region. A total of 1995 records were collected which included data on production performance (n = 1466), reproductive performance (n = 428) and carcass traits (n = 101) from farm record book maintained over a period of 7 years. Productive performance included body weight, ADG and FCR at different stages of growth. The study revealed productive performance was highest in two-breed cross of pigs with 75% H inheritance (HN-75) and three-breed cross (HND) pigs. Reproductive performance included ages at puberty, first conception and first farrowing, along with inter-farrowing interval, pregnancy and farrowing rate as well as litter performance. The HN-75 was found to be having shorter inter-farrowing interval and higher pregnancy rate than other genetic groups. Regarding carcass traits, three-breed cross had a higher dressing percentage and less back-fat thickness than other crossbred pigs. Two breed crosses of pigs were found to be having a higher back-fat thickness than three-breed cross pig, and HN-75 had a better dressing percentage than HN-50. Thus, it was concluded that three-breed cross was recommended for lean meat production, and two-breed cross HN-75 was recommended for both breeding and fattening purposes for subtropical Eastern Himalayan hilly climate.

Slow release exogenous melatonin modulates scrotal circumference and testicular parameters, libido, endocrinological profiles and antioxidant and oxidative stress profiles in mithun.

Mithun (Bos frontalis) is a unique domestic free-range bovine species available in North Eastern hilly (NEH) regions of India and is reared for its protein rich meat. Although, mithun suffers from severe non-cyclical population fluctuations, it is not yet declared as endangered. Therefore, present study was conducted to assess the effect of slow release subcutaneous exogenous melatonin (MT) implant on sexual behaviour, scrotal circumference (SC) and testicular parameters, endocrinological profiles and antioxidant and oxidative stress profiles in mithun during different seasons (winter, spring, summer and autumn) to improve its reproductive efficiency. Experimental mithun bulls (5-6 years of age) were selected and divided randomly into two groups, Gr I: Control (n = 6) and Gr II: Treatment (n = 6; melatonin implant @ 18mg/50 kg B. Wt). Scrotal circumference and testicular parameters [total testicular volume and weight], endocrinological profiles [follicle stimulating hormone (FSH), luteinizing hormone/interstitial cell stimulating hormone (LH/ICSH), testosterone, thyroxine (T4), cortisol, prolactin and melatonin (MT)], sex behaviour profiles [libido score, mating ability score and sexual behaviour score], antioxidant profiles [total antioxidant capacity (TAC), catalase (CAT), glutathione (GSH), glutathione reductase (GSHRx) and superoxide dismutase (SOD)] and oxidative stress profile [malondialdehyde (MDA)] were estimated. Statistical analysis revealed that these experimental profiles differed between treatment and control groups within the seasons and among the seasons within the experimental groups. FSH, LH, testosterone, T4 and MT were higher and cortisol and prolactin were lower in spring and winter than in summer season. Concentration of FSH, LH, testosterone and MT were higher and concentration of T4, cortisol and prolactin were lower in MT treated than in untreated control group. Similarly, sexual behavioural scores, SC, testicular parameters and antioxidant profiles were higher and oxidative stress profile was lower in MT treated than in untreated control group and in winter and spring than in summer season. The study concluded that exogenous slow-release melatonin implantation and spring and winter seasons had significant beneficial effects in improvement of the antioxidant profiles, minimization of oxidative stress with cascading beneficial effects on endocrinological profiles, SC, testicular parameters and libido, which will improve the semen production, higher sperm cryo-survivability and fertility rate in mithun species.

Administration of slow release exogenous melatonin modulates oxidative stress profiles and in vitro fertilizing ability of the cryopreserved mithun (Bos frontalis) spermatozoa.

Mithun (Bos frontalis) is a unique domestic free range bovine species of North Eastern hilly regions of India. The present study was designed to assess the seasonal effect of slow release exogenous melatonin (MT) implant on semen quality parameters (SQP) and in vitro zona binding ability (IVZ) of spermatozoa. The experimental animals were divided into Gr I: Control (n = 5) and Gr II: Treatment (n = 5; melatonin implant @ 18mg/50 kg bwt). A total of 20 semen samples/group in winter, spring, autumn and summer seasons (n = 160), twice per week were collected. Following cryopreservation, samples were evaluated for motility parameters (forward progressive, mobility & velocity by computer assisted sperm analyser (CASA), viability, acrosome integrity, plasma membrane and nuclear abnormality, functional status of mitochondria, enzymatic, antioxidant and oxidative profiles, and IVZ. The study revealed significant (p < 0.05) improvement in total motility, viability, acrosome-, plasma membrane-, and nuclear-integrity, and antioxidant profiles; with highest values in spring and lowest in summer season in the fresh semen in Gr II than the Control. A significant (p < 0.05) improvement in motility parameters, membrane potential of mitochondria, antioxidant profiles and reduction in sperm and nuclear abnormalities, leakage of intracellular enzymes and oxidative stress and IVZ index & binding percentage in post-thaw semen samples in melatonin supplemented than in un-supplemented control group was observed. It can be concluded from the study that slow-release melatonin supplementation can be effectively utilized to improve the antioxidant profiles and reduction of oxidative stress, with cascading beneficial effects on semen quality parameters and fertility status of the mithun bull.

Effects of low-density lipoproteins as additive on quality parameters and oxidative stress following cryopreservation of mithun (Bos frontalis) spermatozoa.

Artificial breeding of mithun poses several challenges including lack of standard protocol for cryopreservation of spermatozoa. This is further complicated by harmful effects of hen's egg yolk (EY) as additive in extender. Purified low-density lipoproteins (LDL) extracted from EY have been shown as beneficial over EY extender for long-term semen storage in several species. This investigation explored use of LDL versus EY on semen quality and oxidative stress following freezing-thawing of spermatozoa. A total of 25 of 50 ejaculates based on biophysical parameters were selected for the experiment. After diluting with the Tris-citrate-glycerol (TCG) extender, each sample was split into three equal aliquots: Group I, control, EY; Group II and Group III contained 8% and 10% purified LDL, respectively. Frozen-thawed samples were evaluated for motility parameters (progressive, and in the bovine cervical mucus penetration test [BCMPT]), viability, sperm and nuclear abnormality, acrosome integrity, and enzymatic (leakage of intracellular contents) and biochemical (oxidative stress) profiles and in vitro fertility (IVF) assay. Study revealed a significant (p < .05) improvement in viability, sperm and nuclear abnormality, acrosome integrity, motility (progressive and in cervical mucus), cholesterol content, and reduction in the leakage of intracellular enzymes in Group II. Moreover, intactness of acrosome and biochemical membranes was protected significantly (p < .05) in addition to significant (p < .05) improvement in binding per cent and binding index in IVF assay in extender containing 8% LDL. These results demonstrate that although cryopreservation of mithun's spermatozoa in EY was comparable with other species, addition of 8% LDL holds a clear advantage over EY or 10% LDL.

Effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa.

The effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa was investigated. Semen samples were collected from five healthy mithun bulls through rectal massage method and cryopreserved in liquid nitrogen. The samples were diluted in Tris-egg yolk-glycerol extender, equilibrated for 4 h at 4 °C and loaded into 0.50-ml straws. The straws were then frozen in liquid nitrogen vapour for 10 min and finally plunged into liquid nitrogen for storage. The required amount of glycerol was added into the diluted samples either in a single dose (3%, 4%, 5%, 6% or 7%; added at 37 °C immediately before equilibration) or in split doses (5%, 6% or 7%; the total amount was divided into four equal parts, and a part was added at 37 °C immediately before equilibration, and the remaining parts were added subsequently at 1, 2 and 3 h of equilibration at 4 °C). In the single-dose addition method, following freeze-thawing, greater (p < 0.05) motility (%) and proportion of live spermatozoa with intact acrosome (LSIA, %) in 5% glycerol (40.6 ± 1.7 and 43.4 ± 1.8 respectively) and lesser (p < 0.05) total morphological abnormalities (%) in 5% (14.1 ± 0.8) and 6% (13.7 ± 1.0) glycerol were observed compared to the other glycerol concentrations. In the split-dose addition method, following freeze-thawing, greater (p < 0.05) motility (%) and LSIA proportion (%) were found in 5% (50.2 ± 1.9 and 53.3 ± 1.8 respectively) compared to 6% or 7% glycerol, but the total morphological abnormalities were not different among the glycerol concentrations. In addition, in all the glycerol concentrations, better (p < 0.05) post-freeze-thaw motility and LSIA proportions were observed when glycerol was added in split doses compared to a single dose. In conclusion, Tris-egg yolk extender with 5% glycerol added in split doses was found most suitable for cryopreserving mithun sperm.

Characterization of shiga toxin producing (STEC) and enteropathogenic Escherichia coli (EPEC) in raw yak (Poephagus grunniens) milk and milk products.

Thirty-one shiga toxin-producing (STEC) and 6 enteropathogenic Escherichia coli (EPEC) were isolated from 87 raw yak milk and 63 'churpi' samples. Of 18 stx(1) positive isolates (48.6%), 14 carried stx(1c) (77.7%). Subtyping of 28 stx(2) positive isolates (75.7%) revealed the presence of stx(2c) (9, 32.1%), stx(2d) (3, 10.7%), stx(2e) (1, 3.57%) and stx(2f) (3, 10.7%) variants. Furthermore, intimin (eaeA), enterohaemolysin (ehxA), autoagglutinating adhesin (saa), iha (adherence conferring protein), efa1 (EHEC factor for adherence), bundle forming pilli (bfpA) and toxB (type III secreted protein encoded on LEE Island, similar to toxin B of Clostridium difficile) genes were detected in 14, 16, 12, 4, 3, 2 and 2 isolates, respectively. Univariate and multivariate analysis depicted that both stx(1) and stx(2) or their variants were more likely to occur in isolates from Arunachal Pradesh (p<0.04) rather than Sikkim. Dendogram constructed on the basis of RAPD and ERIC PCR profile distributed the STEC and EPEC isolates in separate clusters irrespective of their sources and serotypes. The STEC and EPEC isolates exhibited resistance against erythromycin, amikacin, azithromycin, amoxicillin, ampicillin+cloxacillin, cephalothin, furazolidone, gentamicin, kanamycin, streptomycin and tetracycline. This is the first ever report on occurrence and characterization of STEC and EPEC isolated from yak milk and milk products.

Plant morphophysiological and anatomical factors associated with nitrous oxide flux from wheat (Triticum aestivum).

Experiments were conducted to study the dynamics of nitrous oxide (N2O) emission from wheat varieties viz., Sonalika, HUW 468, HUW 234 and DBW 14 grown in alluvial soils of North Bank Plain Agroclimatic Zone of Assam, India. Attempts were made to find out the relationship of N2O emission with plant morphophysiological, anatomical and soil properties. N2O fluxes from wheat varieties ranged from 40 µg N2O-N m⁻² h⁻¹ to 295 µg N2O-N m⁻² h⁻¹. Soil organic carbon and soil temperature have shown significant relationship with N2O flux. The rate of leaf transpiration recorded from the wheat varieties at different growth stages exhibited a positive correlation with N2O emission suggesting that movement of N2O along with the transpirational water flow may be an important mechanism of N2O transport and emission through wheat plants. Anatomical investigation by scanning electron microscope revealed that N2O emission has relationship with stomatal frequency of leaf and leaf sheaths. Variety HUW 234 with the highest stomatal frequency of leaf and leaf sheath also recorded higher seasonal N2O emission compared to other varieties. Seasonal N2O emission (E(sif)) of the varieties ranged from 3.25 to 3.81 kg N2O-N ha⁻¹. Significant variations in E(sif) values were recorded within the varieties.

Effect of method and time of first colostrum feeding on serum immunoglobulin concentration, health status and body weight gain in mithun (Bos frontalis) calves.

The effect of method and time of first colostrum feeding on the concentration of serum immunoglobulin (Ig) was evaluated in mithun (Bos frontalis) calves. The hypotheses were that the variable method and time of first colostrum feeding might affect the level of serum Ig and in turn the growth performance and health status of the claves during the early age. The newborn calves were randomly allotted to one of the four experimental groups - G-1: allowed to suckle the dam at own choice, G-2: separated immediately after birth and allowed to suckle the dam first at 6 h and then at own choice, G-3: bottle fed ad libitum colostrum of its own dam first at 6 h and then at 6-h intervals until 24 h, G-4: bottle fed ad libitum colostrum of its own dam within 1 h, at 6 h and then at 6-h intervals until 24 h. The concentrations of IgG, IgM, and IgA were lowest (p < 0.01) at birth and increased following colostrum feeding irrespective of the experimental group. Highest concentrations of all the Ig classes were observed at 12-24 h after birth. The concentrations then transiently decreased from day 7 to 14, and then steadily increased after day 28. The concentrations of IgG (p < 0.01) and IgA (p < 0.05) were higher in G-1 in relation to the other groups during the first week after birth. Similarly, higher concentration of IgA (p < 0.05) was found in G-1 in relation to the other groups during the rest of the experimental period. The apparent absorption efficiency of colostral IgG was higher (p < 0.05) in G-4 in relation to G-3. Growth rate and health status were not influenced by the method and time of first colostrum feeding. In conclusion, a 6-h delay in the first colostrum feeding reduced the level of serum Ig noticeably.

Intake, digestibility and nitrogen balance in Mithun (Bos frontalis) offered urea-treated paddy straw based feed blocks.

The aim of the study was to determine the effect of feeding feed blocks containing varying proportion of urea-treated paddy straw (UTPS) on dry matter (DM) intake (DMI), nutrient utilization and N balance in Mithun. For the purpose, four adult male Mithun (279.5 ± 8.2 kg) were selected and offered four experimental rations viz. R(1) (Napier fodder + concentrate at 60:40), R(2) (UTPS + concentrate at 50:50), R(3) (UTPS + concentrate at 60:40) and R(4) (UTPS + concentrate at 70:30) in 4 × 4 Latin square design. The DMI % of body weight was 2.59, 2.96, 2.85 and 2.77 and the DMI g kg(-1) W(0.75) was 107, 123, 118 and 115 in Mithun fed R(1), R(2), R(3) and R(4), respectively. The mean DMI was (P < 0.01) higher in animals fed R(2) and R(3) than R(1) and R(4), whereas the water intake was (P < 0.01) higher in Mithun fed R(2), R(3) and R(4) than R(1). The digestibility of DM, organic matter, crude protein, crude fibre, neutral detergent fibre and cellulose were (P < 0.05) higher in animals fed R(2), R(3) and R(4) than R(1). A positive N balance was observed in all the experimental animals, with higher (P < 0.05) values among the animals offered R(2), R(3) and R(4) than R(1). The digestible crude protein and total digestible nutrient intakes were higher (P < 0.05) in Mithun fed R(2) and R(3) than R(1) and R(4). It is concluded that the UTPS can be incorporated up to 70% to formulate the complete feed/feed block and can be used for feeding of Mithun under complete confinement system.

Comparative nutrient utilization, growth, and rumen enzyme profile of mithun (Bos frontalis) and Tho-tho cattle (Bos indicus) fed on tree-leaves-based ration.

A study was conducted to compare the nutrient utilization, growth, and rumen enzyme profile of mithun (Bos frontalis) and Tho-tho cattle (Bos indicus) reared in the same feeding and managemental conditions. For the purpose, male mithun (n = 8) and male Tho-tho cattle (n = 8) of 1.5 years age, selected from the farm of National Research Centre on Mithun, Nagaland, India, were fed on mixed-tree-leaves-based ration as per the requirement of NRC (2001) for cattle for 12 months. Average daily gain (ADG), average dry matter intake (DMI), and feed conversion ratio (FCR) for all animals were recorded. A metabolic trial was conducted at 6 months of the experiment to assess the digestibility coefficient of different nutrients and nutritive value of ration. At 12 months of the experiment, rumen liquor was collected from all animals and analyzed for rumen enzyme profiles, viz., carboxymethylcellulase, xylanase, α-amylase, ß-glucosidase, α-glucosidase, urease, and protease. It was found that ADG (507.8 g vs 392.8 g), DM intake (6.59 vs 5.85 kg/day) and DMI/W(0.75) (98.75 g vs 91.00 g/day), crude protein intake (780 vs 700 g/day), and total digestible nutrient intake (3.65 vs 3.32 kg/day) were higher (p < 0.05) in mithun than cattle. The nitrogen balance was higher and FCR was better (p < 0.05) in mithun compared with cattle. The digestibility coefficient of different nutrients was similar (p > 0.05) between the species. The microbial enzyme profiles of mithun and cattle were not different (p > 0.05). The better growth performance of mithun than cattle as found in the present study clearly indicates that the mithun has higher genetic potential for growth than Tho-tho cattle of north-eastern hilly region of India.

Detection of bovine herpesvirus 1 sequences in yaks (Bos grunniens) with keratoconjunctivitis, using a highly sensitive nested polymerase chain reaction.

Thirty-seven yaks (Bos grunniens) with keratoconjunctivitis and 22 healthy yaks were used to investigate the role of bovine herpesvirus 1 (BoHV-1) in keratoconjunctivitis in yaks. Nucleic acid sequences of BoHV-1 glycoproteins B and E were detected in conjunctival swabs from all yaks with keratoconjunctivitis using a nested polymerase chain reaction (PCR). In 21 yaks, BoHV-1 sequences were detected along with Moraxella bovis (M. bovis) and Neisseria spp. The amplified BoHV-1 sequences were identical, and no nucleotide variation was observed when compared with a BoHV-1 reference strain using single-strand conformation polymorphism analysis of the amplified DNA sequences. Interestingly, BoHV-1 sequences could not be detected in samples from healthy yaks. However, conjunctival swabs from two healthy yaks (9.09%) yielded M. bovis and Neisseria spp. Samples from 35 yaks with keratoconjunctivitis showed positive reactions in an avidin biotin enzyme-linked immunosorbent assay for BoHV-1 antibodies; all the healthy yaks were seronegative. This is the first report of a possible association of BoHV-1 with keratoconjunctivitis in yaks.

Plant physiological and soil characteristics associated with methane and nitrous oxide emission from rice paddy.

Methane (CH4) and nitrous oxide (N2O) are important greenhouse gases causing global warming and climate change. Efforts were made to analyze the CH4 and N2O flux in relation to plant and soil factors from rice (Oryza sativa L.) paddy. Ten popularly grown rice varieties namely Rashmisali, Bogajoha, Basmuthi, Lalkalamdani, Choimora (traditional varieties); Mahsuri, Moniram, Kushal, Gitesh and Profulla (high yielding varieties = HYV) were grown during monsoon season of July 2006. The CH4 and N2O emissions were measured the date of transplanting onwards at weekly interval along with soil and plant parameters. The seasonal integrated CH4 and N2O emission (Esif) from rice ranged from 8.13 g m(-2) to 13.00 g m(-2) and 121.63 mg N2O-N m(-2) to 189.46 mg N2O-N m(-2), respectively. Variety Gitesh emitted less N2O and CH4 amongst all the rice varieties. Both CH4 and N2O emission exhibited a significant positive correlation with leaf area, leaf number, tiller number and root dry weight. Soil organic carbon of the experimental field was associated with both CH4 and N2O emission whereas nitrate-N content of soil was associated with N2O emission. Methane emission showed significant positive correlations with soil temperature and crop photosynthetic rate. Traditional rice varieties with profuse vegetative growth recorded higher CH4 and N2O fluxes compared to HYVs. Gitesh and Kushal having low seasonal CH4 and N2O emission with higher yield potential can be recommended as low greenhouse gas emitting rice varieties.

Early puberty in local Naga boar of India: assessment through epididymal spermiogram and in vivo pregnancy.

Male Naga pig of India, a miniature breed is known for its meat quality and early puberty. No scientific efforts were made to verify the farmers' view that this breed reaches puberty at around 2 months of age. A preliminary study was, therefore, conducted with the objectives: (a) to find out the age at puberty based on mature spermiogram and in vivo pregnancy and (b) to record the sperm morphology in different parts of the epididymis. Animals were selected from two different age groups: group I aged 53 days and 2.4 kg and group II of 85 days and 3.0 kg. Semen samples collected from different sections of epididymis were analyzed for sperm motility, live spermatozoa, and morphological abnormalities. Motility increased (P<0.01) and live spermatozoa and total morphological abnormalities decreased (P<0.001) from caput through cauda epididymis in both the groups. Sperm motility, live spermatozoa and morphologically normal spermatozoa in each section of the epididymis were higher (P<0.01) in group II than I. Boars with >60% progressive motility, >70% live spermatozoa, <15% total morphological abnormalities and <10% abnormal acrosomes in cauda epididymal spermatozoa were considered mature spermiogram. As per this definition, pigs of group II had only mature spermiogram. In vivo pregnancy confirmation indicated that Naga boar could impregnate female as early as 90 days of age. In conclusion, Naga boar attained puberty by not later than 3 months with 3.0 kg, which is the lowest body weight at puberty in this species reported so far, as reflected by mature epididymal spermiogram and in vivo pregnancy confirmation.

Development of methane emission factors for Indian paddy fields and estimation of national methane budget.

A state-wise assessment of methane (CH(4)) budget for Indian paddies, based on a decadal measurement data across India is presented for the calendar year (CY) 1994, the base year for India's Initial National Communication (NATCOM) to the United Nations Framework Convention on Climate Change (UNFCCC), along with national trend from CY 1979 to 2006. The NATCOM CH(4) emission factors (EFs) for Indian paddy cultivation areas, generally having less than 0.7% of soil organic carbon (SOC), have been estimated as 17.48+/-4 g m(-2) for irrigated continuously flooded (IR-CF), 6.95+/-1.86 g m(-2) for rain-fed drought prone (RF-DP), 19+/-6 g m(-2) for rain-fed flood prone (RF-FP) and deep-water (DW), 6.62+/-1.89 g m(-2) for irrigated intermittently flooded single aeration (IR-IF-SA) and 2.01+/-1.49 g m(-2) for IR-IF multiple aeration (MA) paddy water regimes. The state-wise study for 1994 has indicated national CH(4) budget estimate of 4.09+/-1.19 Tg y(-1) and the trend from 1979 to 2006 was in the range of 3.62+/-1 to 4.09+/-1.19 Tg y(-1). Four higher emitting or "hot spot" states (West Bengal, Bihar, Madhya Pradesh and Uttar Pradesh) have accounted for 53.9% of total CH(4) emission with RF-FP paddy water regime as the major contributor. CH(4) emissions were enhanced by factors such as SOC ( approximately 1.5 times due to increase in SOC by approximately 1.8 times), paddy cultivars (approximately 1.5 times), age of seedlings (approximately 1.4 times), and seasons (approximately 1.8 times in Kharif or monsoon than in Rabi or winter season).

Methane emission characteristics and its relations with plant and soil parameters under irrigated rice ecosystem of northeast India.

Methane flux from rice varieties grown under two identical soils of Assam were monitored. In the first experiment, variety Jaya and GRT was grown in sandy loam soil of Lower Brahmaputra Valley Zone of Assam and the second experiment was conducted with variety Jyotiprasad and Bishnuprasad in sandy to sandy loam soils of Upper Brahmaputra Valley Zones of Assam. Methane flux recorded from variety Jyotiprasad and GRT was higher compared to variety Bishnuprasad and Jaya. The seasonal integrated flux recorded was 10.76 gm(-2), 9.98 gm(-2), 9.74 gm(-2) and 11.31 gm(-2) for variety GRT, Jaya, Bishnuprasad and Jyotiprasad, respectively. All the varieties exhibited two methane peaks one at maximum tillering stage and other at panicle initiation stage of the crop. Crop growth parameters such as leaf number, number of tillers and leaf area index (LAI) showed strong positive relationship with total methane flux. In both the experiments it was calculated that CH4 emission was substantially influenced by crop phenology and growth. This study emphasise the relationship of different growth parameters with methane emission.

Studies on thermal degradation and termite resistant properties of chemically modified wood.

A series of experiments were carried out to examine the resistant capacity of a chemically treated hard wood, Anthocephalus cadamba (Roxb) Miq. to thermal and termite degradation. The treatment with thermosetting resins viz. urea formaldehyde (UF), melamine formaldehyde (MF) and phenol formaldehyde (PF) at 31-33 levels of weight percent gain (WPG) increased the strength property i.e. modulus of rupture (MOR) by 7.50-21.02% and stiffness i.e. modulus of elasticity (MOE) by 9.50-12.18% over the untreated one with no remarkable effect on specific gravity. The treated samples were found resistant to termite attack, while the untreated one was badly damaged by termites on 12 months' exposure to a termite colony. The thermal degradations of untreated and treated wood samples were studied using thermogravimetric (TGA) and differential thermogravimetric (DTG) techniques at heating rates 20 and 30 degrees C min(-1) in temperature range 30-650 degrees C. The treated wood was found to be thermally more stable than the untreated one.