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ThesisItem Open Access Evaluation of hepatoprotective effect of ethanolic extract of eugenia jambolana (njaval) leaves on paracetamol induced toxicity in rats(Department of Pharmacology and Toxicology, College of Veterinary and Animal Sciences Mannuthy, 2008) Midhun, M V; Aravindakshan, C MThesisItem Open Access Enhancement of propagation efficiency in exotic varities of heliconia(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2008) Reshmi, C R; KAU; Sheela, V LHeliconias are among the most popular garden plants, both for the ease with which they can be grown and the sheer magnificence of the blooms. Studies were conducted to standardize rapid propagation techniques under in vitro and in vivo conditions. Three heliconia varieties belonging to three distinct groups viz., St. Vincent Red (small erect type), Golden Torch Adrian (hybrid) and Sexy Pink (large pendent type) were selected for the study. For in vitro culture establishment, shoot tip explants were effective. The treatment of shoot tips with 0.10 per cent mercuric chloride for ten minutes followed by dipping in 0.05 per cent mercuric chloride for five minutes (after trimming) resulted in better surface sterilization. Longitudinal cutting of the in vitro established shoot tip with apical dome into two halves and culturing them separately produced the highest number of axillary buds. Addition of 0.05 per cent activated charcoal to the establishment media reduced the media browning and hastened shoot initiation. For culture establishment of all the three varieties, MS medium supplemented with BA 5.00 mg l-1 was found to be the best. Murashige and Skoog medium supplemented with BA 2.00 mg l-1 resulted in the highest shoot proliferation in the variety St. Vincent Red. In Golden Torch Adrian, BA 2.00 mg l-1 + NAA 0.20 mg l-1 gave better results. In the variety Sexy Pink, Kinetin 5.00 mg l-1 + NAA 0.20 mg l-1 was the best. For further multiplication in Sexy Pink, BA 1.00 mg l-1 was sufficient. Solid culture medium was better for shoot proliferation in the variety Sexy Pink. Higher sucrose concentration (40.00 g l-1) increased the multiplication rate, but reduced the length of shoots as well as the number of leaves. Addition of activated charcoal to the media as well as exposure of cultures to light had negative effect on shoot proliferation. Full MS medium was found to be the best for in vitro rooting of the variety Sexy Pink. Addition of NAA 0.50 mg l-1 to the MS medium gave better results for in vitro rooting in Golden Torch Adrian and Sexy Pink. Sucrose @ 30.00 g l-1 was sufficient for in vitro rooting in the variety Sexy Pink. Activated charcoal delayed root initiation and reduced the number of roots in the variety Sexy Pink. Sand recorded 90.00 per cent survival in all the three varieties after two months of planting out. At varietal level, significant difference was evident in the total number of suckers. In the first experiment, the variety St. Vincent Red (3.82) was significantly superior in terms of total number of suckers. However, in the second experiment, St. Vincent Red (4.06) was on par with Golden Torch Adrian (4.10). The variety Sexy Pink produced comparatively taller suckers in both the trials. Varietal variation in the number of leaves was observed only in the earlier stages. During the preliminary field experiment, the variety Sexy Pink excelled in leaf area at almost all stages of observation. Among the three varieties, highest collar girth was recorded by suckers of Sexy Pink variety during the first two stages of observation. However, towards the later stages, it was statistically on par with St. Vincent Red. Foliar spray was superior to rhizome dip in terms of total number of suckers, height of suckers and the number of leaves. In the case of leaf area, both the treatments were more or less on par. Application of growth regulators had pronounced effect on sucker production at all the stages during the first experiment when BA 750 mg l-1 produced the highest number (4.19) of total suckers. In the second experiment, variation was evident only in the total number of suckers. Here, BA 850 mg l-1 produced the highest number (4.33) of suckers and it was on par with BA 700 mg l-1 (4.00) and GA3 650 mg l-1 (3.79). Irrespective of the stage of plant growth, gibberellic acid produced taller suckers and BA 500 mg l-1 resulted in the shortest suckers. BA treatments recorded comparatively higher number of leaves. Growth regulator application had remarkably influenced the leaf area of suckers also. Application of BA 1000 mg l-1 (3.53 cm) and GA3 800 mg l-1 (3.33 cm) recorded higher collar girth in suckers. VG interaction exerted significant variation in the number of suckers. At varietal level, BA 750 mg l-1 produced the highest number of suckers in St. Vincent Red (4.75), GA3 500 mg l-1 in Golden Torch Adrian (4.63) and GA3 750 mg l-1 in Sexy Pink (4.00). Among VG treatment combinations in the second experiment, the highest number of suckers (4.75) in the variety St. Vincent Red was produced by BA 700 mg l-1. The varieties Golden Torch Adrian (4.88) and Sexy Pink (3.75) recorded the highest with BA 850 mg l-1. Gibberellic acid produced taller suckers. In the second experiment, VG interaction had no significant effect on the height of suckers. Regarding the number of leaves, BA resulted in comparatively higher number of leaves in both the experiments. In all the three varieties, BA 850 mg l-1 produced the highest number of leaves. Collar girth was found to increase with increase in the concentrations of BA and GA3 in all the three varieties. The economics of foliar application of growth regulators revealed that BA 850 mg l-1 significantly enhanced the profit in the varieties Golden Torch Adrian and Sexy Pink. Although negligible, BA 700 mg l-1 recorded slight positive response in the variety St. Vincent Red with respect to profit.ThesisItem Open Access Population dynamics and management of aphids in vegetable ecosystem(Department of Agricultural Entomology, College of Agriculture, Vellayani, 2009) Thamilvel, D; KAU; Hebsy, BaiEight species of aphids viz., A. gossypii, A. craccivora, A. spiraecola, A. fabae, A. nerii, H. setariae, M. persicae and L. erysimi were recorded from 32 vegetables in a survey conducted in the four taluks of Thiruvananthapuram district of Kerala. Occurrence of A. gossypii on C. grandis, M. oleifera and P. tetragonolobus; A. craccivora on C. gladiata, P. tetragonolobus and S. grandiflora ; A. spiraecola on A. tricolor, C. sativus, C. tetragonoloba, M. oleifera, M. charantia, M. koeingii, P. tetragonolobus and S. androgynus ; M. persicae on A. tricolor and R. sativu; A. nerii on C. annuum and C. frutescens was recorded for the first time from the State and H. setariae on A. tricolor and A. dubius from South India. One hundred and twenty two other plants were identified as host plants of the different aphids. A. gossypii was the dominant species noted, closely followed by A. craccivora, and A. spiraecola. Maximum species of aphids were recorded on amaranthus followed by winged bean. Among the vegetables surveyed, chilli and coccinia were highly susceptible to A. gossypii and winged bean and cowpea to A. craccivora. Mosaic disease incidence was noted in 10 vegetables. Predators were the predominant group of natural enemies associated with the aphids with the coccinellids constituting the major predatory fauna. Twenty species of coccinellids were recorded from different species of aphids on various host plants of which 13 species were new records from Kerala. M. sexmaculatus was the dominant species followed by C. transversalis, S. latemaculatus and C. septempunctata, Four species of syrphids were recorded of which I. scutellaris was predominant. P. yerburiensis and D. aegrota were recorded for the first time from Kerala. Leucopis sp. was the only Chamaemyiid species recorded from the vegetable fields. The chrysopids, C. carneae and A. octopunctata and the hemerobiid, Micromus sp. were the Neuropteran predators of the aphids recorded of which Micromus sp. was dominant. A. octopunctata was recorded for the first time from Kerala. Eleven species of spiders were observed in the vegetable fields among which, O. javanus, T.mandibulata, O. quadridentatus, O. shweta and Phidippus sp. were the frequently encountered species. Aphidius sp. was the most dominant parasitoid in the vegetable ecosystem. Aphelinus sp. and D. rapae were the other parasitoids recorded. Seven species of ants were observed attending the aphids. Studies on the population fluctuation of A. gossypii in chilli and A. craccivora in winged bean during a cropping season indicated that high population was seen during November and December. Correlation studies revealed a significant and positive correlation between the population of both the aphids with the insect predators, spiders and parasitoids. None of the climatic parameters had any significant influence on the aphid population. Excepting, maximum temperature which had a positive influence, all the other weather parameters viz., minimum temperature, relative humidity, rainfall and wind velocity had a negative influence on the population of the predators and parasitoids. Among the botanicals screened in the laboratory, only neem oil- garlic emulsion 2% and NeemAzal T/S 4 ml/l recorded more than 50 per cent mortality of A. gossypii and A. craccivora. Among the insecticides, the neonicotinoids viz., acetamiprid 0.002% imidacloprid, 0.003%, and dimethoate 0.05% proved superior to all other treatments. Dimethoate 0.05% was highly toxic to the coccinellids, syrphids and a hemerobiid (Micromus sp.) predator under laboratory condition. Between the two neonicotinods, acetamiprid 0.002% registered higher mortality than imidacloprid 0.003% whereas NeemAzal T/S 4 ml/l and neem oil + garlic emulsion 2% were safe to the predators. Foliar application of dimethoate 0.05%, acetamiprid 0.002% and imidacloprid 0.003% gave good control of A. gossypii, A. biguttula biguttula, S. dorsalis and A. dispersus in chilli and A. craccivora, A. dispersus, R. pedestris and M. vitrata in winged bean. NeemAzal T/S 4ml/l and neem oil garlic emulsion 2% too checked the population of the pests appreciably. Dimethoate 0.05% was highly toxic to the predators and parasitoids followed by acetamiprid 0.002% both in the chilli and winged bean fields. Comparatively, imidacloprid 0.003% was less toxic. The botanicals were safer to the natural enemies. Dimethoate 0.05% was highly toxic to soil fauna and flora whereas acetamiprid and imidacloprid were less toxic while NeemAzal T/S 4ml/l and neem oil + garlic emulsion 2% were non toxic. In both the trials, significantly higher yield was obtained from all the treatments. However, no significant difference was noted in the yields obtained from acetamiprid 0.002%, imidacloprid 0.003% and dimethoate 0.05% treated plots. Residues of imidacloprid were detected in chilli and winged bean fruits five days after spraying. While on the tenth day after spraying, residues of acetamiprid, and dimethoate were detected in chilli fruits, only residue of acetamiprid was recorded from winged bean pods. Imidacloprid was below detectable level (BDL). Residues of all the three insecticides were below detectable level when estimated fifteen days after spraying. Based on the results of the study, early detection of aphids on weeds and other host through regular monitoring, proper weed and ant management, conservation of the beneficials, application of neem oil + garlic emulsion 2% or NeemAzal T/S 4ml/l during the early stage of infestation and use of imidacloprid 0.003% when needed are suggested for aphid management in vegetables.ThesisItem Open Access Shelf life of irradiated rabbit meat underaerobic and vacuum packaging(Department of Livestock Products Technology, College of Veterinary and Animal Sciences, Mannuthy, 2009) Sonika, S; KAU; Kuttinarayanan, PPrevention of Food Adulteration Act (1954) as amended in 1998 has permitted irradiation at a dose rate of 2.5 to 4.5 kGy to control pathogenic microorganisms and to extend the shelf life of meat and meat products including poultry products. A study was conducted to evaluate the shelf life of irradiated rabbit meat under aerobic and vacuum packaging. The rabbit meat was prepared by slaughtering locally purchased rabbits under hygienic conditions and was packed in HDPE and PAPE packages at a rate of 120 g each. Half of the packets of aerobic and vacuum packaged samples were subjected to gamma radiation at 2.5 kGy at melting ice temperature and kept immediately at chiller temperature (1 to 4oC) and domestic refrigerator freezer (-6 to -8oC). Samples were analyzed for physical, physicochemical, microbiological, and organoleptic qualities on the day of preparation and on days 3, 5, 10, 15, 20, 25, 30, 40, 45, 50, 60, and 70 of storage or until spoilage, whichever was earlier. The samples were also analyzed for proximate composition on the day of preparation. The dressing percentage of the rabbits subjected to the study was 49.35 per cent. The keeping quality of the rabbit meat was 15 to 18, 17 to 19, 5 to 7 and 7 to 9 days in HDPE IR, PAPE IR, HDPE NR and PAPE NR respectively at chiller temperature. In freezer temperature it was significantly (P < 0.05) increased to 45 to 47, 47 to 49, 25 to 27 and 27 to 29 days in HDPE IR, PAPE IR, HDPE NR and PAPE NR respectively. Irradiation or packaging did not significantly (P < 0.05) affect fat, protein and ash composition but higher moisture percentage was observed in irradiated samples. Swelling of the collagen fibres was noticed in irradiated samples on histological examination. The physicochemical parameter, pH of irradiated and non-irradiated samples varied significantly (P < 0.05) on the day of preparation. On storage the pH values decreased uniformly. The WHC was significantly (P < 0.05) reduced in irradiated samples. The ability of the rabbit meat to retain its water decreased gradually on storage and a reduction of about 40 per cent could be noticed from the initial level. Drip loss was not significantly (P < 0.05) different on the day of preparation. Irradiation had a significant (P < 0.05) effect in enhancing the cooking loss whereas packaging had little effect. Both drip loss and cooking loss was increased significantly (P < 0.05) due to storage under chiller and freezer temperature. Irradiation had a significant (P < 0.05) role in increasing the TBARS value of rabbit meat. As the days of storage enhanced, the TBARS values were increased. Irradiation had a significant (P < 0.05) effect in reducing the TV in both type of packaging. As storage period enhanced, TV increased with significant (P < 0.05) changes among treatments. Irradiation had a beneficial effect on microbiological qualities of rabbit meat. There was a significant (P < 0.05) reduction of nearly three log in APC of irradiated meat from that of control. The irradiation of the samples both in HDPE and PAPE packaging significantly (P < 0.05) reduced the PC of meat on the day of preparation where as storage had significant (P < 0.05) effect in enhancing the microbial load of meat. The colour score was non-significantly (P < 0.05) higher in irradiated samples. The juiciness, tenderness and overall acceptability scores were improved significantly (P < 0.05) due to irradiation, where as flavour score was reduced. The sensory attributes were significantly (P < 0.05) reduced due to storage in all the treatment groups. The keeping quality of rabbit meat was significantly (P < 0.05) increased by irradiation both in chiller and freezer under different packaging. In addition irradiation could effectively control food borne illness by destroying the major pathogenic organism without affecting the sensory and nutritional quality of the product. Considering these advantages it can be recommended that packaging the meat in PAPE packages followed by low dose gamma irradiation and maintaining the cold-chain contribute to extended storage life of rabbit meat.ThesisItem Open Access Forecasting volatility of the indian stock market(Department of Rural Banking and Finance Management, College of Co-operation, Banking and Management, Vellanikkara, 2009) Khadilkar Guruprasad, Hari; KAU; Molly, JosephThe present study on ‘forecasting volatility of the Indian stock market’ was conducted with the main objectives of examining the volatility behaviour of the Indian stock market, to forecast the sector- wise volatility of the Indian stock market and to identify the most efficient volatility forecasting model among the different models used. For the study the biggest stock market in India in terms of total turnover and volume of transactions, ie, National Stock Exchange was selected. For analyzing the volatility behaviour of the Indian stock market as a whole, S&P CNX Nifty index was taken. Five companies representing five different sectors were selected for forecasting sector – wise volatility. The study used secondary data on daily close prices of individual stocks from November 1994 to October 2008, and for Nifty, daily close values, from November 1995 to October 2008 from the website of National Stock Exchange, www.nseindia.com. The study revealed presence of strong volatility in the Indian stock market. The histogram drawn for the volatility of all samples showed that the distribution of volatility was not normal. There was positive skewness and all the distribution of volatility was leptokurtic. This proved the presence of high peak values (squared returns) in the sample data, exposing the evidence of volatility clustering and the possibility for prediction of future volatility. While analysing sector -wise volatility, the diversified sector represented by Reliance Industries Limited showed the highest volatility compared to that of Nifty and the other sectors. In other words, Reliance is the most volatile stock among the samples selected for the study. Reliance and Infosys had good predictability of volatility in the stock market. The best identified model for forecasting the volatility of stock markets is the EWMA. Then comes AR (1) followed by MA (3), RWM and HMM. Random walk model was found suitable for the prediction of volatility of two sectors - IT (Infosys) and engineering heavy (BHEL) only. But the MAPE values of these were high. Historic mean model could not predict the volatility in the stock market with precision, for the index as well as for any of the five companies. Out of three, six, nine and twelve monthly moving averages taken for predicting the volatility three months moving average was found most suitable for all the samples. Prediction of volatility using the most efficient model of EWMA identified indicated decreasing trend of volatility for the next six months, except for Infosys. The confidence limits for the Nifty and the stocks of five companies based on volatility for the sample period found that for Infosys the distribution of volatilities for the out of sample period are coming within the prefixed UCL and LCL and it ensures that the volatility is under control and predictable with high degree of precision. The ever increasing market segments, advancement of technology, widening market reach and multi dimensions of stock market provide ample scope for further research in this area to the advantage of the investors and other market participants.ThesisItem Open Access Effect of seed treatments and shade on seedling growth dynamics of pongamia pinnata (Linn.) pierre in the nursery(Department of Forest Management and Utilisation, College of Forestry, Vellanikkara, 2009) Gururaj Sankeshwar, B; KAU; Gopakumar, SThe present study entitled “Effect of seed treatments and shade on seedling growth dynamics of Pongamia pinnata (Linn.) Pierre in the nursery” was carried out in College of Forestry, Kerala Agricultural University, Vellanikkara, Thrissur during the period of 2007-2009. In the first phase, seeds were subjected to six pre-sowing treatments. GA3 treated seeds recorded highest Germination percentage, Final Mean Daily Germination (FMDG), Germination Value (GV) and Peak Value (PV). The effect of seed treatments were observed on various biometric parameters like height, collar diameter, number of leaves and primary branch. GA3 treated seeds recorded better height and collar diameter during the initial stage of seedling growth. At the end of study cold water seed treatment was found to be effective in enhancing seedling growth. However, none of the pretreatments was observed to cast a significant effect on biomass production and root growth parameters in Pongamia pinnata seedlings. In the second phase, to evaluate seedling growth under different shade conditions, seedlings were placed under 25 per cent shade, 50 per cent shade, 75 per cent shade and full sunlight situations. Shade treatments did not significantly influence height and collar diameter growth of Pongamia pinnata seedlings in the nursery. The maximum leaf production and primary branch production was observed in seedlings kept under full sunlight and 50 per cent shade respectively. Under seventy five per cent shade seedlings produce maximum shoot and root dry weight. The shoot: root ratio and total biomass was also maximum for seedlings kept under 75 per cent shade. Root length and spread were maximum under 50 per cent shade. However, shade did not significantly effect secondary root production. Shade levels also did not influence Pongamia pinnata seedlings with respect to relative growth rate and leaf area. However, Specific leaf area and Leaf area ratio was higher under 25 per cent shade. Highest Specific leaf weight was observed for seedlings under full sunlight. Shade had no significant effect on leaf weight ratio of seedlings. Maximum stomatal number was recorded under 25 per cent shade. In the nursery stage shade is casting an overriding influence with regards to various growth parameters of Pongamia pinnata.ThesisItem Open Access Comparative evaluation of membrane protein and biofilm vaccines against duck pasteurellosis(Department Of Poultry Sciences,College of Veterinary and Animal Sciences, Mannuthy, 2008) Indu, K; KAU; Krishnan Nair, CA research work was undertaken to prepare effective vaccines against P. multocida grown under different conditions and assess their immunopotency in one month old ducklings. The purity of the Pasteurella multocida A: 1 strain (DP1) and A: 4 strain (PA4) was confirmed as per standard procedures. Pathogenicity of DP1 and PA4 was assessed in six to eight week old mice. The isolates killed the intraperitoneally inoculated mice within eight hours and within 24 h when injected by subcutaneous route. Pasteurella multocida A: 1 was used for the preparation of different vaccines. The organism was grown in BHIB for preparation of ordinary bacterin. The in vitro biofilm formation of the organism was assessed by growing it under nutrient restricted conditions. For this, the organism was grown in TSB (0.32 per cent) supplemented with 0.3 per cent bentonite clay. For preparation of OMP suspension, the organism was grown in iron restricted condition viz., BHIB supplemented with 100 µM 2, 2’ Dipyridyl and the OMPs were extracted using sodium lauryl sarcosinate. The protein concentration of OMP suspension was estimated to be 3 mg/ml. Median lethal dose (LD50) of DP1 was 10-7.5, which contained 32 viable cells/ ml and that of PA4 was 10-7.38, which contained 24 viable cells/ ml when determined in one month old ducklings. Oil adjuvant vaccines were prepared using ordinary bacterin, bacterin made from biofilm and OMP suspension and performed the sterility, safety and potency tests of the vaccine employing standard procedures. A total of 260 four week old ducklings were divided into four groups with 65 birds in each group and the first three groups were vaccinated with ordinary bacterin, OMP vaccine and biofilm vaccine respectively. The fourth group served as control. The birds were vaccinated with 0.5 millilitre of vaccine intramuscularly in the thigh region. Blood was collected from all the ducks pre-vaccination, at weekly intervals upto 3 weeks post vaccination (PV) and then at 15 days interval upto 60 days, by cardiac puncture or by jugular venipuncture. Passive haemagglutination using GA-SRBC sensitized with sonicated antigen of DP1 was used to measure the humoral immune response. The IHA titres obtained for biofilm vaccine group on day 14 was very much higher than the other two groups. The antibody titre was observed from day seven onwards for all the groups. All the vaccine groups have shown significant difference from the control group at all the stages of the study. On homologous challenging, biofilm vaccine gave higher protection rates of 80 per cent than the 70 and 50 per cent protection rates of ordinary bacterin and OMP vaccine respectively, when challenged with 100 LD50 dose on day 20 PV. On day 60 PV, biofilm vaccine gave higher protection rate of 70 per cent than the 60 and 50 per cent protection rates respectively of ordinary bacterin and OMP vaccine, when challenged with 100 LD50 dose. On heterologous challenging, biofilm vaccine gave higher protection rates of 70 per cent, while only 50 per cent protection was afforded by both bacterin and OMP vaccine, when challenged with 100 LD50 dose on 20 day PV. On day 60 PV, biofilm vaccine gave higher protection rate of 60 per cent while both the other vaccines gave only 50 per cent protection, when challenged with 100 LD50 dose. All the birds challenged on day 40 PV, either with homologous and heterologous organisms died. In most cases, the death occurred due to coliform infection along with stressful factor such as increased atmospheric humidity due to heavy rainfall at that time. In few cases, birds died due to pasteurellosis which might be due to lack of protective level of antibody titre. Biofilm vaccine proved to be the best among the three vaccines tried. Further field trials are to be done before advocating this vaccine for commercial use.ThesisItem Open Access Growth and survival of penaeus monodon in monosex and mixed sex culture under laboratory condition(Department of Aquaculture, College of Fisheries, Panangad, 2008) Bajaniya Viralkumar, Chhaganlal; KAU; Mohanakumaran Nair, cSexual dimorphism is apparent in the black tiger shrimp, Penaeus monodon with females achieve larger size than the males. This character may be attributed to behavioral and/or physiological differences between the sexes. An experiment was developed to determine if there were advantages in rearing all female or all male P. monodon as opposed to mixed-sex populations. Juvenile shrimps (4.46±0.54 g) were collected from earthen pond and individually hand sexed and stocked in the circular cement tanks. Treatments all male, all female and mixed-sex were stocked @ 8 nos./tank. Each treatment had five replicates. The shrimps were offered commercial shrimp feed. The experiment was conducted for a period of 50 days. At harvest, all female shrimps had shown significantly higher growth than all male and mixed-sex treatment. Survival was not significantly different among treatments. FCR of all female was significantly lower than the all male and mixed-sex treatment. Result of the present study demonstrates a benefit to all female culture of P.monodon against the all male or mixed-sex culture. Thus culture of all female may be commercially more attractive to entrepreneurs. Although additional research is required to find a reliable and quick procedure for separation of the sexes or techniques for the production of all female populations.ThesisItem Open Access Effect of blood urea nitrogen,mineral status and uterine PH on fertility in dairy cows(Department of Animal Reproduction, Gynaecology and Obstetrics, College of Veterinary and Animal Sciences, Mannuthy, 2008) Seena, N S; KAU; Athman, K VAn investigation was carried out with the objective of studying the effect of BUN and uterine pH on fertility in dairy cows under farm and field conditions and also for correlating the mineral status with fertility using 40 crossbred dairy cows selected at random during oestrus, 20 each from those belonging to University Livestock Farm, Mannuthy (Group I) and those brought for insemination at Artificial Insemination Centres at Mannuthy and Kokkalai (Group II). All the cows in Group I were found to be maintained in a relatively high nutritious diet computed as per the scientific feeding standards compared to Group II animals. Detailed clinico-gynaecological examination was carried out and blood samples and uterine mucus were collected from all the selected cows during oestrus for estimation of biochemical parameters and uterine pH respectively. They were inseminated during the most appropriate period of oestrus and were subjected to pregnancy diagnosis at 60 days post insemination. Conception rates in both the groups were compared in relation to each parameter. The mean duration of oestrus was slightly higher in Group II (30.00 ± 2.11 hours) compared to Group I (26.10 ± 1.74 hours). Intensity of oestrus was high, medium and low in 40, 45 and 15 per cent of animals respectively in Group I and 50, 40 and 10 per cent in Group II. Physical changes of reproductive tract viz. degree of vulval oedema and hyperemia of vestibular mucous membrane were more pronounced in animals of Group II compared to Group I, where as degree of tonicity was high in Group I compared to Group II. Characteristics of cervical mucus were also found to be affecting fertility. Better conception rate was obtained in animals with clear and stringy cervical mucus exhibiting typical type of fern pattern. Spinnbarkeit value did not vary much between conceived and non-conceived animals. Uterine pH did not show a marked variation between groups, even though a slightly higher value was recorded in Group I. But, an inverse relationship could be obtained between BUN level in serum and uterine pH during oestrus. Correlation between uterine pH and BUN level was highly significant (P<0.01) with a correlation co-efficient of r = -0.896 and r = - 0.753 in groups I and II respectively. The mean blood urea nitrogen level in animals of Group I was significantly higher (P<0.05) than that in Group II. The BUN level also varied significantly (P<0.05) between conceived and non-conceived animals of both groups. A marginal increase in plasma glucose level could be noticed in conceived animals compared to non-conceived animals of Group I. The mean serum total protein was significantly higher (P<0.01) in Group I compared to Group II. The serum level of minerals viz. calcium, phosphorus, manganese, zinc and copper were also correlated with fertility. The mean level of serum calcium and manganese varied significantly between groups I and II, but there was no significant difference in serum phosphorus, zinc and copper between two groups. Also, a slightly higher mean value was observed for serum calcium, phosphorus, manganese and zinc in conceived animals compared to non-conceived. But serum copper level did not vary between conceived and non-conceived animals. In light of these findings, it can be concluded that the elevation in systemic concentration of urea is likely to impair fertility in dairy cows as a consequence of alterations in uterine environment. The benefits of feeding excess dietary protein and urea to maintain peak milk production should be compared with potential negative effects on fertility. Hence, a good nutritional management is essential for improved fertility in dairy cows.
