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Kerala Agricultural University, Thrissur

The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively. Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively. On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs. In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc. During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU). Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.

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  • ThesisItemOpen Access
    Bacteriological quality of goat milk
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1985) Chakhesang, Kevesiei; KAU; Sukumaran, M V
    A total of 376 aseptically – drawn milk and 46 farm pooled milk samples were collected from the AICRP on Goats for Milk, Mannuthy and subjected to various tests to determine the bacteriological quality. An increase of over 59 and 188 – fold in bacterial number from aseptically – drawn milk to production – and milk for the morning and the evening milkings respectively was noticed. In aseptically – drawn milk samples 61.17% and 64.83% gave a SPC of below 100/ml in the morning and evening respectively. In farm pooled milk samples the SPC exceeded 105/ml in 39.13% of the morning and 65.22% of the evening samples. No psychrophilic bacteria was detected in any of the aseptically – drawn or farm pooled milk samples. The mean thermophilic counts of aseptically – drawn as well as farm pooled milk samples was less than one/ml. Though the mean coliform count of aseptically – drawn milk was found to be less than one/ml, the farm pooled milk samples showed 3,413 and 2734/ml for the morning and the evening samples respectively. The mean MBRT of the morning and the evening samples was 14.91 and 8.93 h for aseptically – drawn milk and 4.57 and 3.83 h for farm pooled milk samples respectively. The correlation coefficient between MBR time and SPC of farm pooled milk of the morning and evening samples was not significant (- 0.21 and - 0.27). The keeping quality of the morning and the evening milk samples (280 C) obtained was respectively 50.48 and 44.70 h for aseptically – drawn milk and 12.87 and 12.04 h for farm pooled milk samples respectively. The correlation coefficient between SPC and keeping quality of farm pooled milk samples was significant (- 0.46) for morning sample while that of evening milk was not significant (+ 0.28). The correlation coefficient between MBRT and keeping quality of farm pooled milk samples was also not significant in both the morning and the evening (+ 0.31 and + 0.13).
  • ThesisItemOpen Access
    Qualitative changes of yoghurt prepared from milk preserved by different methods
    (Department of Dairy Science, College of Veterinary and Animal Sciences,Mannuthy, 1990) Prasad, V; KAU; Sukumaran, M V
    An experiment was conducted to study the qualitative changes of yoghurt prepared from milk preserved by different methods. An attempt was also made to study the efficiency of LP system in controlling psychrotrops in refrigerated milk thereby extending the keeping quality of such stored milk. The efficacy of the system was compared with pasteurized milk and raw milk stored under similar conditions. An exhaustive review of literature has been presented on the use of various preservation methods employed in milk, quality of yoghurt and other related aspects. The methods of analyses of some important components of milk and yoghurt has been detailed. The milk after collection were divided into three portions and used for various treatments A (raw milk as such), B (laboratory pasteurized) and C )LP activated). Samples in each treatment were again divided into four parts and stored under refrigeration for 0, 24, 48 and 72 hours for further analysis and yoghurt preparation. When raw milk was stored under refrigeration, acidity developed to a significantly high level (P < 0.05) at the end of 72 hours of storage whereas no significant increase in activity was noticed in treatments B and C. This result was corroborated by a decrease in both psychrotrophic and total bacterial counts in milk under treatments B and C. So it was concluded that the development of acidity in treatment A could be due to bultiplication of microbes particularly psychrotrophs. In B and C its growth was arrested by the treatments. Hydrogen peroxide and thiocyanate were detected in all raw milk samples at a level of 3.78 and 7.33 ppm respectively. The level of H2 O2 and SCN – used for the activation of LP system for the study were found to be adequate, since the psychrotrophic count in milk at the end of 72 hours in treatment C was less than that found in treatment B. The residual H2 O2 and SCN – contents at the end of 72 hours were found to be within the normal level found in milk thus having no health hazards, by this method of preservation. When yoghurt samples were prepared from stored milk no significant differences between treatments were noticed in the values of fermentation period, acidity, pH, total proteins and total solids. A significant increase in NPN and tyrosine values were noticed in yoghurt prepared from milk under treatment A indicating extensive proteolysis in milk during storage under this treatment. However, no difference was noticed between treatments B and C. Diacetyl and acetaldehyde were produced at a desirable level in yoghurt samples under all the three treatments. A proper ratio of Str. Thermophiles – 6 and L. bulgaricus – 4 was found to be maintained in all yoghurt samples. On organoleptic evaluation the yoghurt prepared from milk under treatment C could not be distinguished from other two treatments. In fact, yoghurt under C got a higher total score on organoleptic evaluation than A and B. Low score for body and texture, and falvour was observed under treatment A. This may be attributed to the effect of growth of psychrotrophs in raw milk during refrigeration. From the results, it was concluded that good quality yoghurt can be prepared from milk stored under refrigeration following pasteurization or LP activation. Yoghurt samples prepared from milk stored under treatment A was found to be of inferior quality when compared to B and C. The result also confirmed that LP system can be recommended as a safe preservative for extending storage life of refrigerated milk. When such stored milk was used for yoghurt production, no significant difference in the quality was noticed when compared to yoghurt under treatment B. Suggesting that LP activated milk can be conveniently and economically used for the production of fermented milk products like yoghurt without any apparent harmful effect.
  • ThesisItemOpen Access
    Preparation of mozzarella cheese using skim milk filled with coconut milk
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1994) Gnana Selva, Johnson; KAU; Mukundan, M
    A detailed study was carried out to determine the quality of coconut fat filled milk for the preparation of Mozzarella cheese and why drinks. Literatures based on filled milk products has been reviewed, apart from the preparation of cheese and why drinks. The control samples of Mozzarella cheese and whey drinks were prepared using cow’s milk. Experiment I products were prepared from milk in which 50 per cent of milk fat was replaced with coconut fat. Experiment II products were prepared from cheese milk in which 100 per cent of milk fat was replaced with coconut fat. All the samples of milk were standardized to 4 per cent fat. A total of 6 trials were carried out to obtain reliable data for statistical analysis. The acidity, pH, stretchbility and FDM content were found to be similar in control, experiment I and II Mozzarella cheese. Eventhough, the control Mozzarella cheese were found to have slightly higher yield protein, fat and lower moisture content, the experimental I and II. Mozzarella cheese also satisfied the requirements for good quality Mozzarella cheese. The control Mozzarella cheese got maximum score on sensory evaluation than the experiment I and II Mozzarella cheese. Pineapple and Lemon falvoured control, experiment I and II whey drinks were found to be equally acceptable with nodifference on storage studies ar 5 + loC. Total bacterial count on whey drinks were also made. The studies revealed that the cow milk in which the milk fat replaced to the extend of 50 per cent and 100 per cent with coconut fat can be effectively utilised for preparation of Mozzarella cheese. The quality of such cheese is comparable with that made from cow milk.
  • ThesisItemOpen Access
    Detergent potential of enzymes of dairy microflora and their effect on the shelf life of milk products
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 2010) Beena, A K; KAU; Geevarghese, P I
    A study was conducted to assess the detergent potential of a spoilage protease enzyme obtained from the microflora of dairy plant environment. An attempt was also made to study the impact of selected enzyme producers on the shelf life of curd (dahi) and sterilised skim milk. A total of 71 bacterial isolates obtained from dairy environment were screened for their ability to produce spoilage enzymes like proteases lipases and lecithinases. Based on the spoilage potential, Pseudomonas aeruginosa (P12) isolated from pasteurised milk and Bacillus cereus (S4) isolated from sterilized skim milk were selected for further work. The influence of spoilage enzymes on selected physico-chemical characteristics of curd (dahi) and sterilized skim milk was evaluated by preparing the products from milk precultured with isolate P12 and S4. In general, proteolysis of milk was found to have an adverse effect on the quality of products. The stimulatory effect of proteolytic products of P12 and S4 on curd starters was evident from the higher values of acidity, firmness and syneresis in treated curd. The spoilage enzymes adversely affected the overall quality and shelf life of curd. In treated sterilised milk, tyrosine and NPN values were highly elevated. A linear correlation was found to exist between off-flavour and proteolysis. Curd and sterilised skim milk prepared from milk precultured with proteolytic organism were significantly different from that of control. The possibility of exploiting an alkaline protease from spoilage organism in dairy plant sanitation was also looked into. Environmental conditions for the production of alkaline protease by a psychrotrophic strain of Bacillus cereus (S4) was optimised in whey based medium. The protease used in this trial preferred an alkaline medium to remain stable. The enzyme was found to be stable over a wide temperature range of -10°C to 80°C and a pH range of 7.0 to 12.0. The metal ions Ca++, Mg++, Zn++ and Hg++ enhanced the enzyme activity. Lack of inhibition by Hg++ suggested lack of disulphide bonds in the active site of enzyme. Significant inhibition of activity by serine inhibitors indicated an essential serine residue in the active site of enzyme. The deleterious effect of EDTA on enzyme activity showed the supportive role of divalent cations. Marked residual activity on treatment with β-mercaptoethanol indicated the absence of cysteine residue for the enzyme. Enhancement of protease activity in the presence of surfactants and stability in the presence of H2O2 signified its potential to be used as detergent additive. Qualitative assessment of cleaning efficiency of inbuilt formulation substantiated the superiority of enzyme based formulations. Ammonium sulphate fractionation, dialysis and gel filtation using seralose 4B and Seralose 6B were effective in purifying the protease preparation by 141.31 fold. The purified protease was found to be a homogenous preparation of molecular weight of 50.5 kDa as determined by SDS PAGE.
  • ThesisItemOpen Access
    Development and evaluation of different vaccines against duck pasteurellosis
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 2010) Jesto, George; KAU; Krishnan Nair
    This study was undertaken to develop biofilm vaccines against duck pasteurellosis using oil, saponin and aluminium hydroxide as adjuvants and to experimentally evaluate their immunogenicity in ducks. Identity of P. multocida serotype A: 1 (DP1) used for study was confirmed by biochemical tests and by PM-PCR and pathogenicity was established in Swiss albino mice before vaccine production. The LD50 (11 w) of the DP1 isolate determined was 10 CFU / bird and MDT was 23.75 h in 11 week old ducklings when a high dose of 3 X 10 6 CFU of P. multocida per bird was given. At 11 Weeks age MDT gradually increased as the dose of inoculum decreased. In 21 week old ducks, the LD50 (21w) of the isolate DP1 was estimated to be 3 ×108 CFU of P. multocida and it showed that the Kuttanad duck had decreased susceptibility to pasteurellosis with age. On light microscopic studies planktonic cells appeared to be Gram negative coccobacillary, while biofilm cells were Gram negative and pleomorphic. Electron microscopic studies revealed that P. multocida could form well differentiated classic biofilm and 0.32 per cent TSB media supplemented 0.5 per cent chitin seemed to be excellent medium for biofilm formation by P. multocida. Four different vaccines viz. OV, OBV, SV and SAV were prepared and all of them were found to be sterile and safe. The oil adjuvanted vaccines (OV and OBV) offered better protection compared to saponin and aluminium hydroxide adjuvanted vaccine groups (SV and SAV) following primary vaccination, up to seven weeks. The modified oil adjuvanted vaccine prepared was not only found to be homogenous, but also more efficient in stimulating a humoral immune response and hence may be recommended. The oil adjuvanation gave better protection than saponin and aluminium hydroxide adjuvanation. The SAV gave better protection than SV which might be due to the presence of aluminium hydroxide which potentiated the immunostimulating ability of saponin. The combined vaccine (SAV) although was found to be better than single vaccine (SV) they cannot be used as a substitute to oil adjuvanted vaccines. The booster vaccination was found to have added advantageous effect on protection and is a must, to prevent losses. Pasteurella biofilms although found to be weak in inducing a primary immune response had the potency to evoke a more powerful secondary response compared to planktonic cells. Vaccination done at six weeks age followed by booster vaccination at 16 weeks age seemed to be a better modification of existing schedule and may be recommended. In histopathological studies, lymphoid hyperplasia was observed in spleen in survived control birds and in SV and SAV vaccine groups that did not survive challenge test, which indicated the persistence of Pasteurella organisms through mild infection in them following experimental challenge. Lymphoid depletion was observed in caecal tonsil in experimental pasteurellosis as in spleen. As the survived vaccinated birds following challenge test showed normal intact caecal tonsil, the course of disease and lesions might be less prominent in vaccinated birds during infection process. The well developed bursa observed in OV and OBV birds that survived challenge test indicated that the humoral immune response was well induced in them compared to other groups. The designed primers E1 and E2 amplified the gene E and hence, this pair of primers could be used for the production of amplified Gene E sequences for further studies on recombinant ghost system. In conclusion, 0.32 per cent TSB media supplemented 0.5 per cent chitin seemed to be an excellent medium that support classical biofilm formation by P. multocida. Booster vaccination definitely had added advantageous effect on protection. Immunization at 6 weeks of age with OV followed by booster vaccination at 16 weeks age with OBV seemed to be a better modification of existing schedule and may be recommended. In histopathological studies, the lesions were less prominent in vaccinated birds than control birds which indicated that the vaccines were effective.
  • ThesisItemOpen Access
    Effect of preservatives on milk solids in cow and buffalo milk
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 2001) Radha, K; KAU; Sathian, C T
    Pooled milk samples were collected from cow and buffaloes maintained at the University Livestock Farm at weekly intervals. Three chemical preservatives viz., formalin (0.4 per cent), potassium dichromate (0.4 per cent) and bronopol (0.1 per cent) were studied for their efficiency of preservation. Calculated levels of preservatives were added and the samples were stored at room temperature in dark place. Major milk constituents like fat, total solids and solids not fat were estimated in control and preserved samples. Physical properties of milk such as pH, titratable acidity, clot on boiling test, lactometer reading as well as efficiency of preservation were studied in control and preserved milk samples .. Milk samples treated with formalin could be stored up to 90 days without any spoilage changes. A cream plug formed after 24 hours of storage and a white sedimentation at the bottom appeared after one month of storage. Potassium dichromate treated samples could be stored for 30 days. There after the samples curdled and became green in colour towards the end of the storage period. 11 Bronopol preserved cow and buffalo milk samples could be stored for 24 and 16 days respectively and samples became mild pink in colour as the storage period advanced. There was a significant increase in titratable acidity in cow and buffalo milk samples preserved with all the three chemical preservatives. The increase in acidity was steady and progressive in formalin and bronopol preserved samples. But an abrupt increase in acidity was noticed in potassium dichromate preserved samples immediately after the addition of preservative and there after a successive decrease was noticed. The pH values showed a significant decline during storage in preserved milk samples. Decline in pH was abrupt in potassium dichromate treated samples whereas it was gradual in samples treated with the other two preservatives. Formalin heated milk samples remained COB negative throughout the storage period of 90 days, whereas potassium dichromate and bronopol treated samples became COB positive after 15 and eight days of storage respectively. No significant variation was noticed in fat percentage of preserved milk samples estimated by Gerber method. But a slight decrease in fat per cent was observed in formalin and III potassium dichromate treated samples. The concentration of Sulphuric acid used was increased to 94 per cent for estimating fat percentage in formalin preserved milk samples. Formalin preserved samples showed inconsistent changes in fat percentage estimated by Milko- Tester. So this method cannot be recommended for formalin preserved milk samples. Bronopol treated milk samples showed lesser variation in milk fat percentage estimated by Milko-Tester when compared to potassium dichromate and formalin. There was a non-significant increase in total solids and solids not fat content in potassium dichromate preserved samples. Potassium dichromate preserved samples showed significant increase in lactometer reading, where as formalin and bronopol treated samples did not show any significant changes in lactometer reading. Formalin appears to be ideal for the existing standard methods of estimating milk solids. With the popularization of instrumental methods for fast and accurate analysis of milk constituents, formalin will not be suitable as a milk sample preservative in future. Further, formalin and potassium dichromate have deleterious effects on human health and environment. Even though bronopol is little expensive, it is best suited for instrumental analysis of milk constituents and safe for handlers. So, bronopol is recommended as a preservative for the near future.
  • ThesisItemOpen Access
    Use of condensed coconut water in yoghurt
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1996) Malarkannan, S P; KAU; Geevarghese, P I
    An attempt was made to incorporate condensed coconut water in partial replacement of MSNF at 25 and 50 per cent level in yoghurt and to study the properties of the product which were compared with normal yoghurt. An exhaustive review of literature on the various physico – chemical properties of yoghurt and other fermented milk products has been presented. The procedure for the analysis of coconut water and condensed coconut water for its chemical composition, mineral profile and method of condensation has been described. The quantity of ingredients for yoghurt preparation was derived by linear programming model. The treatments were divided into TC (control), T2 (25 per cent replacement of MSNF using condensed coconut water without gelatin), T3 (T2 + gelatin at 0.5 per cent level), T4 (50 per cent replacement of MSNF using condensed coconut water without gelatin) and T5 (T4 + 0.5 per cent gelatin). A pre – trial was conducted to find out the ideal combination of starter culture and gelatin to be added to give good quality yoghurt. A combination of four per cent starter culture with 0.5 per cent gelatin produced good quality yohurt and this combination was used in the subsequent trials. A pilot heat stability test was conducted in treatment mixes to find out the amount of trisodium citrate required to provide sufficient heat stability. Yoghurt mixes prepared were analysed for titratable acidity, pH and total solids. Statistical analysis revealed no significant difference between control and treatments for the above. No significant difference was observed in pH and fat between the control and treatments. A significant difference (P < 0.01) in titratable acidity, protein and NPN percentage was observed between control and treatments. The curd tension and viscosity showed a decreasing trend with increasing level of replacement but this properties improved to certain extent by addition of gelatin. The setting time and NPN content showed an increasing trend as replacement level increased and this may be due to high mineral and NPN content in coconut water. There was no significant difference in tyrosine value between the control and treatments T2 and T3. No significant difference was observed in L. bulgaricus count and coliform count between control and treatments, whereas but S. thermophiles and yeast and mould count showed significant difference between control and treatments which may be due to a stimulatory factor in coconut water for yeast and mould and inhibitory factor for S. thermophiles resulting in slow growth. Organoleptic quality revealed that 25 per cent replacement of MSNF with or without addition of gelatin produced comparable scores as that of control yoghurt. A savings of 13.95 per cent and 8.14 per cent in cost can be achieved by 25 per cent replacement of MSNF with or without addition of gelatin respectively. The results of the experiment revealed that 25 per cent replacement of MSNF with condensed coconut water can be successfully tried in preparing yoghurt without affecting the physic – chemical and organoleptic properties together with considerable reduction in cost.
  • ThesisItemOpen Access
    Microbiological quality and shelf-life of raw cow`s milk preserved by lactoperoxidase system
    (Department of Dairy Science, College of Veterinary and Animal Sciences, Mannuthy, 1998) Selvin Joe, J; KAU; Mukundan, M
    A detailed study was carried out to determine the micro-biological quality and shelf- life of raw cow's milk preserved by lactoperoxidase (LP) system. Literature related to the LP-system have been reviewed . •• A total of 6 trails were conducted to obtain reliable data for statistical analysis. In each trail, three litres of raw cow milk was divided into three equal parts of one litre each. One part was kept as a control (C) and LP-system was activated in the other two parts one part with 20: 10ppm (Tl) and other with 20:20ppm (T2) (SCN-:H202), with in two hours of production of milk. The milk samples were stored at 30 +1 DC . . Before the activation of LP- system the micro-biological quality of raw milk, samples were analysed. After the activation of LP-system the micro-biological quality of control and experimental group milk samples were analysed once in every 3 hours, till the samples showed positive on clot-on-boiling (COB) test. Standard plate count, Coliform count, Titratahle acidity, pH, Methylene blue reduction time, one hour Resazurin reduction test, Clot-on boiling test and Alizarin - Alcohol test were the parameters studied. The mean initial SPC of milk samples was 5.280 log cfu per ml. The control milk samples remained 'Good' quality only for 3 hours storage, while the LP-treated milk samples of both Tl and T2 remained 'Good' quality even after 9 hours of storage. 11 \ 1 \ 383 The standard plate count and coliform count (CC) of control milk samples showed a steady increase from the initial period itself, whereas in the LP-treated milk samples of T1 and T2 the SPC and CC showed a reduction than the initial count after 3 hours of storage and both SPC and CC slightly exceeded the initial count even after 6 hour of storage . .. Based on the titratable acidity, the control milk had the acceptable quality (0.18 per cent lactic acid) of only upto 6 hours while the LP-treated milk remained with in the acceptable limit for 12 h. According to the Alizarin - Alcohol test, the control milk remained stable only for 3 hours and the LP- treated milk remained stable for 9 hours of storage at 30+ 1 DC. The milk samples of control group had the shelf-life of 12 hours where as the LP-treated milk samples of T1 and T2 had the shelf-life of 18 hours based on the clot-on-boiling test. The micro-biological quality and shelf-life of milk samples, both T1 and T2 did not show significant difference during the entire period of storage.
  • ThesisItemOpen Access
    Somatic cell count and its influence on the quality of milk in cross-bred cows
    (Kerala Agricultural University;Thrissur, 2001) Sathian, C.T.; KAU; Mukundan, M