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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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ThesisItem Open Access Effect of processing and freezing procedures on the acrosome morphology of buck spermatozoa(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1998) Ranjini, A; KAU; Prabhakaran Nair, KSix pooled semen samples (two ejaculates) of good quality from five Malabari crossbred bucks were processed and frozen in two different protocols to evaluate the effect of processing and freezing procedures on the acrosome morphology of buck spermatozoa. In protocol I, the samples were diluted 10 fold in Tris buffer before centrifuging twice and the final pellet was re-suspended in the non glycerolated fraction of Tris yolk diluent. The sample was glycerolated (six per cent), equilibrated (four hours), frozen (eight minutes), and thawed (250 C for 30 seconds). In protocol 11, centrifugation was done only once, after 15 fold dilution in Tris buffer. The re suspended pellet was glycerolated (seven per cent), equilibrated (three hours), frozen (10 minutes) and thawed (60° C for 10 seconds). The semen characters such as motility, live sperm, sperm abnormalities and acrosome abnormalities were evaluated at the end of washing and initial extension (stage I), cooling to 5° C (stage II), glycerolisation and equilibration (stage Ill) and freezing and thawing (stage IV). The results were compiled to evaluate the effect of different processing and freezing procedures on the semen characters in general and acrosome morphology in particular. The semen sample used for split sample dilution had a mean volume of 1.3282± 0.067 ml, creamy in colour, DDDD density, ++++ mass activity, pH of 7.275 2± 0.040 and a concentration of 2972 2± 293 millions per ml. No significant difference in the above semen characters were found between bucks. The initial sperm motility of 82.000 2± 0.606 was found to drop significantly during processing and freezing and the final post thaw motility obtained was 44.000 2± 0.790 in protocol I. Similarly in protocol II the initial motility dropped from 81.375 2± 1.089 to 44.750 2± 1.075 at the end of stage IV. Even though there was significant drop in motility between stages in both the protocols, there was no significant difference in the corresponding stages of the two protocols. It could be inferred that good post thaw motility was obtained in both the protocols. The fact that a single washing and centrifugation was only adopted in protocol II makes it a more acceptable procedure for buck semen freezing. The mean live sperm percentage of fresh semen was evaluated using both NE and NEG staining technique. The percentage of live sperms of 90.050 2± 0.801 was found to decrease to 54.250 2± 0.593 after freezing and thawing in protocol by NE staining. Similarly in protocol 11, the mean percentage of live sperms was found to reduce to 53.125 2± 0.793 with the same staining. Even though there was significant difference in the live sperm percentage between stages within protocol I and II no significant difference in the live sperm percentage between the corresponding stages of protocol I and I I . With NEG staining the initial live sperm percentage of 80.850 ± 1.494 was found to drop to 54.875 ± 0.677 in protocol I as against 53.400 ± 0.730 in protocol II. While there was significant difference in the live sperm percentage between stages within protocol I and II there was no variation between corresponding stages of the two protocols. A significantly lower percentage of live sperms was recorded with NEG staining when compared with NE staining probably on account of the fact that the differentiation of live and dead sperm was difficult in the former staining method as live sperms were stained light blue instead of colourless. The mean percentage of abnormal sperms of 3.050 ± 0.245 in fresh semen did not register any significant increase during processing. However, there was significant increase in the percentage of sperm abnormalities during freezing and thawing with the final abnormality percentage of 7.125± 0.706 in protocol I and 6.300± 0.36 in protocol II. The initial acrosomal abnormality of 8.825 in the fresh semen steadily rose to 23.375 in protocol I as against 19.825 in protocol II at the end of stage IV. There was no significant difference in the percentage of various acrosomal abnormalities between corresponding stages of the two protocols. However, there was significant increase in the acrosomal abnormalities during glycerolisation, equilibration, freezing and thawing under both the protocols. It was concluded that the processing and freezing under two different protocols did not significantly alter the post thaw motility, percentage abnormal and dead sperms and acrosomal abnormalities. A good post thaw motility and low acrosomal abnormality was obtained with a single washing of buck semen with 15 fold Tris buffer which was comparable with double washing with 10 fold Tris buffer.ThesisItem Open 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, MA 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.ThesisItem Open Access Metabolic profile of downer cow syndrome(Department of Clinical Medicine, College of Veterinary and Animal Sciences,Mannuthy, 1994) Mhachuvino Catherine, Khatsu; KAU; Alikutty, K MThe metabolic profile of ‘Downer Cow’ syndrome in field conditions was studied. Fourteen field cases of ‘Downers’ in crossbred dairy cows aged three to thirteen years, ranging from 250 to 300 kg body weight from Trichur district were selected at random and utilized for the study. Fourteen apparently healthy crossbred dairy cows of similar age group and body weight, maintained under similar conditions of feeding and management from the area from which the clinical cases studied were also selected at random and utilized as the healthy controls. Samples of blood for haematological and biochemical parameters, urine and dung from both healthy and diseased animals were collected and analysed using standard methods. Analyses of the data from fourteen diseased animals indicated a higher incidence in Jersey crossbred cows during summer season. Prominent clinical signs were sternal recumbency exhibiting hindquarter weakness and reduced feed and water intake. However, the affected animals remained bright and alert with no evidence of any systemic disturbances. The clinical data were within physiological limit. Highly significant increase in PCV and significant increase in Hb but no significant difference in ESR, RBC and WBC were observed. Lymphopenia, neutrophilia and eosinopenia were observed with no variation in basophils and monocytes counts. Biochemically, hypocalcaemia,hypophosphataemia, hypoproteinaemia and hypoalbuminaemia were obtained from ‘Downers’ with no significant variation in blood glucose, urea nitrogen, sodium, potassium, magnesium and albumin/globulin ratio. Urinalysis revealed no consistent result indicative of any systemic involvement and no parasitism on dung examination microscopically.ThesisItem Open Access Assessment Of Bacteriological quality Of Raw Milk In Trichur And Its Public Health Importance(Department of Veterinary Public Health, College of Veterinary and Animal Sciences,Mannuthy, 1995) Anju Raghunathrao, Kapre; KAU; Nanu, EIn the present study an effort has been made to assess the bacteriological quality of raw milk obtained from three different sources in Trichur. A total of 21 individual and seven pooled samples were collected from each sources (S1, S2 and S3), over a period of five months. The samples were subjected to different bacterial counts and also for the isolation and identification of S. aureus and E. coli. The isolates were tested for their sensitivity to various chemotherapeutic agents. The average total viable count of individual milk samples from S1, S2 and S3 were 7.5 x 104, 1.4 x 105 and 2 x 105 CFU per ml respectively. Significant difference (P < 0.01) between the counts from S1 and S2; and S1 and S3 was noticed. The average coliform count for S1 was 2.4 x 10, for S2 was 4.8 x 104 and for S3 was 3.8 x 103 CFU per ml. There was significant difference (P < 0.01) between the counts from S1 and S2 ; S1 and S3 ; and S2 and S3. The average counts for thermotolerant coliforms in samples from S1, S2 and S3 were 2.2 x 10, 2.4 x 104 and 2.4 x 103 CFU per ml. The counts from S1 and S2 ; and S1 and S3 differed significantly (P < 0.01). The average faecal streptococcal counts for the sample from S1, S2 and S3 were 1.5 x 102 , 2.1 x 103 and 1.7 x 103 CFU per ml. Significant difference (P < 0.01) between the counts from S1 and S2 , and S1 and S3 was noticed. The staphylococcal counts in samples from S1, S2 and S3 averaged 5.7 x 102, 2.8 x 103 and 6.8 x 103 CFU per ml respectively. Significant differences (P < 0.01) between the counts from S1 and S2 , and S1 and S3 were noticed. The average S. aureus count in samples from S1 was 8.5 x 10, from S2 it was 1.8 x 102 and from S3 , 7.1 x 10 CFU per ml. The average E. coli counts in samples from S1, S2 and S3 were 2 x 102, 1.2 x 104 and 1.5 x 103 CFU per ml respectively. The counts in samples from S1 and S2 ; S1 and S3 ; and S2 and S3 differed significantly (P < 0.01). The average total viable count in pooled milk samples from S1 , S2 and S3 were 4 x 104 , 1.8 x 106 and 2.1 x 105 CFU per ml respectively. Significant difference (P < 0.01) between the counts from S1 and S2 and S1 and S3 was noticed. The average coliform counts at 370C of incubation in the pooled samples from S1, S2 and S3 were 5.5 x 10, 2 x 105 and 6.4 x 103 CFU per ml respectively. The counts from S1 and S2, S1 and S3 ; and S2 and S3 were found significantly different (P < 0.01). The average thermotolerent count in samples from S1, S2 and S3 were 2.8 x 10, 3.6 x 104 and 4.4 x 103 CFU per ml respectively. Significant difference (P < 0.01) in the counts of S1 and S2 ; and S1 and S3 was noticed. The average faecal streptococcal count in samples from S1, S2 and S3 were 2 x 102, 4.8 x 103 and 2.9 x 103 CFU per ml respectively. Significantly different (P < 0.01) counts were noticed between S1 and S2 ; and S1 and S3 was noticed. The average staphylococcal count in samples from S1 was 9.2 x 102 from S2 was 5.3 x 104 and from S3 was 1.3 x 104 CFU per ml. The counts in samples from S1 and S2 ; and S1 and S3 were significantly different (P < 0.01). The S. aureus counts in milk samples from S1, S2 and S3 averaged 1 x 102, 4.8 x 102 and 1.1 x 102 CFU per ml respectively. The average E. coli count in samples from S1, S2 and S3 were 2.7 x 102, 8.9 x 104 and 1.9 x 103 CFU per ml respectively. Significant difference (P < 0.01) between the counts of samples from S1 and S2 ; S1 and S3 ; and S2 and S3 was observed. All the individual samples from S1 were either of very good or good grades (95.24 and 4.76%) respectively. All the pooled milk samples from this source was of very good grade. Most of the individual samples from S2 were of very good or good grades ( 76.20 and 23.80%) respectively, but the pooled milk samples from S2 were of very good, good, fair and poor grades (42.84, 28.60, 14.28 and 14.28%) respectively. Among the individual samples from S3 source all were of either very good or good grades (80.95 and 19.05%) respectively. Pooled milk samples from the same source had very good and good grade (57.14 and 42.86%) respectively. None of the samples from this source were of fair or poor grades. Of the 60 suspected colonies isolated, 54 were identified as S. aureus. Antibiogram of S. aureus isolates showed highest sensitivity to cloxacillin (100%) and gentamicin (100%) followed by amoxicillin (87.03%), chloramphenicol (77.80%) and penicillin – G (35.20%). Of the 70 suspected colonies isolated 66 were identified as E. coli. The E. Coli. Isolates were most sensitive to gentamicin (96.96%) followed by amplicillin (93.92%), furazolidone (80.30%) and carbenicillin (15.155). Doxycycline was least effective drug with no sensitivity and high resistance (90.90%).ThesisItem Open Access Pathology of hypothyroidism in pigs(Centre of Excellence in Pathology, College of Veterinary and Animal Sciences,Mannuthy, 1995) Prasanna, K S; KAU; Sreekumaran, TAn experimental model of hypothyroid state was induced in piglets, using thiourea with the objectives of studying the sequence of clinico pathological changes and its influence on the animal health and growth. Tweleve Large White Yorkshire male piglets of 2 – 3 months age were selected for the study. The animals were divided into control group of six animals and experimental group of six animals. Experimental hypothyroidism was induced by feeding thiourea daily for a period of three months at the dose level of 50 mg per kg body weight. Haemogram, body weight, plasma proteins, serum cholesterol and serum thyroxine values were estimated at periodic intervals. The piglets were subjected to detailed autopsy after sacrifice. Gross lesions were recorded and detailed histopathological examination of tissues was carried out. During the course of experiment all the experimental animals recorded stunted growth and appreciable reduction in feed intake and alopecia of neck and shoulder regions. There was significant increase in blood cholesterol values and plasma protein level in thiourea fed group. A significant reduction in serum thyroxine level was also recorded. There was significant increase in the relative weight of thyroid, adrenal and pituitary glands of experimental animals. Gelatinisation of subcutaneous fat and dilatation of right ventricles were common findings at autopsy. Histologically the thyroid glands exhibited varying degree of hyperplastic changes and depletion of colloid in the follicles. Hyperplasia and hypertrophy of the lining epithelium was also observed. Predominant histological changes in the pituitary was hyperplasia and hypertrophy of the basophil cells and degranulation of the acidophil cells. Adrenal glands showed diffuse hyperplasia of zonafasiculata and accessory cortical nodule formation. Skin revealed acanthosis, hyperkeratosis and keratinisation of harifollicles. In all the hypothyroid animals testis showed varying degree of tubular degeneration. A random survey study was conducted to assess the thyroid status of pigs from different parts of Kerala using serum thyroxine as the marker. This concluded that most of the animals had the normal range of serum thyroxine levels.ThesisItem Open Access Microbial degradation of mimosine in goats(Department of Animal Nutrition, College of Veterinary and Animal Sciences,Mannuthy, 1995) Prabhakaran, P; KAU; Devasia, P AAn investigation was carried out to find out the extent of in vitro microbial degradation of pure mimosine (T1) and that of immature leaves (T2), mature leaves (T3), tender stems (T4) and seeds (T5) of L. leucocephala using strained rumen liquor obtained from three rumen fistulated Saanen – Malabari crossbred goats maintained under standard conditions of feeding and management. The proximate chemical composition and mimosine content of different edible parts of leucaena during the months of May, June and July were determined. While immature leaves and seeds had higher crude protein content, seeds had higher crude fat, tender stems had higher crude fibre and mature leaves had higher ash content compared to other edible parts of subabul. The average mimosine concentrations of T2, T3, T4 and T5 were 12.11 + 0.05, 4.89 + 0.02, 3.90 + 0.04 and 10.70 + 0.08 per cent respectively during May; 11.66 + 0.06, 5.23 + 0.03, 3.62 + 0.03 and 10.44 + 0.05 per cent respectively during June and 9.96 + 0.05, 4.92 + 0.03, 3.73 + 0.02 and 9.51 + 0.04 per cent respectively during July on a dry matter basis. The average mimosine concentrations of strained goat rumen liquor incubated with 37.50 mg/100 ml of added mimosine in pure form or as immature leaves, mature leaves, tender stems and seeds showed significant reduction at every 12 hr intervals from 0 to 48 hr of incubation, the final average concentrations being 23.98 + 0.37, 23.14 + 0.37, 22.20 + 0.28, 23.12 + 0.52, 23.35 + 0.37 mg/100 ml of SRL. The percentage of in vitro degradation in respect of T1, T2, T3, T4 and T5 increased significantly at every 12 hr intervals of incubation from 0 to 48 hr, even though the degradation was incomplete with all treatments, the average percentage degradation at 48 hr of incubation being 31.69 + 1.02, 34.49 + 1.18, 37.12 + 0.99, 34.54 + 1.50 and 33.41 + 1.03 respectively. The overall average rate of disappearance of mimosine in µg.ml-1 . h-1 in respect of T1, T2, T3, T4 and T5 for the entire period of 48 hr of incubation were 2.33, 2.54, 2.74, 2.54 and 2.44 respectively with highest rates during 0 to 12 hr, lower rates during 24 to 36 hr and least rates during 36 to 48 hr. The production of ammonia and VFA coincided with the active degradation of mimosine, there being faster degradation upto 12 hr of incubation with highest concentrations of ammonia and VFA at 12 hr of incubation. The overall results indicated that the rumen microorganisms of crossbred goats degrade mimosine to DPH, ammonia and VFA and that mimosine does not inhibit the microbial activity, even though the possible role of leucaena endogenous enzymes in the partial degradation of mimosine recorded in the present study cannot be ruled out.ThesisItem Open Access Effect of dried spleen as growth stimulator in kid rations(Department of Animal Nutrition, College of Veterinary and Animal Sciences,Mannuthy, 1994) Shyama, K; KAU; James, C SAn investigation was carried out to assess the effect of dried spleen as a growth promotant in kid rations. Twenty four female Malabari kids with an average body weight of 8.5 kg were distributed randomly and as uniformly as possible into four groups (groups 1, 11, 111 and IV) of six animals each, with regard to age and weight. The four dietary treatments A, B, C and D were allotted to the kids in the groups 1, 11, 111 and IV respectively, ration A with a concentrate mixture containing 16 per cent crude protein supplemented with dried buffalo spleen at the rate of 0.1 per cent, ration B forming the control diet at 16 per cent protein level without incorporation of spleen, ration C with a concentrate mixture containing 12 per cent crude protein supplemented with dried buffalo spleen at the rate of 0.1 per cent, ration D forming the control diet at 12 per cent protein level. Jack leaves formed the sole source of roughage to the animals. The experimental duration was 120 days. The results indicated that incorporation of dried spleen in the ration enhanced the growth performance of animals, especially in animals maintained on low level of protein, as evidenced by the cumulative and average daily weight gain registered in that descending order being 7.52 kg and 62.64 g, 7.4 kg and 61.67 g, 6.88 kg and 57.36 g and 5.00 kg and 41.67 g for the animals maintained on rations C, A, B and D respectively. The efficiency of feed and protein utilisation also exhibited the same trend. It was also noticed that, a cost of production per kilogram gain of Rs.32.58 and 26.14 were registered for animals maintained on spleen incorporated rations (rations A and C) as against Rs.35.08 and 38.63 respectively for the animals maintained on corresponding control groups (ration B and D) indicating a better cost efficiency in spleen incorporated groups, especially in animals maintained on low level of crude protein in the ration. The haematological studies reveal that R.B.C., W. B. C., haemoglobin, plasma protein, plasma calcium, phosphorus and magnesium were within the normal range prescribed for the species. The animals maintained on ration C showed a significant increase (P < 0.01) in plasma calcium level when compared to that of the control. Digestibility studies reveal no significant difference in digestibility of dry matter and nitrogen free extract between the four groups. Animals maintained on the spleen incorporated rations (groups 1 and 111) showed better digestibility (P < 0.01) of crude protein and ether extract than the respective control groups (groups 11 and IV). Incorporation of dried spleen could not bringforth any influence on fibre digestion. The results of the balance experiment showed better retention of nitrogen, calcium, phosphorus and magnesium in the animals maintained on spleen incorporated diets. The higher retention of these parameters could be substantiated by the comparatively lower faecal and urinary excretion of these, in animals maintained on spleen incorporated rations (rations A and C). An overall assessment of the results, indicated that incorporation of dried buffalo spleen in the ration of goats, at the rate of 0.1 per cent, certainly augment the nutrient utilisation by increasing the digestibility and retention, and can be recommended as a harmless natural growth promotant with economic benefit.ThesisItem Open Access Isolation and identification of viruses from waterfowls seen in Kerala(Department of microbiology, College of veterinary and animal sciences, Mannuthy, 1997) Bindu, M S; KAU; Krishnan Nair, GIn the recent years, frequent outbreaks of poultry diseases have caused significant economic losses and among the various sources of infection, freeflying migratory birds and waterfowls are reported to be an important source for the introduction of disease to domestic flocks. These freeflying pirds and waterfowls abound in the waterlogged areas of Kerala especially Alleppey, Kottayam, Thrissur and Malappuram districts. Heavy losses were reported each year due to severe outbreaks of duck plague and duck pasturellosis resulting in the wiping out of the duck population in the state. This may be due to the introduction of the disease agents by migratory waterfowls. Hence a study was undertaken to elucidate the role of waterfowls in the spread of diseases to domestic poultry and ducks. A total of 52 waterfowls were caught from different parts of Kerala of which 15 were lesser whistling teals and 37 were gargany. Postmortem examination of these birds were carried out and the required materials were collected. Impression smears from the cut surface of the liver revealed intranuclear inclusion bodies in the hepatic cells in four cases (Bird Nos. 17, 23, 27 and 49) and two haemagglutinating agents were isolated from the cloacal swabs of the bird numbers 18 and 22. The haemagglutinating agents developed lesions in the chicken embryos which died 3 to 5 days after inoculation. the allantoamniotic fluid of the affected embryos agglutinated teal and chicken erythrocytes. The lesions exhibited by the embryos infected with Ta were congestion of the CAM and embryos while in T22 the embryos were stunted, curled and at the same time congested. The liver of the embryo had yellowish brown patches. The haemagglutination activity of both the viral isolates were tested with red cells of various species like cattle, horse, human '0', duck, rabbit and pig but was negative in all cases. Both the isolates lost their infectivity and haemagglutination property at 56°C for 30 min. the infectivity and HA activity of the viral isolates T18 and T22 were retained at pH 7.2 and were completely destroyed at pH 3.2 and pH 9. Both the isolates were sensitive to treatment with chloroform, revealing both as enveloped viruses, wherein the infectivity was completely lost and HA activity was considerably reduced. In the case of Tl8 HA activity was reduced from 512 to 16 and for T22 from 128 to 8. The nucleic acid types of the viral isolates were confirmed by inoculating the isolates to chicken embryo fibroblast cultures pretreated with 100 µg and 200 µg per ml of IudR which led to the conclusion that Ta was a RNA virus and T22 a DNA virus. The ELD50 of Ta and T22 were 107 ELD50/ml and 106 ELD50/ml. The ICPI, MDT and IVPI. were calculated as for NDV. The ICPI for the isolates were 0.83 and 0.30 for T18 and T22 respectively, MDT was 120 hr for both and the IVPI was calculated to be zero in both cases, indicating that both the isolates were nonpathogenic. In cell cultures both the isolates produced CPE which affected the whole monolayer by 96 hrs. In the case of Tl8 the CPE was characterised by rounding and clumping of cells, the infected cells showing a tendency to get separated from the neighbouring cells leaving long cytoplasmic strands, syncytium formation with four or five nuclei and severe cytoplasmic vacuolation. For T22 the CPE was characterised by rounding and cytoplasmic vacuolation and karryorhexis. Intranuclear and intracytoplasmic inclusion bodies could be demonstrated. The pathogenicity studies of both the isolates were carried out in one week old and six week old ducklings and chicken, for which both were nonpathogenic and did not exhibit any clinical signs or mortality. But viral infection was established in six week old chicks by virus isolation till the 14th day of infection from the cloacal swabs for both the isolates. The sera collected from these birds revealed an antibody titre of 16 for T¬18 and 8 for T22 indicating the infection. The antigenic relationship of the isolates was examined with NDV, EDS-76 and fish viruses (FV and F6), of which T22 did not show any antigenic similarity with any of the viruses. But T1B on the contrary exhibited antigenic relationship with the fishviruses FV and F6 but no antigenic similarity with NDV and EDS-76. The antigenic similarity exhibited by T18 with the fish viruses leads to the conclusion that waterfowls may be disseminating the viruses responsible for the outbreak of epizootic ulcerative syndrome in fishes. The morphological features of T18 by electronmicroscopy revealed an enveloped virus with a size of 150-185 nm with pleomorphic forms and peplomers of a length of 18-20 nm. Except the length of the peplomers it similated a paramyxovirus. The morphology of T22 was not studied due to technical defects.ThesisItem Open Access Performance of desi x exotic cross-bred layers(Department of Poultry Science, College of Veterinary Science, Mannuthy, 1992) Jayanthy, M V; KAU; Leo, JosephData were collected on egg production performance of two cross-breds viz. desi X Austra White (DAW) and desi X New Rock (DNR) from 20 to 40 weeks of age. The birds in each cross consisted of naked neck and normal neck varieties. DNR cross birds were significantly heavier at 20 and 40 weeks of age than DAW cross birds. The body weight in Naked neck and normal neck varieties comparable in both crosses. Age at sexual maturity was 184 and 189 days in DNR and DAW crosses respectively. Hen housed and hen day egg numbers were similar in both crosses (37.61 and 47.61 vs 34.40 and 47.81), while the naked neck birds in both crosses showed higher hen housed and hen day egg number between the varieties in DAW cross was significant (53.82 Vs 34.86). The eggs were significantly heavier in DNR cross than in DAW cross (46.74 Vs 44.88) whereas the varieties with in both crosses laid eggs of similar size. The mean daily feed consumption and feed efficiency were also similar in both crosses (106.61 g and 4.09 Vs 104.95 g and 4.93). In DAW cross, the naked neck birds registered a better feed efficiency. While DNR birds were multicolored and laid brown eggs, DAW crosses consisted of only black, grayish white with black patches and grey birds which laid tinted eggs. Broodiness was observed in both the crosses. Egg quality was excellent in both the crosses and varieties with in crosses, at 32 weeks of age. Livability was also similar in both crosses though it was poor. Considering the overall performance, the DNR cross was adjudged as a better cross for the backyard.
