Loading...
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.
Browse
7 results
Search Results
ThesisItem Open Access Milk protein polymorphism and milk composition in Vechur cattle(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1996) Thirupathy Venkatachalapathy; KAU; Sosama, IypeThe native cattle of Kerala have been evolved through several generations of natural selection against high humidity, heavy rainfall and hot climate. They have been considered as non – descript animals, but there has been variety with characters distinguishing from others and known as Vechur Cattle of Kerala. The Vechur cattle had their origin in Vechur near Vaikom of Kottayam district of Kerala. They were very popular four decades back for their relatively higher milk production compared to other local cows. The extremely small size of the cow, good adaptation and high disease resistance are the traits very much favoured by the farmers. Farmers preferred Vechur cattle for ploughing in marshy lands because of the small size and light weight. The emergence of crossbreeding led to the gradual reduction in traditionally reared Vechur cattle. Under this circumstances, the present work was undertaken to characterise the Vechur cattle of Kerala by studying (a) certain genetic markers in milk (b) milk components like fat, total solids and solids not fat percentage (c) fat globule size and distribution and (d) iodine value. The Vechur cows maintained under the scheme on “Conservation of germplasm of Vechur cattle” formed the material for the study. Milk proteins such as casein and whey proteins were studied by polyacrylamide gel electrophoresis in horizontal dimension (Thompson and kiddy, 1963). The fat, total solids, solids not fat percentage of milk and iodine value of milk fat were estimated as prescribed by Indian Institution Standards. The fat globule size was measured under microscope by fitting an eye piece micrometer to the eye piece of the microscope. The statistical analysis were done as suggested by Snedecor and Cochran (1967). The influence of stage and time of milking were worked out using least squares analysis of variance as described by Harvey (1986). Three proteins α, β and k – casein were identified in casein system. At αsl – casein locus three phenotypes viz. BB, and CC determined by two allele B and C were observed. Frequency of CC phenotype (0.64) was highest a followed by BC (0.22) and BB (0.14). Frequency of B and C allele were 0.25 and 0.75. The β – casein locus consisted three phenotypes viz. AA, AB and BB with A and B allele. The frequency of AB phenotype was highest (0.57) followed by AA (0.29) and BB (0.14). Frequency of A allele was 0.57. At k – casein locus two phenotypes AA and AB with A and B allele were identified. The frequency of AB was (0.83) and frequency of A allele was 0.59. Two whey proteins α – lactalbumin and β – lactoglobulin were identified. At α – lactalbumin locus two phenotypes AA and AB with two allele A and B were observed. The frequency of AA and AB phenotypes were 0.57 and 0.43. The frequency of A and B allele were 0.78 and 0.22 respectively. The β – lactoglobulin locus consisted of three phenotypes viz. AA, AB and BB with A and B allele with frequency of 0.57, 0.29 and 0.14 respectively were identified. The frequency of A allele was 0.71. The frequency of C allele at αsl – casein locus was lower than the other Indian breeds like Sahiwal, Tharparkar, Red Sindhi and Rathi, but higher than exotic breeds like Jersey and Holstein and crossbred cattle of Kerala. The A variant at β and k – casein locus had frequency lower to other Indian breeds, exotic breeds of cattle and crossbred cattle of Kerala. The A variant at α – lactalbumin and β – lactoglobulin locus had much higher frequency than other Indian, exotic breeds of cattle of cattle and crossbred cattle of Kerala. B variant in vechur cattle was lower in frequency compared to other Indian breeds. The average milk fat percentage for 1 – 44 weeks of lactation was 5.95 + 0.12, 6.62 + 0.13 in the morning and evening respectively and the mean milk fat percentage for morning and evening milk was 6.23 + 0.19. The mean milk fat percentage at first week was 4.05 + 0.19, 4.65 + 0.17 and by 20th week of lactation was 5.92 + 0.08, 6.55 + 0.07 in the morning and evening milk respectively. The evening milk had uniformly higher fat percentage than morning milk. The fat percentage showed an increasing trend with advancing stage of lactation. The least squares means for morning and evening milk were 5.99 + 0.03 and 6.62 + 0.03 respectively and overall mean was 6.13 + 0.04. The mean total solids percentage of milk at first week was 12.64 + 0.17 and 13.57 + 0.19 in the morning and evening milk and it steadily increased to 14.75 + 0.13 and 15.31 + 0.18 in the morning and evening milk by 20th week of lactation. The average total solids percentage in milk from 1 – 44 weeks of lactation was 14.79 + 0.13 and 15.53 + 0.13 in the morning and evening respectively and the average for morning and evening together was 15.16 + 0.11 per cent. An increasing trend was noticed in total solids percentage as the lactation advanced. The evening milk showed uniformly higher total solids percentage compared to morning. The least squares mean was 15.02 and the adjusted mean for morning and evening was 14.85 + 0.05 and 15.55 + 0.05 percent. Least squares analysis of variance showed a significant effect of time of milking and stage of lactation on milk fat and total solids percentage of milk. The average solids not fat percentage from 1 – 44 weeks of lactation was 8.84 + 0.12 and 8.92 + 0.14 in the morning and evening milk respectively. The average for morning and evening milk was 8.88 + 0.13 and least squares mean was 8.90. The mean solids not fat percentage of milk at first week was 8.60 + 0.24 and 8.93 + 0.22. It was 8.83 + 0.11 and 8.76 + 0.15 percent at 20th week of lactation in the morning and evening milk respectively. No trend of increase was noticed in the solids not fat percentage in relation to the stage of lactation. The least squares analysis of variance showed no significant effect of time of miling and stage of lactation on solids not fat percentage. Total solids and solids not fat did not have strong association in general. The positive correlation between total solids and fat percentage were not significant. The negative correlation between fat and solids not fat percentage were also not significant. The milk fat and total solids percentage were higher than other Indian breeds of cattle, but lower to buffalo. The solids not fat percentage of milk was similar to other Indian breeds of cattle. The mean size of fat globule was 3.21 µ and the range was 2.54 to 4.07 µ. The mean diameter of fat globules was found to be 3.02 + 0.05 µ in the morning and 3.40 + 0.05 µ in the evening milk. The mean size of fat globules estimated in goat (Malabari and their crosses), crossbred cattle and Murrah buffalo were 2.60 µ, 4.87 µ and 5.81 µ respectively. The average fat globule size was found to be decreasing as the lactation advanced. The proportion of small size fat globules were found to be increased and the larger size of fat globules decreased towards the end of lactation. No correlation was noticed between fat globules size and fat percentage. The iodine value ranged from 28.61 to 30.29 and the average iodine value was 29.60 + 2.20. Based on available reports this appeared to be similar to buffalo, higher than goat and lower than cows. The size of fat globule (3.21 µ) was higher than the goat and lower to the other breeds of cattle and buffalo. Since the milk fat has higher production of smaller size fat globules and saturated fatty acids, it would be therapeutically useful in malabsorption syndromes due to its easy digestability. The larger proportion of small size fat globule is associated with high phospholipid content because of greater surface area. Phospholipids are important in the development of nervous system in babies. Thus Vechur cow milk appear to be suitable for infants and even sick. Studies on more number of cows are required for confirmation of results. It can be concluded that Vechur cattle of Kerala has unique characteristics of its own and have separate identity from other breeds of cattle not only by its small size but also due to its milk protein variants, composition of milk, size of fat globules and level of saturated fatty acids.ThesisItem Open Access Prevalence of yeast and yeast like fungi in bovine mastitis and their in vitro drug sensitivity(Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1995) Sukumar, K; KAU; James, P CThe present investigation was undertaken to identify the the biochemical polymorphism at serum alkaline phospha tase (SAP) loci and to study the heterogenity of SAP variation in crossbred cattle It was also envisaged to analyse the association of SAP variation and traits of economic importance such as milk production and composition of milk One hundred and ten animals belonging to two different crosses of local nondescript cattle viz Crossbred Holstein Friesian (57) and Crossbred Brown Swiss (53) were typed for SAP variance by standardising Horizontal Polyacrylamide Gel Electrophoresis (PAGE) Two genotypes FS and SS were determined The highest frequency of FS genotype was in Holstein Friesian crossbred than in Brown Swiss crossbred The genotype FF was absent in both the crossbreds The highest frequency of SS genotype was in Brown Swiss crossbred than in Holstein Friesian crossbreds Two alleles namely pF and P$ with two phenotypes FS and SS were identified as SAP locus pT allele had the frequency of 0 20 and pS allele had the frequency of 0 80 in the pooled crossbreds Both the Holstein Friesian crossbreds and Brown Swiss crossbred are in genetic equilibrium at the SAP loci No association could be established between milk yield (305 days) and serum alkaline phosphatase level A non significant negative correlation existed between milk fat percentage and SAP level whereas a significant positive correlation existed between milk SNF percentage and SAP level The correlation between SAP level and milk total solids were found to be negative and non significant in Brown Swiss crossbreds whereas a non significant positive correlation existed between the SAP level and milk total solids in Holstein Friesian crossbreds Animals belonging to the FS genotype are better milk producers compared to the SS genotype For higher fat percentages the performance of SS genotype was compara tively better The performance of SS genotype is better for producing milk with more than 8 5 percentage of SNF FS genotype performed better for producing milk having higher percentage of total solidsThesisItem Open Access Genetics of body dimensions of Malabari goats and its cross in Kerala(Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 1994) Raj, Menon; KAU; Stephen, MathewThe main objectives of this study were: (1) to study the bodyweight and body dimensions of Malabari goats and its Alpine half breds, (2) to estimate the genetic and phenotypic correlations between bodyweight and different body dimensions in various genetic groups and (3) to study any other major factors affecting bodyweights and body dimensions. The study was conducted in 92 goat kids reared at the All India Co-ordinated Research Project on goats farm at Mannuthy, Thrissur. A comparative study was made on the native Malabari with its third generation cross with the exotic Alpine breed. The mean body length, heart girth and height at withers at birth wera 25.68 ± 0.53, 27.37 ± 0.46 and 29.66 ± O. 60 cm and 26.01 ± O. 16, 28.23 ± 0.23 and 30.24 ± 0.45 in male kids of Malabari and Alpine x Malabari crossbreds respectively. In the females the corresponding values were 25.63 ± 0.073, 27.56 ± 0.68 and 25.53 ± 0.48 and 25.3 ± 0.17, 27.60 ± 0.32 and 29.14 ± 0.35 cm. The mean body length, heart girth and height at withers of male Malabari and Alpine x Malabari goats at 60.39 ± 0.81, 59.66 ± 0.82 and 58.18 ± 0.91 12 months were 61.42 ± 0.90, 61.12 ± 0.90 and 59.04 ± 1 . 01 cm and 64. 19 ± O. 81, 64. 60 ± O. 73 and 61. 98 ± O. 9 cm respectively. The corresponding values for females were 58.36 ± 0.81,59.0 ± 0.7 and 58.36 ± 0.72 and respectively. There was no significant difference between the birth weights of- male and female Malabari kids and between the birth weights of the two genetic groups. But the difference was significant in the Alpine x Malabari crossbreds. There was significant difference in the bodyweight at 12 months of age between male and female Alpine x Malabari crossbred kids. No significant difference was observed in the bodyweight at 12 months between the two genetic groups. During the experiment period mean maximum and minimum temperature were 34.55 ± 1.2 and 22.03 ± 1.4 °c respectively. Season had a significant effect on the body weight at six, none and 12 months of age in Alpine x Malabari crossbreds. The effect of type of birth was not significant on the birth weights in Alpine x Malabari crossbreds and Malabari kids. Type of birth had no significant effect on the 12 months body weight in both the genetic groups. analysis showed non-significant Least squares effects of season and sex on the body weights in Malabari kids while in the Alpine x Malabari the effect of sex on body weights was significant at all the ages studied. Season at six, nine and 12 months of age had significant effects on bodyweight in Alpine x Malabari crossbreds Breed had no significant effect on body weights. The heritabilities of bodyweights at various ages were higher in Malabari when compared to Malabari x Alpine crossbreds. The highest phenotypic correlations were observed between the bodyweight and heart girth in both genetic Genotypic correlations between different groups. traits were found to be low at different ages in both the genetic groups. The highest coefficients of determination were observed at the age of six months for both the prediction equations.ThesisItem Open Access Genetic polymorphism of milk proteins in goats(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1996) Raja, T V; KAU; Nandakumaran, BThe present investigation was undertaken to identify the biochemical polymorphism at different milk protein loci and to establish their inheritance pattern in Malabari and its exotic cross viz., Alpine X Malabari. It was also envisaged to analyse the association of different milk protein variants with lactation milk yield. Hundred goats belonging to Malabari (50) and Alpine X Malabari (50) were typed for milk protein variants employing horizontal Polyacrylamide Gel Electrophoresis (PAGE). The milk protein loci studied were Alpha S1 casein, Alpha S2 casein, Beta casein, kappa casein and Beta lactoglobulin. Two Alpha S1 casein variants, the faster Alpha S1 casein F and the slower Alpha S1 casein S with three phenotypes Alpha S1 casein AA, Alpha S1 casein AB, and Alpha S1 casein BB were observed. S allele had the frequency of 0.52 in Malabari and 0.70 in Alpine x Malabari crossbreds. The gene frequency of Alpha S1 casein F and Alpha S1 casein S were 0.48 and 0.52 in Malabari and 0.30 and 0.70 in Alpine X Malabari crossbreds, respectively. The frequency of S allele was higher in both the populations. Alpha S2 casein locus exhibited three phenotypes viz., AA, AB abd BB controlled by two allels A and B. A allele had the higher frequency of 0.71 in Alpine x Malabari crossbreds compared to 0.62 in Malabari. Higher frequency of AA phenotype was found in Alpine x Malabari (0.52) and that of AB phenotype in Malabari (0.44). Two alleles namely A and B contributed three phenotypes viz., AA, AB and BB at the beta casein locus in both the populations studied. Malabari showed higher frequency of B allele (0.55) while Alpine x Malabari had higher frequency of A allele (0.60). Beta casein AB phenotype had higher frequency in Malabari breed (0.54). Kappa casein locus showed two alleles A and B contributing three phenotypes viz., AA, AB and BB. The frequency of A allele was higher in both the population. The phenotype AA was higher in Alpine X Malabari crossbreds (0.56) while Malabari had higher frequency of AB phenotype (0.48) Two alleles namely A and B with three phenotypes AA, AB and BB were identified at Beta lactoglobulin locus. The phenotype AA was dominant in Alpine x Malabari crossbreds (0.50) and the frequency of BB phenotype was almost similar in both Malabari and Alpine x Malabari crossbreds (0.14 in Malabari and 0.12 in Alpine x Malabari crossbreds). The gene frequency of Beta lg A was found to be 0.65 in Malabari and 0.67 in Alpine x Malabari crossbreds. Both the populations studied were in genetic equilibrium with respect to these milk five protein loci. No significant diversity was found to exist between genetic groups. The genetic variability in the populations was calculated by estimating the heterozygosity. The overall heterozygosity in different populations indicated that the Malabari breed had comparatively higher degree of herozygosity (0.4711) followed by Alpine x Malabari crossbreds (0.4209). In Malabari maximum heterozygosity was observed at Alpha S1 casein loci (0.4992). In Alpine x Malabari maximum heterozygosity was observed at Beta casein locus (0.4800). The study of association between the genes controlling synthesis of milk protein showed significant association between the Beta casein with the Beta lactoglobulin Bb types in Alpine x Malabari crossbreds. All the other combinations of genes did not show any significant association. Milk protein variants were not found to be associated with the lactational yield (120 days) of the goats. The present study could establish the existence of biochemical polymorphism at Alpha S1 casein, Alpha S2 casein, Beta casein, Kappa casein and Beta lactoglobulin loci in Malabari and Alpine x Malabari crossbreds studied.ThesisItem Open Access Milk protein genetic variants in crossbred dairy cattle(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1995) Madhavan, K; KAU; Nandakumaran, BThe present investigation was undertaken to identify the biochemical polymorphism at different milk protein loci and to establish their inheritance pattern in crossbred cattle. It was also envisaged to analyse the association of different milk protein variants with lactation milk yield and incidence of mastitis. One hundred and thirty five animals belonging to three different crosses of local nondescript cattle viz. crossbred Jersey (50), crossbred Brown Swiss (45) and crossbred Holstein Friesian (40) were typed for milk protein variants by standardising horizontal polyacrylamide gel electrophoresis. The milk protein loci studied were α S1 – casein, β – casein, k- casein and β – lactoglobulin. Two alleles namely B and C with three phenotypes BB, BC and CC were identified at α S1 – casein locus. B allele had the frequency ranging from 0.61 to 0.63. β – casein locus exhibited three phenotypes contributed by two allels A and B. A allele had the highest frequency of 0.81 in crossbred Brown Swiss and it ranged from 0.71 to 0.81 among different crossbreds. Highest frequency of AA phenotype was in crossbred Brown Swiss (0.67) and that of AB phenotype was highest in crossbred Jersey (0.29). Two alleles namely A and B contributed three phenotypes viz., AA, AB and BB at k - casein locus among different crossbreds studied. Crossbred Jersey showed the highest frequency of A allele while crossbred Brown Swiss (0.69) had the highest frequency of B allele (0.44). K – casein AA phenotype had the highest frequency in crossbred Jersey (0.52) and AB phenotypes had the highest frequency in crossbred Brown Swiss (0.51). β – lactoglobulin locus showed two alleles A and B contributing three phenotypes viz., AA, AB and BB. The frequency of A allele was highest in crossbred Holstein Friesian (0.46) and that of B allele in crossbred Brown Swiss (0.60). AA phenotype had the highest frequency in crossbred Holstein Friesian ( 0.25) while crossbred Jersey had the highest frequency of BB phenotype (0.38) and AB phenotype was highest in crossbred Brown Swiss (0.44). The observed and expected phenotypes among different genetic groups at all the four milk protein loci viz. αS1 – casein, β – casein k – casein and β – lactoglobulin were tested by Chi – square test. All the populations studied were in genetic equilibrium with respect to these four loci. This trend is suggestive of neutral role of the three milk protein loci in the population. The genetic variability in the crossbred population was calculated by estimating the heterozygosity was at β – lactoglobulin locus. In the crossbred Brown – Swiss maximum heterozygosity was seen at the k - casein locus. The overall heterozygosity in different crossbred population indicated that the crossbred Holstein Friesian had comparatively highest degree of heterozygosity (0.4603) followed by Crossbred Jersey (0.4346). In crossbred Jersey αS1 – casein types showed significant association with β – casein types. k – casein phenotypes were significantly associated with β – lactoglobulin types. In crossbred Brown Swiss also αS1 – types were found to be linked with β – casein types. β – casein BB phenotype and k – casein variants were found to be linked. β – lactoglobulin phenotypes and β – casein types were also found associated in crossbred Brown Swiss. In the case of crossbred Holstein Friesian all the milk protein variants except β – casein and k – casein were found to be associated. Milk protein variants were not found to be associated with first lactation milk yield or the incidence of mastitis in all the crossbred population studied. The present study could establish the existence of biochemical polymorphism at αS1 – casein, β – casein k – casein and β – lactoglobulin loci crossbred Jersey, crossbred Brown Swiss and crossbred Holstein Friesian cattle studied.ThesisItem Open Access Comparison of immune response of the indigenous and cross bred cattle of Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, 1994) Francis Bastin, P; KAU; Sosamma, IypeThis research work aimed at comparing the immune responses of indigenous and crossbred cattle of Kerala and finding out association if any, with common diseases and also maternal immune response and the neonatal calf diseases and mortality. Thirty adult local indigenous cattle, their 36 calves, 40 adult crossbred cows and their 40 calves formed the material for the study. Primary humoral response to the test antigen, human red blood cells was assessed at zero, seven and 14th day. Secondary immune response to the test antigen was assessed on day three, seven and 14 after booster injection at 14th day. The antibody titre was assessed by direct microhaemagglutination technique. Cell mediated immune response to contact sensitizer 2,4-Dinitrochlorobenzene (DNCB) was assessed by application of two per cent solution on zero and first day followed by percutaneous challenge at the 14th day. Double fold skin thickness and area of reaction were recorded. Humoral and cell mediated immune response, the influence of genetic group, association with diseases and mortality, influence of maternal immune response on the calf immune response and association with calf diseases and mortality were assessed. The antibody titres were expressed as 1oge + 1 to make the distribution normal. Peak primary immune response was reached by day 14 (2.13) and peak secondary response was on seventh day of secondary immunization (2.98). No significant differences were observed between primary and secondary immune response in different genetic groups namely indigenous and crossbred cattle and also in different age groups viz. dam and calf. The correlation between primary and secondary immune response except in indigenous cows, were highly significant. The cell mediated immune response peaked by 24th post 2,4-Dinitro chloro benzene challenge both in indigenous and crossbred cattle (7.0 mm). No significant association could be detected between the incidence of diseases and mortality with humoral as wel1 as cell mediated immunity. Similarly association between maternal and calf immune response was also not significant. Indigenous cows had lower incidence of respiratory diseases and mastitis compared to crossbred cattle (od2 = 3.8 and 19 respectively). Similarly local indigenous calves had significantly lower mortality (oc2 = 8). The results of the study suggests that primary immune response could be used as an index of secondary immune response. The study also suggests that immune response to a single antigen might not be indicative of general disease resistance. Further, apart from the immune response traits in the present study, there might be several factors which influence the immune response, disease resistance and disease susceptibility.ThesisItem Open Access Chromosome Profile Of Cross-Bred Bulls In Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1994) Gopakumar, C P; KAU; Raghunandanan, KCytogenetic study was conducted on 53 young cross-bred (Bos Taurus x B. indicus) bulls stationed at the farm at Dhoni, belonging to Kerala Livestock Development Board. Young bulls included those selected for superior semen quality and others just started producing semen. The bulls were classified into Jersey cross, Holstein-Friesian cross and Brown-Swiss cross based on the paternal line. The semen quality and related attributes of the bulls were recorded, and the association between these traits and the karyological parameters were determined. Comparative chromosome study were performed in the three genetic groups. Metaphase spreads for staining and G-banding were obtained by peripheral leucocyte culture technique. The basal medium used for culturing was RPMI 1640 and mitosis was initiated in lymphocytes by a combination of phytohemagglutinin and pokeweed mitogen. The G-banding was done by incubating the chromosome spreads in 2 x SSC containing trypsin solution for 45 minutes at 660C. Karyological parameters such as chromosome number, morphology, relative length, arm ratio and centromeric index were studied. The nature, number and position of G bands were also examined. The reproductive attributes recorded included age at first semen collection age at freezable semen production, volume of semen, sperm concentration, total sperm output in first ten collections, number of ejaculates accepted for freezing and total freezable sperm output in first ten collections, and the morphological abnormalities of sperms. All the bulls except one, exhibited a diploid chromosome complement (2n=60, XY) in their cells. There were 29 pairs of acrocentric autosomes and a sub-metacentric x chromosome. The Y chromosome was sub-metacentric in Holstein-Friesian cross, and apparently metacentric in other two genetic groups. In one bull diploid/tetraploid mosaicism was observed with 6.67 per cent of lymphocytes carrying 120 chromosomes. The mean relative length of longest and shortest autosomes were 6.0174 ± 0.0273 and 1.6186 ± 0.0101 respectively. The X and Y chromosomes had a mean relative length of 5.5918 ± 0.0401 and 1.9636 ± 0.0396 respectively. In the X chromosome the arm ratio was 2.47 ± 0.04 and the centromeric index was 28.74 ± 0.33. A total of 405 bands were identified in the karyotype of the bulls. The G-banding pattern of cross-bred bulls in Kerala was not previously investigated, and hence the banding pattern observed in the study would be useful for cytogenetic screening of bulls in the state. On Analysing the semen quality and related attributes of the bulls it was found that one of the bull was oligospermic. The semen of this bull exhibited a high frequency of loose sperm heads. Semen of another bull was found to contain abnormal percentage of sperms with persistant proximal cytoplasmic droplet. A third bull produced semen in which the frequency of sperms with knobbed acrosome defect was very high. All the three bulls had produced ejaculates which were found unsuitable for freezing. The incidence of diploid/tetraploid mosaicism was detected in the bull producing sperms with knobbed acrosome defect. None of the ejaculates of this bull was suitable for freezing. However, further study was essential to conclude on the association between mixoploidy and knobbed acrosome defect or its influence on semen freezability. The other two bulls with seminal abnormalities exhibited cytogenetic profile similar as that of bulls producing normal semen. The effect of genetic group on the morphometry of sex chromosomes was found to be insignificant. However, the Y chromosome morphology was observed to be a suitable marker for identifying Holstein-Friesian crosses among the cross-bred bulls used for breeding in Kerala.