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ThesisItem Open Access Marker assisted selection for milk production traits in vechur cattle(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences Mannuthy, 2005) Shymaja, Uthaman; Raghunandanan, K VThesisItem 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 Characterisation and evaluation of the dwarf cattle of Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1994) Girija, C R; KAU; Sosamma, IypeThe native cattle of Kerala have been treated as non descript animals always eventhough they possess some special features. The dwarf cattle often called as Vechur were very popular in Central Travancore until 35 years back. With the emergence of the crossbred population of cattle the traditionally reared local cattle have gradually suffered genetic erosion. Under this circumstance, the present work was undertaken to characterize and evaluate the germplasm of local dwarf cattle of Kerala by studying (a) the karyotype and morphology of chromosomes using G-banding (b) the population structure by means of gene frequencies of different blood proteins (c) the growth and production performance. The characterization and the evaluation would help in finding out the genetic differences of the dwarf cattle which will help in deciding about the conservation of their germplasm as a reserve for the future. The dwarf cattle maintained under the ICAR scheme on “Conservation of germplasm of Vechur cattle of the coastal area and the dwarf cattle of the high ranges of Kerala” formed the material for the study. The characterization and evaluation was carried out through the cytogenetic, immunogenetic and polymorphism studies as well as through the description of the growth and production traits. Karyotype analysis was carried out using peripheral blood leukocyte culture technique described by Halnan (1977) and Halnan (1989) with suitable modifications. G-banding of chromosomes were done by the method described by Thiagarajan (1993). Blood protein polymorphism systems such as Haemoglobin and transferring were studied by poly acrylamide gel electrophoresis in horizontal dimension. (Gahne et. al. 1977) with suitable modifications. The statistical analysis of the growth and production data were done as suggested by Snedecor and cochran (1967). The diploid chromosome number of the dwarf cattle was found to be 60, with 29 pairs of autosomes and one pair of sex chromosomes. All the autosomes and the ‘Y’ chrosome were acrocentric. The X chromosome was submetacentric. The relative length of the autosomes ranged from 1.757 to 5.431 per cent. The relative length of the X and Y chromosomes were found to be 5.591 per cent and 2.875 per cent respectively. In the karyological array, the X chromosome occupied the first position. The X chromosome was biarmed and the arm ratio and centromere index obtained were 2.182 and 0.314 respectively. The karyotype and morphometric measurements resembled the finding in Bos indicus group of cattle. The G-banding pattern of chromosomes revealed 72 regions and 314 G-bands. The Y chromosome had 7 G-bands in the ‘q’ arm which resembled the ‘q’ arm of Bos taurus described in the international system for cytogenetic nomenclature of domestic animals. There were two haemoglobin variants HbA and HbB and three phenotypes viz. HbAA, ,HbAB and HbBB , in the population. The heterozygocity was found to be 0.4815. The population was found to be in genetic equilibrium with respect to the Haemoglobin locus. Six transferring phenotypes controlled by three alleles TfA, TfD and TfE were observed. The frequency of TfE (0.359) allele in the dwarf cattle was as high as the frequency of the allele reported in the zebu cattle. The absence of transferring variants like TfF, TfH, TfN and TfG and higher frequency of TfE allele are probably indicative of the genetic isolation of the population from exotic breeds. The absence of TfB and TfF allele which is present in Gir, Hariana, Kankrej, Kangayam, Ongole, Red Sindhi, Sahiwal and Tharparkar also indicates that the dwarf cattle has not inherited genes from the above cattle breeds. The body weights and measurements of calves at birth studied showed that the male calves had a higher body weight (12.55 ± 0.31 kg with a CV of 7.86 per cent) than female calves (10.78 ± 0.40 kg with a CV of 15.02 per cent). The same trend was observed with regard to the birth body measurements also. The heart girth measurement and body weight showed a positive correlation from birth to the 24th fortnight. There is a 100 per cent increase in the birth weight by the 5th fortnight and a three-fold increase by the 10th fortnight. The average daily gain in weight for the four periods I e., fortnights 0-6, 7-12, 13-18 and 19-24 were 0.160 ± 0.011, 0.167 ± 0.018, 0.212 ± 0.011 and 0.139 ± 0.015 respectively for female calves and 0.188 ± 0.023, 0.145 ± 0.016, 0.116 ± 0.025, 0.242 ± 0.049 kg respectively in male calves. During the period from birth to 6th fortnight the growth rates in males and females were similar. The gain in body weight per day during the periods from 7 to 12th and 13 to 18th fortnight was comparatively less for males but the trend reversed during the period of fortnights for 19 to 24th. The average body weights of adult females and males were 126.90 ± 3.56 kg (CV 16.39%) and 210 ± 15.75 kg (CV 14.95%) respectively. The body measurements such as length, heart girth and height (in cms) in females were 97.5 ± 1.12 (CV 5.85%), 115.60 ± 1.32 (CV 5.82%) and 87.53 ± 0.82 (CV 4.82%) respectively. The corresponding figures in males were 111.5 ± 3.77 (CV 6.76%), 146.0 ± 2.92 (CV 3.99%) and 107.5 ± 1.35 (CV 2.50%) respectively. The average body weights and measurements were lesser than those reported in other Indian breeds and crossbred cattle. The total lactation milk production performance of the dwarf cattle was 471.68 ± 38.72 kg (CV 45.29%) in an average lactation length of 217 ± 16.50 days (CV 32.20%). The average daily yield was 2.17 ± 0.11 kg (CV 29.48%). The dwarf cattle attained a peak yield of 3.71 ± 0.16 kg (CV 21.5%) in 23.23 ± 1.703 days (CV 37.38%). The milk production performance eventhough was lesser than crossbreds or some recognized Indian breeds, the milk production in comparison with the body size was reasonable. Considering the morphology of the Y chromosome, the Hb as well as Tf polymorphism and their allelic frequencies, it is to be summarized that the stock of dwarf cattle of Kerala maintained at Kerala Agricultural University is genetically isolated from the other cattle breeds of the country and world. The body size and milk production of the cow indicates its suitability for a farmer who requires milk just for home consumption. The study strongly confirms the necessity of conservation of the dwarf cattle of Kerala which is the smallest variety available in India and perhaps in the world itself.ThesisItem Open Access Evaluation of boer halfbreds for development of meat goat strains suited for Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2004) Jeeva, L; KAU; Nandakumar, PThe tremendous potential of goat production in Kerala State is constrained due to the non-availability of meat type of goats suited to our climatic conditions. Malabari goats native to Kerala and improved Alpine Malabari (AM) grows to around only 8.5 and 11 kg respectively, imposing severe restrictions on commercial exploitation of these breeds. Introgression of Boer inheritance into Australian feral goats has led to the development of Australian goat meat industry and utilization of Boer goats to improve local goats in Maharashtra has paid rich dividend. With this background, the present investigation undertaken in Alpine Malabari crosses (AM) by infusing Boer inheritance was undertaken at University Goat and Sheep Farm was to evaluate the suitability of Alpine Malabari x Boer (AMB) crosses as a meat strain suited to Kerala State. Data on one hundred goat kids, 50 each belonging to 2 genetic groups, AM and AMB were subjected to least squares analysis to resolve the effect of genetic group, sire, month of birth and sex on type of birth, litter weight at birth, birth weight, body weight at first, second, third, fourth, fifth and sixth month, pre- weaning mortality, incidence of neonatal diseases, litter size at weaning, average daily gain in body weight, phenotypic correlation, viability and adaptability. Average litter size at birth (LSB) among Alpine Malabari (AM) and , Alpine Malabari x Boer (AMB) kids was 1.79±0.48. Alpine Malabari kid had a significantly (P:S0.05) higher litter size ~t birth of 2. I 2±0. I 6. Month of birth had a highly significant (P~O.OI) effect on litter size at birth with highest litter in July (2.2±0.17). Sire influences were highly significant on litter size at birth while sex had no significant influence on litter size at birth. Mean litter weight at birth was 3.77 kg and it was not found to be significantly affected by genetic group and sex. Month of birth and sire had highly significant associations with litter weight at birth. Alpine Malabari x Boer kids had a highly significant (P::::O.Ol) and higher body weight from birth to sixth month of age. Body weight in AMB kids was 2.38,6.01, 8.92 and 11.65 kg while AM kids had only 1.8,2.87,3.05 and 4.30 kg respectively at birth, one, two and three months respectively. Buck had a highly significant influence on birth weight of kid and body weight at first, second and third month. Month of birth had a significant influence on birth weight and body weights at first, second and third month. Incidence of enteritis was 0.31, respiratory infection 0.08 and pre- weaning mortality was 0.07. Effects of genetic group and sire were significant on respiratory infections and not on incidence of enteritis and pre-weaning mortality. Month of birth did not exert significant influence on respiratory infections, enteritis or pre-weaning mortality. The mean body weights at fourth, fifth and sixth month in AM and AMB crosses were 10.34 kg, 11.96 kg and 13.68 kg respectively. The effect of genetic group on body weights at fourth, fifth and sixth month was highly significant and superior in AMB crosses with 13.62 kg, 15.73 kg and 17.79 kg respectively while it was only 5.76 kg, 5.84 kg and 6.81 kg respectively in AM crosses. Sire effects were highly significant on the body weights at fourth, fifth and sixth month. Month of birth contribute to the body weights to a highly significant level and kids born in April and December were found to have higher body weights from fourth to fifth month. Sex of the kids was not found to influence the body weights from fourth to sixth month. The mean average daily gain in body weight (ADG) from birth to third month was 7r.36 g, from third to sixth month was 65.7 g and birth to sixth month was 66.7 g. AMB crosses had a highly significant ADG of 104.89 and 86.58 compared to 35.19 and 39.1 g during 0-3 and 0-6 month respectively. Sire influences were highly significant on ADG from 0-3 and 0-6 month. Month of birth had a highly significant effect on ADG and highest ADG was for kids born during April. Birth weight had a highly significant positive correlation with average daily gain in body weight from birth to third month and average daily gain in body weight from birth to sixth month and body weights from first to sixth month. Correlation between respiratory infections and pre-weaning mortality were highly significant. Average daily gain in body weight from birth to third month had a highly significant negative correlation with respiratory infection and pre-weaning mortality. Significantly higher litter size at birth in AM crosses over AMB crosses direct to the feasibility of AM genotype of enhancing litter size at birth which might partially be also contributed by use of oestrus synchronization on frozen semen technology in production of AMB crosses. Modulation of litter size at birth by month of birth reflect on the environmental factors influencing the ovulation rate, conception rate and embryonic survival. Monthly body weights from birth to six months was found to be highly superior in AMB crosses indicating the Boer superiority in enhancing body weights of AMB crosses. Significant effect of sire on these trait suggest of the additive genetic effect which might improve body weight in Boer crossbred goats. Contribution of month of birth on bodyweight probably influenced by ambient temperature, availability of biomass, offers potential for improvement of these traits by appropriate managemental strategies. Increased incidence of diseases in AM genetic group with higher pre-weaning mortality is worth for further investigation. ADG 0-3, ADG 0-6 were significantly higher in AMB crosses highlighting the importance of Boer development in improvement of growth rate of goats. The role of month of birth in variations in ADG partially reflect on the environmental conditions can adversely affect the growth rate. Phenotypic correlations, which were positive and highly significant between birth weight, ADG and body weight are suggestive benefits of early selection on birth weights for enhanced, slaughter weights. The negative correlation of ADG and incidence of pneumonia, pre- weaning mortality and enteritis could be used for the development of goats adapted to local climatic conditions.ThesisItem Open Access Genetic polymorphism of major histocompatibility complex class II genes(Department of Animal Breeding, Genetics and Biostatistics, College of Veterinary and Animal Sciences, Mannuthy, 2010) Remya John, v; KAU; Raghavan, K CThesisItem Open Access Chromosome profile of zebu x taurus cattle in Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1988) Raghunandanan, K V; KAU; Mukundan, GA study was undertaken to evaluate and compare the chromosomal status of Local non – descript, half – bred Jersey, half – bred Holstein Friesian and Jersey cattle and to assess the incidence of chromosomal aberrations causing physiological disorders. The cattle owned by Kerala Agricultural University. Indo – Swiss Project and farmers formed the material for the study. In all, 102 animals consisting of 71 normal and 31 abnormal, were subjected to the study. Peripheral blood leukocyte culture technique with heparinised whole blood was used for chromosome analysis. The medium was TC 199 with phytohaemagglutinin M as mitotic inducer and colchicine as mitotic arrester. The cells in metaphase were harvested and air dried smears stained with Giemsa. Good spreads were photographed and karyotypes prepared. The efficiency of medium was tested using mitotic drive and mitotic index, which were between 32 to 33 per cent and 5 to 6 per cent respectively. Colchicine treatment of 0.1 ml (0.0001%) for 1 hour yielded clear visible chromosome spreads. The blood samples stored for varying time at 50C indicated that the whole blood transported in ice bath (50 C) is to be used within 12 hours after collection for lymphocyte culture. In normal cattle, diploid chromosome number was found to be 2n = 60 with 29 pairs of autosomes and one pair sex chromosome. The males were heterogametic. All the autosomes were acrocentric in Local, half – bred Jersey, half – bred Friesian and Jersey whereas the x chromosome was biarmed and a large submetacentric in all the genetic groups. The Y chromosome was polymorphic being acrocentric in Local and submetacentric in exotic bulls. No satellite was observed in any of the chromosomes. The relative length of largest and smallest autosomes were 6.5080 and 1.3473 per cent in Local, 6.4735 and 1.2250 per cent in half – bred Jersey, 6.2190 and 1.3788 per cent in half – bred Friesian and 6.9125 and 1.3096 per cent in Jersey respectively. The difference in relative length of autosomes between different genetic groups was not found to be significant. The relative length of x chromosome was 7.2838 per cent, 7.0313 per cent, 6.5138 per cent and 6.3166 per cent in Local, half – bred Jersey, half - bred Friesian and pure Jersey respectively. The differences between genetic groups were significant. In the karyotypic array based on relative length, the x chromosome occupied a first position in Local, half – bred Jersey, half – bred Friesian whereas in Jersey it was in between first and second pair of autosomes. The relative length of Y chromosome was 2.9415 per cent, 2.5745 per cent and 2.9375 per cent in Local, Jersey and Holstein Friesian respectively. The difference Local and Holstein Friesian was not significant. In karyological array the Y chromosome occupied a position between 15th and 16th pair of autosomes in Local and Holstein Friesian whereas in Jersey it was between 15th and 20th pair. The arm ratio of x chromosome was 2.043, 1.986, 1.739 and 1.690 in Local, half – bred Jersey, half – bred Friesian and Jersey respectively. In Local cattle the centromere was located away from mid point compared to other genetic groups. The distance between mid point and centromere was lowest in Jersey. The arm ratio of Y chromosome of Jersey and Holstein Friesian was 1.21 and 1.66 respectively. The location of centromere in Y chromosome of Jersey was more towards centre than that of Holstein Friesian. The centromere index of x chromosome was 0.365, 0.329, 0.338 and 0.372 in Local, half – bred Jersey, half – bred Holstein Friesian and Jersey respectively. The values for the centromere index confirm the findings obtained for arm ratio with regard to the proximity of centromere to the mid point of the chromosome. Among the 31 abnormal cattle, chromosomal aberration were observed in one 4 ½ years old sterile Jersey heifer, one Free martin and one Local bullock with abnormally developed secondary sexual characters. Infertile cattle showing repeat breeding, poor semen quality and poor libido did not exhibit any aberration. In the sterile Jersey heifer, 59/60 mosaicism was observed. The Free martin exhibited 60 XX/60 XY chimaerism having 14 per cent of the cells with XY type and others with XX type. The local bullock revealed abnormal development of teats and secretion of milky fluid. The mitotic spreads were of tetraploid nature (4n = 120) in 4.5 per cent cells and the diploid (2n = 60) in others. This animal was diploid tetraploid chimaera or mixoploid. The present study brought out findings that relative length, position in the karyotypic array, arm ratio and centromere index of sex chromosomes shall serve as tool for identification of inter – breed differences and that the occurrence of tetraploidy stimulate the activity of the female secondary sexual characteristics in male cattle.ThesisItem Open Access Evaluation of Lactation Performance of Zebu x Taurus Cattle in Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences,Mannuthy, 1983) Stephan, Mathew; KAU; Mukundhan, GAn investigation was undertaken to evaluate the lactation performance of the crossbred cattle (Zebu x Taurus) and to compare the performance of Brown Swiss and Jersey crosses under field conditions so that a breeding policy could be recommended. First lactation milk yield in 305 days, age at first calving and first lactation length were the characters studied. For this, data on the Brown Swiss crossbred maintained by the farmers at Mavelikkara and Kattappana and on Jersey crossbreds at Kanjirappally and Chalakudy under the milk recording – cum – progeny testing scheme of the Kerala Livestock Development and Milk Marketing Board were utilized. The observations spread over a period of four years from 1978 to 1981. The uncorrected average first lactation yields were 1508.8 + 14.3 kg in Brown Swiss half – breds, 1562.6 + 28.7 kg in unclassified Brown Swiss crosses, 1380.3 + 47.0 kg in Jersey half – breds and 1558.0 + 31.5 kg in unclassified Jersey crosses. The least squares means of first lactation yields in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 1482.0 + 19.7 kg, 1544.7 + 32.4 kg, 1359.2 + 57.4 kg and 1559.8 + 37.3 kg respectively. The Duncan’s multiple range test showed that the Jersey half – breds had significantly lower production compared to all other genetic groups. The production of unclassified Jersey crosses had been significantly higher than the Brown Swiss half – breds as well as Jersey half – breds. Least squares analysis on pooled data and Brown Swiss half – breds showed the significant influence of age at first calving, year of calving and sex of the calf on first lactation milk yield. But, season of calving did not significantly influence the milk yield. The uncorrected average age at first calving in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half _ breds and unclassified Jersey crosses were 46.0 + 0.4 months, 38.4 + 0.6 months, 41.7 + 1.4 months and 39.5 + 1.2 months respectively. The least squares means of age at first calving in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 46.0 + 0.5, 38.0 + 0.8, 41.1 + 2.1 and 38.9 + 1.5 months respectively. Brown Swiss half – breds had significantly higher age at first calving compared to the other three groups which were homogenous. The effect of year on age at first calving was not significant in Brown Swiss half – breds while pooled data analysis showed a significant effect of year on age at first calving. The uncorrected average lactation lengths in Brown Swiss half – breds, unclassified Brown Swiss crosses, Jersey half – breds and unclassified Jersey crosses were 300.5 + 0.5 days, 299.6 + 1.0 days, 295.6 + 2.4 days and 295.3 + 1.7 days, respectively. This shows that all the crossbreds had fairly good lactation length. Lactation milk yield and age at first calving are economically important to the farmer and in this context these two characters are to be considered together. The results obtained do not indicate the superiority of either Brown Swiss or Jersey crossbreds, over the other. The introduction of both Brown Swiss and Jersey improved the milk production of the cattle of Kerala. While aiming at a further improvement, emphasis should be given to the merit of the sires rather than the specificity of the exotic breed or the percentage of exotic inheritance.ThesisItem Open Access Chromosome profile of Indian elephants ( Elephas maximus indicus)(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1988) Sakthi Kumar, A; KAU; Mukundan, GA karyological study in Indian elephants using peripheral venous blood collected from 7 tuskers, 7 cow elephants and one makhna belonging to some temples and private owners of Trichur District was undertaken with objectives of a) to evolve a technique for chromosome studies of elephants. b) to find out the chromosome number in Indian elephants, and c) to suggest sex chromosome mechanism in sex determination. Standardization of technique Comparison of efficacy of phytohaemagglutinin – M (Difco) and Poke – weed mitogen (GIBCO), in two different culture media namely TC 199 and RPMI – 1640, as mitogens showed that phyto – haemagglutinin – M yielded a mitotic index of 0.33 and 0.66 per cent in medium TC 199 and RPMI – 1640 respectively; poke – weed mitogen yielded a mitotic index of 5.33 and 5.66 per cent respectively in TC 199 and RPMI – 1640. Statistical analysis revealed that the efficacy of the two different media used was not significantly different, whereas the efficacy of two mitogens differed significantly at five per cent level. Poke – weed mitogen was found to be better than phytohaemagglutinin – M as far as indusing mitoses in elephant lymphocyte cultures over a 72 hour culture period was concerned. Colchicine treatment using 0.1 ml colchicine solution (0.0001%) for a period of one hour yielded satisfactory chromosome preparations. Karyotype The karyotype of the tusker, cow elephant and makhna revealed a diploid chromosome number of 2n = 56, comprising of 54 autosomes and 2 sex chromosomes. The autosomes were classified into 6 submetacentric and 21 acrocentric chromosomes. The X – chromosome was a submetacentric in all the three groups of elephants whereas the Y – chromosome was a small acrocentric in the tusker as well as the makhna. Analysis of relative length of chromosomes showed that the largest chromosome pair measured a relative length of 6.973 per cent and the smallest chromosome was the Y – chromosome measuring a relative length of 1.710 per cent. Position of centromere on the basis of centromeric index suggested that the centromere was farthest from the centre of the chromosome in the second autosome pair and nearest to the centre in the X – chromosome among the submetacentric chromosomes. Neither autosomes nor sex chromosomes possessed satellites on karyological examination. The elephants studied exhibited XX/XY sex chromosome mechanism. The cow elephant possessed XX sex chromosome complement while both tusker and makhna possessed XY sex chromosome complement. A comparison between the karyotypes of tusker and makhna did not show any variation in (a) basic number, (b) relative length (C) position of centromere, (d) absence of satellites on the chromosomes and (e) the sex chromosome complement. It may be concluded that tusklessness in makhna is not associated with either euploidy or aneuploidy.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 solids