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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 Evaluation of holstein crossbred bulls based on milk composition of progeny(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1997) Radhika, G; KAU; Sosamma IypeSire evaluation programmes in Kerala state, so far have been hinged around milk production alone, and no emphasis has been laid on milk constituents. The milk constituents like fat and solids not fat determined the market value and consumer's receptivity of milk. Reports on sire evaluation on the basis of milk constituents were seriously lacking in literature and hence the present investigation was undertaken with a view to compare the crossbred sires on the basis of milk yield, fat, total solids, and solids not fat percentages and their yields. 1284 milk samples belonging to 222 animals (103 progenies of Holstein crossbred bulls with superior genetic worth and 119 contemporaries) calved during the period 1995~96 formed the material for the study. These animals belonged to farmers in the area of six AI centres around Thrissur and also the animals maintained in three University Livestock farms. Milk samples were collected during early, middle and late lactation both in morning and evening, and the samples were analysed for fat, total solids and solids not fat percentages. Milk fat percentage was estimated by Electronic Milk Tester with frequent standardisation with Gerber's method. Total solids percentage was determined by Gravimetric method and solids not fat by finding the difference between total solids and fat percentages of milk. Fat, total solids and solids not fat yields were calculated by multiplying the percentages of these constituents with cumulative milk yield for each stage for lactation and adding. -- The statistical analysis was done as per standard procedure. Least squares technique as described by Harvey (1986) was employed to analyse the effects of centre, sire and season on the characters studied. The effect of centre was highly significant, while effects of sire and season were non- significant. The overall average 305 day milk yield was found to be 1829.68 kg. The progenies in the first lactation had higher averages compared to the contemporaries in different parities. Among the centres progeny average of 305 day milk yield was maximum for University Livestock Farm, Mannuthy (2800 kg) followed by Ramavarmapuram (2426.71 kg). University farm milk samples revealed higher values for 305 day milk yield, fat, total solids and solids not fat percentages compared to field milk samples. Among the centres, Arimbur recorded comparatively higher fat percentages during all stages of lactation. An important result from legal point of view was that,66.67 per cent of cows in the early stage of lactation, recorded morning milk fat per cent below the legal standards of 3.5. In case of solids not fat, 46.5 per cent were below the PFA standard of 8.5 per cent. Total solids and fat percentage showed an increasing trend with the progress of lactation. But such a trend was not observed for solids not fat percentage. Heritability estimates were calculated by paternal half-sib method for milk yield and its composition. Milk fat percentage had the highest heritability estimate of 0.326iO.234. The estimates of sire merit of Holstein Friesian test bulls for 305 day milk yield.fat, total solids and solids not fat percentages and yields, were computed by three methods of sire evaluation viz., daughter's average, contemporary comparison and least squares means. The yield characteristics were found to have more genetic variance than the corresponding percentages and hence preferred for sire evaluation. Since there was slight difference in the ranking of sires by these methods there is a need to study the accuracy of evaluation by different methods and then to choose the best method for evaluation under field conditions. The observation on the low milk fat and solids not fat percentages pinpoints the necessity of urgently amending PFA act for the benefit of the farmers.ThesisItem Open Access Evaluation of sister chromatid exchanges in cattle reared in a radio active belt area of Southern Kerala(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1999) Dinesh, C N; KAU; Raghunandanan, KA cytogenetic investigation on the effect of long-term background radiation on cattle was carried out in this study. It involved the analysis of sister chromatid exchanges (SCEs) which was the most sensitive and quickest mammalian system to find out the effect of mutagens on genetic material. The technique standardized for sister chromatid differentiation (SCD) involved culturing of lymphocytes in RPMI-1640 medium and incorporation of 5-bromo-2-deoxy uridine (BrdU) at 20th hour of incubation. The cells were harvested at the end of 70th hour and the thionine stained~slides were exposed to UV light for one hour at a distance of one foot from the UV source. analysed for SCE. Metaphase spreads showing SCD were Cattle reared in the four coastal wards of Chavara Panchayat (Kovilthottam, Cherusseribhagam, Kolangarabhagam and Kari thura) were taken as experimental group. Cattle from University Livestock Farm (ULF) , Mannuthy, which has no reports of background radiation, formed the control group. The mean SCE frequency per cell was found to be 1.536 ± 0.249 and 3.368 ± 0.273 for control and experimental groups, respectively. The range and number of SCEs/cell/generation for control animals were 0 to 5 and 0.768, respectively. In the experimental group it was 0 to 9 and 1.684. Thus an increase of 119.27 per cent in SCE frequency was recorded in high background radiation area when compared to that of control. The mean SCE frequencies for cattle of Kovilthottam, Cherusseribhagam, Kolangarabhagam and Karithura were 4 ± 0.966, 2.563 ± 0.584, 3.206 ± .411 and 3.389 ± 0.504, respectively and the SCE ranges were 0 to 7, 0 to 6, 0 to 7 and 0 to 9. There was no significant difference in SCE frequency among the four wards. The difference between SCE frequencies of Kovilthottam, Kolangarabhagam and Karithura to that of control was significant. This could be due to the effect of high background radiation on DNA and chromosomes. However, difference in SCE frequency between Cherusseribhagam and control was not significant. This could be due to non- homogenous distribution of monazite deposits in the coastal belt. Though the increase in SCE frequencies in Karithura, Kolangarabhagam and Kovilthottam were statistically significant, cattle reared in this area did not reveal any deviation in physiological and phenotypic performance. Thus this study indicates that SCE frequenc,y for cattle reared in Chavara panchayat with high background radiation was significantly higher than that of control group. This discloses the occurrence of chromosomal damage in this area though these cattle performed normally. This may be because of the repair mechanism or balanced by exchange mechanism during active replication of chromosomes.ThesisItem Open Access Immunogenetic influences on litter traits, viability and growth in broiler rabbits(Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 1999) Marykutty, Thomas; KAU; Nanadakumar, PA detailed investigation into the genetic and environmental factors influencing litter traits, growth and viability among three temperate broiler breeds of rabbits namely New Zealand white, Grey Giant and Soviet Chinchilla, maintained at rabbit research station under the Centre for Advanced Studies in Animal Genetics and Breeding of Kerala Agricultural University was undertaken. The effect of breed and sire on litter traits, growth and viability were assessed. Association among these traits were estimated. In an attempt to ascertain the genetics of humoral immune response of broiler rabbits, antibody response to chicken RBC was analysed. The influence of breed, sex and sire on humoral immune response was ascertained. Heritability of humoral immune response was worked out. The interrelationship between humoral immune response, growth and viability was estimated. Litter size at birth averaged 4.37 ±0.15 among rabbits. The effect of breed and sires within breed was not significant on this trait. Grey Giant rabbits had highest litter size at birth. Overall mean for litter weight at birth was 227.36 ± 6.81 g. Breed and sire effects were not significant on litter weight at birth. Grey Giant breed had highest litter weight at birth of 236.70 ± 14.74 g. Breed differences were significant (P:5 0.05) for the litter size at weaning among broiler rabbits. Grey Giant had largest weaning litter size of 1.96±0.25 followed by New Zealand White (1.87 ±0.24) and Soviet Chinchilla (1.18 ± 0.21). The effect of sires on this trait was not significant. The effect of breed on litter weight at weaning was significant (P:5 0.05). Grey giant had heaviest litter weight at weaning with a mean of 1084.15 g New Zealand White and Grey Giant had weaning litter weight of 1073.88 g and 707.96 g respectively. Sire component of variance was not significant for this trait. Pre-weaning mortality among the three breeds of broiler rabbits averaged 76.20%. The influence of breed on preweaning mortality was significant (P :50.05). New Zealand White rabbits had least preweaning mortality and Grey Giant suffered from maximum preweaning losses. Preweaning mortality among the litters of various sire groups were not differed significantly. Phenotypic correlation coefficient among litter size traits and litter weight traits studied were positive and highly significant (p:5 0.01). Litter size traits had highly significant (P:5 0.01) positive correlation with litter weight traits. Pre-weaning mortality had a highly significant (P:50.01) negative correlations of (-)0.27, (-)0.85 and (-)0.81 respectively with litter weights at birth and at weaning and litter size at weaning. Association between litter size at birth and preweaning mortality was significant (P:5 0.05) and negative. Genetic correlations of litter size at birth with litter weight at birth and litter weight at weaning were highly significant (P:=:; 0.01) and positive. Litter weight at birth had a highly significant (P:=:; 0.01) genetic correlation with litter size at weaning. Overall mean of body weight at weaning was 611.73 g among rabbits. Effect of breed and sire was not significant on this trait. Grey Giant, New Zealand White and Soviet Chinchilla respectively had weaning weight in grams of 641.92, 614.33 and 564.36. Body weight at 12 week averaged 1168.41 g in broiler rabbits. Though the breed effect was not significant, Soviet Chinchilla had heaviest body weight at 12 week with a mean of 1237.66 g followed by New Zealand White (1132.97 g) and Grey Giant (1121.19 g). The effect of sire was significant(p :=:;0.05) for the variation body weight at 12 week. Effect of breed, sire and sex on Forssman antibody titre to chicken RBC was not significant. Forssman antibody titre (1 + loge) averaged 0.11 in the population. Antibody response to chicken RBC peaked 7 day post immunisation with a mean of 4.208 and dwindled to a mean of 3.454 and 2.932 respectively on 14 and 21 day post immunisation. The effect of breed was not significant on 7 and 14 day post- immunisation antibody titres to chicken RBC. However, 21 day post- immunisation antibody titres to chicken RBC was significantly (P::; 0.05) influenced by the breed. Soviet chinchilla rabbits consistently had higher antibody titres with a mean of 4.3715,3.6320 and 3.2903 at 7, 14 and 21 day post-immunisation. Though not significant, males had higher antibody titres to chicken RBC compared to females. sire had significant effect on 7th day (P = 0.0486), 14th day (P = 0.0218) and 21 st day (P = 0.0047) post- immunisation antibody titres. Heritability estimates were high for the immune response traits. Phenotypic correlation between 7, 14 and 21 day postimmunisation antibody titres were highly significant (P::; 0.01). Association of Forssman antibody titre with postimmunisation antibody titres were not significant. Body weight at weaning had significant (P::; 0.05) negative correlation of (-)0.18 and (-)0.19 respectively, with 14 and 21 day postimmunisation antibody levels to chicken RBC.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.