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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access 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 Blood group and biochemical polymorphism in the Malabari breed of goat and its exotic crosses(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1989) Nandakumaran, P; KAU; Mukundan, GRealising the importance of blood groups and biochemical polymorphism in livestock improvement a study was undertaken in 305 adult goats of Malabari breed and its exotic crosses viz. Saanen x Malabari and Alpine x Malabari, to identify the blood group factors and polymorphism, if any, at haemoglobin, potassium and erythrocyte glutathione (GSH) loci and their utility as genetic markers for selection. Standard haemolytic test and absorption technique were performed to produce monovalent reagents and to type the goats. The different haemoglobin types were detected employing horizontal starch gel electrophoresis. The potassium concentration in whole blood and the GSH concentration in erythrocytes were estimated by Flamephotometry and Spectrophotmetry respectively. Twelve blood group reagents M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11 and M12 were produced during the present study from the nineteen polyvalent goat sera obtained from Switzerland. The phenotypic frequencies of different blood group factors were different from each other among the three genetic groups. The blood group factors M4, M10 and M12 were not observed in the Malabari goats. In electrophoretic separation, 94 per cent of the goats showed only one haemoglobin band (HbAA) and six per cent showed two bands (HbAB). HbBB was not observed in any of the genetic groups. Inheritance pattern of Hb alleles revealed that they inherit as autosomal co-dominant alleles. The frequency of HbA allele was 0.98 in Malabari and Saanen x Malabari and 0.97 in Alpine x Malabari, the difference being non significant. It was observed that the goat populations were in Hardy-Weinberg equilibrium with respect to the haemoglobin locus. The genetic group had no effect on the concentration of whole blood potassium. The frequency distribution of potassium concentration in the pooled population showed a distinct bimodality, on the basis of which the goats were classified into two distinct types viz. LK ( < 22 meq/1) and HK ( > 22 meq/1). 76.39 per cent of the pooled population were the LK type, a situation not reported in Indian goats. The potassium phenotypes are controlled by two autosomal alleles, KL (determining LK) and KH (determining HK), the KL being dominant over KH. The gene frequencies of KL and KH were 0.53 and 0.47 in Malabari, 0.50 and 0.50 in Saanen x Malabari and 0.52 and 0.48 in Alpine x Malabari, the difference among the three genetic groups being non significant. The genetic groups had significant effect on the potassium concentration in LK type goats, but such effect was not noticed in HK type goats. The genetic groups had significant effect on the erythrocyte glutathione (GSH) concentration. The frequency distribution of GSH concentration in the pooled population revealed a bimodality. Goats with GSH concentration of > 60 mg/100 ml RBC were classified as GSH-high type and those with < 60 mg/100 ml RBC were classified as GSH-low type. The frequency percentage of GSH-high type in the pooled population was 85.26. Among the three genetic groups, Alpine x Malabari had the highest frequency of 88.48 per cent and Malabari had the lowest frequency of 76.56 per cent. Inheritance pattern of GSH phenotypes showed that in goats GSH types are controlled by two autosomal alleles GSHH (determining GSH-high type) and GSHh (determining GSH-low type), the GSHH being dominant over GSHh. The frequencies of GSHH and GSHh were 0.51 and 0.49 in Malabari, 0.62 and 0.38 in Saanen x Malabari and 0.66 and 0.34 in Alpine x Malabari, without any significant differences among the genetic groups. The frequencies of potassium and GSH alleles and also their concentration did not change over the two generation in any of the genetic groups except in Saanen x Malabari, wherein the mean GSH concentration GSH-high type goats of third generation was significantly higher than that of the second generation. Sex did not influence the concentration of potassium and GSH. A valid conclusion could not be drawn on the effect of sire on the potassium and GSH concentration in its offspring. Studies revealed that haemoglobin, potassium and GSH were not genetically associated. Haemoglobin type had no effect on packed cell volume and concentration of potassium and GSH. The LK type goats had significantly higher packed cell volume in all the genetic groups. The potassium type had no effect on the concentration of GSH in the crossbred goats but in Malabari the HK types had significantly higher concentration in GSH than that of LK types. Goats with HbAA phenotype had heavier body weight at different ages when compared to that of HbAB type. However, the differences was significantly only for the weight at one year in Malabari and weight at nine months in crossbreds. Haemoglobin type had no effect on the production traits. In general, the growth and production traits were not seen influenced by the potassium and GSH types.ThesisItem Open Access Serum immunoglobulin level in kids and its association with growth and mortality(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1981) Nandakumar, P; KAU; Rajagopala Raja, C AVarious aspects of transfer of passive immunity from the dam to the kid and its probable associations with various parameters as genetic group type of birth, birth weight, survivability and growth were studied. The sera of neonatal male kids were subjected to Zinc Sulphate turbidity test and the optical density values were converted into Ig concentration (mg/ml) using the prediction equation prepared from known strengths of commercial bovine gammaglobulins. Pre – colostral Ig levels were estimated in five kids. They were then bled at bihourly intervals to locate the post colostral peak. The trend in post colostral serum Ig level and the effect of periods and individuals on it were analysed. Magnitude of peak Ig level was estimated in 51 kids. The trend in serum Ig levels was estimated in ten kids on alternate days during the first week and weekly once thereafter upto eight weeks. The variation due to individuals and periods were analysed. The effect of genetic group on the post colostral peak of serum Ig level were analysed in 20 Saanen x Malabari (SM) 13 Saanen x Saanen – Malabari (SSM) and 12 Sannen x Alpine – Malabari (SAM) kids. The effect of type of birth on post colostral peak level of serum Ig in 12 single kids, 31 twins and 8 triplets were studied. The correlation between birth weight and post colostral peak of serum Ig in 51 kids was estimated. The mean post colostral peak level of serum Ig in kids died within two months was compared to that of population. The percentages of mortality in kids with above and below 70 mg/ml of serum Ig were calculated separately. The correlation between post colostral peak level of serum Ig and weight gain at 56 days was also calculated. The correlation between weekly trend in serum Ig level and the corresponding body weights was calculated. The pre – colostral Ig level ranged between zero and 0.94 mg/ml with a mean of 0.4156 mg/ml. The Ig level rose rapidly in sera and reached a peak level in a mean duration of 17.36 hours, where after that began to decline gradually. The variation between individuals and periods was found significant. The Ig level at the peak ranged between 42.975 and 107.64 mg/ml with a mean of 73.588 mg/ml. The mean Ig level was the highest on the third day. The Ig level declined gradually by 6 – 7 weeks of age reaching a mean level of 25.3279 mg/ml whereafter it began to rise again. There were significant variations in the above trend between individuals and periods. The genetic group had significant effect on the post colostral peak level of serum Ig. The means of Ig level in SM, SAM and SSM kids were, 76.9399 mg/ml, 69.7828 mg/ml and 60.0569 mg/ml respectively. The means of Ig level at the peak was 78.014 mg/ml in single kids, 75.0091 mg/ml in twins and 61.4406 mg/ml in triplets, though the difference were statistically not significant. The positive correlation of 0.2620 noticed between birth weight and post colostral peak level of serum Ig was also not significant. Kids died within two months had significantly lower mean Ig level at the post colostral peak (56.771 mg/ml) than the population mean (73.5881 mg/ml). The mortality rate was 44 per cent in kids with below 70 mg/ml serum Ig and the same was only 3.84 per cent in kids with and above 70 mg/ml of serum Ig. The negative correlation of (- 0.1554) between post colostral peak level of serum Ig and weight gain at 56 days was not significant. The positive correlation of 0.6932 between weekly trend in serum Ig level and body weight during corresponding periods was significant.ThesisItem Open Access Genetic studies on polymorphism of some blood proteins in goats(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1984) Shamsuddin, A K; KAU; Mukundan, GBlood samples collected from goats maintained in the farm under All India coordinated Research Project on Goats for Milk of Kerala Agricultural University, Mannuthy, formed the materials for this study. These blood samples were typed employing horizontal starch – gel – electrophoresis to study the polymorphism of haemoglobin, transferrin, albumin and amylase. In all 188 goats comprising 40 Malabari, 72 Saanen x Malabari (halfbred) and 76 Alpine x Malabari (halfbred) were involved in the study. Inter and intra population variability was studied. Genetic interrelationship among some growth, production and reproduction traits viz. body weights at birth, 3 months, 6 months and 12 months, age at first kidding, first lactation yield (120 days), peak yield and interkidding interval was determined. Two haemoglobin variants, the faster HbA and slower HbB with two phenotypes HbAA and HbAB were observed. The gene frequency of HbA in Malabari, Saanen halfbred and Alpine halfbred goats was 0.9750, 0.9792 and 0. 9671 respectively and that of HbB in these three genetic groups was 0.0250, 0.0208 and 0.0329 respectively. The frequency of HbA allele was higher in all the populations. Four transferrin phenotypes TfAA, TfAB, TfBB and TfAC controlled by three co – dominant alleles TfA , TfB and TfC were observed. The fast moving variant was designated as TfA followed by TfB and TfC. In Malabari goats TfAC was not observed. The frequency of TfAB type was higher in all the genetic groups. The gene frequencies of TfA, TfB and TfC in Malabari goats were 0.4500, 0.5500 and zero respectively. TfC allele was not observed in Malabari goats. Three Tf alleles namely TfA, TfB and TfC were revealed in the crossbred populations with a preponderance of TfA allele. The frequencies of TfA, TfB and TfC alleles in Saanen halfbreds were 0.5278, 0.4236 and 0. 0486 and in Alpine halfbreds were 0.5329, 0.4539 and 0.0132 respectively. The allelic frequencies of haemoglobin and transferrinloci were suggestive of Hardy – Weinberg equilibrium in all the three population or goats. Magnitude of inter population variability among the three genetic groups was negligible. The autosomal co – dominant mode of inheritance for Tf alleles was demonstrated by analysis of segregation patterns observed in pedigrees. Significant association was observed between the TfAA phenotype and economic traits such as birth weight, first lactation yield and peak yield. Polymorphism was not observed for the albumin and amylase systems. Maximum heterozygosity was observed at the transferrin locus. Highest average heterozygosity was exhibited by the Saanen halfbred goats. Among the four biochemical of blood studied, transferrin reflected a great scope for serving as a genetic marker to be used in selection of goats for improved milk production.ThesisItem Open Access Inheritance of chick weight and egg production in white leghorn birds(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1983) Rose Job, T; KAU; Sosamma, IpeA research work was undertaken in two strains of White Leghorn birds to study the inheritance of chick weight and egg production. The birds maintained at the poultry farm under All India Co – ordinated Research Project on Poultry for Eggs, Mannuthy were utilized for the study. The mean values for six – week body weight (g), eight week body weight (g) and egg production upto 280 days of age (number) were 319.4 + 1.4, 452.9 + 1.8 and 71.5 + 0.4 for N strain and 351.2 + 1.7, 513.7 + 2.2 and 80.6 + 0.5 for P strains. Least squares analysis for effect of generations and hatches within generations were carried out. Generation effects were significant for the three characters in both the strains. Effect of hatches within generations were also found to be significant except for egg production in first generation batches and for six – week body weight in second generation hatches in N strain. The data were adjusted for the generation and hatch effects. Adjusted data were used to estimate heritability, genetic, phenotypic and environmental correlations. The heritability estimates in N strain were 0.223 + 0.112, 0.642 + 0.078 and 0.433 + 0.099 for six – week body weight 0.278 + 0.108, 0.372 + 0.068 and 0.325 + 0.095 for eight – week body weight and 0.219 + 0.095, 0.379 + 0.077 and 0.298 + 0.095 for egg production based on sire, dam and sire + dam components of variance respectively. The respective estimates in P strain were 0.405 + 0.110, 0.341 + 0.103 and 0.373 + 0.101 for six – week body weight, 0.354 + 0.110, 0.443 + 0.094 and 0.398 + 0.118 for eight – week body weight and 0.530 + 0.102, 0.230 + 0.130 and 0.380 + 0.131 for egg production. The genetic correlation estimates between six – week and eight – week body weight were found to be high and positive in both the strains. The phenotypic correlations were also found to be positive but lower compared to genetic correlation and similar in both the strains. The environmental correlations had also been positive though of still lesser magnitude in both the strains. In general, the correlation estimates between chick weights and egg production were found to be very low in both the strains. The results were not suggestive of any strong relationship between chick weights and egg production. Out of these three characters, only egg production deserved consideration in selection as chick weight in White Leghorns cannot be considered as an economic trait. It was estimated that an improvement of 7.57 eggs per generation could be expected in both the strains for standard deviations of 16.04 and 15.41 and heritabilities of 0.219 and 0.230 in N and P strains respectively, when selection of males is 8.5 per cent and females 16 per cent.ThesisItem Open Access Inheritance of body weight,egg weight and age at first egg in white leghorn birds(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1982) Valsala C, Joseph; KAU; Mukundan, GAn investigation was carried out to study the inheritance of body weights, age at first egg and egg weight in White Leghorn birds. The data required for the study were collected from two strains of White Leghorns maintained in the Farm under All India Co – ordinated Research Project for Eggs, Mannuthy. The Least squares analysis of variance was carried out to find out the effect of hatches on the traits under study. Since the effect of hatch was significant, the data were adjusted for this effect and utilized to estimate heritability, genetic, phenotypic and environmental correlations among body weights and age at first egg. Hatch effect was not significant for egg weight. The averages for body weights (g) at 20 weeks and 40 weeks, age at first egg (days) and egg weight (g) were 1181.5 + 2.8, 1457.0 + 4.0, 166.0 + 0.30 and 51.7 + 0.10 for N strain and 1245.9 + 5.4, 1518.6 + 5.7, 162.1 + 1.1 and 51.7 + 0.10 for P strain respectively. The heritabilities based on sire, dam and sire + dam components of variance were 0.25 + 0.00, 0.36 + 0.01, 0.31 + 0.01, for body weight at 20 weeks; 0.22 + 0.00, 0.50 + 0.03, 0.36 + 0.00 for body weight at 40 weeks; 0.20 + 0.00, 0.22 + 0.03, 0.21 + 0.00 for age at first egg and 0.43 + 0.00, 0.62 + 0.03 and 0.52 + 0.01 for egg weight respectively. In P strain the respective estimates were 0.25 + 0.02, - 0.19 + 0.12 and 0.03 + 0.04 for body weight at 20 weeks; 0.44 + 0.00, 0.27 + 0.04 and 0.35 + 0.02 for body weight at 40 weeks; 0.06 + 0.00, - 0.11 + 0.04 and 0.00 + 0.02 for age at first egg and 0.28 + 0.01, 0.95 + 0.04 and 0.61 + 0.02 for egg weight respectively. The genetic correlations between body weights at 20 weeks and 40 weeks and between body weights and egg weight were positive, between body weights and age at first egg negative and between age at first egg and egg weight positive. Environmental and phenotypic correlations between the traits were generally of low magnitude.