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Theses

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1981 - 19844
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Subject: Animal Genetics and Breeding × End date: 1986 × Start date: 1981 × Thesis Type: M.V.Sc. ×
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    ThesisItemOpen 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, G
    An 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.
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    ThesisItemOpen 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 A
    Various 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.
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    ThesisItemOpen 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, G
    Blood 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.
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    ThesisItemOpen 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, G
    An 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.