Browsing by Author "Stephen Mathew"

Now showing 1 - 6 of 6

Body weight and its association with age at first calving and milk production in crossbred cattle of Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2000) Siddalingswamy Hiremath; Stephen Mathew
The present study was undertaken with a VIew of estimating body weights of crossbred calves in the field conditions of Kerala at birth, three, six and twelve months of age and to find association of these body weights with age at first calving and first lactation milk yield. The data for the present study were taken from the records of ICAR Field Progeny Testing Scheme of Centre for Advanced Studies in Animal Genetics and Breeding, Kerala Agricultural University. The data were of the 1993-2000 period. Body weights at birth, 3, 6, 12 months and at calving were predicted from body measurements using Minnesota formula given by J ohnson,( 1940). The data were analyzed using least squares analysis of variance to study the effects of non-genetic factors on different traits under study. The data adjusted for significant non-genetic factors .. were used to study the effect of sire and for estimating heritability and correlation among body weights and between body weights and age at first calving and between body weights and first lactation milk yield. The overall average body weights of crossbred calves at birth, 3,6 and 12 months of age were 26.0 ± 0.38 kg, 48.7 ± 1.26 kg, 74.1 ± 2.81 kg and 151.0 ± 7.74 kg, respectively. Least squares analysis of variance has shown that the effect of season of birth was significant (P~0.05) only on body weight at six months of age. The influence of period of birth was significant for all body weights upto one year age except for body weight at six months of age. Centre was a significant source of variation for all body weights upto one year age, The mean Age at First Insemination, Age at first calving and Weight at first calving of crossbred cattle were 689.3 ± 22.9 days, 1013.6 ± 21.74 days and 284.9 ± 7.71 kg respectively. The season of birth did not affect age at first insemination, age at first calving and weight at first calving. The significant (P~0.05) influence of period of birth and centre were 11 observed on age at first insemination and age at first calving only but not on weight at first calving. The effect of period of calving and centre on first lactation milk yield was significant whereas the effect of season of calving and age at first calving did not affect first lactation milk yield. The average first lactation milk yield of crossbred cows was 1958.5 ± 30.74 litres. The sire wise means of body weight at six months of age, weight at first calving and first lactation milk yield did not differ significantly but sire effect was significant (P~0.05) in all the other traits. Heritability estimates were calculated by paternal half sib method for different traits under study. The low heritability estimate was obtained for birth weight, body weight at six months of age, age at first calving and weight at first calving. But the heritability estimates of body weight at three months of age and body weight at twelve months of age were high. Age at first insemination was moderately heritable. The heritability estimate of first lactation milk yield was -0.069 ± 0.05. iii Association among body weights and that between body weights and age at first calving followed no definite trend. However, the genetic correlation (0.46) between body weight at six months and first lactation milk yield and high, positive (> 1) genetic correlation between body weight at twelve months and first lactation milk yield indicates strong genetic association of body weight at six months and body weight at twelve months with first lactation milk yield and their relationship can be used advantageously for selection of heifers for milk production under field conditions
Evaluation and comparison of polymorphism of beta casein gene in vechur and crossbred cattle of Kerala
(Department of Animal Breeding, Genetics and Biostatistics, College of Veterinary and Animal Sciences, Mannuthy, 2010) Muhammed, E M; Stephen Mathew
Evaluation of lactation milk yield and polymorphism of alpha-lactalabumin gene in crossbred cattle of kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2007) Reshmi R Chandran; Stephen Mathew
The present study was carried out to assess the milk yield of crossbred cattle of Kerala by studying four different zones of the state viz. northern, southern, central and highlands and to analyse the association of α-lactalbumin gene polymorphism with milk production of crossbred cattle in Kerala. One day milk yield of 500 animals from each zone, at a lactation stage of 7-13 fortnights after calving was recorded. From this one-day milk yield 305-day milk yield of crossbred cattle was predicted using the formulae given by Iype (1991). The predicted lactation milk yield was used for estimating average milk yield of crossbred cattle in Kerala. The overall least squares mean of 305-day milk yield was 2351 ± 28.9 kg. Least squares analysis of variance has shown that different zones and parity exerted significant effect on 305-day milk yield (P ≤ 0.05). The highest least squares means for 305-day milk yield was in southern zone and the lowest was in central zone. The least squares mean for 305-day milk yield according to parity was highest in second parity, followed by third parity and the lowest was in fifth parity. Genomic DNA samples isolated from 25 crossbred cows selected at random from each zone was subjected for PCR-RFLP of α-lactalbumin gene at two different specific loci. On successful amplification the expected 166 bp and 429 bp fragments were obtained. Digestion of 166 bp amplified product with Mnl1 enzyme revealed similar pattern of digestion for all animals studied, indicating the absence of α-LA/Mnl1 (+) in the population. Restriction of 429 bp amplified product with Bsp12861 enzyme revealed two digestion patterns (indicating the presence of two α-LA/Bsp12861 alleles). The gene frequencies of α-LA/Bsp12861 (+) and (-) alleles were 0.08 and 0.92 respectively. In the crossbred population studied, none of the animal showed α-LA/Bsp12861 (+/+) genotype. The average milk yield of 79 α-LA/Bsp12861 (+/+) genotypes was 2779 kg and that of 16 α-LA/Bsp12861 (+/+) genotypes was only 2364 kg. However, the difference was statistically non-significant. It is suggested to conduct further research in large samples to confirm the findings and to identify other polymorphic loci associated with milk yield.
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) Stephen Mathew; Mukundan, 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.
Genetics of body dimensions of Malabari goats and its cross in Kerala
(Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 1994) Raj Menon; Stephen Mathew
The main objectives of this study were: (1) to study the bodyweight and body dimensions of Malabari goats and its Alpine half breds, (2) to estimate the genetic and phenotypic correlations between bodyweight and different body dimensions in various genetic groups and (3) to study any other major factors affecting bodyweights and body dimensions. The study was conducted in 92 goat kids reared at the All India Co-ordinated Research Project on goats farm at Mannuthy, Thrissur. A comparative study was made on the native Malabari with its third generation cross with the exotic Alpine breed. The mean body length, heart girth and height at withers at birth wera 25.68 ± 0.53, 27.37 ± 0.46 and 29.66 ± O. 60 cm and 26.01 ± O. 16, 28.23 ± 0.23 and 30.24 ± 0.45 in male kids of Malabari and Alpine x Malabari crossbreds respectively. In the females the corresponding values were 25.63 ± 0.073, 27.56 ± 0.68 and 25.53 ± 0.48 and 25.3 ± 0.17, 27.60 ± 0.32 and 29.14 ± 0.35 cm. The mean body length, heart girth and height at withers of male Malabari and Alpine x Malabari goats at 60.39 ± 0.81, 59.66 ± 0.82 and 58.18 ± 0.91 12 months were 61.42 ± 0.90, 61.12 ± 0.90 and 59.04 ± 1 . 01 cm and 64. 19 ± O. 81, 64. 60 ± O. 73 and 61. 98 ± O. 9 cm respectively. The corresponding values for females were 58.36 ± 0.81,59.0 ± 0.7 and 58.36 ± 0.72 and respectively. There was no significant difference between the birth weights of- male and female Malabari kids and between the birth weights of the two genetic groups. But the difference was significant in the Alpine x Malabari crossbreds. There was significant difference in the bodyweight at 12 months of age between male and female Alpine x Malabari crossbred kids. No significant difference was observed in the bodyweight at 12 months between the two genetic groups. During the experiment period mean maximum and minimum temperature were 34.55 ± 1.2 and 22.03 ± 1.4 °c respectively. Season had a significant effect on the body weight at six, none and 12 months of age in Alpine x Malabari crossbreds. The effect of type of birth was not significant on the birth weights in Alpine x Malabari crossbreds and Malabari kids. Type of birth had no significant effect on the 12 months body weight in both the genetic groups. analysis showed non-significant Least squares effects of season and sex on the body weights in Malabari kids while in the Alpine x Malabari the effect of sex on body weights was significant at all the ages studied. Season at six, nine and 12 months of age had significant effects on bodyweight in Alpine x Malabari crossbreds Breed had no significant effect on body weights. The heritabilities of bodyweights at various ages were higher in Malabari when compared to Malabari x Alpine crossbreds. The highest phenotypic correlations were observed between the bodyweight and heart girth in both genetic Genotypic correlations between different groups. traits were found to be low at different ages in both the genetic groups. The highest coefficients of determination were observed at the age of six months for both the prediction equations.
Utilization of half-sibs information to increase the accuracy of young bull selection
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2003) Sajeev Kumar, T; Stephen Mathew
The present study was conducted to compare the breeding values of bulls in different sire evaluation methods and to explore the possibility of information on dam's yield and half-sibs in sire evaluation methods utilizing the data from Progeny Testing Scheme of KLD Board. Total 25 bulls, which had minimum of fifteen progeny and ten half-sibs were used. Out of 1212 records, progeny and half-sibs had 847 and 365 respectively distributed in 43 centres. The overall mean of first Lactation milk yield (FLMY) of progenies, half-sibs and both together were 2389.0 ± 23.46, 2131.0 ± 36.34 and 2311.3 ± 20.00, kg, respectively. Different centres and years of calving exerted significant effect on FLMY but season and age at first calving did not influence FLMY. Heritability estimate of FLMY was found to be 0.221 ± 0.077. Estimated sire merit (ESM) of bulls were estimated using ten indices viz. based on performance of dam (M), based on performance of paternal half-sibs (HS), based on performance of dam and paternal half-sibs (M+HS), based performance of dam, paternal half-sibs and progeny (M+HS+P), simple daughter average (SDA), contemporary comparison (CC), least squares (LS), KLD Board method, BLUP without considering relationship of sires (BLUP-l) liand BLUP considering relationship of sires (BLUP-2). The range ofESM were '+62.8745 to +396.8055, -157.169 to +287.358, -24.591 to +316.516, -193.877 to + 307.601, kg for M, HS, M+HS and M+HS+P respectively. The SDA and ESM of CC ranges were 2153.8 to 2663.2 and -1628.80 to 1876.58, kg respectively whereas CC index ranged from -258.79 to +406.74, kg. The ESM of LS, KLD Board, BLUP-I and BLUP-2 ranges were -450.92 to +567.69, _ 111.83 to +513.78, -329.8 to +370 and -332.8 to +362.6, kg, respectively. Rankings of sires by different methods were not the same but ranking by SDA, LS and KLD Board method was almost similar with rank and product-moment correlations around one. Ranking by CC, BLUP-l and BLUP-2 were similar with very high rank and product-moment correlations. The average standard error (SE) of SDA, LS, KLD Board, BLUP-l and BLUP- 2 were estimated. BLUP-J followed by BLUP-2 had lowest SE and SDA had the highest. The results are suggestive of opting for BLUP procedures for sire evaluation in Kerala. Additional information on dam and half-sibs did not have much advantage if more progeny records are available for sire evaluation.