R. K. Taggar

Genetic polymorphism of promoter region of lactoferrin gene and its association with mastitis resistance in Jersey crossbred cattle

Lactoferrin, a protein found in variety of body secretions, acts as a defense factor in the mammary gland. Total of 50 samples of blood and milk of Jersey crossbred cattle were collected from the Government Dairy Cattle farm, Belicharana. Genomic DNA was isolated and specific primer was used for the amplification of the promoter region of lactoferrin gene. The PCR product comprised of 115 bp. The PCR product was digested with Taq I restriction enzyme. The amplicon has no restriction site and all the 50 animals revealed only one type of genotype (HH) with respect to Taq I / PCR-RFLP. The same PCR products were subjected to SSCP. Amplicons were initially denatured with denaturing agents and then run on native PAGE which was later silver stained. All the 50 samples revealed one type of banding pattern viz., two bands. Single genotype was present in all animals. Hence promoter region of Lactoferrin gene is monomorphic in crossbred cattle under the present study. Somatic cell count was done by staining milk samples with Newmans stain. A total of 19 milk samples had somatic cell count of less than 1,00000 cells/ml with no history of mastitis were considered as resistant, while other 20 samples having somatic cell count more than 5,00000 cells/ml with mastitis were considered as susceptible. Though variation in response to mastitis resistance was detected, no association was established. The reason being that promoter region of lactoferrin gene was monomorphic with respect to Taq I / PCR-RFLP and PCR-SSCP.

Genomic imprinting in mammals-A review

Genomic imprinting refers to an epigenetic mark that distinguishes parental alleles and results in a monoallelic, parental-specific expression pattern in mammals. The alleles of imprinted genes are marked epigenetically as discrete elements termed imprinting control regions with their parental origin in gametes through the use of DNA methylation, at the very least. Imprinted genes are normally involved in foetal growth and behavioural development. Consequently, aberrant imprinting disturbs development and is the cause of numerous well-known imprinting disorders, including Beckwith-Wiedemann syndrome, Prader-Willi syndrome, Cancer and Angelman syndrome.

Genetic studies on wool production traits in Rambouillet crossbred sheep in J & K State, India

Data on 4186 lambs pertaining to 94 rams of Rambouillet and their crosses over the ten years (1998–2007) at Government Sheep Breeding and Research Farm, Reasi, Jammu, were studied. The averages were 1.49±0.009 kg, 5.52±0.02 cm and 21.25±0.01 μ for greasy fleece weight (GFW), staple length (SL) and fiber diameter (FD) respectively. The highest CV (%) was observed for greasy fleece weight where as the lowest CV (%) was observed for fiber diameter. The least-squares means were 1.51±0.02 kg, 5.64±0.04 cm and 21.27±0.03 μ for greasy fleece weight, staple length, and fiber diameter respectively. The effect of year of lambing had significant effect (P<0.01) for all the traits under present study. The effect of season of lambing was non-significant for all the traits. The effect of sex was significant (P<0.01) for greasy fleece weight only. However, no systematic trend was observed over the year, season of lambing and sex for all three the traits studied. The estimates of heritability were high for GFW (0.49) and FD (0.55), where as for SL it was low (0.15). The genetic and phenotypic correlations were either negative or low and in some cases it was both low and negative. These estimates revealed that there is scope for genetic improvement of these traits through appropriate selection methods and index.

Genetic analysis of performance traits of Jersey cows in sub-temperate environment of Himachal Pradesh, India

The evaluation of production performance of Jersey cows were essential for their genetic improvement in sub-temperate region. The present investigation was conducted on 439 records of 196 Jersey cows maintained at Dairy farm, Himachal Pradesh Krishi Vishvavidyalaya, Palampur for 25 years (1984-2008) . The production traits considered for the present study were 305 days lactation milk yield, peak yield, lactation length, average milk yield per day of lactation length and average milk yield per calving interval. Heritability, genetic and phenotypic correlation coefficients were estimated for these traits. Periods showed highly significant effect of periods on these traits while season and parity had highly significant effect except in 305day lactation milk yield and lactation length. These production traits showed significantly higher values in winter seasons except peak yield and lactation length which showed higher values in summer and rainy season respectively. These traits did not showed a consistent trend in different periods. In third lactation these traits showed better performance except lactation length which is higher in second lactation. The heritability estimates of these traits were found very low except 305 day lactation milk yield and peak yield . The genetic associations among these traits were positive and high except association of lactation length with other traits which were negative and low..The phenotypic associations were observed low to high and negative except LMY×MY, LMY×AMY/LL and LMY ×AMY/CI.

Studies on Genetic and Non-Genetic Factors Affecting Performance Traits of Frieswal Cows.

A total of 601 lactation records of 205 Frieswal cows (Holstein Friesian and Sahiwal crossbred) from 1st to 4th parity over a period of 9 years from 1998 to 2006 maintained at Military farm, Jammu Cantonment (J&K, India) were used to estimate performance of reproduction and production traits and to study the effect of genetic and non genetic factors on performance traits. The overall averages for age at first service (AFS), age at first calving (AFC), gestation length (GL), dry period (DP), calving interval (CI), lactation length (LL), total lactation milk yield (TLMY) and milk yield per day of lactation length (MYDL) were estimated as 20.53 ± 0.44 months, 29.72 ± 0.45 months, 278.43 ± 1.54 days, 116.85 ± 4.40 days, 423.46 ± 6.15 days, 305.05 ± 4.51 days, 3087.00 ± 62.60 kg and 10.10 ± 0.16 kg, respectively. The effect of genetic group of sire was significant on age at first service, age at first calving, calving interval, lactation length, total lactation milk yield and milk yield per day of lactation length whereas effect of period was significant on all reproduction and production traits except for gestation length and lactation length. The effect of parity was significant only on dry period and milk yield per day of lactation length whereas effect of season was non-significant on all reproduction and production traits except for calving interval where it had significant effect.