Dairy At Glance

Diagnosis of Genetic disorders and identification of favourable economical traits

for dairy animal improvement programme in India

 

By

Dr R K Patel

Principal Scientist (Animal Biotechnology)

Sandor Proteomics Pvt Ltd., Hyderabad

Email: rk_patel@sandor.co.in


  1. Chromosomal analysis / Karyotyping:

Reduced fertility or infertility is a major problem in Indian cattle and buffaloes. Reproductive failure in animals may be because of several reasons including poor feeding, management, poor quality of AI etc. However, it can be also due to genetic reasons e.g. chromosomal abnormalities which are usually associated with reduced fertility / infertility, embryonic loss, foetal waste and internal or external genital malformation. Chromosomal abnormalities account for a substantial losses in animals production and quite a few bulls reared for breeding cannot be used effectively due to problems related to fertility. The chromosomal abnormalities can affect a large population in two ways: i) it can be transmitted to large population through Artificial Insemination programme and ii) it can cause repeat breeding problems in females because of embryonic losses, and poor semen quality in breeding bulls. All these animals can be karyotyped even at calf hood stage. Subsequently, abnormal animals can be culled to avoid the risk of transmission and minimize the cost on rearing of abnormal animal.

  1. Genetic Diseases

Several genetic disorders in animals, controlled by recessive genes, are the cause of concern worldwide. With the wide use of AI, these genetic diseases can spread to large population as animals carrier of the disease look normal. These disorders are HF breed specific. In India, where HF animals are extensively used for crossbreeding programmes, it has become necessary to screen all HF and their crossbreds to minimize the risk of spreading these diseases among future bulls and bull mothers. The diagnosis is based on molecular techniques. The cases of carriers for various genetic diseases could be much higher than what are reported if regular screening of genetic diseases is performed for every breedable animal.

  1. Bovine Leukocyte Adhesion Deficiency (BLAD) Syndrome is very common worldwide, causing impaired neutrophils, which fail to combat invading organisms or infection especially in newborn calves. New born may die due to persist infection.

Some of BLAD carriers reported in India

S No.

No of bulls tested

BLAD carrier bulls

References

 

Number

%

1.

150

2

1.33

Padeeri et al., 1999

2

711

23

3.23

Patel et al., 2006

3

55

2

3.64

Yathish et al., 2010

4

55

1 (affected)

1.82

Yathish et al., 2010

5

42

2

4.76

Patel et al., 2011

6

120

2

1.67

Roy et al., 2012

 

Bovine Dermatosparaxis also known as cutaneous asthenia or Ehlers–Danlos syndrome is skin disorder causing fragility of the skin due to collagen dysplasia in number of breeds including Holstein. Many cases reported worldwide, however, we have standardized the molecular test and investigating 131 cattle.

 

  1. Bovine Citrullinaemia is urea cycle disorder, wherein one of the enzymes; rgininosuccinate synthetase (ASS) is impaired in function, causing neurological problem and subsequent death of animal due to accumulation of ammonia in brain.

Some of Citrullinaemia carriers reported in India

S No.

No of bulls tested

Citrullinaemia carrier bulls

References

 

Number

%

1.

150

1

0.67

Padeeri et al., 1999

2

120

2

1.67

Gaur et al., 2012

  1. Deficiency of Uridine Monophosphate Synthase (DUMPS) is causing early abortions due to impaired enzyme which stops cell division in embryo cells, leading to repeat breeding problems.

First case of DUMPS carrier reported in India

S No.

No of bulls tested

Citrullinaemia carrier bulls

References

 

Number

%

1.

86

1

1.16

Gaur et al., 2013

  1. Factor XI deficiency syndrome is bleeding disorder. Factor XI is one of more than a dozen proteins involved in blood clotting responsible for coagulation of blood during bleeding is impaired, causing death of animal due to continuous bleeding.

Some of FXI carriers reported in India

 S. No.

No of bulls tested

FXI carrier bulls

References

 

Number

%

1.

595

2

0.34

Patel et al., 2007

 

  1. Complex Vertebral Malformation (CVM) is vertebral anomalies causing still birth. The Impaired protein molecules fail to transport nucleotide sugar and a coenzyme which required for vertebral formation.

          Some of CVM carriers reported in India

S NoS No.

No. of bulls

tested

     CV carriers bulls

References

No..                       

%

1

52

12

23.07

Mahdipour et al. (2010)

2

60

1

1.67

Kotikalapudi et al., (2013)

 

  1. Bovine Dermatosparaxis also known as cutaneous asthenia or Ehlers–Danlos syndrome is skin disorder causing fragility of the skin due to collagen dysplasia in number of breeds including Holstein. Many cases reported worldwide, however, we have standardized the molecular test and investigating 131 cattle.
  1. Marker Assisted selection in Animal breeds

Most of the economically relevant traits for animal production (birth weight, weaning weight, growth, reproduction, milk production, carcass quality, etc.) are complex traits controlled by many genes, and they are additionally influenced by the environment. The sequence of a gene can differ between individuals. These differences are called genetic variants or alleles that may regulate the production of different quantities. If an allele is positively related to the production trait is known as favourable allele/gene. Tests have been developed to identify whether an animal is carrying a segment of DNA that is positively or negatively associated with the trait of interest.

  1. Kappa Casein: Two major genetic variants of κ-casein – A and B have been identified. κ-casein gene variant ‘B’ would be more desirable than ‘A’ variant since it is linked with higher casein, cheese yielding capacity, total protein, fat content in the milk curd firmness.
  2. Beta-lactoglobulin: Two genetic variant of β-lactoglobulin- A and B have been identified. Variant ‘B’ would be more desirable than ‘A’ as it is linked with higher protein and fat.
  3. Diacylglycerol O-acyltranferase 1 (DGAT1): Two genetic variants of DGAT1- K and A have been identified.  In particular, the allele encoding the lysine 232 variant (K) is more desirable than A as it is linked with higher milk fat synthesis.
  1. Prolactin is also responsible for the development of mammary gland and milk production. Two genetic variant of prolactin – A and B have been identified. A-allele is favorable as it is linked with bigger size of mammary gland, which may be directly proportional to more milk production.
  1. Pituitary-specific transcription factor 1 (Pit-1) activates expression of the prolactin, thyrotropin and GH genes in the anterior pituitary gland. This gene is another candidate for milk production marker. Two genetic variants- A and B have been identified. A-allele is more favourable for milk and protein yields.
  1. Bovine Leptin is a protein synthesized by adipose tissue and it is involved in the regulation of feed intake, energy balance, fertility and immune function. Two genetic variants – A and B have been identified. B allele is more favourable for improving milk production without negative energy balance and low fertility.
  1. Identification of Murrah Buffalo based on DNA markers

Based on a combination of 12 microsatellite markers, Murrah buffalo may be classified as Murrah, Grade Murrah or Non-Murrah (patent technology).

  1. Parentage Verification in livestock species

Paternity test in animal is becoming very important for accurate selection of future sires to increase production and reproductive traits. We provide paternity test for cattle, buffaloes, goats, camels and all ruminant species. The test is based on microsatellite markers

Akshay Sadana

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Posted Date : 31/03/2015 Posted By : Admin