selectionof dairy animals

SELECTION OF HIGH QUALITY

ANIMALS,METHODS OF SELECTION & MONITORING

THE PERFORMANCE OF HERD

Dr. SONAWANE AKSHAY S(ANIMAL NUTRITION)

Selection :- It is the process in which certain individuals in a population are given opportunity to produce offspring of desirable traits.

SELECTION OF HIGH QUALITY ANIMALS :- IMP. POINTS REGARDING SELECTION OF ANIMALS :-

Animal should be selected based upon its breed characters and milk producing ability

History sheet or pedigree sheet which are generally maintained in organized farms, which gives complete history of animal

The cow should allow anybody to milk and should be docile

The maximum yield by dairy cows are noticed during the first five lactations , so generally the selection should be carried out during first/second lactation

Three successive complete milking has to be done and an average of it will give a fair idea regarding production by a particular animal

Maximum yield is noticed till 90 days after calving

Milk vein :- A tortuous ,big bulging and zig-zag milk vein is prominent in front of udder on both side of belly

A dairy cow should have well proportionate head & neck, wide nostrils, prominent facial veins, large bright eyes & dewlap with gracious folds

BREEDS CHARACTERS OF HIGH YEILDING DAIRY COWS :-

Attractive individuality with feminity, vigour, harmonious blending of all parts, impressive style

Animal should have wedge shaped appearance of body

The udder should be well attached to the abdomen

The skin of the udder should have a good network of blood vessels

All four quarters of the udder should be well demarcated with well placed teats

Teat placement & size :- Teat should be about 2 inches long, cylindrical and placed squarely under each quarter(not to one side or another side)

Selection of animal for milk production :-

Breed characters

Body conformation Body weight

Ancestors performance

Health condition

Age

Number of lactations

Date of delivery

Month of pregnancy

If non-pregnant, how many times it came in to heat

The udder should be in good shape & easy to milk

Methods of selection :- 1.Mass selection :-

The selection is based on individuals performance Animal may be selected for breeding on basis of its

performance in one/more characters. The selection is effective when only one character is

taken at a time than many characters The offspring's will show higher performance than their

parents. this is because mass selection increase the occurrence of the desirable genes in a population.

2. Tandem selection :-

Selection of one trait for a given period of time followed by selection for a second trait and continuing…. in this way all imp. traits are selected.

Tandem selection is practiced for only one trait at a time and the selection is continued till the desired character is achieved.

This method has drawback as achievement made in the first character in the first period is lost when attention is directed to another character unless the character selected are genetically related.

3. Independent culling method :-

In this method of selection ,a few characters are considered at a time and a minimum standard is set for each trait.

Selected animals should meet minimum standard for each of the characters.

The effectiveness of this method depend upon the standard kept for each of the traits.

Individual who do not achieve the minimum standard ,which are already fixed within stipulated time are automatically culled from stocks.

4. Selection index :-

Selection index is a method of artificial selection in which several useful traits are selected simultaneously and it is based on total scour card / index

Total scour index is combined value of all character under consideration of giving weightage to each character depending upon its economic value.

In this method each character depending upon the heritability and economic value .

It is the most effective method of selection.

Monitoring the performance of herd :- Objectives :-

Routine action, observations are useful for early detection of problems

Herd/ group level:- To monitor the success of current management with goal of early detection of problems/ deviation from the management programs.

Individual level :- To identify cows at high risk for disease with the goal of intervention for these individuals to prevent/mitigate clinical disease.

Methods of Monitoring :-1. Clinical disease records :-

A starting point for assessment of peri-partum health is to have accurate records of the farm specific incidence of the clinical disease of importance of herd.

This would typically include the no. of cattle that had dystokia, Retention of Placenta, Milk fever, Metritis or that were culled or dried in early lactation.

2. Measurement of feed intake :-

Adequate feed intake by all peri partum cattle is important for health & production.

It is therefore desirable to measure feed dry matter intake (DMI) in prepartum and early postpartum cows.

Although measurement of only group average intake may be possible in commercial free stall barns.

3. Milk production :-

Milk production is expected to increase rapidly in early lactation and a consistent rise should result from good health and feed intake.

Therefore daily measurement of milk production in the first weeks of lactation gives idea about health of animal i.e. if cows suffering with diseases then milk production will be decreased.

4. Body condition scoring :-

It is the method of evaluating fatness or thinness in cows

Body condition influences productivity, reproduction, health and longevity of dairy cattle

Thinness or fatness can give idea about nutritional deficiencies , health problems or important herd management

Over conditioning or fatness, may result from poor nutrition

A fat cow is more susceptible to metabolic problems and infections, and is more likely to have difficulty at and after calving.

Under conditioning or thinness, can frequently lower production and milk fat levels because of insufficient energy & protein reserve to maintain production.

References, Essentials of Animal production &

Management - Ramadhar Singh

Textbook of Animal breeding – S.S Tomar Internet

Thank you…..!!!!