SIRE EVALUATION-Different methods.

1. NTR College of Veterinary Science,
Gannavaram.
Department of Animal Genetics and Breeding.
AGB:607-Cattle and Buffalo Breeding .
SIRE EVALUATION
S.THAMIZHARASI
GVM/19-005.

2. SIRE EVALUATION
• The aim is to select genetically superior bulls to bring
out genetic improvement in the productive as well as
reproductive performance of the herd.
• Sire evaluation is one of the most impotant in
selection and animal breeding.
• The effectiveness of sire evaluation is the backbone
of any breed improvement programme as the
contribution of sire is higher than the dam path for the
overall genetic improvement for a trait.

3. BULL

4. • The results of progeny testing are expressed in the
form of an index, which is the index of the genetic
worth of the sire, and such an index is known as sire
index.
• In other words, an attempt to express what a sire
would have produced, if he had been a cow is the sire
index of the bull. It is the operational part of progeny
testing called as sire proof.
• Based on sire index a numerical value is obtained
which indicates the production ability of the sire. The
sire index helps in ranking the bulls in order of their
merit to choose the best.

6. • The different indices developed for two
purposes viz. indices, which simply rank the
sires, and the indices, which provides the
estimates of breeding value of sires.
• The breeding value is estimated for indexing in
a single herd as well as for indexing in many
herds.

7. Different Methods of Sire
Evaluation
• Simple Daughter’s Average Index.
• Equi-parent Index/Intermediate Index.
• Corrected Daughter Average Index.
• Contemporary Daughter Average Index.
• Corrected Contemporary Daughter Average
Index.
• Best Linear Unbiased Prediction (BLUP ).
• Least Square Technique.

8. • Maximum Livelihood Method.
• Restricted Maximum Livelihood(REML).
• Regession Index/Rice Index .
• Tomar Index.
• Herd Mate /Stable Mate Comparison.
• Contemporary Comparison.

9. Simple Daughter’s Average Index
(Edwards,1932)
_
_ I = D
• where D is the average of all daughters of a sire under
test.
• This is the simplest way to evaluate the breeding worth of
the bull from their daughter’s production performance.
• If the number of daughters per sire is large and if all the
daughters are included without selection, this provides the
sound basis of selection.
• The defect in this method is that it does not consider the
production level of the dams allotted to the sire.

10. Equi-parent Index or Intermediate Index
or Yapp’s Index or Mount Hope Index
• Hanson (1913) proposed this index and it is also called as Yapp’s
index (1925) or Mount Hope index because it was first used at
Mount Hope Farm in 1928.
_ _
• I = 2D – M
_
where D = average for daughter of the sire;
_
M = average for dams of the daughters
This index is based on the principle that the two parents contribute
equally to the genetic make up of the progeny. This index places
the daughter exactly half way between production level of the dam
and genetic worth of the sire .

11. • This index aims at adjusting the daughter average
for the varying production level of the dams but
suffers from the defect that it overcorrects for the
differential production levels of dam mated to
different sires i.e. if the set of cows mated to a sire
is inferior to the average, the index over estimates
the sire’s breeding worth and vice versa.
• To minimize this defect, dam-daughter pair should
be selected randomly.

12. Corrected Daughter Average Index / Krishan’s
Index (Krishnan,1956)
_ _ _
• I = D – b (M - H)
_
where D = Average of the daughters of the sire;
_
M = Average of the dams of the daughters
_
H = Herd / breed average;
b = Regression of daughters record on dam record = 0.5 h2
• This index eliminates the disadvantages of simple daughter’s average
index and equiparent index.
• It corrects the daughters average for the influence of differential
production level of dams.

13. • The term b (M –H) in the index is the
correction for the genetic superiority or
inferiority of the set of dams allotted to a sire
over the herd average.
• It is four times as efficient as intermediate
index.
• However, it suffers from the defect that it does
not take into the consideration of performance
of contemporaries living at the same time.

14. Contemporary daughter average index
• The sire index was proposed by Sundaresan et al.
(1965). In this index the records of the daughters of a sire
are compared with the daughters of all other sires in the
same herd born in the same season.
_ _ _
• I = H + n/n+k(D - CD)
where H = Herd average;
n = No. of daughters per sire
D = Daughters average;
CD = Contemporary daughters average
• k = Constant based on sire error
variance

15. Corrected Contemporary Daughter Average
Index /Dairy Search Index / Sundaresan index .
• The index was proposed by Sundaresan et al. (1965)
and it was developed at NDRI, Karnal and it is also
known as Dairy Search Index.
• The index is an extension of the contemporary
daughter average index.
• This index uses the performance of contemporaries
and the variation in the number of daughters in the
progeny group in estimating the breeding worth of the
sire.

16. • It also corrects non-genetic effects like year and
season and for the differences in production level
of dams allotted to different sires.
• In this index only first lactation 305-day milk
yield of the daughters are taken into
consideration.
• (Contemporaries are those individuals that are in
same year, same season along with the daughters
of the bull under test).

17. _ _ _ _
I = H + n/n+12 (D – CD) – b (M – CM)
where H = Herd average;
n = No. of daughters per sire
_
D = Daughters average;
_
CD = Contemporary daughters average;
_
M = Dams average;
_
CM = Contemporary dams average;
b = 0.5h2, Intra sire regression of daughters on
dams .

18. Best linear unbiased prediction
(BLUP)
• This was developed by C.R Henderson (1973), which
is the most efficient and powerful method of sire
evaluation than the other conventional methods.
• It estimates expected breeding value (EBV) of sire
by adjusting the data for all known non-genetic
sources such as for herd, year and season effects, age
of the dam, parity etc.

19. • It uses all available information (i.e. the
information provided by the daughters,
information from other relatives) more efficiently
and more flexibly in estimating the breeding
values .
• Animals across contemporary groups can also be
compared. It provides estimates of breeding
values of many sires born in different years and
different locations simultaneously and also
provides the estimates of response to selection.

20. • BLUP also eliminate errors due to complications such
as non-random mating, environmental trend over time,
bias due to culling and selection.
• The model that describe the effect of sire and herd-
year-season is as follows:
• Yijk = µ + Hi + sj + eijk
• Where Yijk = performance of kth progeny of jth sire
in ith herd-year-season
µ = overall mean
Hi = effect of ith herd-year-season (fixed
effect)
sj = effect of jth sire (random effect)
eijk = residual error

21. Least Square Technique.
• The sire constant are obtained by least square
techniques which adjust the data for all the
environmental effects including the non orthogonality
in data.
• These sire constant are used in getting the sire index
as
• I = 2nh 2/4+(n-1)h2(Si )
• Where Si is the sire constant for i th sire .