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101
GRAANGIDS
2017
GRAIN GUIDE
The following is revealed by an analysis of the genetic merits of
Bull 1
:
• He will breed excellent weaners with a good pre-weaning growth rate (four stars and a
123 genetic index mark for calf growth – therefore pre-weaning growth).
• His good genetic value for milk means that his daughters will also wean heavy calves (three
stars with a genetic index mark of 109 for milk).
• He will breed fertile daughters with his genetic index mark of 106 – therefore three stars. Both
his genetic merit of 109 for ‘age at first calving’ (AFC) and ‘inter-calving period’ (ICP) of
104 are above average for the breed.
• His daughters’ mature body weight will be a bit heavier and will therefore require a bit more
upkeep than the breed average (two-and-a-half stars and a genetic index of 97).
• As his genetic figure for calving ease is below the breed average (82 genetic index with two
stars), he is not recommended for covering heifers, but rather adult cows.
• This bull will also breed a progeny with an excellent growth rate in the feedlot, as is reflected by
the outstanding ‘growth value’. The genetic merit indicates a breeding value index of 121 (four
stars) – therefore 21 index marks above the active animals in the breed.
Bull 2
is also one with excellent genetic merit. Although his genetic merit for pre-weaning (‘calf
growth’ – 104 with three stars) and post-weaning (‘growth value’ – 106 with three stars) growth, as
well as ‘milk’ (108 with three stars), are considerably better than the breed average, Bull 1 is better
in these respects than Bull 2. However, Bull 2 has other advantages over Bull 1, namely that he
can be used for heifers because the genetic merit for calving ease is at breed average (two-and-a-
half stars out of five, with a breeding value index of 98). This particular breed is known for smaller
calves at birth. Furthermore, his daughters will not require more upkeep – with a genetic merit for
breeding mature body weight daughters (100 breeding value index with three stars). Over and
above the fact that his sons will have above-average vigour (GDT index of 105), they will not fall
short with respect to scrotum circumference (SC) (115 breeding value index). The progeny of Bull 2
will also mature later – as is reflected in the shoulder height breeding value index (‘height’) of
106 (compared to Bull 1’s value of 132). This is in line with the mature body weight breeding
values (‘mat. weight’) of the two bulls.
These examples serve as proof that bulls can be selected judiciously if the buyer understands what
the figures mean. For more information, contact the writer at 082 331 9923 or
japie@studbook.co.za.
Japie van der Westhuizen, SA Stud Book and Animal Improvement Association
Table 1: Genetic merits of
Bull 1
as indicated in the catalogue at a recent auction.
Table 2: Genetic merits of
Bull 2
as indicated in the catalogue at a recent auction.
CALVING EASE MILK
CALF
GROWTH
UPKEEP
GROWTH TEST
FERTILITY
COW
VALUE
GROWTH
VALUE
PRODUC-
TION
VALUE
Selection W
98
31
108
45
104
51
100
17
106
26
Birth
weight
Birth
Mat.
Milk
Weaning
weight
Post-
weaning
Mature
weight GDT Kleiber VOV Length Height
SC AFC ICP
BV index
97 100 108 104
103 100 105 -
-
101 106 115 105 99 105
35
106
39
106
36
Estimated
BV
1,5
33
-,05
28
6,4
45
14,3
51
22,9
36
27
17
108
37
90
37
-
28
40
17
42
20,4
41
-10,4
36
-5,1
23
Measure-
ments
-
212 (91) 341 (91)
423
(93)
-
-
-
-
-
-
Semen donor: No
Tests: TB and CA free
Inoculation: Blackleg,
botulism and anthrax
Remarks:
-
CALVING EASE MILK
CALF
GROWTH
UPKEEP
GROWTH TEST
FERTILITY
COW
VALUE
GROWTH
VALUE
PRODUC-
TION
VALUE
Selection W
82
30
109
64
123
60
97
34
106
26
Birth
weight
Birth
Mat.
Milk
Weaning
weight
Post-
weaning
Mature
weight GDT Kleiber VOV Length Height
SC AFC ICP
BV index
86 90 109 123
123 103 124 96,04 -
127 132 97 109 104 124
41
121
68
124
46
Estimated
BV
2,31
33
0,32
26
6,6
54
23,7
60
38,6
59
31
34
183
64
131
64
-
57
71
35
74
10,1
72
-14
34
-65
19
Measure-
ments
-
- (-)
- (-)
- (-)
100 10,91 -
1 366 1 245 285
Semen donor: No
Tests: TB and CA free
Inoculation: Blackleg,
botulism and anthrax
Remarks:
-