Journal of the Department of Agriculture, Journal of the Department of Agriculture, Western Australia, Series 4 Western Australia, Series 4
Volume 2
Number 10 October, 1961 Article 5
1-1-1961
Selecting a herd sire Selecting a herd sire
R A. Bettenay
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Bettenay, R A. (1961) "Selecting a herd sire," Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 2: No. 10, Article 5.
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ON THE DAIRY FARM
*
SELECTING A HERD
SIRE
The herd sire need not be a show champion, but he should be a pure bred of acceptable appearance
By R. BETTENAY, Dairying Division Adviser
T
HERE is now ample evidence t h a t most of t h e differences in production between herds a r e determined by feeding a n d management, with differences in genetic merit playing a relatively minor role.It seems t h a t t h e quickest way to increase production is by improved feeding, whilst in some herds m u c h production is being lost by faulty milking techniques.
This should not be t a k e n to m e a n t h a t improving t h e breeding—and so the upper limit of production—of your herd is not important, because it h a s been shown t h a t t h e cow with the greatest potential p r o - duction—that is t h e "best" cow—is likely to be the best cow a t all levels of feeding.
Any genetic improvement is p e r m a n e n t and can be t r a n s m i t t e d from one generation to t h e next.
The farmer h a s two practical methods of improving t h e genetic merit of his h e r d :
• By actively culling low producers.
• By m a t i n g t h e remainder to a bull which is likely to throw daughters b e t t e r t h a n their dams.
How t h e n c a n you select such a bull a n d in what h e r d s are you likely to find him?
Should be Pure Bred
Your h e r d sire should be a pure bred animal of acceptable a p p e a r a n c e and with n o obvious defects. For this reason it is important to inspect t h e a n i m a l and any close relatives including t h e dam, full or half-sisters and, of course—if you are interested in a n older bull—any progeny t h a t are available.
If t h e d a m is a n aged cow, so much t h e better. We are interested in breeding
animals which will produce at a high level over a long life time, a n d a cow t h a t has stood up to the test of time without losing her desirable dairy "type" is t h e kind we want.
Proven Sires
I n W.A. there seems little point in r e - commending t h a t you buy a proven sire, or even the son of a proven sire, as no official Sire Surveys have yet been published.
There are many difficulties in t h e way of proving sires where daughters are all within the one herd as it is difficult t o know how much production h a s been influenced by conditions within t h e herd.
This can be partly overcome by using a daughter—dam comparison method of surveying, or by comparing d a u g h t e r s ' productions to those of other animals of the same age in the herd, if there are any.
The daughters of bulls used a t A.B.
centres are spread over a great n u m b e r of herds a n d it is acceptable, in this case, to compare bulls on t h e basis of t h e aver- age production of a number of their daughters.
Although officially proven sires are not available you should, in selecting a bull,
803 Journal of Agriculture, Vol 2 No 10, 1961
go carefully t h r o u g h t h e production records of t h e h e r d a n d inspect half- sisters for type a n d production. Inspect all half-sisters, not j u s t t h e best few, as a good even line is b e t t e r t h a n a few t o p - n o t c h e r s a n d a lot of culls.
Relationship t o Tour Own Herd
I t is a fairly common belief t h a t you should buy a future sire from t h e same strain a s your p r e s e n t bull, but t h e r e seems to be n o scientific justification for this.
I t could be justified in t h e case of deliberate line-breeding to keep your herd related to a p a r t i c u l a r a n i m a l of proven worth, a l t h o u g h t h e r e is certainly n o reason why you should not r e t u r n to buy a second bull from a h e r d if you are well satisfied with t h e progeny of t h e first bull.
Other t h i n g s being equal however, i t seems t h a t you are likely to obtain equally good results from a bull not related to your herd, as t h i s c a n introduce a certain a m o u n t of hybrid vigour by t h e i n t r o d u c - tion of genes n o t p r e s e n t in t h e original strain.
Where to Look for a Bull
It seems obvious t h a t you should look to t h e P u r e Bred breeders whose herds have been u n d e r official test for a long time and who have h i g h production records, when you wish to p u r c h a s e a replacement sire.
This is certainly a good s t a r t i n g point and, after all, t h e only way you c a n be certain a cow c a n produce a t a h i g h level is to feed h e r well a n d n o t e results. By t h e same token a cow which h a s h a d every opportunity a n d h a s n o t produced well h a s demonstrated t h a t she h a s little genetic merit, a n d h e r son would probably not be a n asset t o your h e r d .
I have already suggested, a n d experi- ments have proved, t h a t t h e r e a r e good a n d bad cows in every h e r d , a n d t h e genetic difference between t h e top herds and t h e lowest h e r d s is n o t likely to be very great. If t h i s is so t h e n it is obvious t h a t a bull from t h e best cow in a n y herd is likely to be a good buy if h e is a pure bred.
Certainly it seems preferable to select a bull from a cow averaging 350 lb. fat in a h e r d averaging 250 lb. fat, r a t h e r t h a n from a cow averaging 400 lb. fat where the h e r d average is 450 lb.
Butterfat Test I m p o r t a n t
Finally, it is known t h a t b u t t e r f a t test is more highly inherited t h a n t o t a l milk production. This m e a n s t h a t a bull from a high testing s t r a i n c a n be expected to pass on a greater proportion of t h e differ- ence to your herd t h a n a bull from a herd giving more milk b u t w i t h n o h i g h e r test t h a n your own.
DAIRY SIRE SURVEYS
While no official sire surveys have been published in Western Australia, a number are now in progress. These are associated mainly with the Artificial Breeding Centres.
To measure effectiveness in increasing production and as a means to "proving"
the Artificial Breeding sires it is essential that as many heifer calves bred in the scheme as possible be marked. All A.B. members are therefore asked to co-operate by having their calves marked. In other cases in the grade and pure bred herd recording schemes the only calves marked are those sired by bulls for which the owners make application for a survey.
The herd recorders are required to mark calves in herds under test, while the A.B. Field Operators mark others.
The code used allows identification of the individual by a letter sequence in the right ear and as the daughter of a particular sire by a letter code in the left ear. The season of birth is also determined from a further letter code in the left ear.
On marking each calf the officer hands the owner a certificate showing the code and the name of the sire, and a duplicate is forwarded to the A.B. centre and filed for future reference, while a triplicate remains in the book as a further check reference if required.
As marked calves come into production their yields can be related to their sires, and the comparative value of these can then be assessed.
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