Efficient Crossbreeding Requires Pedigree Bulls
A weak bull is the most expensive investment a cattle farmer could make. Such a bull could prove to be an expensive mistake because his daughters will remain in the herd for 10 years or longer, well after the farmer has stopped using the bull.
Arthur de Villiers (Jnr), Bonsmara newsletter December 2009.
Crossbreeding is standard practice in cattle farming and it is done all over the world. However, research has shown that in most cases the crossbreeding program lacks planning and is therefore not very efficient.
Crossbred bulls are the offspring of a crossbred mother with a purebred bull, or a crossbred mother with a crossbred bull. Purebred breeds were developed firstly through natural selection brought about by the environment, and secondly because of selection by humans to fulfill specific needs for milk, meat, adaptability etc.
Pure breeds can be developed through crossbreeding after many generations of purposeful breeding and selection for certain breed- and production characteristics; (this has been done in the case of the Bonsmara breed.) Farmers use crossbred bulls because they believe that crossbred bulls increase production as a result of hybrid vigor (=the phenomenon that the calf is better than the average of Sire and Dam); and because crossbred bulls are generally cheaper than purebred animals.
The question is whether a crossbred bull will indeed improve production?
The bull-component in a breeding herd is only about 3-4%, but the genetic make-up of every calf is, obviously, for 50% determined by the bull. Altogether 87% of the genetic make-up of a calf is determined by the bulls that were used in the previous 3 generations, as females from the various bulls are used as replacement heifers. This means that up to 90% of progress in a herd is brought about by the selection of the bull.
In separate trials the average weaning weight at 205 days of Angus, Brahman and Charolais showed the following results:
- Purebred calves (within the same breed, i.e. Angus X Angus): 186 Kg
- Calves out of purebred bull X purebred cow of different breeds
(i.e. Angus X Charolais=F1): 200 Kg
- Calves out of F1 cows X purebred bulls: 208 Kg
- Calves out of F1 cows X crossbred bulls: 199 Kg
From these tests it is clear that the use of crossbred bulls did not result in a higher weaning weight, and that crossbred cows weaned 13% heavier calves.
A Farmer needs to take the following into consideration:
- The biggest advantage in crossbreeding is achieved by using F1 cows (purebred X purebred of different breeds)
- Because crossbred mothers are so successful, it is assumed that crossbred fathers will be the same, however, scientific research proves that this is not the case.
- Accurate breeding values and performance test results are hardly ever available in crossbred bulls
- The availability of outstanding crossbred bulls is a problem
- Crossbred bulls sometimes seem good because of the hybrid vigor however this improvement cannot be passed on; hybrid vigor as such is not hereditary.
The question remains if crossbred bulls are actually cheaper. The farmer really does not know what he gets if he uses a crossbred bull. Without accurate figures like: birth weight, performance testing, a second opinion about genetic defects (breed inspectors) etc. he is taking a big chance.
To establish the breeding value of an animal it is necessary to integrate performance figures with accurate pedigree information. The more knowledge about the pedigree and the more measurements have been done, the more accurate the breeding values will be. Only stud breeders normally keep pedigree information. In addition, registered animals are the only ones where performance testing has been used as an objective selection tool. The time has gone where an animal is registered, or becomes a “stud animal” simply because of its pedigree status. Nowadays, an animal has to be proved to be superior because of origin as well as its own performance ability.
However it is also very important that an animal is visually appraised to ensure that its functional efficiency and that it lives up to the minimum breed standards.
Although commercial farmers do make some progress, mainly by selecting for reproduction (fertility) and weaning weight, they are still dependent on stud breeders to produce excellent herd sires to improve their herds.
An effective crossbreeding program that truly improves the progeny is not a simple practice. It requires specific management knowledge, infrastructure and the continuous supply of pedigree parent stock. When a farmer buys a bull, he should be thinking of profit& loss – think of the progeny. The bull he buys will remain in the herd for 4 to 5 years and his daughters will have an effect on his profit & loss for a decade or longer. A good guideline is that the price of the bull should be the equivalent of 4 to 5 steers.
A weak bull is the most expensive animal that a farmer can invest in. The farmer will have to calculate: is it worth it to save money on a bull when he will use it for at least 4 years, will get a minimum of 120 calves and is assured of a strong genetic base – performance, registration and functional efficiency – of this bull? Cattle farmers that choose to use crossbred bulls must realize that the apparent advantages cannot be maintained in the long run.
If a farmer is unable, or not prepared to keep records, the easiest way to achieve progress in his herd is to use bulls from herds where this IS done. He does not have to keep records himself but should buy performance tested bulls.