One benefit of crossbreeding is being able to quickly alter particular characteristics of a herd for a specific purpose as follows.
To cater to a particular market
Terminal sire systems give the breeder an opportunity to change sires rapidly so that calves can be changed according to market demands or resources.
Example 1: The lean beef market.
The use of European sires such as Limousin, Charolais and Simmental will give a markedly leaner product with the first cross.
Example 2: The high quality Japanese market.
Angus, Murray Grey and Angus x Hereford are preferred by the Japanese because they produce a more marbled product than some of the leaner European breeds.
To increase production
Example 1: Use of European breeds to produce heavier weights.
In general, European breeds have a larger mature size than British Breeds. Therefore the result of a cross between a British and European breed will be an animal with a mature size somewhere in between the two breeds.
Example 2: Use of dairy breeds to increase milk production.
Figure 1 demonstrates the increase in milk production of a dairy cross cow over that of a British beef breed cow.
To remedy a problem
Example 1: Reduce eye cancer in Herefords by crossing with nearly any other breed.
A combination of lack of dark pigment around the eye and hooding over the eye predispose Hereford cattle to eye cancer.
Example 2: Increase heat and tick tolerance by crossing with Bos indices breeds.
Bos indices cattle originated from Asia and therefore tolerate tropical conditions far better than British or European breed cattle which originated from the colder European climate.
Bos indicus/British crosses increase production under tropical to semi-tropical conditions. These breeds combine the benefits of both breeds, i.e. the high fertility and increased growth rate of the British breeds with the increased heat and tick tolerance of the Brahman breed.
Complementarily of male and female traits
Certain crossbreeding systems allow the breeder to match traits of the bull breed to traits of the crossbred cow.
Normally this means that the breeder chooses a bull breed that will transmit rapid growth and desirable carcase traits to progeny while the crossbred cow provides a live, healthy calf every year.
Complementarity can work in a negative way in poorly designed cross-breeding programs. For example, large terminal sire breeds bred to small, young, hard-calving cows can result in excessive calving difficulty, or a small bull breed mated to a large cow breed can result in an inefficient cow/calf unit in terms of feed conversion.
Crossbred cows “designed” to match an environment
This practice has been carried out very effectively in Northern Australia, for example, where the drought, tick and heat tolerance of the Brahman breed has been combined with the fertility, carcase and early maturity of the British breeds to produce the Braford, Santa Gertrudis and Droughtmaster.
These breeds can range from 3/8 to 5/8 Brahman content. The choice of Brahman percentage will depend on the environment, i.e. the more tropical the environment the higher the Brahman content.
Beef producers in Southern Australia can do a similar thing with specific European, British and dairy breeds.
Composite breeds are made up of two or more different breeds and have been developed by stabilising a crossbred line. Apart from the initial crossing in the developmental phase, the use of composite breeds involves straight breeding, not crossbreeding.
To be successful, development of a composite breed requires a large herd size or a group of co-operators.
Examples of composite breeds include:
Braford (3/8-5/8 Brahman and 5/8-3/8 Hereford), Bee maker (1/4 Simmental, 3/4 Hereford), Simford (1/2 Simmental, 1/2 Hereford)
The aim of a new composite is to combine the advantages of hybrid vigour and a blend of desirable breeds with the simplicity of straight breeding management.
An example of the use of composite breeds in the United States is the Beef Booster program.
This program has been developed to produce five different composite strains of cattle, each made up of several different breeds and each designed for a specific purpose.
Examples of these composite strains include: Strain (or name of composite breed): TX
Function: to produce sires that, when mated to maternal-type cows, will produce progeny that excel in carcase attributes and growth rate.
Breeds used: Charolais base with infusions of Holstein-Friesian, Maine Anjou and Chianina.
Strain (or name of composite breed): M1
Function: Maternal ability, low cancer incidence, easy care, winter hardiness.
Breeds used: Angus base, with infusions of North Devon and Welsh black.
Strain (or name of composite breed): M3
Function: To produce sires whose progeny have light birthweights and are born easily. M3 sires are used over heifers.
Breeds used: The M3 strain started from a variety of small cows which had no record of calving difficulty. Other breeds include Jersey, Longhorn, Red Poll and Shorthorn.
Composites retain a significant portion of the first cross heterosis. A four breed composite with equal proportions of each breed retains 75% of its F1 heterosis. The fewer the number of breeds used, the lower the heterosis.