- 1 What is the purpose of crossbreeding?
- 2 What are the advantages and disadvantages of crossbreeding in dairy cattle?
- 3 What are the benefits of cross breeding in humans?
- 4 Is there too much variability in using crossbreeding?
- 5 How is cross breeding important in agriculture?
- 6 How did crossbreeding affect agriculture?
- 7 Why is crossbreeding beneficial?
- 8 What are the benefits of crossbreeding?
- 9 Why is crossbreeding important?
- 10 What is the advantage of crossbreeding?
- 11 What is a composite breed?
- 12 What breed of cows are mated to a third breed of sire?
- 13 What is crossbred progeny?
- 14 What is single breed cow herd?
- 15 How to design a crossbreeding system?
- 16 Why do breeders use crossbreeding?
- 17 What is the benefit of crossbreeding?
- 18 Is crossbreeding better than first generation?
- 19 Where did composite breeds originate?
- 20 What is a composite breed?
- 21 How to get the most out of crossbreeding?
- 22 Is there too much variability in crossbreeding?
- 23 What are the benefits of crossbreeding?
- 24 What factors to consider when designing a crossbreeding program?
- 25 What is the best system for milk production?
- 26 What is additive genetic merit?
- 27 Can heterosis be used to crossbreed?
- 28 Is crossbreeding a long term program?
- 29 Why is fertility declining in dairy?
- 30 Why do dairymen crossbreed?
- 31 How many breeds of cattle should be used in crossbreeding?
- 32 What is the opposite of inbreeding depression?
- 33 How much does inbreeding increase in Holstein?
- 34 Is the Holstein breed alone?
- 35 Can you crossbreed Holsteins?
- 36 What is the diversity of crossbreeding?
- 37 What are the advantages of crossbred dairy cattle?
- 38 What are the disadvantages of crossbreding?
- 39 What is the performance of a crossbred?
- 40 What is the goal of crossing species?
- 41 What is hybridization in biology?
- 42 What is a bester hybrid?
- 43 How much do grouper hybrids survive?
- 44 How to evaluate hybrids?
- 45 Is crossbreeding indistinguishable?
- 46 Is crossbreeding good for aquaculture?
- 47 Introduction
- 48 Why Consider Crossbreeding Now?
- 49 What Are The Breed Resources?
- 50 What Issues Should Be Considered in Crossbreeding?
- 51 Three-Breed Rotational Systems with Purebred Ai Sires
- 52 Identification Is Important
- 53 References
- 54 Author Information
The Advantages of Crossbreeding
- Maternal Heterosis. Maternal heterosis is the advantage realized by using a crossbred cow versus a straight-bred cow. …
- Breed Complementarity. Another advantage of crossbreeding is the opportunity to capitalize on breed complementarity. …
- Direct Heterosis. …
- Breed Effects. …
- Capturing Maternal Heterosis. …
- Capturing Direct Heterosis. …
Design a cow herd that fits the environment. Use breeds for the cow herd that are similar. Use a terminal sire breed that fits the market. Use a system that is manageable over many generations.Jul 2, 2012
What is the purpose of crossbreeding?
· Crossbreeding is a mating system that complements genetic improvement. Crossbreeding results in heterosis, which is the opposite of inbreeding depression. Heterosis is a bonus that comes on top of the average genetic level of the two parent breeds, and should be about 5 percent for production and at least 10 percent for mortality, fertility, health and survival.
What are the advantages and disadvantages of crossbreeding in dairy cattle?
Although many beef producers choose to breed only purebreds, crossbreeding can result in significant advantages to beef producers. First, beef producers will be able to capture heterosis (also called hybrid vigor), which can improve conception rates, health, weight gain and other traits important for profitability of a beef operation.
What are the benefits of cross breeding in humans?
Is there too much variability in using crossbreeding?
How is cross breeding important in agriculture?
Crossbreeding provides the breeder the opportunity of combining the desirable characteristics of two or more breeds, thus achieving a higher overall performance level of desired traits among the crossbred animals than would generally be found within a given breed.
How did crossbreeding affect agriculture?
Abstract. Crossbreeding, considering either terminal or rotational crossing, synthetic breed creation or breed replacement, is often promoted as an efficient strategy to increase farmers’ income through the improvement of productivity of local livestock in developing countries.
Why is crossbreeding beneficial?
Crossbreeding improves more lowly heritable traits More lowly-heritable traits-such as milk production, longevity, reproductive fitness-will result in more heterosis than highly heritable traits such as carcass traits.
What are the benefits of crossbreeding?
Another advantage of crossbreeding is the opportunity to capitalize on breed complementarity. This involves evaluating the strengths and weaknesses of potential breeds and selecting those that complement each other. The result should be an animal that has the best traits of those breeds.
Why is crossbreeding important?
Crossbreeding is an important part of the beef industry because of the variation in environments and markets available in the US. It should be accomplished with specific goals in mind and with a long-term commitment. by Dr. John Comerford.
What is the advantage of crossbreeding?
A review by Reuter (2001) of several crossbreeding experiments showed that crossbred cows had a 9 percent advantage in calving rate and an 8 percent advantage in calf weaning weight over their straight-bred counterparts.
What is a composite breed?
Composite breeds are most often used to address specific environments , and this can be shown in the significant number of composite breeds that use Brahman in the cross (Brangus, Santa Gertrudis, Beefmaster) to capture adaptability to hot environments while adding other breeds to capture weight or carcass traits.
What breed of cows are mated to a third breed of sire?
Crossbred cows of two breeds are mated to a third breed of sire:
What is crossbred progeny?
The crossbred progeny of two breeds are mated back to one of the parental breeds: Good use of breed effects. Two breeding groups. Replacements produced. Maintains good level of consistency in calf crop. Some inconsistency in the cow herd.
What is single breed cow herd?
A single-breed cow herd is mated to sires of a second breed: Simple. Cow herd is a single breed. Only one breeding group. Maximizes breed influence. 15% increase in weight/cow exposed. No source of replacements.
How to design a crossbreeding system?
To effectively design a crossbreeding system, use these standards: Design a cow herd that fits the environment. Use breeds for the cow herd that are similar. Use a terminal sire breed that fits the market. Use a system that is manageable over many generations.
Why do breeders use crossbreeding?
Others will continually use crossbreeding to make sure there is a constant level of heterosis within the herd. The level of crossbreeding that the breeder uses also depends on what they are trying to select for within the herd. Pro-Cross is a popular system that selects for multiple traits. Pro-Cross (3)
What is the benefit of crossbreeding?
One of the main benefits of using crossbreeding is that there is less inbreeding within the herd and an increase in heterosis, which is the increase of the performance of an individual when compared to the average performance of their parents. Heterosis is also sometimes called hybrid vigor.
Is crossbreeding better than first generation?
They found that crossbreeding has shown a significant improvement in functional traits such as fertility and survivability, but this compared first generation animals. Further research needs to be conducted on the effects of crossbreeding in subsequent generations. This also is specifically looking at European and North American conditions, so more research would need to be done in order to collect data from other parts of the world.
Where did composite breeds originate?
Composite breed developed in St. Croix in the US Virgin Islands that arose from selecting for heat tolerance, being polled, gentle temperament, and good production. Recent research has found traces of Zebu DNA, when it was initially thought Senepol only arose from Red Poll and N’Dama. Girolando (2):
What is a composite breed?
Many breeds that we know today arose from crossbreeding and were once considered “composite breeds,” another term for a breed that has arisen from crossbreeding. After generations of selection, the crossbreed starts to become more uniform phenotypically and genetically. Senepol (6):
How to get the most out of crossbreeding?
In order for a producer to get the most out of crossbreeding, they must be willing to commit to using the program for several generations . Some farmers do not have the time and/or money to do this, so this a large factor to consider if interested in starting crossbreeding.
Is there too much variability in crossbreeding?
There is too much variability in using crossbreeding. At the start of the implementation of crossbreeding, the uniformity within a herd will be thrown off, which is to be expected. This lack of uniformity can be costly to the producer, especially if they do not commit to the crossbreeding program in the long term.
What are the benefits of crossbreeding?
dairy producers already practicing crossbreeding showed that the respondents desired improvements in fertility, calving ease, longevity, and milk component percentages.
What factors to consider when designing a crossbreeding program?
Here are some factors to consider when designing a crossbreeding program – given that almost all producers choose to include the breed of cows currently in the herd by default: Breed additive merit: Breeds used in crossing programs need to function well as dairy cows.
What is the best system for milk production?
Three-breed rotational systems utilizing AI-proven, purebred sires appear most useful to most dairy producers. Three-breed systems, at equilibrium, maintain 86 percent of full heterosis and can reduce large differences from one generation to the next in rate of maturity, mature body size, milk components, and associated nutritional requirements that some two-breed rotational systems may create. Two-breed rotational systems maintain 67 percent of full heterosis and do create bigger “swings” from generation to generation for traits where the two-parent breeds differ greatly.
What is additive genetic merit?
The additive genetic merit of pure breeds and of the animals within those breeds needs to be known and utilized to the producer’s advantage. With proper information, dairy producers who consider crossbreeding can predict the probable performance of the crossbred animals produced by their program (s).
Can heterosis be used to crossbreed?
Heterosis alone will not guarantee success in a crossbreeding program. A major portion of success will result from additive genetic merit for different traits that bulls and cows transmit to their offspring. The additive genetic merit of pure breeds and of the animals within those breeds needs to be known and utilized to the producer’s advantage. With proper information, dairy producers who consider crossbreeding can predict the probable performance of the crossbred animals produced by their program (s). There are no easy or quick ways to answer the important questions surrounding dairy crossbreeding, but we can use what we do know and be aware of work in progress to give us further direction.
Is crossbreeding a long term program?
Crossbreeding is more widely practiced by dairy producers every year. A crossbreeding program should be seen as a long-term proposition. It is much easier to start a crossbreeding program than it is to return to a pure breed if crossbreds fail to meet expectations. Knowledge of the breed resources available and the strengths and weaknesses of each breed should guide decisions of which breeds to use in a crossbreeding program.
Why is fertility declining in dairy?
Fertility has declined in U.S. purebred dairy populations as a correlated response to selection for higher yields and/or from inbreeding depression.
Why do dairymen crossbreed?
So now what? Well, some California dairymen have turned to crossbreeding to reduce high culling losses. The details of crossbreeding are much too extensive to discuss here. However, the take-home messages are:
How many breeds of cattle should be used in crossbreeding?
Crossbreeding systems with dairy cattle should use three breeds to capitalize adequately on the benefits of heterosis.
What is the opposite of inbreeding depression?
Crossbreeding results in heterosis, which is the opposite of inbreeding depression.
How much does inbreeding increase in Holstein?
Inbreeding is increasing at about 0.1 percent per year in the Holstein breed, which is causing increased inbreeding depression, especially for mortality, fertility, health and survival.
Is the Holstein breed alone?
genetics dominate the dairy industry worldwide, this is not just a U.S. problem. Sixty-four percent of the world’s Holstein breed traces back to just three sire levels: Elevation, Blackstar and Chief. But the Holstein breed is not alone; most other breeds are in a similar situation.
Can you crossbreed Holsteins?
If you turn to crossbreeding, be sure to have a plan. According to University of Minnesota data, the cross needs Holsteins for the third or fourth generation. As for purebreds, someone needs to provide the animals for crossbreeding. Consult your artificial insemination distributor for details.
What is the diversity of crossbreeding?
One should be aware when crossbreeding that with early generations of crosses, there may be considerable diversity with regard to size, body condition, and other traits, depending on the breeds utilized.
What are the advantages of crossbred dairy cattle?
The major advantage of crossbred dairy cattle is that they exhibit the strengths of all breeds from which they descend with an added advantage of heterosis. Heterosis tends to be most important for lowly heritable traits such as fertility and survival.
What are the disadvantages of crossbreding?
The major disadvantages are that crossbreds also have the weaknesses of the breeds from which they descend and heterosis in initial crosses declines with any backcrossing to parental breeds. Rotational crossbreeding plans, particularly with three breeds, can maintain substantial heterosis, but maintaining a rotational crossbreeding program requires …
What is the performance of a crossbred?
The performance for a particular crossbred for a trait will be a combination of the breed merit for that trait of the breeds which make up the crossbred and the heterosis for that trait which is expressed in the crossbred. That combination can be higher than the breed merit for that trait of the superior breed in the crossbred’s makeup.
What is the goal of crossing species?
Combining traits. At times, the goal of crossing species or lines is not to capitalise on heterosis but rather to combine certain traits , such as the fast growth of pure striped bass with the hardiness of their smaller relatives, the white bass.
What is hybridization in biology?
Hybridisation, in the strictest sense, involves the crossing of related species. Some examples include crossing striped bass with white bass, channel catfish with blue catfish, or Nile tilapia with blue tilapia. In contrast, when distinct stocks, lines or varieties of the same species are crossed, the most appropriate term is crossbreeding, …
What is a bester hybrid?
The Bester is not only illustrative of the productive combination of desirable characters in a first generation hybrid, but also of how to develop a synthetic strain of fish. Beginning in Japan, first generation Bester were crossed among themselves to produce second generation fish (since parental lines were not available), and this strategy was subsequently adopted in a number of locations. As a result, not all Besters are created equal. Some Bester populations are now 7 generations removed from the original hybrids, and are routinely used for backcrossing with pure species. Some Russian and Ukrainian scientists now refer to the Bester as Acipenser nikoljukini in honor of Dr Nikolyukin. Similarly, most lines of red tilapia found throughout the world are the result of crossing first generation hybrids among themselves in relatively closed populations until certain desirable characters become fixed. Accordingly, a red tilapia from Colombia may be notably different from one in Thailand.
How much do grouper hybrids survive?
tukula males was recently reported. At 11 days post-hatch, hybrid survival was roughly 40 percent, while that of pure E. awoara was only 5 percent (pure tukula was not available for the analysis). At 4 months of age, hybrids weighed 24.1 g on average compared to 21.3 g for E. awoara. By 13 months, however, this modest advantage had increased to 409 g vs 129 g!
How to evaluate hybrids?
The best approach to these evaluations involves a design that includes both pure lines and their reciprocal crosses (line 1 females by line 2 males, and line 2 females by line 1 males). Even more complex designs, involving multiple parental lines, can be accommodated if suitable incubation and rearing facilities are available. Mating designs involving more than two lines are typically referred to as diallel crosses.
Is crossbreeding indistinguishable?
In fairness, the distinctions between strains, races and species are often blurred to a point where crossbreeding or hybridisation are essentially indistinguishable. Advertisement. Sometimes, producing these crosses is easily accomplished, but occasionally a lot of work is involved.
Is crossbreeding good for aquaculture?
The pros and cons of crossbreeding and hybridisation in aquaculture. Heterosis, the well-known concept of “hybrid vigour”, has been utilised to improve fitness-related traits – like growth, fecundity and disease resistance – in a number of cultured aquatic species over the years. During the past year or so, a number of interesting new studies …
Why Consider Crossbreeding Now?
Some things have changed in the last 50-plus years. 1. Intensive selection for higher yields and better type has changed the dairy cow, regardless of her breed. Fifty-year-old results may no longer be appropriate. 2. Inbreeding levels are increasing in purebred populations. 3. Fertility has declined in U.S. purebred dairy populations as a correlate…
What Are The Breed Resources?
Table 1 shows seven of the most promising breeds for crossbreeding programs. It includes reasonable estimates of breed averages for production traits, the traits about which we know the most. Population size and young sire sampling efforts, as well as production characteristics are important when choosing breeds. Many other factors, such as body size of mature animals, ferti…
What Issues Should Be Considered in Crossbreeding?
Crossbreeding programs are long-term decisions. Producers should plan crossbreeding strategies carefully and have reasonable expectations of the process. By the time the first crossbred female reaches breeding age, a decision must have been made as to the breed of the sire to which she will be mated. Within two years after that, the next generation of crossbred fe…
Three-Breed Rotational Systems with Purebred Ai Sires
Crossbreeding plans should take advantage of the genetic resources available in pure breeds. Crossbreeding programs using purebred sires from major dairy breeds in Table 1 offer the considerable advantages of genetic evaluations and a wide choice of service sires through AI. Such programs are strongly recommended. No alternative plans, such as using lesser known dai…
Identification Is Important
While inbreeding is not a major consideration for crossbreeding programs, it can occur with backcrosses to breeds previously used. If a crossbred cow is related, even remotely, to her purebred mate, some inbreeding will exist in their crossbred progeny. Accurate and complete identification of ancestry is recommended for all crossbred dairy animals. Properly identified cr…
Weigel, K.A. and K.A. Barlass. 2003. Results of a producer survey regarding crossbreeding on US dairy farms. J. Dairy Sci. 86:4148-4154.
Bennet Cassell, Virgina Polytechnic and State University (Virginia Tech) Jack McAllister, University of Kentucky