Invited Review: Crossbreeding in Dairy Cattle: A Danish Perspective

Abstract

The value of crossbreeding in livestock species has been known for a long time; it has been used heavily within beef cattle, pig, and poultry production systems for several decades. This has not been the case for dairy production but lately there has been increased interest in crossbreeding dairy breeds. This review focuses on the practical and theoretical background of crossbreeding and describes the gain to be expected using systematic crossbreeding in dairy production. In Denmark, 24% of dairy farmers would consider starting crossbreeding programs within their herd. Evidence for the value of crossbreeding is documented with special emphasis on results from a Danish crossbreeding experiment. This experiment included 1,680 cows from 3 breeds and their crosses. In general, at least 10% heterosis can be expected for total merit, mainly due to increased longevity and improvement of functional traits. A minor part of heterosis for total merit is due to heterosis for production traits. For production, there is evidence of recombination loss using continued crossbreeding programs, which does not seem to be the case for longevity and total merit. However, recombination loss should be investigated more carefully as crossbreeding is becoming more popular. A prerequisite for crossbreeding to be beneficial on a long-term basis is that genetic gain within the parental breeds not be reduced. As long as the crossbred cow population constitutes less than 50% of the whole population, and young bulls can be tested through crossbred offspring, this prerequisite can be fulfilled. Crossbreeding can increase dairy income substantially, especially in management systems requiring a high level of functional traits.

The use of crossbreeding with beef bulls in dairy herds: effects on calving difficulty and gestation length

“…If genetic advances in the most economically important factors do not accompany crossbreeding practices, the practices will only achieve limited success (Sørensen et al, 2008). Results from the present study would allow producers to make informed decisions to minimise the impact that the studied traits (specially calving difficulty) have on herd cost.…”

“…A common European practice in dairy production is to inseminate dairy cows with semen derived from beef cattle if the calves will not be used for milk production on the dairy farm (Sørensen et al, 2008;Dal Zotto et al, 2009). Wolfova et al (2007) have established a superior financial value from the meat of dairy and beef crossbreeds when compared with pure dairy cattle.…”

Multigenerational hybridisation and its consequences for maternal effects in Atlantic salmon

“…Understanding the genetic architecture of population divergence allows for the prediction of generational trajectories of hybrids by their phenotype and relative fitness, both of which can influence adaptation, speciation and conservation-or economical-agricultural breeding strategies (Lynch, 1991;Burke and Arnold, 2001;Sørensen et al, 2008). A particular genetic architecture, such as the presence or interplay of dominance (interaction of alleles at the same locus) and epistasis (interaction of alleles at different loci), governs the genotypedependent trajectory of the phenotype and the mechanisms of hybrid fitness across generations (Lynch, 1991).…”

Estimation of nonadditive genetic influences on standard lactation production (305 days) in upgrading of Serbian-Fleckvieh to Holstein-Friesian cattle breed

“…All the traits of the crossbred F 1 progeny are partly under the influence of non-additive genes, i.e. dominance (interaction among the alleles of a single gene) and epistasis (gene interaction between loci), which means that in the F 1 generation, heterosis is a result of domination (mostly positive) and epistasis (often negative), as confirmed by Sörensen et al (2008). Fuerst and Sölkner (1994) argue that, due to non-additive genetic effects, the crossed population differs from the initial population (or the breed used for crossing) particularly in the amount of produced milk.…”