the
BEEFMASTER Pay Weight
a publication dedicated to serving commercial cattlemen and produced by Beefmaster Breeders United SPRING 2023
Vol. 9, No. 1
Section 1
www.beefmasters.org
Planned Crossbreeding Systems by Lance W. Bauer, PhD., Beefmaster Breeders United Beef producers are
average of the two parent always looking for a way to breeds. There are two types of increase the profitability of heterosis to take advantage of, their operations. To do this direct and maternal heterosis. they use selection criteria Direct heterosis refers to the that will help them increase heterosis of the animal itself, weaning weights, yearling and maternal heterosis refers weight, rib eye area, marbling, to the heterosis of the dam of stayability, and pregnancy the animal. The amount of rates. Many times, producers heterosis can be estimated by look at EPDs and recorded the percent of heterozygous weights and records to do this, gene pairs, where one gene and those are very valuable comes from one breed and numbers in the selection another from the other breed. process, but one thing that With this in mind, an F1 may get overlooked sometimes animal has the maximum is the value of crossbreeding. amount of direct heterosis and Crossbreeding helps to a F1 dam has the maximum optimize these traits and can amount of maternal heterosis. be a simple tool when used in Direct heterosis will a thought-out crossbreeding affect and improve most system. traits in a calf. Heterosis Advantages of Crossbreeding has the most effect on lowly Crossbreeding provides heritable traits but will also two advantages to using be observed on weight traits straight bred animals, first which are moderately heritable there is heterosis or hybrid and carcass traits which are vigor and the second advantage highly heritable. With these is breed complementarity (in moderately heritable traits, the a properly designed system). level of heterosis to be expected Breed complementarity is moderate, from 5-10% and is taking advantage of the with the highly heritable traits strengths of the different breeds the level of heterosis to be used in the system. In a wellexpected is around 0-10%. designed crossbreeding system, Maternal heterosis is the producer can maximize extremely important because the effect of both of these many of the maternal traits advantages. are lowly heritable traits. Heterosis or heterosis Reproduction, maternal is the ability of the cross bred ability, longevity and other offspring to outperform the traits that deal with overall
cow productivity are lowly heritable traits and heterosis has the greatest affect on lowly heritable traits. The expected levels of heterosis for these lowly heritable traits typically ranges from 10-30%. To calculate the level of heterosis the equation is: Level of Heterosis=((Average of crossbred animalaverage of parent breeds)/ average of parent breeds) X100. For example, if level of heterosis is being calculated for weaning weight in a Beefmaster X Angus cross and the average weaning weight on the particular Beefmasters used is 675 and the average for the particular Angus used is 650, and the average weaning weight of the calves is 700 pounds the level of heterosis can be calculated to be 5.7%. Level of Heterosis=((700-662.5)/662.5) X100=5.7%. Taking full advantage of heterosis is done when a system is in place the utilizes a crossbred female to produce crossbred calves. There are different crossbreeding systems that are very successful at utilizing and maximizing both types of heterosis. Direct heterosis is important because it directly impacts the weight and carcass traits of the calf and increased weight and better carcass traits lead to increased profits for the producer. Maternal heterosis is extremely important in the overall productivity of the cow, impacting things such as fertility and longevity, both of which lead to more calves that are raised by a cow in her lifetime. The more calves a cow can raise in her lifetime makes her more valuable to the producer. Another way to help effectively utilize heterosis
is to use cattle that are Bos indicus influenced, Bos indicus X Bos taurus cross cattle tend to exhibit a higher level of heterosis than Bos taurus X Bos taurus cross cattle. The other big advantage of crossbreeding is the ability to take advantage of breed complementarity. Different breeds of cattle have different strengths that they are known for and a well-planned crossbreeding system can take advantage of the strengths of two or more breeds. For example, if a producer is looking to use a terminal cross, it would be a good idea to utilize a breed known to be a good mother for the dam and a sire that is known for growth and carcass. A good cross in this case could be a Beefmaster dam and a Charolais sire, taking advantage of the maternal ability of the Beefmaster and the growth and carcass from the Charolais. When looking at breed complementarity it is also important to use breeds that work in the production environment. Types of Crossbreeding Systems When determining what type of system to use, a producer needs to look at their herd size, time, management requirements and the target market. Some crossbreeding systems produce replacement females to go directly back into the herd and others require the producer to purchase replacement females. These are all factors that need to be analyzed before selecting the preferred crossbreeding system. Composite Breeds Composite breeds are crossbred animals that are
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