13 March 2008

6 minute read

North America

According to the North American Limousin Foundation, while management strategies offering some immediate relief do exist, investment in genetic inputs to combat rising costs is a longer-term endeavor. That is because of generation interval; the accuracy of selection; and the shortage of available selection information for traits associated with inherent fertility, longevity and feed efficiency. Nonetheless, substantial opportunity exists, through exploiting the advantages of strategic crossbreeding and smart bull selection, to combat higher costs and improve net return.

Crossbreeding and selection for improved systemwide production efficiency are the genetic weapons for combating higher costs. It is important to wage the battle for genetic improvement in efficiency through selection on many fronts: reproduction; management ease; feed utilization; the production of liveweight that yields a high quantity of healthy, tender, tasty, affordable retail products; and mating systems that take advantage of hybrid vigor (heterosis) and breed complementarity.

A sensible place to start the battle against costs is with high genetic merit for reproductive efficiency. For argument’s sake, let us define “reproductive efficiency” as affordable replacement-heifer development and cow-maintenance costs that result in high pregnancy rates during a reasonably short breeding season with built-in cow longevity.

Because most reproductive traits have low heritability, the most powerful genetic tool for reproductive efficiency is maternal heterosis from adapted, carefully constructed crossbred cows. Research indicates crossbred cows have more than a year’s advantage in longevity and 30 percent greater lifetime productivity compared to straightbred cows.

Add selection pressure for a variety of reproductive traits in the bulls you buy to produce replacements, and you are on your way to winning the battle against high replacement rates and feed costs. Traits that either directly or indirectly affect reproduction, replacement rates and related costs include scrotal circumference (age at puberty), calving ease (direct and maternal), stayability, optimal milk and frame size, and visually evaluated functional traits (such as fleshing ability, structural soundness, and teat and udder quality). Genetic predictions for heifer pregnancy also can help identify sires that will produce the most fertile replacements.

Scarce or unaffordable labor represents a threat to most cow-calf enterprises. Selection might mitigate at least some of that risk, especially for important traits associated with calving. Selection for high fertility and calving ease, which yield a short calving season free of labor-intensive observation and calving assistance, can reduce the need for added labor. Calves that are born easily (with sensible birth weights and accompanying vigor) from relatively docile yet maternally oriented cows (with optimal milk and sound teats and udders) help to reduce headaches and the need for labor. Seedstock producers should put the Beef Improvement Federation’s (BIF’s) new teat and udder scoring system to use during calving season.

Bull selection based on expected progeny differences (EPDs) for moderate birth weight, high calving ease (both direct and maternal), adequate but not excessive milk, calm docility, and attention to sound pedigrees for teat and udder quality equals less labor. With cow-calf producers averaging just older than 55 years, they are sure to appreciate replacement heifers and cows with the genetics and heterosis for short, hassle-free calving seasons.

Genetic information that yields effective sire selection for efficient feed utilization – both the use of forage by the cow herd and of concentrates in the feedyard – is not widely available for most populations of beef cattle. That said, data and technology are emerging rapidly for traits associated with feed utilization. Although not yet validated by the National Beef Cattle Evaluation Consortium (NBCEC), at least two companies have DNA tests for efficiency, as measured by residual feed intake, in various stages of commercialization. The NBCEC Web site (www.ansci.cornell.edu/nbcec) offers the latest information about official industry validation of such tests.

A growing number of research institutions, private bull tests and individual seedstock producers have installed equipment that measures feed intake and enables comparison of animals for conversion efficiency. Cow-calf producers should stay abreast of emerging technology related to feed conversion. As results are released, producers need to be aware of the end points (for example, live weight, carcass weight, fat and marbling deposition, and retail-product yield) chosen to express feed conversion. Producers also need to differentiate between tools that rank animals for forage utilization (for selecting efficient cows) versus concentrate conversion (for feedyard efficiency) and recognize those might be somewhat different traits.

Breed differences exist that enable producers to select for feed efficiency indirectly. For cow-calf producers, research from the U.S. Meat Animal Research Center (USMARC) demonstrates the Limousin breed’s favorable maternal efficiency in low- and high-feed–availability situations. Generally, the breed’s moderate size and milk contributed to its favorable rank, regardless of feed availability, when compared to most other British and Continental breeds.

There are several selection tools available to facilitate selection for lower maintenance requirements. In a nutshell, selection for moderate size (that is, frame score 5 or 6), optimal milk EPDs and easy fleshing should yield favorable results. Genetic predictions for maintenance energy (ME) and cow energy value ($EN) – both derived from cow weight, condition scores and milk EPD data – help identify bulls that produce lower maintenance cows.

The Limousin breed’s primary strengths are muscularity and efficient systemwide conversion of feed to nutritious, healthy, tender retail product. On a liveweight basis, a 10 percent improvement in postweaning feed conversion (for example, from 6.6 pounds of dry matter to 6.0 pounds) over 600 pounds of live gain (that is, in-weight of 650 pounds and out-weight of 1,250 pounds) equals about $30 per head difference in total feed cost. That is 5¢ per pound less expensive cost of gain (COG), assuming a conservative ration cost of $170 per ton.

If selling finished cattle on a carcass-weight basis and the animals that are 10 percent more efficient also have 1.5 points higher dressing percentages (for example, 64.5 percent versus 63.0 percent), that is another $27 per head difference in value. Beyond conversion of feed to live and carcass gain, the Limousin breed’s notable advantage in muscularity contributes to superior yield grade and associated retail-product yield.

Those breed strengths help combat higher costs. With the help of data generated from the North American Limousin Foundation’s (NALF’s) Visions Quest (VQ) cattle-feeding and carcass-discovery program, new DNA-based tools that enable accurate individual animal selection for efficient, systemwide feed conversion are under development.

In the meantime, data from VQ and individual Limousin breeders have improved carcass EPDs’ accuracies, enabling cow-calf producers to select Limousin and Lim-Flex® seedstock more effectively for adequate levels of ribeye area (REA), which favorably affects dressing percentage and yield grade, and sufficient levels of marbling (quality grade). Most efficiently converting feed into carcass value (that is, weight, yield and quality grade) significantly enhances economic efficiency.

Arguably, the most profitable way to exploit all of crossbreeding’s efficiency advantages (heterosis and breed complementarity) is to have efficient, moderate, fertile, long-lasting, productive crossbred cows adapted to the environment. Then mate them to high-performance, terminal sires with genetics for weaning and finished weights and carcass traits matched to the target market. With that system, producers can take advantage of maternal heterosis in the cows, thus minimizing replacement costs. Terminal sires maximize calf heterosis and breed complementarity and allow high-performance growth and carcass genetics without needing the cow herd to support the added costs of such.

With oil prices currently greater than $100 per barrel; corn at more than $5 per bushel; and prices for commodities, forages, pasture and other inputs climbing to new plateaus, the cost side of the beef-production equation is poised to affect genetic and management decisions significantly throughout the supply chain. Long-term, producers should not overlook selection and crossbreeding as powerful tools to combat higher input costs.

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