A Publication of:
OSU Extension - Fairfield County
831 College Ave., Suite D, Lancaster, OH 43130
and the
BEEF Cattle questions may be directed to the OSU Extension BEEF Team through Stephen Boyles or Stan Smith, Editor
You may subscribe to this weekly BEEF Cattle letter by sending a blank e-mail to beef-cattle-on@ag.osu.edu
Previous issues of the BEEF Cattle letter
Issue # 582
Improving Cowherd Reproduction via Genetics, Part 2 of 2 - Wade Shafer, ASA Director of Performance Programs
Last week in this publication we focused on the positive impact of cross-breeding and how direct selection affects cowherd reproduction. This week, let's begin with some thoughts on Direct Selection and it's impact on herd reproduction: A well-entrenched view of both commercial and seedstock producers is that the "cows left standing" after culling on the components of reproduction (e.g., pregnancy status and calf loss) are genetically superior. By extension, it is presumed that a great deal of progress in reproduction is made through rigorous culling and the retention of heifers out of dams making it to advanced ages. Though this may seem like a reasonable deduction, it is generally not the case.
Unfortunately, little genetic headway is made by simply culling cows that do not achieve reproductive thresholds. This may seem counterintuitive. Why wouldn't getting rid of the offenders improve your genetics for reproduction? The main reason lies in the fact that measures of reproduction tend to be lowly heritable (estimates typically run between 5-20%). And, with lowly heritable traits, an animal's own performance is not a good indicator of its genetic level for the trait. Therefore, many open culls may be genetically above average or even superior for reproduction. By the same token, several cows kept because they are bred will be genetically inferior for it - certainly not an outcome that will yield much improvement.
So, how do we directly select for reproduction? Because a cow's reproductive performance is expressed later in life, and even then it only provides a very cloudy picture of her genetic merit, are we relegated to making little to no selection progress for reproduction? Heck no! We can clear the clouds with reproductive EPDs.
Though EPDs always provide the best estimate of an animal's genetic merit, they are especially valuable when applied to low-heritability traits. This is because, when an animal's own record is a poor indicator of its genetic makeup, gathering information on its relatives is the only means we currently have of getting a clear picture of the animal.
You may ask yourself, "If an animal's own performance does not tell us much, what can be gained by records on its relatives?" It is not that a single relative record brings much to the mix (obviously it adds even less than the animal's own record); it is that there is strength in numbers - an animal can have many relatives with records, but only one record on itself. Through the use of EPDs we utilize information on all of an animal's relatives and, in doing so, chip away at the cloud with each record that flows in.
With a low-heritability trait expressed later in life like reproductive function, the cloud clears slowly - but it will clear. In fact, if an animal has enough progeny records, we can see its genetic merit for reproduction as clear as a bell.
Fortunately the seedstock industry now has EPDs that are, for the most part, direct measures of reproductive function: stayability (STAY) and heifer pregnancy (HP). Researchers at CSU (Snelling et al., 1995) developed the prototype for STAY, which was unveiled to the industry by the RAAA a few years later. The US breeds currently calculating STAY: Gelbvieh, Limousin, Red Angus, Salers and Simmental.
Colorado State University later developed HP based on work by Doyle et al. (2000) and implemented it for the RAAA National Cattle Evaluation in 2001. While the Angus Association of America has released a trial version, the RAAA is the only breed to publish an official HP at this point. Unfortunately, neither STAY nor HP is currently calculated on non purebred seedstock, though there are plans to do so in the future.
Though STAY and HP have potential shortcomings (e.g., seedstock breeders' culling practices are probably not in lock step with the commercial industry and breed association culling records tend to be sketchy), in my opinion they are the most effective selection tools available for improving reproductive function. What's more, based on computer simulation efforts by USDA researcher M. D. MacNeil, the economic impact of stayability when selecting a sire to keep replacement females is nearly twice that of the next closest trait, while the relative importance of heifer pregnancy is on par with the most important carcass or growth traits (personal communication) - so these reproductive EPDs certainly warrant a great deal of attention in the selection process.
Obviously, if you are a commercial producer you do not have the luxury of using STAY or HP to select replacement females; however, if you select sires with superior EPDs in these areas the reproductive function of your cowherd is likely to improve over time. Given their relationship to stayability, you may also gain some reproductive ground by selecting sires with lower milk, smaller mature size and better maternal calving ease EPDs. (In the future, these relationships will be accounted for in the computation of reproductive EPDs in the manner birth weight is incorporated in the prediction of calving ease - eliminating the benefit in considering them separately; however, they are not currently factored into the calculation of STAY or HP.)
Summary: In closing, I must reiterate that crossbreeding needs to be at the center of any effort to improve the reproductive function of your cowherd. The dramatic impact of heterosis on reproductive performance is crystal clear - no herd should be without it! Though reproductive improvement through selection is possible, it is generally limited to utilizing reproductive EPDs when selecting your herd sires. By combining crossbreeding with the selection of superior sires you will position your enterprise to excel in the most vital area of beef cattle production - cowherd reproduction.
Literature Cited:
Beckman, D. W., S. E. Speidel, B. W. Brigham, D. J. Garrick, and R. M. Enns. 2006. Genetic parameters for stayability and body condition score in beef females. Proc. West. Sect. Am. Soc. An. Sci. 57:93-95.
Cundiff, L. V., Nuiiez-Dorniguez, R., Dickerson, G. E., Gregory, K. E., and R. M. Koch. 1992. Heterosis for lifetime production in Hereford, Angus, Shorthorn, and crossbred cows. Journal of Animal Science. 70:2397-2410.
Doyle, S. P., Golden, B. L., Green, R. D., and J. S. Brinks. 2000. Additive genetic parameter estimates for heifer pregnancy and subsequent reproduction in Angus females. Journal of Animal Science. 78:2091-2098.
Martinez-Velazquez G., K. E. Gregory, G. L. Bennett and L. D. Van Vleck. 2003. Genetic relationships between scrotal circumference and female reproductive traits. Journal of Animal Science. 81:395-401.
Rogers, P. L., Gaskins, C. T., Johnson, K. A., and M. D. MacNeil. 2004. Evaluating longevity of composite beef females using survival analysis techniques. Journal of Animal Science. 82:860-866.
Snelling, W. M, Golden, B. L., and R. M. Bourdon. 1995. Within-herd genetic analyses of stayability of beef females. Journal of Animal Science. 73:993-1001.
EDITOR's NOTE: Improving cowherd reproduction via genetics will be but one concept Dr. Shafer will focus on during the Ohio Beef Cattle Breeder Conference being hosted on the campus of The Ohio State University by Dr. Tom Turner and staff of the American Simmental Association on April 30 beginning at 3 p.m. Details follow below.
Breeder Conference Focuses on "Tools to make better cattle and better beef"
Mark Wednesday, April 30 on your calendars to attend the Ohio Beef Cattle Breeder Conference being hosted on the Campus of Ohio State University by Dr. Tom Turner and staff of the American Simmental Association. Focus of the conference will be utilizing "Tools to make better cattle and better beef".
In the history of the world, no one has made more effort to characterize and compare beef genetics than the U.S. Meat Animal Research Center in Nebraska. The challenge is to effectively interpret and utilize their data in a fashion that optimizes a cattleman's returns to genetic improvement afforded by maximizing heterosis. In light of our present high feed cost environment, our future success depends on using all the tools available to make better cattle and beef.
Throughout the program, seven "truths of the cattle business" will be explored. These include
This futuristic program will begin in the Animal Science Building auditorium on the main campus of The Ohio State University at 3:00 p.m., and conclude at 6:45 with supper compliments of the American Simmental Association and the Ohio Beef Council. The program is free, but reservations are requested and may be made by contacting Stan Smith at smith.263@osu.edu or 740.653.5419 X 24.
Forage Focus: Evaluating Alfalfa Stands - Marvin Hall, PSU Forage Specialist
As alfalfa begins spring growth many producers are looking at alfalfa stands questioning if they are worth keeping another year or should they be harvested early and rotated to corn this spring. Unfortunately this is not always a yes or no decision.
Established Stands: The magic number of plants that traditionally indicated when it is time to rotate out of an established alfalfa stand is 4 - 5 plants per square foot. However, depending on fertility and weed invasion, alfalfa stands with 4 - 5 plants per square foot can yield as much as a stand with many more plants per square foot. The correlation between plants per square foot and yield is very low since individual alfalfa plants respond to decreasing stand density by producing more stems. Increased number of stems per plant compensates for fewer plants and maintains the yield.
A better indicator of the productivity than the number of plants is the number of stems per square foot. Fields with 55 or more stems per square foot produce maximum yields. As the stem number declines below 55 per square foot yields begin to decline. Once stem numbers falls below 40 per square foot alfalfa fields begin to lose profitability and should be rotated out of alfalfa.
Alfalfa plantings made last fall or this spring: Plant density in new alfalfa seedings should be a minimum of 15 plants per square foot. This greater density is needed because the plants have not developed large crowns yet and will consequently have fewer stems per (directly related to yield) plant than older plants.
Make Pasture Fertilizing Pay - Bruce Anderson, Extension Forage Specialist, Nebraska Ag Extension
Spring is approaching and cool-season grass pastures soon will green-up. As with other crops, grass growth is stimulated by fertilizer. With nitrogen fertilizer costing over 60 cents per pound this spring, though, producers may be asking whether it pays to fertilize pasture.
Our Nebraska research shows that you get one pound of additional calf or yearling gain for every pound of nitrogen fertilizer applied. However, this fertilization rule-of-thumb assumes that the amount applied is within our general recommendations, which are based on the potential amount of extra grass growth expected. This is affected mostly by moisture. It also assumes that your grazing management will efficiently harvest this extra growth.
If you fertilize pasture in spring and then let animals graze continuously on one pasture throughout the season, much of the extra growth is wasted. They trample, manure and foul, bed down on, and simply refuse to eat much of the grass. Eventually, less than one-third of the extra grass ends up inside your livestock.
To make fertilizer pay, manage grazing so more of what you grow actually gets eaten. Subdivide pastures with some cross-fences and control when and where your animals graze. Give animals access to no more than one-fourth of your pasture at a time, and preferably less. Then graze off about one-half of the growth before moving to another subdivision. If your pastures aren't already subdivided into at least four paddocks, your fertilizer dollar might be better spent on developing more cross-fences and watering sites.
Follow these suggestions and more of your pasture growth will be eaten and you're likely to get more profits from your efforts.
Weekly Roberts Agricultural Commodity Market Report - Mike Roberts, Commodity Marketing Agent, Virginia Tech
LIVE CATTLE futures on the Chicago Mercantile Exchange (CME) were up on Monday with the exception of the nearby April contract. The APR'08LC contract closed at $87.875/cwt, off $0.025/cwt but $0.450/cwt higher than a week ago. This contract was under pressure by talk of deliveries against it. JUNE'08LC futures were up $0.300/cwt at $89.500/cwt and $1.750/cwt higher than last Monday. Futures were supported by higher cash cattle. Trading between $85-$86/cwt last week, live cattle are expected to be up $0.50-$1/cwt this week. The USDA 5-area-average for Friday, April 4 was placed at $86/cwt. See Fig. 1 below for trend. Trading was light on Monday.
Figure 1. The red line represents 2008.
Months farther out were the biggest gainers as trade estimates for lower placements are being forecast below year-ago-levels for March and for April. USDA will release its next cattle-on-feed statement on April 18 showing how many cattle were in feedlots as of April. On Monday, USDA put choice cutout values at $137.18/cwt, up $0.09/cwt. The choice/select spread was off by $0.09/cwt at $0.73/cwt. Folks are willing to pay a little more for meat as of MondayJ. According to HedgersEdge.com, the average beef plant margin for Monday was estimated at a negative $16.70/head vs. a negative $28.80/head a week ago. The average packer buy was estimated at $86.87/cwt with estimated breakeven at $85.54/cwt. USDA placed Monday's slaughter at 126,000 head vs. 125,000 head a week ago. Cash sellers should consider pricing some cattle on the rally. Cattle prices could go higher on lower supply.
FEEDER CATTLE at the CME closed up on Monday. The APR'08FC contract finished at $99.000/cwt, up $0.40/cwt but $0.30/cwt lower than a week ago. MAY'08FC futures were up $0.825/cwt at $101.925/cwt and $0.70/cwt higher than last Monday. Gains were made on corn losses and news that cash cattle might be bid up later in the week on shorter feeder supplies. Overhead resistance was encountered in early trading on sliding feeder prices and thinking that feed prices were going to take off again. Corn lost near the close helping to prop up prices late in the day. The CME Feeder Cattle Index for April 3 was placed at $98.72/cwt, off $0.13/cwt. It might be a good idea to hold off sales if adequate corn inputs were bought when corn was down or you're grazing pasture instead of high priced wheat. Feeders just might rally somewhat indicating we have come through a bottom in prices.
Visit the OSU Beef Team calendar of meetings and upcoming events
BEEF Cattle is a weekly publication of Ohio State University Extension in Fairfield County and the OSU Beef Team. Contributors include members of the Beef Team and other beef cattle specialists and economists from across the U.S.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status. Keith L. Smith, Associate Vice President for Ag. Admin. and Director, OSU Extension. TDD No. 800-589-8292 (Ohio only) or 614-292-1868
Fairfield County Agriculture and Natural Resources
