Striking A Balance
Feb. 1, 2001 Ron Torell and Clint Peck
How much is too much? Setting the parameters for milk EPDs with an eye on frame score.
Milk and frame. If you're a young range cow carving out a living in the Nevada desert, too much of either may lead to your demise. But, if you're a mature cow living on lush Virginia pastures, too little milk and frame may be a waste of resources.
"The growth needs of a young cow, combined with the feed requirements for excessive milk and a large frame, is usually too much for our feed base," says Jon Griggs, manager of Maggie Creek Ranches, Elko, NV. But, if he can get a low- to moderate-milk and moderately-framed cow to her fourth year in good flesh, with a third calf in her, that cow will usually stay on the ranch, he says.
"The largest percentage of cows that drop out of our program are the three- and four-year-olds," agrees Alan Sharp, Ruby Valley, NV. "The reason they drop out is failure to rebreed, in spite of everything we do with heifer development and feeding a balanced ration as two-year-olds."
Griggs goes on to say that crossbreeding can be a factor to consider when setting parameters for milk expected progeny differences (EPDs). "But, you pay for heterosis by having a crossbred or composite cow that may need more input than a straightbred. And, if she's a heavy milker, even more inputs are required," he adds.
Robert Whitacre, Winchester, VA, has the opposite problem. The area receives more than 30 in. of annual precipitation.
"Feed is not a problem here, so milk and frame are less of a concern," says Whitacre, a commercial cattleman. "A smaller framed, lower-milking cow does not work for us. She gets over-fleshed and weans a smaller calf compared to the type of cow we can support. That type of cow winds up in the cull pen fairly rapidly here."
Whitacre, a field representative for Accelerated Genetics, puts it simply: "Extremes have a way of creating problems. It is not uncommon for us to wean 700-lb. calves. There is a limit, however."
Whitacre sells a lot of semen from frame score 7 bulls with Angus milk EPDs of +27 and more, but he tries not to exceed a 7.2 frame or much more than +30 on milk for Angus.
Assessing The Situation "Getting the cow to that third calf is the challenge," agrees Ken Conley, manager of the University of Nevada Gund Research and Demonstration Ranch located north of Austin, NV. "Over the years, we've had to implement several management strategies to keep these young cows in the herd."
Conley is convinced the cause of many open young cows is too much milk and frame coupled with the added nutrient requirements of being a young cow.
"To compound the situation, we would select replacement heifers that had the heavier weaning weights," Conley says. "Then we wised up and realized that those heifers raising the largest calves were open and thin come pregnancy-check time."
So how much milk and frame is too much?
"There's not much scientific data available to guide producers as to the correct milk EPD or frame size for various feed resources," says John Crouch, director of performance programs for the American Angus Association. "Research does show that the higher the milk EPD and the larger the frame of the animal, generally the higher the nutrient requirement of that animal."
However, according to Crouch, exceptions such as the high-milking, smaller-framed cow or the large-framed, low-milk EPD cow or the crossbred, easy fleshing cow that defy all the rules.
"We know the breed average for the current population of Angus cattle is a +14," he explains. "Each individual must determine how much milk is enough based on feed quality, quantity and management of young and mature cows."
Too much can be devastating under harsh and dry conditions. However, too little can result in lost income that could have been passed on to the calf from the maternal component, concludes Crouch.
To compound the situation, one must consider many variables when setting a ranch's maximum milk EPD criteria.
"There's no cut and dried answer," states Larry Leonhardt, Shoshone Angus, Cowley, WY. Leonhardt has studied this question on his registered Angus ranch for the past 20 years. The type of cow, supplementation, level of heterosis, weaning strategy and maturity level of the cowherd are all factors that can influence how much milk a ranch can handle under various forage and range conditions.
"You need to have enough milk and frame to make a calf, but not so much as to create open, young, thin cows in the process," says Leonhardt. " I recommend a rancher start with average and adjust from there."
A word of caution from Leonhardt, though. "Average" may be too much for semi-arid regions and not enough for the higher precipitation zones. Also, average milk for some breeds of high-nutrient demanding cattle may be too much as a starting point.
"Average always gives you fewer problems. Yet, as a registered bull seller, average is hard to sell," he adds. "You can hardly give a below-average milk EPD bull away."
Milk And Marbling? The bottom line is an old story. The cow has to match the environment - but there is a new twist as more EPDs are added to a bull's profile.
Jim Gosey, University of Nebraska beef cattle specialist, has tracked research on the effects of cow size and milk production for several years. Gosey suggests looking at your oldest cows and using them as a guide, or looking at the heifers that are falling out of your program.
"If possible, look at the sires of these two classes of cows and determine what milk EPDs they had at time of purchase," he says.
Gosey also says to take into account if the ranch sells calves or yearlings. "If you're selling yearlings, milk is less important than if you're selling calves."
Gosey warns against any single-trait selection, including the current fascination with marbling EPDs. Furthermore, he says, some sires that excel in marbling also are well above their breed average for milk EPD.
Review of breed differences with regard to milk level and marbling shows a definite trend for higher levels of marbling to be associated with higher levels of milk production. For most traits, moderation and balanced trait selection are the key concepts to keep in mind.
Breeds that have the ability to produce higher levels of milk also have heavier organ weights. And, heavier organ weights equate to greater nutrient needs, not only during the time cows are lactating but also during the time they're not lactating.
Rick Rasby, University of Nebraska beef specialist, says this data from USDA's Meat Animal Research Center in Clay Center, NE, suggests that milk production may be as big a drag on the cow's system as frame size.
"This is not to say that frame size is not important, but both need to be considered," says Rasby. "Again, moderation may be the safest route until you can determine what best fits your environment and feed resource base."
A moderately-framed cow would have a mature weight of 1,100-1,175 lbs. at a moderate body condition score of 5. Moderately-framed cows are considered frame score 4 and 5 (1 to 9 scale). Large-framed cows are frame score 6 to 9 with mature weights between 1,250 to 1,475 lbs. and above. Small-framed cows are frame score 1 to 3 with mature weights of 955-1,030 lbs.
Rasby's advice - evaluate your feed resource. If you have limited feed, stick with the moderately-framed cow.
