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Linear measuring points to better grass-fed genetics

A Manitoba grass-fed beef producer uses a set of 
homemade calipers to select the best cattle

measuring a cow's girth

As consumers continue to drive demand for grass-fed beef, some producers are rethinking their cattle genetics to select for animals that will be the most productive on forages.

Brian Harper has been using linear measuring as part of his beef genetic selection process since 2007, and has seen steady improvements in the quality of his grass-fed herd. Harper, who raises Lincoln Red and Shaver Beefblend cattle near Brandon, Man., breeds only the top 10 per cent of his cows — determined through linear measuring — with his premier sire to maximize the best genetics.

“You can’t improve your cow herd by just culling,” says Harper. “You need to select from the top, and that starts by using the bull with the most prepotent (showing greatest potential) paternal genetics you can find, and always breeding him with your best cows. It may take two or three generations to get what you need but I’ve seen definite improvements in the quality and efficiency of my herd over the past five years.”

Linear measuring is not about a gene pool, but rather a tool that enables the producer to identify structural weaknesses and strengths that are genetic, and thus heritable. Linear measuring shows how different body measurements correlate to indicators of potential fertility and production efficiency. The process allows producers to select bulls and cows for breeding that have the highest levels of reproduction, the best ability to efficiently utilize grass, low maintenance requirements, and the ability to produce prime-quality meat.

At a recent workshop, Harper demonstrated to producers how he takes measurements of the rump, body length, neck, shoulders and heart girth with specially designed calipers that he says any enterprising farmer could easily fabricate in his or her shop. Harper feeds the measurements into a computer program which ranks the cows or bulls according to the measurements, and from this ranking Harper picks animals with the most desirable genetics for his breeding program.

The ideal grass-fed cow

“The ideal cow that will perform well on grass should have rump width wider than the rump length,” says Harper. “As well, wide shoulders equal to the rump length, and a deep chest or large heart girth, which is larger than the total topline, will provide optimal grass utilization.” Harper says every extra inch of girth that is greater than the topline equates to 37 pounds more meat, and conversely, every inch of girth that is less than the total topline equals a deficit of 37 pounds of meat.

Harper also emphasizes the importance of producing milk that is high in butterfat.

“The average beef cow today produces about eight ounces of butterfat a day, which is around four per cent of butterfat content in the milk. A calf receiving eight ounces a day will have an approximate average daily gain of about 1.6 lbs./day. We need our cows to produce 13 to 16 ounces of butterfat a day — or greater than six per cent butterfat content — to achieve an average daily gain of 2.25 to 2.5 lbs./day,” says Harper.

To develop efficient and productive genetics, Harper leaves his calves nursing their mothers for 10 months, which allows the calf’s gut to develop so it can process forages more efficiently.

“The calf requires the high nutrition found in its mother’s butterfat for at least 10 months to provide better efficiency and a low maintenance animal,” says Harper, noting it’s important once calves are weaned they receive high-quality forages.

A superior sire

An ideal bull will have a shoulder measurement wider than its rump length, says Harper. “A wide-shouldered bull produces more sperm cells and live semen, and his calves will be born on time, and within five per cent of his actual birth weight. His daughters will also have wider rumps indicative of high fertility. The aim of these selection and breeding practices is to make the male offspring of the bull genetically superior to itself, so they can eventually replace him as the lead sires for the herd.”

Harper learned linear measuring from Gerlad Fry, an Arkansas cattleman who is an astute student of Dr. Jan Bonsma of Pretoria, South Africa. Bonsma, during many years of research as he developed the Bonsmara breed, evolved the linear measuring method, and Fry developed the software Harper uses. Bonsmara cattle are a cross of native South African and European cattle breeds which produce high-quality meat and thrive under drought and harsh conditions.

Other indicators of forage efficiency

There are other indicators besides just linear measurements which can tell a lot about the health of a cow or bull, and their potential to produce healthy offspring that will also do well on forage, says Harper.

“The hair coat, and hair patterns, and even colouration of the animal will tell you a lot about what is happening inside the animal’s body,” he says. “For example, a well-defined adrenal hair whirl that is located between or ahead of the shoulders, coupled with a slender, smooth, hourglass cannon bone, and a loose, supple hide indicates tender, gourmet meat. Yellow flakes on the tail reveal an animal that is high in butterfat production, which is also associated with tender meat. As well, an animal with a dark line that runs the full length of the top of its back, and a large thymus whirl, shows its glandular system is active. Animals showing these signs will not get sick and neither will their calves.”

Harper continues to improve the genetics of his herd by using linear measuring, and says the bar is constantly rising. “When I first started I wouldn’t use a bull that scored less than a three on the linear measuring ranking, but now I won’t use one scoring under 3.5, which shows how the breeding program is making progress,” he says. “I also use other management techniques, such as holistic management and high stock density to improve soil health and the mineral cycle of my pastures. I haven’t had to vaccinate my herd for five years because my cows are healthier. I am producing nutrient dense beef that more health conscious consumers are demanding, and improving profitability by making the best return from the grass that grows on my farm.”

Details on the linear measuring process

Brian Harper says linear measurement is about creating balance. Cattle that are not balanced display defects and generally are not productive or efficient in a forage-only environment.

Cow measurements

Here are more details on how linear measurements are taken, and recommendations for ideal measurements to maximize productivity on forages:

  • Rump length — measured from the rump to the hip. Should ideally be 38 to 40 per cent of body length.
  • Rump width — should be a minimum of 2.5 inches wider than the rump length by 12 months of age to give higher fertility and fewer calving problems.
  • Rump height — a frame score of four (around 48 inches) is recommended.
  • Body length — a 2/3 measurement from a spot in between the shoulder blades to the rump. When the body is too long the loin becomes stretched and irregular and produces less meat.
  • Neck length — from the body measurement point to the poll of the head. It should be half of the body length or one-third of the topline.
  • Shoulder width — should be at least equal to rump length.
  • Heart Girth — should be equal or greater than the topline for improved vigour, adaptability and forage efficiency. A narrow, pinched girth creates glandular dysfunction making the cow and its calves more susceptible to stress and disease.
  • Flank — should be two inches to 10 inches larger than the heart girth.

Bull measurement

Linear Measuring and measurement recommendations for bulls are the same as for cows, with the exception of the following:

  • Shoulder width — To be considered superior, a bull should be at least six to eight inches wider in the shoulder than the rump length, with a minimum allowance of 2.5 inches wider than the rump length.
  • Rump width percentage — to determine the percentage, divide the rump width by the rump height. For the best sires the goal is to have a minimum rump width of 44 per cent, with 46 to 50 per cent of his rump height being ideal.
  • Flank — should be equal to total topline.
  • Heart girth — Should be two inches or greater than the topline for maximum meat production, adaptability, fertility and performance on grass.

For more information about linear measuring contact Brian Harper by calling 1-204-724-0936 or by email.

About the author


Angela Lovell

Angela Lovell is a freelance writer based in Manitou, Manitoba. Visit her website at or follow her on Twitter @angelalovell10.



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