Beef Magazine is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Nutritional content of crop residue

Garner extra value by grazing cattle on crop residues.

With corn, sorghum and soybean harvest completed, it's time to garner extra value by grazing cattle on crop residues. Here are some nutrient pointers from Rich Rasby, University of Nebraska-Lincoln professor of animal science.

The corn cob and stalk are lowest in protein, energy and palatability. The leaf and husk are intermediate in nutrient quality, but high in palatability. The grain is highest in nutrient quality.

Research indicates about two times more residue is left in an irrigated field (over 5,000 lbs./acre) compared to a dryland field (2,500 lbs./acre).

Many of the nutrient-quality aspects described for corn can also be applied to grain sorghum stubble. However, there are at least two differences — the grain sorghum leaf is generally higher in protein than a corn leaf, but sorghum grain isn't utilized by the cow as well as corn grain because the sorghum berry's hard outer coat makes it difficult to digest.

Be aware that cattle can founder while grazing grain sorghum fields with excessive amounts of grain left after harvest.

Meanwhile, the TDN content of the soybean leaf, pod and stalk are low (35-41%). The low energy content for soybean stubble residue is due to the high lignin content, especially in the stem. Lignin is the indigestible cell wall component of the plant.

The nutrient content of crop residue fields does decrease due to weathering. The greatest nutrient loss is energy content in the husk and leaves. Also, nutrient losses are greater in wet, humid conditions due to increased decomposition and weathering.
Rick Rasby,
University of Nebraska-Lincoln

Creep grazing is often used in the beef industry to supplement calves before weaning. Bermudagrass pastures usually supply adequate nutrition for pregnant or lactating cows; however, they're usually low in quality for growing calves.

Producers may offer higher-quality forage to calves using small creep grazing paddocks. Tifton 85 is a higher-quality and higher-yielding forage than Coastal bermudagrass. Tifton 85 has higher dry matter and fiber digestibility than Coastal, resulting in higher gains and utilization by cattle.

Aeschynomene, or American joint vetch, is a high-quality tropical legume. One might expect use of aeschynomene creep grazing to improve gains in calves on Coastal compared with Tifton 85.

Despite the higher quality of Tifton 85, calf performance was improved on both kinds of bermudagrass pasture. Cow and calf performance was improved and cow stocking rates were higher for Tifton 85 pastures, resulting in higher 91-day summer average daily gain and adjusted weaning weights for calves (1.76 vs. 2.11 lbs.; 527 vs. 534 lbs., Coastal vs. Tifton 85).

Calves with access to aeschynomene creep-grazing paddocks had higher average daily gains and weaning weights (2.01 vs. 1.85 lbs.; 549 vs. 532 lbs., creep vs. no creep). Cow and calf performance were improved by grazing Tifton 85 and by aeschynomene creep grazing during the summer before weaning of calves in September.
V.A.Corriher, et al, J. Anim. Sci. Vol. 83, Suppl. 1/J. Dairy Sci. Vol. 88, Suppl. 1

Tenderness is one of the most important characteristics when measuring the palatability of meat and it's influence on the consumer's eating experience. It's also one of the most difficult to measure.

One measure for tenderness has been found in the calpastatin concentration in meat. Calpastatin, a protein, is a regulator for meat tenderness. More specifically, it's one of three proteins that make up the calpain protealytic system.

Calpastatin is the inhibitor of the other two proteins — µ-calpain and m-calpain. Changes in meat tenderness during the aging process are the result of the calpain protealytic system's ability to degrade cytoskeletal proteins, which are responsible for the structural integrity of muscle fibers.

University of Missouri (MU) researchers are studying a fluorescence dual binding biosensor to detect calpastatin. The ability to detect calpastatin concentration in beef with a biological sensor at the time of grading would lead to the more accurate assessment of the overall palatability of beef, say the MU researchers. Meat can be labeled as tender or tough, according to the measured calpastatin levels, allowing the processor to grade beef more easily and with greater accuracy.

The biosensor uses the distance-dependant chemical transduction method of fluorescence resonance energy transfer (FRET) to measure the calpastatin concentration.

In a nutshell, researchers were able to determine that the FRET dual-binding technique will detect calpastatin. The next step is to determine if the biosensor can detect specific, biologically active levels of calpastatin in meat to correlate those levels with tenderness measurements.

Hopefully, the sensor may eventually be available to commercial operations to help correctly sort carcasses as tough or tender, providing the ability to market meat as guaranteed tender. This would help recapture millions of dollars lost due to inadequate tenderness.
Grant et al. Biosensors and Bioelectronics 21 (2005) 438-444

Raising early-weaned replacement heifers in drylot settings typically costs more and takes longer than traditionally weaned animals. A South Dakota State University study examined raising these early-weaned replacement heifers on range with dried distillers grains as supplements. They found it was a cost-effective alternative to the drylot setting.

Researchers at the Antelope Range Research Station near Buffalo looked at the range setting to develop the early-weaned heifers. Developing heifers isn't a common practice in northern South Dakota because of the perception such as system can't maintain adequate reproduction.

The study used dry distillers grains as a supplement to make up for the range's lower-quality forage. Dried distillers work well because they're rich in protein, fat and fiber.

Heifers were fed for 52¢/head/day — compared to the cost of feeding drylot heifers at 74¢/head/day. Researchers found the range-raised replacement heifers were developed at a lower cost with the same reproductive success. They also achieved the same performance in weight gain, average daily gain and reproductive performance compared to the more traditionally developed drylot heifers.

The study was first done in 2003-04 and repeated in 2004-05 with similar results.
Greg Lardy, The Ranch Hand newsletter, North Dakota State University

TAGS: Feed Nutrition