Healthier cattle in the feedlot may translate to tastier and more tender meat on the plate, according to Oklahoma State University researchers.

Beef researcher Glen Dolezal and graduate student Brett Gardner examined the lungs of cattle at slaughter and found that lesions in the lungs from respiratory ailments accurately reflected reduced feedlot performance, carcass weight, marbling and exterior fat levels. Carcasses of cattle with lesions also received lower U.S. meat quality grades. Based on lesion observations, the researchers could also predict yield of lean meat.

Researchers also noted a link between lung lesions and less tender meat. However, it was unclear if that was cold-induced because the cattle were leaner, or if there was an enzymatic change prompted by infection. Those are questions that still need answers, Dolezal says.

For more information contact Glen Dolezal, Oklahoma State University, at 405/744-6616.

Heat tolerance of tropically adapted breeds crossed with a temperate breed is similar to heat tolerance among purebred tropical breeds, University of Florida researchers say.

Researchers investigated heat tolerance and growth rate in two trials under ambient conditions in central Florida. Trial 1 in 1994 involved 38 Brahman (B), 21 Senepol (S), 19 B x Angus (A), 20 S x A and 20 Tuli (T) x A heifers. Trial 2 in 1995 included 13 A, 35 B, 30 S, 23 B x A, 17 S x A and 28 T x A heifers.

Measurements were made on three consecutive weeks during the hotter and cooler seasons of 1994 and 1995 and included rectal temperature (RT), respiration rate (RR), temperament score (TS), blood packed-cell volume (PCV) and plasma cortisol concentration (CORT).

On the hottest date in trial 1, RT was not different between B and B x A or between T x A and B x A, but RT was lower in S x A than in either S or T x A. On the hottest date in trial 2, RT and RR were higher in A than in B, S and crossbred heifers. RR was higher in B x A than in B. On the coolest date in trial 2, RR was slightly lower in B than in A and B x A.

In trial 1, using initial body weight, average daily gain (ADG) of T x A was not different from ADG of B x A or S x A. In trial 2, adjusted ADG was higher in B, S and crossbreds than in A.

These data indicate that heat tolerance in F1 crosses of tropically adapted breeds (Tuli, Senepol, Brahman) with a temperate breed (Angus) is similar to heat tolerance displayed by purebred tropical breeds (Senepol, Brahman), Florida researchers concluded. Based on the study, they suggest Tuli or Senepol could be used in crossbreeding programs as an alternative to Brahman as a source of heat tolerance.

For more information contact Tim Olson, University of Florida, at 352/392-2367.

Whole soybeans have potential to replace soybean meal in finishing rations, according to University of Missouri animal scientist Monty Kerley.

Over a 58-day finishing period, 80 steers were divided into four treatment groups and fed a concentrate-based diet containing 0, 8, 16 or 24% whole soybeans. All rations were balanced for 15.25% crude protein.

In each treatment, whole soybeans replaced 0, 33, 67 or 100% of soybean meal in the diet and 0, 3, 6 and 9% of the corn in the diet.

No differences were found among the groups in average daily gain, total gain, final body weight, carcass weight, quality grade, backfat, ribeye area or yield grade. However, researchers did see a slight trend toward better quality grade with increased amounts of whole soybeans in the diet. This may have been due to increasing amounts of fat from soy oil in the diet, Kerley says.

Researchers concluded that whole soybeans can replace all of the soybean meal and some of the corn in conventional feedlot diets without adversely affecting steer performance. However, for whole soybeans to be an economical replacement for soybean meal, the beans should be 94% or less the cost of the soybean meal, says Kerley.

For more information contact Monty Kerley, University of Missouri, at 573/882-0834.

Wasps may help with feedlot fly control, Alberta researchers have found. A two-year survey among 22 Alberta feedlots has identified a naturally occurring parasitic wasp that kills stable flies and house flies.

Trichomalopsis sarcophagae is a tiny native wasp that acts as a natural biocontrol agent by laying eggs inside fly pupae. When the wasps hatch, they eat the developing flies. The wasps are harmless to people and livestock.

"These parasites by themselves are unlikely to provide sufficient fly control. Their use is intended as part of an overall integrated pest management program that includes improved sanitation and more selective use of herbicides," says project coordinator Kevin Floate of the Lethbridge Research Centre.

If further study is successful, the wasp could be commercially available as a control option to producers within five years.

For more information contact Kevin Floate, Lethbridge Research Centre, at 540/327-4561.

Fluorescent spectroscopy could soon be used to detect fecal contamination on fresh meat, according to Agricultural Research Service microbiologist Mark Rasmussen

Meat packers currently visually inspect carcasses for fecal contamination. With the new technology, this job will be faster, easier and more accurate. The hand-held detector can illuminate fecal contamination on meat within seconds. Identified contamination can then be removed with a knife or the carcass can be treated using various washing methods.

For more information contact Mark Rasmussen, ARS-USDA National Animal Disease Center, at 515/239-8458 (mrasmuss@nadc.ars.usda.gov).

"Research Roundup" is compiled by Kindra Beitelspacher at 612/851-4671 or Kindra_Beitelspacher@intertec.com

SAVE For September Haying CRP fields keeps hay quality up, say North Dakota State University (NDSU)researchers. CRP fields with greater than 33% alfalfa and hayed periodically provided higher nutritional quality hay than fields with minimal alfalfa and lacking a recent history of haying.

Hay samples from CRP fields with greater than 33% alfalfa and hayed since 1993 had a higher crude protein (CP) content (mean of 10.8%) than those fields not hayed since 1993, however acid detergent fiber (ADF) did not differ. Hay samples from CRP fields with less than 33% alfalfa and hayed since 1993 had a higher CP content (mean of 8.1%) and ADF than those fields not hayed since 1993.

These data indicate that CRP fields hayed using a three-year rotation or less would produce a higher quality hay than fields hayed using a four-year or greater rotation.

Researchers suggest haying CRP fields prior to grass maturity and full-bloom alfalfa (prior to July 15) would dramatically increase CP content and lower the ADF value of hay.

Depending on time of haying, periodic haying may also improve the nesting success of ducks, researchers say.

For more information contact Kevin Sedivec, North Dakota State University, at 701/231-7647.