Under this plan, the FDA asks “animal pharmaceutical companies to revise the FDA-approved use and conditions on the labels of these products to remove production indications.” The plan also would “change the current over-the-counter (OTC) status to bring the remaining appropriate therapeutic uses under veterinary oversight.” 

In short, antimicrobial drugs that are considered important in human medicine would no longer be permitted in feed or water for production purposes (improved weight gain, efficiency, etc.) and those same antimicrobial drugs used in feed to water to treat, control or prevent sickness in food animals would require veterinary approval. Click here to view the FDA announcement.

Residual feed intake efficiency vs. bull fertility

A 112-day performance test (on a ration of 53 percent corn, 39 percent alfalfa silage) was conducted over six years on 328 crossbred bulls. ADG and RFI were calculated. Two RFI values were calculated, one of which included an adjustment for differences in mid-test ultrasound rib-fat thickness. At the conclusion of the tests (at average age of 417 days) 110 bulls were selected for breeding. On these bulls, scrotal circumference (SC) was measured and samples taken to evaluate sperm motility and viability.

As has been found in some other research, high RFI (low efficiency) bulls were also significantly less efficient measured as gain:feed, consumed more feed, and were not different in ADG than low RFI bulls. When halved into two groups of 55 high RFI and 55 low RFI bulls, there was no significant difference in SC, sperm motility or sperm viability.

The authors then compared the 10 bulls lowest in RFI (which might be done if exercising extreme genetic selection for that trait) and the 10 highest RFI bulls. The 10 bulls with highest RFI values were significantly highest in sperm motility and viability. Also, when RFI included adjustment for ultrasound fat, the 10 high-RFI bulls were significantly higher in SC.


The authors concluded that young bulls with highest efficiency may have decreased fertility traits “which is an undesirable effect of selection for improved efficiency that needs to be addressed through multiple-trait selection.” That is, as is generally true for all traits, single-trait genetic selection should be avoided. (Can. J. Anim. Sci. 93:185; Univ. of Guelph, Univ. of Saskatchewan, No. Dak, St. Univ.)

What do those labels on food mean?
Consumers are confronted with a sometimes bewildering array of labels on food, often with similar wording. To a typical consumer, is there any distinction between the USDA-approved terms of “natural” and “naturally raised”? Probably not. But the first term deals only with how a product is processed, if at all, and the second deals with how an animal is produced. How about “grassfed” and “grass finished”? The USDA has a definition for grassfed and so does the American Grassfed Association, which is much more detailed and restrictive. There is no specific definition for grass finished.

A current publication lists 84 terms shown on labels. Of those, 48 have no legal or regulated definition and 8 have independent third-party certification. Some terms would be familiar to anybody raising cattle, such as those dealing with USDA quality grade. Many deal with animal welfare or environmental topics and others address things perceived by some to affect health, other than official inspection for safety and wholesomeness. Click here to view the list.

What is the right cow size?

A recent article in the popular press indicated it is 1,350 pounds. How was that determined? By working back from an “ideal” carcass weight. A large cattle-feeding company said 850-pound carcasses have the largest potential profit. Assuming typical dressing percent, that equates to a live slaughter weight of about 1,350 pounds. In general, slaughter weight of steers at ½-inch fat cover is thought to be about the same weight as that of the cow used to produce that steer, if the sire and dam are genetically equivalent.

What if 1,350-pound cows are too large for the production conditions? Maybe 1,200-pound cows fit best. If their steers are fed to 1,350 pounds they will probably be less efficient and fatter than desired. But, if fed to 1,200 pounds, those steers efficiency and fatness should be about the same as the 1,350-pound steer out of the 1,350-pound cow. The 1,200-pound steer should yield a carcass of about 750 pounds, certainly acceptable and even preferred for some uses. In short, for the cow/calf producer, even one retaining ownership through carcass grid marketing, there are more things that should determine optimum cow size than the desires of a feeder.

Handling and management of animal health products

Proper use of animal health products is essential in order to obtain maximum benefit. A study was conducted of 129 producers’ and 47 retailers’ refrigerators used to store products. Temperatures were recorded every 10 minutes for at least 48 hours; 31 percent of producers’ and 34 percent of retailers’ refrigerators maintained recommended temperatures in the recommended range of 2° to 7° C. >95 percent of the time. But 33 percent of producers’ and 17 percent of retailers’ refrigerators were in the correct temperature range <5 percent of the time. These results were similar to some other studies, but showed slightly lower compliance with temperature recommendations.

Among producers

  • 94 percent gave injections in the neck
  • 88 percent mixed modified-live vaccines only as needed and protected them from sunlight
  • 94 percent kept vaccines in a cooler
  • 88 percent read and followed labels
  • 72 percent kept vaccination records at least one year
  • 72 percent disassembled syringes to clean
  • 64 percent cleaned syringes with hot water only
  • 46 percent changed needles at least every 20 animals
  • 44 percent changed needles as needed

Among retailers

  • 67 percent trained employees to answer questions regarding products
  • 66 percent offered customers ice packs
  • 60 percent trained employees to handle products
  • 49 percent provided product information
  • 44 percent monitored refrigerator temperature with a thermometer but 41 percent did not
  • 40 percent provided ice to purchasers routinely
  • 29 percent provided ice and a Styrofoam cooler
  • 26 percent said ice and product information was the producers’ responsibility. (Prof. Anim. Sci. 29:313; Univ. of Idaho)  end mark

Dr. Stephen Hammack is professor and extension beef cattle specialist emeritus at Texas A&M University. This originally appeared in the Beef Cattle Browsing newsletter.