Cow temperament tied to production

The personality of livestock may seem secondary to productiveness, but research shows the two may be connected.

In a study at the Brown Loam Research Station managed by Mississippi State University, researchers have studied the link between a cow’s temperament and performance. Rhonda Vann, research professor in the Department of Animal and Dairy Sciences and at the experiment station, pioneered work on this front.

“For the past decade we’ve been trying to determine whether cattle temperament is related to growth performance and immune function, and if temperament is inherited by offspring,” Vann says.Her research has found poor temperament to have a myriad of negative effects on performance.

To assess temperament, scientists conduct two tests. First, the cow is put into a pen and approached by the researcher. Calm animals move slowly and can be approached. Aggressive or temperamental animals may run into fences or even attempt to trample humans in the pen. Based on this interaction, the cow is awarded a pen score of 1 through 5 (1 being calmest, and 5 being most temperamental).

Next, they are scored on their flightiness. Each animal is herded into a chute and timed as they leave it over a fixed distance of 6 feet. The resulting time is their exit velocity. Finally, both scores are averaged to determine overall temperament. Extremes either way can be problematic.

“Very docile animals don’t fight to get through diseases. They’re down on the ground with the first symptoms and require more veterinary care. Temperamental cows, on the other hand, won’t show any symptoms until they’re too sick to treat,” Vann explains. “You want the in-between cows that show illness early enough to be treated, but have enough fight to survive.”

The project also indicated temperament is inherited. In a study conducted with Brahman-influenced calves, researchers found that temperament can be passed to offspring. The researchers found that pen scores and exit velocities were correlated to the amount of the stress hormone, cortisol, circulating in the cow’s blood. Thus, each calf was likely to have inherited a temperament similar to its parents, allowing for genetic selection.

In conclusion, cattlemen can affect overall profitability by assessing the temperament of their cattle and culling those animals that are problematic.

Selecting trace minerals for receiving

Trace minerals have many physiological functions in beef cattle, including vitamin synthesis; hormone production; enzyme activity; collagen formation; tissue synthesis; oxygen transport; energy production; and other physiological processes related to growth, reproduction and health. Thus, trace minerals must be supplemented to beef cattle diets when forages and rations are deficient or have incorrect proportions.

Traditionally, trace minerals in animal feed are categorized as either inorganic (primarily sulfate and oxide forms) or organic. “Organic” simply means the mineral is bound to an organic material, generally amino acid complexes, proteinates, chelates, polysaccharide complexes and propionates.

Issues associated with health and management of newly received cattle continue to pose significant challenges to the beef industry. Shipping fever, or bovine respiratory disease complex (BRD), accounts for about 75% of morbidity and 50%-70% of mortality in U.S. feedlots. The incidence of BRD is greater within the first days after feedlot arrival (receiving period); usually the first four to eight weeks in which relocated beef cattle adjust to their new environment.

University of Arkansas research investigated the effects of inorganic or complexed sources of trace minerals (zinc, copper, manganese and cobalt) on beef heifer growth performance, morbidity and mineral status during a receiving period.

In this study, 287 crossbred beef heifers [509 pounds (lb.)] arriving on three delivery dates were used in a 42-day receiving trial. Heifers were processed after arrival, stratified by Day -1 body weights and allocated randomly to eight pens (11-13 heifers per pen, 24 pens total). Within truckload, pens were assigned randomly to dietary treatment (12 pens per treatment).

Heifers were housed on 1.04-acre grass paddocks, provided ad libitum Bermuda grass hay and provided dietary treatments in grain supplements fed daily. Treatments consisted of supplemental zinc [360 milligrams (mg) per day], copper (125 mg per day), manganese (200 mg per day), and cobalt (12 mg per day) from complexed (Zinpro Availa® 4) or inorganic sources (sulfates). The heifers were observed daily for clinical BRD.

There tended to be a treatment-by-day interaction for body weights. Body weights were not different on Day 0 and Day 14, but heifers supplemented with complexed trace minerals had greater body weights on Day 28 and Day 42. Calves receiving complexed trace minerals were 9 lb. heavier than those receiving inorganic sources by Day 42.

Supplementing cattle for the first 42 days with complexed trace minerals resulted in greater overall average daily gain (ADG) than supplementing with inorganic sources (1.72 lb. vs. 1.54 lb.). Heifers supplemented with inorganic trace minerals had greater BRD incidence (58% vs. 46%).

In conclusion, in this study, replacing inorganic sources of trace minerals with complexed sources of trace minerals (zinc, copper, manganese and cobalt) improved growth performance and decreased morbidity treatments and associated medication costs during the 42-day receiving phase. Trace mineral source had no effect on liver mineral concentrations during the 42-day receiving trial.

The researchers note, “These results demonstrate the variability observed in trace mineral concentrations in [the liver] and highlight the continued need to better understand factors that influence liver mineral concentrations. These calves experienced stress through sale barn exposure, commingling and transportation, which may have influenced differences in trace mineral source bioavailability.”

These data were obtained from a research update published by Oklahoma State University.