Effects of calves’ disposition in the feedlot

Effects of calves’ disposition in the feedlot
by Bonnie Warnyca - 10, 2011

Anything that affects a calf’s profitability is worth noting and according to an ongoing study conducted at 18 Iowa feedlots fed through the Iowa Tri- County Steer Carcass Futurity (TCSCF), various disposition traits affect the bottom line.

Using a Beef Improvement Federation disposition scoring system of one to six; 1=docile; 2=restless; 3=nervous; 4=flighty; 5=aggressive and 6=very aggressive or killers; researchers evaluated calf performance levels on over 13,000 calves. Cattle were disposition scored on-test, re-implant and during 1st sort and prior to 2nd sort for harvest. No calves were disposition scored on arrival.

Calves were divided into three groups based on disposition score: docile (DC), restless (R) and nervous to very aggressive (NVA). Retired Iowa State University (ISU) Extension Beef Specialist and currently TCSCF Cooperative Manager, Darrell Busby, said the findings recorded 72.4% scoring docile; 21.8% were restless and 5.8% were judged to be aggressive.

As the disposition score increased, final weights, hot carcass weights, ADG and marbling scores decreased while cost of gain increased (1.33, 1.48 and 1.51 USD/kg). NVA calves were less efficient (6.97 kg/kg) compared with D (6.86 kg/kg) and R (6.84 kg/kg) calves. The rib-fat was identical for DC and R calves (1.14 cm), but lower for NVA calves (1.05 cm).

Note: Wild cattle gain less and eat less. The N calves proved to be more efficient in the study because they have less fat cover and higher lean meat content.

Once the cattle were processed, the results showed a marked quality difference between the docile and restless and aggressive groups. The following chart shows the break-down into grades as well as the animals that qualified for the Certified Angus Beef program.

All in all, the docile calves had better feedlot performance, improved carcass merit and greater profitability than those calves that were more aggressive.

Disposition Summary:
Docile calves compared to aggressive calves were:

- Feedlot gain was reduced by 8.2%

- Feed/Gain as determined by the Cornell Net Carbohydrate Model was reduced by 1.8%

- % Choice or better was reduced by 15.9% points or 20%

- Standards were increased by 3% points or 115%

- Returns were reduced by $62.19

Note: Carcasses from more excitable cattle have greater tendency to produce less tender and more borderline dark cutters.

Busby and the team also identified that more than twice as many aggressive cattle died as compared to docile animals and cited a couple of reasons.

He says, “Pen checkers can miss some of the early signals of a calf that is getting sick. Nervous calves most likely do not look depressed when they have their head up and watching every movement. It’s also human nature to leave a wild animal alone for a day or two hoping they will improve.”

“In the last few years and since this study came out, there are now as many wild animals pulled due to sickness as the docile calves. The death losses unfortunately are still the same and are still double that of docile animals.”

The study also included heifers and in the beginning researchers found that there were more disposition problems in heifers. It makes some sense, since feeder heifers are non-replacements and they tend to have wilder dispositions, are either too large framed or too small framed which affect the final numbers. All round, the researchers have found that both steers and heifers over the past five years tend to have less disposition problems.

An animal’s disposition is inherited and influenced by management
While a calf may enter the feedlot pegged as an R or an NVA, there are ways to reduce their level of stress.

Recommendations to reduce the stress for feeder calves include no hot shots or drastically reduce the use of hot shots; use solid-sided alleyways; use a tub or a Bud William’s designed box where a handful of calves are let in at one time and then sent down a single-file alley.

“Most feedlots go through the low stress handling training which has helped to effect positive change,” says Busby.

“One of the most effective ways to reduce stress handling is to reduce the noise. No yelling by the handlers and using rubber-mounted chutes made a huge difference on the level of stress felt by the cattle. In fact, the work on reducing the noise around these cattle was originally done in Alberta and we continued using some of those findings in our study.”

The Tri-Country Carcass Futurity is a cooperative for cow/calf producers that retain ownership through to slaughter. In the past ten years, the group has fed roughly 76,000 head. Feedlots must bid to feed these animals. The Futurity is run by a board of ten directors including cow/calf producers, a veterinarian, pharmaceutical rep and a Certified Angus Beef feedlot specialist. Futurity staffers continue to collect the data and develop reports for consignors.