Using Bull Gain Tests


2016 RGVBCA Bull Test ultrasound-webWritten by Joe C. Paschal

When I was an animal breeding graduate student at Texas A&M back in early ‘80s, the philosophy was that there was not much to be gained from bull testing, especially if the purpose was to select for the fastest gaining bull on feed (which would in turn be selecting for bigger and bigger – but not necessarily more productive cattle). I don’t know if others thought this way but I certainly agreed with this philosophy, and still do. However, in the years since, bull testing has gotten to be more than just feeding bulls to gain the most weight in the shortest period of time possible.

In 1979 when I worked for the American International Charolais Association in Houston as their Director of Breed Improvement (and Foreign Marketing) it was my responsibility to review the bull gain tests across the US and report on the results of Charolais (and Charbray) bulls in those tests in the Charolais Journal . At that time most of the tests were run by universities or colleges with animal science or agriculture departments and were 140-day tests that measured total or average daily gain. Some measured hip height or frame score and a few included scrotal circumference. Most of these tests were on feed in a test station or a feed yard but a few were on forage, notably one in Dothan, Alabama run by the local county extension agent. Forage tests depended on rainfall to produce forage and it was a good one but even today the majority of gain tests are still some sort of grain feeding program.

As an Extension Livestock Specialist I have been working with several bull tests for almost 30 years. Some are still being conducted, others shut down and new ones begun. One of the oldest was the Jim Wells County Bull Test which was begun near Alice, Texas in the early 1950s. It was being conducted at Chapparosa Ranch near La Pryor when I got back to South Texas in 1988. The bulls were fed in large traps to allow them to exercise. It moved around to several locations but at its highest point in numbers we tested over 400 bulls of several breeds (Beefmaster, Brahman, Brangus, Hereford, Santa Gertrudis, Simbrah to name a few) for a 140-day feeding period. In addition to gain data we collected hip height, scrotal circumference, sheath scores and pelvic area. Later, ultrasound measurements were added. Initially ribeye area (REA) and fat thickness were collected but later marbling score or intramuscular fat (IMF) and rump fat were included. Rump fat is considered a measurement of adaptability in females but affects cutability. This test was run by a group of dedicated committee members (all cattlemen) and headed up by the county Extension agent. It was discontinued in 2004 as interest waned and the committee had been reduced in size due to age.

A second long running bull test that I am associated with was initiated in 1998. The Rio Grande Valley Beef Cattle Association (RGVBCA) is made up of Rio Grande Valley purebred breeders and headed up by the county extension agents in Hidalgo, Cameron, Willacy and Starr. It has tested 1,246 bulls from 328 consignors across Texas representing several different breeds. These bulls are measured for gain plus frame, scrotal circumference, pelvic area, sheath score and ultrasound REA, fat thickness, IMF and rump fat thickness. This test is run at Rio Beef Feedyard at Linn, Texas. At the same time as the bull test, the RGVBCA offers a heifer development program which lasts 90 days. Data collected on the heifers includes ADG, frame score, pelvic area, navel flap score and reproductive tract score. Finally, the program also offers a steer feedout program (since 2010) that allows consignors to feed and collect feeding and carcass data on their cattle.
Over the years there have been changes. Bulls are fed for only 112 days, since research has shown that rankings for gain don’t change much if you feed 28 days more. It also saves on feed costs. Over the past several years there has been a lot of interest in docility scoring (flight or chute exit speed, chute scores and pen scores). Dr. Courtney Daigle, Assistant Professor of Animal Science (Animal Welfare) at Texas A&M University, and I used pen scoring to evaluate the Brahman bulls in the ABBA Bull Test at Texana Feeders. Also, most bull tests use some sort of a ratio or weighting of traits to develop an index to compare bulls of the same breed and age group, rather than just ranking the biggest or fastest growing.

In a couple of instances my interaction with a bull test was short-lived or late off the mark. I remember one late night phone call from a consignor at a new regional bull test complaining of foundered feet, bloat and even deads when some eared breed cattle were fed high levels of ground corn in their rations. Not only was the ground corn contributing to the problem but it was also well above the FDA threshold for corn containing aflatoxin that could be fed to breeding cattle (100 ppb is the limit, and this was well above that).

Some bull tests begin on forage and measure gain there, and then finish the cattle on grain at the same or a different location. Not surprisingly, cattle gain different and rank differently at each location or ration.

Preparing bulls for testing is important. Most tests have health recommendations for vaccinations, internal and external parasite control and some have a requirement for a veterinary inspection or health certificate. This should be done well in advance and that includes any stressful activities such as dehorning or branding. Bulls should be healed from these actions before being sent to a test facility.

In some tests, bulls can be fertility tested (Breeding Soundness Examination or BSE) as part of the test or before being shipped home or to an after the test bull sale. Genetic testing is also conducted, for production traits as well as genetic recessives. In the past few years some bull tests have incorporated the Grow Safe System® to measure feed efficiency (actually Residual Feed Intake or RFI). This requires an extended adjustment period, frequent weighings and an RFID tag in the ear. As a measure of feed efficiency, the RFI is not related to other production traits so selection to improve it should not increase size on the average. A negative RFI (less feed consumed per pound of gain than expected) is desirable. All of these can be added costs but if bull buyers are willing to pay for it, then it is money well spent. Bull testing is not cheap but most offer the ability to collect a lot of useful data, including genomics results, in an inexpensive and timely fashion. Most of us won’t have all the equipment that is necessary or the ability to buy feed in bulk.

There are a number of bull gain tests that Brahman breeders can participate in and would be welcome at in Texas and across the Southern US. Some might be conducted by Brahman breeders, such as the ABBA Bull Gain Test at Texana Feeders near Floresville, Texas. Some Brahman breeders conduct their own on-the-ranch tests. The Genetic Development Center near Navasota, Texas, regularly conducts bull tests that include RFI determination. There are also tests run by producers of other breeds like Tom Brothers Ranch near Campbellton, Texas. Ellen Tom and her family have been testing Simbrah, Simmental and Beefmaster bulls for several years and wse one of the sites considered for the ABBA Program. There are other feedyards, including Graham Land and Cattle Co. Feedyard near Gonzales, Texas (the site of the ABBA Feedout Program for many years) that have a long history of testing bulls. They conduct the Braford bull test for United Braford Breeders. Each may collect and report data for different traits; you have to decide which is best for your selection goals.

Bull testing is a tool, much like scales, a breeding soundness examination or a genomics test. In itself it gives you an idea of the performance level for a series of traits but the results need to be combined with all the data before any selection decision is made.


Pruebas de ganancia de Toro da a los criadores de Brahman la oportunidad de desarrollar sus toros en condiciones estandarizadas y recopilar datos de rendimiento que no normalmente pueden ser capaces de recoger o pagar. La mayoría de las pruebas de ganancia toro recogen datos para calcular el rendimiento de peso (GDP o peso al día de edad), marco de cuerpo,la circunferencia escrotal y el área costillar de ultrasonido, el espesor de grasa y grasa de cadera. Además, algunas pruebas de ganancia toro, como el realizado por ABBA asignarán puntajes de disposición, realizar pruebas de ADN y realizar exámenes de solvencia de cría. Algunos criadores podían permitirse el lujo de tener todas estas mediciones y pruebas llevadas a cabo de manera oportuna y alimentar a los toros durante 112 días. Los resultados de estas pruebas deben ser utilizados para equilibrar rasgos, hay un rasgo debe ser el único criterio de selección, pero cada rasgo debe ser ponderada por su valor económico al utilizar los resultados en un programa de selección.