April 13, 2024

Weekly Genetic Review: Are Bull Breeders Collecting the Right Performance Data?

SELECTION for improvement within a beef herd or breed depends on several factors.

The first is to have access to information that allows an individual producer to assess where the top and bottom levels of performance lie within a chosen group of animals. In its simplest form, information can be as basic as a visual observation of a group of animals. At the other end of the scale, information may include visual observations, performance, and genotypic data.

The intention in this process is to identify the animals that presented the highest level of genetic and phenotypic merit for the chosen characteristics and maintain them as a focus for reproduction and performance improvement. Increasing the amount of information helps to increase both the precision and the confidence that a producer will have in their choices.

Even at the basic level, where producers can select livestock visually, it is very rare for this to be the only source of information. Invariably there will be a sheet of paper that may have weaning weights and often some backstory such as a heifer calf, a late calf as a result of a longer calving or other information that helps interpret the visual assessment being performed. .

In many cases, this approach is part of normal evaluation and selection practice, such as when producers may be considering which heifers to retain for membership.

When it comes to bull selection, a greater amount of information is needed to make accurate decisions. Again, the level of information that can be provided to guide a bull selection decision varies from raw data and visual selection to the inclusion of performance and genotype information.

EMA Scan Questions

Some recent comments from Beef Central readers have raised questions about the collection of some of this information and the value it can provide to growers or seed breeders. One of the main questions raised was the value of the data collected and provided at the time of sale to the Ocular Muscle Area (EMA) of bulls of different breeds.

In the experience of the producer who made contact, there was a feeling that the EMA data had increased by 30 cm2 over a period of ten years. The issue is that this was perhaps related to digitalization and not actual genetic enhancement. If this were the case, producers’ concerns focused on the value of this data to buyers and its usefulness in selection decisions.

The challenge of using data is firstly understanding what the data describes. As red meat producers, there is a desire to increase the amount of salable red meat from each animal sold.

Selecting a larger EMA size, measured in square centimeters, is a focus for many growers. Identification of animals with higher EMAs is possible and can be done in several ways.

Information provided directly from an ultrasound scan – raw data – needs to be used with some caution

At the most basic level, there is a visual selection of the muscle volume that an animal (or its progeny) presents. However, the widespread use of ultrasonography has allowed almost all bull breeders to collect and provide data to potential customers on this trait, as well as use the data to contribute to programs of recoding performance and improving estimated breed values.

Information provided directly from an ultrasound scan – raw data – in other words, needs to be used with caution. The level of caution needs to be increased in some circumstances, especially in events such as multi-vendor sales.

Raw data is just that. This is data collected about an animal at a single moment. These data reflect both the genetic potential of the animal and the environmental conditions in which the animal was raised.

Separating the main influences (genetic or environmental) behind a set of raw data is virtually impossible to do in the field or in sales. In addition to these two main factors, there are additional influences on the raw results, ranging from the animal’s age to its actual weight. Raw data can provide a point of comparison with two bulls in a pen. But estimating their genetic merit and the contribution they can make to a herd is much less useful.

The additional risk, especially in a multi-vendor sale or other event that uses only raw data, is that this data does not truly represent what is happening in a breed.

Increased sizes, or sale weights over a period of years, do not actually mean that the breed as a whole is increasing (or decreasing) in these traits. There may well be other localized factors at play that impact the observed trends.

Again, these factors can range from environmental issues (like the season in the local area) to something as simple as a new supplier coming in with a larger offering and a different phenotype, which can change the average raw data. sales.

In some cases, the change in EMA may even be due to raw data collected at a different location in the eye muscle, or by a different scanner, such as the 10/11 rib rather than the 12/13 rib. Again, without knowing these details, making an assumption about a trend is not as valid as it may have initially been considered.

It is in these circumstances that performance records, and particularly BreedPlan EBV, become most useful. Although they cannot be used to compare the breeds that may be offered in a multi-vendor sale, within the breeds themselves a comparison is possible.

BreedPlan EBVs are standardized at the 12/13 rib to a standardized Warm Standard Carcass Weight (HSCW) measured at 650 days of age. In terms of selection, the objective is to find an animal with greater genetic merit and use it to improve the herd. In the case of EMA, the intention is to improve future progeny, so genetic merit as described by an EBV will be more useful than the raw data from EMA bulls at the time of sale.

Ultrasound scanning has proven extremely useful in identifying animals and collecting data to support successful selection. However, raw data, whether collected by weighing an animal or scanning to assess AME or fat, is less useful in making long-term herd improvement decisions.

The raw data should be seen for what it really is, a measurement at a particular point in time for that animal.

While it is easy to ask whether bull buyers or breeders are getting the correct information, perhaps a better question should be “are breeders using the information in the correct way?”

Alastair Rayner is a director of RaynerAg, an agricultural consultancy service based in NSW. RaynerAg is affiliated with BJA Stock & Station Agents. He regularly lists and sells cattle to clients, as well as participating in bull sales to support client purchases. Alastair provides pre-sale selections and ratings to seed growers in NSW, Qld and Victoria. He can be contacted here or through his website www.raynerag.com.au

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