BREEDPLAN and The Bull Buyer

The Bull Buyer’s Dilemma

Buying bulls at multivendor sales can be difficult. It is hard to tell if some stock looks better because of the feed they are on or because they are genetically superior. Certainly, you can visually check structural aspects, temperament and other characteristics, and you may have had experience with some studs or sire lines. A better indicator of likely breeding values, for example on growth rates, milking ability, carcase attributes, female fertility and feed efficiency levels, would be of great help when considering desired characteristics in progeny.

Buying bulls on a property allows better comparison within that herd, but how do you compare these cattle with cattle from other herds?

BREEDPLAN Can Help

BREEDPLAN is the Australian and international beef cattle performance recording and evaluation scheme. It has been available since 1985, and there are now more than 2000 seedstock herds enrolled in Australia. Almost 40 beef cattle breeds are represented.

As a testimony to BREEDPLAN’s international standing, most of the New Zealand stud industry is now enrolled, together with the Hereford, Salers, Braunvieh and Shorthorn associations in the United States, and several breeds in South Africa. There are also enrolled herds in Canada, Europe, Thailand, Argentina and Mexico.

Calculation of Breeding Values

BREEDPLAN is a computer-aided system for estimating the breeding values of cattle — hence the estimates are called estimated breeding values (EBVs). This is done by measuring the performance of individual animals, for example for growth, calving ease and carcase attributes, and comparing this performance with that of their contemporaries run in the same conditions. This is, of course, an age-old technique.

What is clever about BREEDPLAN is that sophisticated computer programs are utilised to incorporate information from pedigree records, thereby allowing much more than just the information on an individual animal to be used. The known performances of relatives (parents, brothers, sisters and progeny) are included in the bank of information in order to improve the accuracy of an EBV.

Data on trait correlation is also used. For example, we know that weight gains to yearling and to 2-year-olds generally ‘go together’. If, for example, two bulls weigh similarly at yearling but differ at 2 years of age, the initial yearling EBVs are adjusted a little because BREEDPLAN ‘suspects’ that some random non-genetic events may have influenced the yearling weights. This is later confirmed or otherwise by the performance of progeny, and the EBVs may be further adjusted. However, only EBVs produced in the same BREEDPLAN analysis can be directly compared.

In these and other ways, increasingly accurate estimates of breeding values are progressively made.

Bull Selection Exercises

• Exercise 1: Growth, Milk and Mature Weight EBVs
• Exercise 2: Fertility EBVs
• Exercise 3: Carcase EBVs
• Exercise 4: Calving Ease EBVs, and accuracy

In the exercises that follow, assume that bulls are sound and fertile.

For simplicity, accuracies are not given in Exercises I, II and III; however, they are used in Exercise IV and are discussed in detail in other Agnotes in this series.

Growth, Milk and Mature Weight EBVs

Exercise 1

Three buyers (buyers 1–3, see below) are selected from the sire list given in Table 1. Which bull should each buyer choose?

Buyer 1 sells vealers but also breeds replacement heifers. Increasing the level of milk production in this herd would improve profitability.

Buyer 2 wants to increase yearling and final weights and avoid calving difficulty. The main product is heavy steers. Replacement heifers are retained.

Buyer 3 is straightbreeding in a harsh environment where cows with high EBVs for milk are slower to rebreed. Large mature cow size is also not favoured. Increased growth rate in 2-year-old steers is sought.

Fertility EBVs

• Scrotal size (SS) is an indicator of male fertility. More important, bulls with a high Scrotal Size EBV are known to breed females that are more fertile. Scrotal Size EBVs are given in centimetres. Bulls with high figures will breed sons that have a bigger scrotal size and daughters that have earlier puberty and shorter calving intervals.
• The female fertility trait, Days to Calving (DC), is also available for breeds providing the necessary joining and calving information. Days to Calving EBVs predict the interval between commencement of joining (or artificial insemination) and calving. Sires with negative Days to Calving EBVs are preferred, as they will breed daughters that have shorter calving intervals.

(Note that ‘Calving Ease’ and ‘Gestation Length’ EBVs are also being provided by some breeds — see Agnote DAI-303 Calving ease EBVs.)

Exercise 2

Using the catalogue example given in Table 2, advise each buyer (buyers 1–3, see below) on bull choice. Assume all bulls have adequate scrotal size for the current mating load.

Buyer 1 has a commercial purebred herd turning off 2-year-old steers and seeks to improve female fertility while maintaining heavy steer weights.

Buyer 2 intends to use the bull as a terminal cross-over crossbred cows, selling both the heifers and steers as finished yearlings.

Buyer 3 wishes to increase the scrotal size in this stud herd. Yearling bulls are sold; in the past, some have been marginal for scrotal size. This buyer’s clients are predominantly breeders of yearling steers.

Carcase EBVs

BREEDPLAN is also actively involved in collecting data on carcase traits. Commercial scanning services accredited by breed societies are available to measure the following on live cattle:

• Rump and Rib Fat Depth
• Eye Muscle Area (EMA)
• Intramuscular Fat Percentage (IMF%)

Most breeds produce the above EBVs, along with the following EBVs:

• Carcase Weight
• Retail Beef Yield Percentage (RBY%)

Wherever possible, BREEDPLAN also collects abattoir carcase data, particularly on marbling and other meat quality factors, to contribute to these EBVs. Overseas information on sires of some breeds is ‘imported’ to further strengthen the Australian analysis.

The improvement of these carcase EBVs has recently accelerated, as data from the Cooperative Research Centre (CRC) has contributed to the design of the BREEDPLAN Carcase EBV system used since 1999 (all CRC cattle have BREEDPLAN links). Since 2000, Carcase EBVs have been predictions of the differences expected in a 300kg steer carcase, that is, at a weight endpoint  (rather than to the ‘age end point’ used up until 1999).

Exercise 3

Table 3 gives Carcase trait EBVs for a selection of sires from a British breed catalogue. Which bull should each of buyers 1 and 2 buy?

Buyer 1 sells yearling steers to a feedlot which is long-term feeding for Japan, and has been advised to increase size and growth to 2 years, reduce fatness, maintain or improve muscularity, and improve marbling.

Buyer 2 breeds yearling steers from European × Dairy cows. This buyer has difficulty in finishing yearling steers, and seeks to improve on this.

Calving Ease EBVs and Accuracy

Calving Ease EBVs are currently available for several breeds, with other breeders collecting data for later analysis. These are developed from birthweight, gestation length and calving ease records.

Calving difficulty is scored by the breeder. The scores differ a little according to the breed. They are generally:

• no assistance;
• light pull;
• hard pull; or
• caesarean.

Calving Ease EBVs are expressed as:

• percentage greater (+); or
• percentage lesser (–);

than calving ease for base animals. That is, positive figures (+) indicate better calving ease.

Exercise 4

In this exercise, percentage accuracy figures are also given.

Advise the following buyers on their bull choice according to the information given in Table 4.

Buyer 1 seeks a terminal sire to join with crossbred heifers for yearling production. Calving ease is of moderate importance.

Buyer 2 is straightbreeding for yearling production and wishes to improve calving ease of the females.

Buyer 3 is straightbreeding and seeks a sire to join with heifers. Calving ease is of considerable concern to this breeder of grass-finished yearlings.

BREEDPLAN’s Role in Artificial Insemination and Embryo Transfer

As well as assisting bull buyers, BREEDPLAN also plays an important role in the fields of artificial insemination (AI) and embryo transfer (ET). These techniques result in ‘superior’ genetics being quickly spread, so it is imperative that only top cattle are used. Whether it is growth rate, fertility, carcase traits or calving ease that is important to the bull buyer, BREEDPLAN will greatly assist in the identification of suitable cattle.

Answers to Exercises

Exercise 1

Exercise 2

Exercise 3

Exercise 4

Further information

See other Agnotes in this series for further information on BREEDPLAN and EBVs.

About the author

Brian Sundstrom is Cattle Breeding Coordinator with NSW Agriculture. Part of this role involves technical specialist and advisory work with BREEDPLAN from an office at the Agricultural Business Research Institute (ABRI) at Armidale. His other role is with the Beef CRC group.