Customized Selection Indices for
Specific Production Systems and Markets

M.T. Lazenby, S.P. Miller and J.W. Wilton
Center for Genetic Improvement of Livestock
Animal and Poultry Science, University of Guelph

Summary

Economic selection indices are used to identify the bulls and cows that have the greatest potential to return the most profit to an integrated beef production enterprise. Customized economic selection indices offer the next phase of index selection by matching the index model to the specific production and marketing situations of individual farms. The development of customized selection indices will enable cow-calf producers to select animals which best suit their operation, management style and production system. An overview of the customized economic selection index, currently under development at the Centre for Genetic Improvement of Livestock (CGIL), is provided.

Introduction

Economic selection indices are used globally to improve the genetic potential of most commercial livestock species. Indices are based on the economic situation the product is produced in and consider all revenues and costs of the production system. Beef Improvement Ontario (BIO) has recently introduced two selection indices, developed at CGIL, for use by Ontario producers when selecting bulls completing the Bull Evaluation Program.

Often when selecting an animal for breeding purposes, such as a herd bull, producers are faced with genetic information on many important traits. Some of these traits include birth weight, growth traits such as feed intake and weaning and post weaning gain, maternal traits and carcass traits such as backfat and intra-muscular fat. Most likely, no bull will be outstanding in all of these traits. When deciding on which bull to buy the buyer is forced to make trade-offs on which traits they feel are most important and beneficial. Economic selection indices helps the decision making process by providing balance to the various traits. This is done by calculating the correct amount of trade-off between the traits based on the revenue they generate and cost of production. An example of one trade-off between traits would be a bull that has excellent growth potential but also a higher expected birth weight in his progeny. On one hand we would expect increased profit from the increase in growth through fewer days to market, less feed consumption and perhaps increased carcass weight. However, the increased birth weight will increase calving difficulty and the frequency of harm or death to the cow and/or calf leading to a decrease in the profit of the farm. Economic selection indices balance this trade-off by placing the proper economic value on each trait considering the costs and returns to the farm operation.

Each farm operation is different from the next. For example, some farms may produce all of their own herd replacements, sell replacements, or buy all of their replacement heifers. Also, different farms will produce market calves for sale under different production systems between weaning and slaughter. As well, the opportunity to sell market animals to a specialized or niche market because of specific qualities of the carcass may provide increased revenue. These differences change the economics of the operation and change the economics under which the selection of sires and cows should occur. Customized selection indices offer this extra level of compatibility for producers to ensure the right animals are selected for their individual situation.

Materials and Methods

Information provided by each individual farmer is the foundation for the customized economic selection index. Information regarding herd size, predominant breed of the herd, genetic averages of the herd, calving rate, replacement rate, feed costs and the production and marketing system used for the weaned calves (direct to feedlot; backgrounded on hay and then to feedlot; backgrounded on hay, pastured for summer then to feedlot) is included in the animal selection process. The producer also decides which final market is being targeted for their cattle. The target market could be a specialized or niche market or a more standardized market such as one that requires a large lean carcass with A marbling, such as the grocery store, or one requiring a light weight carcass for smaller cuts with AAA marbling desired by restaurants.

The genetic information gathered on bulls at Bull Evaluation Centres across Ontario provide the inputs on the bulls which are best suited for each farm operation. The traits considered for selection are those included in the genetic evaluation of bulls in BIO's Beef Herd Improvement Program (BHIP) and the Bull Evaluation Program (BEP). Expected Progeny Difference/Across Breed Comparison’s (EPD/ABC’s) are provided for each trait allowing bulls to be compared for additive genetic merit despite breed. Information regarding birth weight, direct weaning gain and maternal weaning gain is supplied from the BHIP. Traits evaluated in the BEP are post-weaning gain, feed intake, backfat at end of test, rib-eye area at end of test, and scrotal circumference at end of test.

The Ontario Farm Management Accounting Program and market information sources provide economic information for the selection index computer model. In the model revenue is generated through cattle and cull cows sales. Calculated costs include pre-weaning and post-weaning fixed and variable costs. Among the variable costs considered for the cow-calf operation are veterinary costs associated with changing birth weight, feed costs in the herd associated with changing growth of the calf and costs associated with increases in milk from the cow and increased mature cow size and level of cow fertility. Variable costs in the feedlot include feed and yardage. Days on feed are predicted to account for yardage and maintenance feed costs. Feed intake in the feedlot is estimated from predicted weight gain in the feedlot, days on feed and predicted feed to gain ratio as calculated in the BEP.

Results and Discussion

The information provided by the producer is used to develop a computer model of the beef herd. The genetic information from each bull is then introduced into the herd model. Based on the economic information and calculations present in the model a Predicted Dollar Difference (PD$) is calculated for each bull. PD$ represents the expected extra dollars of margin (revenue - costs) the bull would return compared to the margin returned by an average (ABC’s = 0) bull. A list of the bulls, which best suit, the producer’s situation, from all evaluated bulls in the province, is then provided. Initial results have shown significant differences in the bulls chosen depending upon the production system used and the market produced for.

The computer model of the herd would also consider the numerous variables of the farm's production system and match bulls to optimize the various management options. For example, if a producer was backgrounding calves before sending them to the feedlot the computer may indicate that Bull A would provide the most profit potential. However, if the management system changed such as animals were sent straight to feedlot, then Bull B would be the best bull for the situation, even more profitable than Bull A under the initial management program of backgrounding followed by feedlot. In this way the genetics of the herd are optimally matched to the management programs to maximize profit.

Significance to the Industry

Customization of index selection principles would have a major effect on the province's beef producers. Matching the genetics of the animals in a herd to the management, production and marketing situation will improve the profitability and efficiency of the beef operation and optimize genetic levels for individual producers.

Acknowledgements

Funding from the Natural Sciences and Engineering Research Council and Beef Improvement Ontario is greatly appreciated.