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  1. Bryan Corrigan describes how he developed the Rennylea herd from a commercial base and always refers to commercial functionality as the basic selection criteria.
  2. The Breeding goal is integral to improving overall herd performance, and Bryan has had a long term vision for the herd which is fine tuned when new tools become available.
  3. Commercial returns are based on the amount of beef produced per hectare, rather than per head, and moderating cow size is integral to optimising returns.
  4. Measurement is a key tool in improving the hard to measure traits, the great success story for Angus cattle has been the improvement in carcase performance since measurement was introduced in 1998.
  5. Ruth Corrigan describes how recently, genomics has become a new tool to improve the accuracy of measurement at a young age, and the level of integrity and commitment of the Rennylea team.



RENNYLEA Angus is a family grazing business based in the Murray Valley in Southern NSW. Settled by the Corrigan family in 1870, Ruth and Anthony Corrigan are the fifth generation of the Corrigan family to work in the business, working with their parents, Bryan and Lucinda Corrigan. Angus cattle were introduced to Rennylea in 1952, Bryan commenced artificial breeding in the herd in 1974, and Rennylea Angus was enrolled in Group Breedplan when it commenced in 1985. Today there are 1,500 cows in the herd, and a total of 3,500 cattle on 7 properties located at Bowna and Culcairn.

The Rennylea herd vision is to be a supplier of elite genetics that meets our customers’ needs in a quality driven, profitable and ethical value chain.

The Rennylea mission: “Rennylea Angus are a package of genes designed to lower cost of production and increase net profit per hectare creating a product that meets high quality market specifications.”

In a cow / calf operation, depending on the age and weight of turnoff, between 60 and 80% of dry matter consumed by the herd is maintaining the cow herd. So when we look at beef production on an enterprise basis, it is a paradigm shift from looking at individual animal performance, to a per hectare approach . These 2 approaches are fundamentally different. An average of 70%, consumed by the cowherd, means that only 30% is consumed by the portion of the herd which produces the high quality young product, steers and heifers.



  1. Optimum performance, not maximum: Too much is made of maximizing performance. When one looks at enterprise performance, a different perspective is gained with the realization that kilograms of beef per hectare, produced efficiently makes one appreciate cattle that must work under pressure in variable seasons. The cattle that will work will be moderate framed, moderate to low birthweights, with above average growth.
  2. The Cow Factory must be efficient: Efficient, functional, fertile cows. The moderate farmed cow will rebreed quickly and calve without any fuss. We define high fertility by the Average Day of Conception, ADC. Set the herd up for life by:

The crux of an efficient cow herd is:

*joining cows and heifers for a maximum of 6 weeks, after culling empties and minimum culling of heifers.

*AVERAGE DAY OF CONCEPTION should be less than 20 days across the herd. At Rennylea Day 15 is the ADC.

*bulls fertility tested and structurally sound
*emphasis on moderate mature cow weight, slightly positive fat
*no tolerance of dystocia, moderate to low birthweight estimated breeding values.



Twenty years ago, ultrasound scanning became available which enabled the performance industry to start changing the genetics for carcase quality, fat and muscle. Rennylea commenced selecting for intramuscular fat, EMA and optimum fat cover to optimise carcase performance, and maternal performance.

Along the way we have learned that it is possible to develop a very high marbling herd without costing grass, in other words, marbling is a ‘free’ trait.

The average marbling and eye muscle area profile in the Rennylea herd is in the top 5% of the Australian Angus database. The exceptional carcase performance enables Rennylea clients to access premium market and achieve preferred supplier status.

Finally, the optimum carcase size for high quality beef cattle in Australia is higher than in previous years. Currently buyer consensus is that an average carcase of 325 kg is the target for domestic and international markets.

This has influenced the Rennylea breeding goal. The cattle are designed to have below average birthweight, calve easily, grow very quickly to 400 days and have a moderate maturity pattern. Rennylea has a unique genetic profile where the 400 day performance is similar to the mature cow weight, even though the 600 day performance is above breed average.


The best way to measure the efficiency of our production system is through financial benchmarking. All financial data is fed into a standardized collection system and at the enterprise level, fixed costs are apportioned to each enterprise. This has enabled us to fine tune the profit, measured on a per hectare basis for our clients

The challenge in the genetics industry is to create sustainable profits for the commercial producer, and the supply chain. The Rennylea genetics herd runs on pasture, aiming for a sustainable, perennial, pasture base. The cowherd is evaluated for its efficiency to produce and reproduce under restricted feed. Maternal genetics have a profound effect on productivity and profitability.


For commercial producers the useful figures are Cost of Production per kilogram beef, labour efficiency, enterprise profitability.

Using genetics from Rennylea who has a tight fertility management program, large management groups and a clear breeding goal, gives genetic gain in the commercial traits and adds high market suitability for grass and grain fed value chains.

IT'S A NO BRAINER!  Genetic improvement is cumulative and permanent and Rennylea has a very clear breeding goal.

Features and Benefits of the Rennylea Herd.

  • Commercial focus since 1952, giving you confidence in the tight management focus
  • Clear breeding goal, no fads or short term diversions that detract from genetic improvement
  • Below average birthweight, fast growth to 400 days, >growth to 600 days, moderate maturity pattern, slightly positive fat, elite EMA and Intramuscular fat (top 4% on 1400 calves)
  • Use of artificial breeding, AI, ET, to multiply superior maternal and paternal genetics in 6 week joinings and calvings – unique in large scale global ET programs
  • Impeccable performance recording, all phenotypes and genotypes measured every year, data you can trust, genetic trends published in every bull catalogue giving full transparency
  • Large management groups with tight calving, to increase the accuracy of the genetic predictions
  • Every cow assessed every year for structure, type and performance to ensure sound phenotype
  • Five star herd for completeness of recording, recognised by peers
  • Low birthweight and calving ease
  • Top 5% herd for marbling and eye muscle area, to meet high quality market specifications
  • Moderate phenotype, well muscled and structurally sound for phenotypic appeal
  • Quality Assurance, JBAS8, LPA, 5 Star Group Breedplan, every animal is DNA parent verified in addition to their genomics performance traits
  • The Rennylea Point of Difference, Australia’s highest Angus marbling and EMA herd combined with high fertility genetics

We are proud of our Vision, CREATING YOUR FUTURE IN BEEF



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