VN April 2021

Vetnuus | April 2021 30 Regulars I Zoetis Livestock Column Oestrus synchronisation coupled with artificial insemination are techniques that are commonly used by dairy producers. Most dairy producers opt for imported sire genetics to avoid inbreeding but also to propel their herd’s genetic progress. Information on the different available sires are accessible either online or compiled into a hard copy catalogue by each respective semen company. This allows producers access to the genomic data of the sires available in different countries from the various companies. Most dairy producers are very comfortable with the interpretation of genomic predictions when selecting their sires. Depending on the goal(s) on the farm, producers will often select bulls that suit their future plans and goals, whether it may be to increase milk production, milk solids, productive life, fertility etc. Genetic progress in herds that select genomic or proven sires and utilise these genetics via artificial insemination is clear. The decision of which dam to match with a particular sire is usually made with less information. Dam information is often based on visual appraisal, previous performance, fertility and disease records, and/or parent average. These methods however, have limitations in terms of the reliability of the information it can provide. Genomic tests that are now available for female animals can provide producers with a more reliable option to base their breeding and culling decisions on. This means that with genomics, it is possible to more accurately predict the genetic potential of female animals for a wide range of traits. This can lead to more selective and precise breeding decisions, thereby utilising expensive sire genetics, sexed semen or beef semen with more certainty. Included in the Zoetis genomic test Clarifide Plus are the proprietary cow and calf wellness traits, which are direct genetic predictions for common diseases and conditions that can impact profitability on a dairy farm. Profitable animals are those that are healthy, long- lived, fertile and productive, needing minimal intervention. With the wide variety of genetic traits now suddenly at their disposal, producers might feel overwhelmed with an information overload. This is where a selection index can play a critical role. The aim of a selection index is to combine the different traits available into a single figure per animal, making it easier for producers to rank animals according to merit. These selection indexes have been carefully formulated, considering the deleterious effects different genes can have on each other. Different selection indexes also place emphasis on different traits, making it possible for a producer to select the selection index most appropriate to their goals and needs. An important part of the Clarifide Plus offering is the dairy wellness profit index (DWP$). The DWP$ is a multi-trait selection index incorporating traits that affect production, fertility, conformation, longevity, liveability, calving ability, milk quality, polled results as well as the cow and calf wellness traits previously mentioned. Higher DWP$ scores identify animals that has the genetic potential to generate more income over her lifetime and could potentially stay in the herd for longer, with lower risk of developing certain conditions. A recently published study validated just that. 1 The study was a retrospective analysis involving five herds based in different locations across the United States, encompassing 2185 genomically tested Holstein cows born in 2011, amongst other inclusion criteria. A DWP$ value was generated for each animal using the 2018 formulation and animals were then ranked into quartiles based on their score. Since theDWP$was formulated toestimate thepotential lifetime profit of an animal, various factors over the lifetime of each animal were evaluated. There were several significant findings in this particular study when comparing the top 25 % versus the bottom 25 % ranked DWP$ animals. Zoetis Animal HealthPages FOR ANIMALS. FOR HEALTH. FOR YOU. Genomics validated Dr Chantelle Erwee, Zoetis South Africa (Pty) Ltd, Technical Manager: Ruminants