RZorganic- Longevity and health for sustainable animal welfare

RZorganic is a new breeding value for the German Holstein breed that is specifically designed to fit the needs of organic and extensive farms. It will be published for the first time with the August 2023 breeding value estimate and released in the vit bull database. It is available for all genomicly tested (typed) female Holsteins and bulls with German breeding values. Since no health breeding values are exchanged via Interbull, the new breeding value cannot be estimated for bulls with pure Interbull breeding values.

Based on the special conditions and requirements for organic dairy farms, the RZorganic sets a clear focus on functionality. The high weighting (2/3) of useful life (38% RZN) and direct health traits (RZGesund 21%) aims at preventing early and avoidable retirements. Body condition (5% BCS) and maternal calving traits (3% RZKm) are also included as additional functional traits. The inclusion of BCS is expected to improve the body condition of the animals and lead to a higher resistance.

Organic and extensive farms aim to supply their animals primarily from their own basic feed, supplemented with regional, organic-certified feed as far as possible. The excellent performance and high genetic potential of the German Holstein breed leads to the challenge of feeding and caring for the animals according to their performance, especially in early lactation. In relation to the high economic importance of the performance traits, especially the ingredients, moderate milk quantities with good ingredients are therefore needed. The RZorganic addresses this challenge in the performance component through two aspects.

Compared to RZG and RZ€, milk yield is weighted less heavily with a total of 27%. The protein and fat quantities are taken into account in a ratio of 2:1 in line with market conditions. Generally, the dairy purchase price reflects the fat and protein content of the milk.

A new feature in German breeding is probably the negative consideration of the milk quantity with 6%. This component is intended to reduce the energy-free milk quantity and the lactose content in the milk via the correlation of these traits to the milk quantity. This means that pure milk quantity sires are specifically penalized here. The overall breeding progress is thus significantly slowed down in milk quantity, but is still slightly positive due to the consideration of fat and protein quantity.

More detailed explanations are available for the main publication on the vit page.

The RZorganic was developed in cooperation with the Ökologische Tierzucht gGmbH (ÖTZ), the BRS, the Rechenzentrum vit and Prof. Swalve (Uni Halle). Research results from the Longlife project, which was led by Prof. König (University of Giessen) and Prof. Swalve, were taken into account in the development (Quelle: orgprints.org/id/eprint/38467).

The development partners aim to evaluate and further develop the breeding value on a regular basis. Further requirements and possible development steps, e.g. for additional traits, have already been collected in exchange with practitioners and consultants during the development phase.