Abstract

Organic milk production is an important sector of the US dairy industry. Productive life, defined as the time that a cow remains in the herd after first calving, is a trait of economic importance in organic dairy farming affecting the age structure of the herd and replacement costs. Productive life is of economic importance for inclusion in breeding objectives for organic milk production, which determine its value for selection. The objective of this study was to estimate the economic value (EV) of productive life for cows on certified organic dairy farms in the US using a farm-simulation model. Annual net farm income (NFI) per cow was calculated as gross income minus production costs. Income was derived from the sale of milk, disposed animals and other income. Milk income was calculated as US$ 0.809/kg milk. Cost of organic feed was US$ 0.308/kg DM. The average productive life of the herd was 1,302 d with an annual replacement rate of 22.1%. The herd NFI was US$ 520.70/cow and the EV for productive life was US$ 1.24/d. This value is higher than the EV of productive life included in the Net Merit (US$ 0.69/d) or Grazing Merit (US$ 0.43/d) indexes used for conventional US dairy cattle.

N, Lopez-villalobos, AP Schinckel, and MM Schultz

New Zealand Journal of Animal Science and Production, Volume 78, Lincoln, 128-131, 2018