ChileanJAR

Two hundred and fifty lactations from a farm located in Osorno, southern Chile, were analized according to the following calving seasons: I, spring; Il, summer; IlI, autumn and IV, winter.
The length of lactation was similar for the spring, autumn and winter season, but tended to be lower for the summer calving season (I: 226 ± 15; Il: 204 ± 94; m: 222 ± 3171; IV: 239 ± 16); The same was true for total milk production, with values for season I, Il, III and IV of 2395 ± 208; 1934 ± 986; 2353 ± 230 and 2317 ± 205, respectively.
Different pattern of lactation were found for the various season. These were influenced by the pattern of forage productionfrom pasture, and it is important to adapt the calving season to the production characteristics of the sward. Feed supplementation is required in order to increase milk production per cow independent of calving season.