INFLUENCIA DE FACTORES NO GENéTICOS EN LA PRODUCCIóN DE LECHE DEL SIBONEY DE CUBA

in order to determine the influence of non-genetic factors in siboney de cuba milk production, a retrospective evaluation was carried out from 13 656 lactation records of 75 dairy farms belonging to the genetic livestock enterprise ？nazareno？. the behavior of non-genetic factors such as: dairy farm, year of birth, calving number, season, year and the interaction of these last two factors was evaluated by a general linear model using a covariance analysis, followed by the duncan's multiple range test modified by kramer. duration of breastfeeding was used as covariate. milk production average at 244 days was 202.11kg ± 590.38 and that of total milk of 2 685.5kg ± 540.07 under grazing conditions. the duration of lactation averaged 308.89 ± 55.17 days. values showed siboney de cuba adaptation potentialities to macro-environmental conditions prevailing in the country. the non-genetic factors influence in the 40 to 45 percent of the variations in milk yield and total milk respectively, with significant differences found for the years of birth, dairy farms, calving number and the interaction season-year. the influence of lactation duration in milk production was also significant. it is recommended to consider these non-genetic factors to analyze the differential behavior of animals and estimate milk production in each condition.