Raffrenato, E.Blake, R.W.Oltenacu, P.A.Gambina, M.Licitra, G.2013-05-072013-05-072013-01Raffrenato, E, Blake, RW, Oltenacu, PA, Gambina, M & Licitra, G 2013, 'A multilevel model with clustered management practices differentiating dairy herd environments in southeastern Sicily', Livestock Science, vol. 151, no. 1, pp. 58-65.1871-1413 (print)1878-0490 (online)10.1016/j.livsci.2012.09.016http://hdl.handle.net/2263/21447Herd environments constitute productivity potentials, or aggregate opportunity outcomes, resulting from management actions taken with the available inputs. Management outcomes from cow nutrition, udder health and milking practices were quantified with the help of surveys of 254 dairy producers in southeastern Sicily. Objectives were to disentangle environmental opportunities by disaggregating herd effects into causal inputs. Average ME milk production was 8640 kg/lactation for the 183 Friesian herds containing 35 lactating cows and 10 dry cows. Seventy-one Brown Swiss herds averaged 6443 kg ME milk from 25 lactating and 10 dry cows. For Friesian (Brown Swiss) herds 10 (11) management practices affected milking performance and 9 (8) practices influenced somatic cell concentration (P<0.05). Multilevel analysis and herd clustering procedures differentiated low from high opportunity herd environments but altering relative weightings among management practices did not further discriminate them. This clustering methodology helps ensure unbiased estimation of management input effects and could help target priority management substitutions and technical support priorities in dairy extension programs.en© 2013 Elsevier. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Livestock Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Livestock Science, vol. 151, no. 1, 2013. DOI : 10.1016/j.livsci.2012.09.016Herd environmental definitionsManagement practicesAnimal breedingPostprint Article