화학공학소재연구정보센터
Energy Conversion and Management, Vol.51, No.5, 955-958, 2010
Cultural energy analyses of dairy cattle receiving different concentrate levels
Purpose of this study was to conduct cultural energy analyses of dairy cows receiving different levels of concentrate. Data were acquired by conducting a survey on 132 dairy farms selected by the stratified random sampling method. Dairy cattle farms were divided into three groups according to concentrate level and were analyzed. Accordingly concentrate levels were assigned as low (LLC) (<40%, 52 farms), intermediate (ILC) (40-50%, 36 farms) and high (HLC) (>50%, 44 farms). Cultural energy used for feed for cows was calculated by multiplying each ingredient with corresponding values of ingredients from literature. Transportation energy was also included in the analysis. Total cultural energy expended was highest for LLC (P < 0.05). Cultural energy expended for feed constituted more than half of the total cultural energy and was highest for LLC (P < 0.05). Cultural energy expended per kg milk and per Mcal protein energy was higher for LLC (P < 0.05). Efficiency defined as Mcal input/Mcal output was better for ILC and was worse for LLC (P < 0.05) and HLC was intermediate thus not differing from other groups. Results show that cultural energy use efficiency does not linearly increases as concentrate level increases and increasing concentrate level does not necessarily mean better efficiency. Thus optimum concentrate level not interfering cows performance should be sought for sustainable dairy production. (C) 2009 Elsevier Ltd. All rights reserved.