Effect of concentrate level on sustainability of beef cattle production

The purpose of this study was to conduct a cultural energy analyses of beef cattle receiving different levels of concentrate. Data were obtained via questionnaire from 100 beef cattle farms selected by a stratified, random sampling method. Beef cattle farms were divided into three groups according to concentrate level and were analyzed. Accordingly concentrate levels were assigned as low (< 55% 35 farms), intermediate (55% to 65%, 34 farms) and high (> 65%, 31 farms). Cultural energy used for feed for treatments was derived from their corresponding lot feed consumption and their corresponding values from the literature. Transportation energy was also included in the analysis. Since the objective of the study was to evaluate cultural energy analysis of the feeding systems, energy that the calves had deposited in their Muscle and fat tissue when they were bought was deducted from carcass energy. Total cultural energy expended was highest for cattle receiving a low level of concentrate (p < 0.05). Feed energy constituted more than half of the total cultural energy and was highest for cattle receiving a low level of concentrate (p < 0.05). Energy expended per kg live weight did not differ among groups by concentrate level (p > 0.05). Cultural energy per Mcal protein energy was highest for cattle receiving a low level of concentrate and was lowest for cattle receiving an intermediate level of concentrate (p < 0.05). Cultural energy for cattle receiving a high level of concentrate was intermediate and thus did not differ significantly from the other groups (p > 0.05). Efficiency, defined as Mcal input/Mcal output, was better for cattle receiving an intermediate level of concentrate and was worse for cattle receiving a low level of concentrate (p < 0.05). Efficiency for cattle receiving a high level of concentrate was intermediate and thus did not differ significently from the other groups (p > 0.05). Results showed that efficiency does not linearly increase as concentrate level increases; thus, in order to be more sustainable, a strategy of decreasing concentrate level without interfering with cattle performance should be considered.