Effect of some factors of variability on carcass weight of organically reared beef

Introduction - During the last few years, organic production has showed an increasing trend. This trend is mainly due to the EU supporting policy, in order to guarantee food security and sustainable productions for the future. In addition, since the nineties, producers and consumers have shown a growing interest towards organic production and the market have been developed. Moreover in Tuscany, a lot of farmers which own marginal land and/or forested areas have decided to turn to organic livestock, both for the ethical value of their products and for the greater bargaining power that the goods have on the market. Aim - The aim of this research was to study the effects of some variability factors on carcass weight. Materials and methods - Breed, slaughtering age, sex, season of birth, interactions year x management, breed x age and sex x age on carcass weight of 457 cattle slaughtered during the period 2001-2011 were evaluated. The animals were Chianina, Maremmana, Limousine and crossbreed Maremmana x Limousine veals and were raised in the same farm in Tuscany. The animals received the same feed and were slaughtered at an average age of 18/24 months, depending on the breed and sex. Data were stratified on the basis of the slaughtering age (five levels), then a statistical analysis was performed. Results and discussion - Chianina and crossbreed Limousine x Maremmana gave heavier carcasses: 389.3±6.39 and 323.4±5.41 kg, respectively. In general the farming system (conventional or organic) did not affect carcass weight. Chianina cattle showed a wide range of slaughtering weights. Moreover in the farm, the larger number of Chianina beef was slaughtered between 22 and 26 months like Limousine and crossbreeds, whereas Maremmana was slaughtered between 18-22 months. Males had heavier carcass than female: 353.2±4.35 vs 299.4±5.85 respectively but the differences between sexes were significant only after 18 months. The management system (conventional/organic) and the season of birth did not affect the carcass weight of cattle. Conclusion - The management system (conventional/organic) do not seem to influence the productivity, indeed it does not affect the carcass weight of beef cattle. On the other hands the choices of management play an important roles on productivity as demonstrated by the effects of the slaughter age and the breed on the carcass weight.