Cardoon Meal as Alternative Protein Source to Soybean Meal for Limousine Bulls Fattening Period: Effects on Growth Performances and Meat Quality Traits

SIMPLE SUMMARY: Beef cattle feeding strategies are commonly based on soybean meal utilization as a fundamental protein source. This feed, though, might have negative environmental impacts on the major areas of production and is becoming very expensive. Cardoon (Cynara cardunculus L.) is a resilient crop which represents a good opportunity in reclaiming and remediating unutilized lands. Cardoon seeds are rich in oil, which is extracted for industrial purposes, and the related by-products (press cake and meal) are characterized by high protein content and essential fatty acids. The aim of this study was to evaluate cardoon meal as a protein source during the Limousine bulls’ fattening period, in order to study a suitable alternative to develop and create low-input and low-emission feeding strategies. The results obtained in terms of growth performances showed no statistical difference between bulls fed the by control diet (containing soybean meal as main protein source) and animals fed by the experimental diet, where soybean meal was partially replaced by one containing cardoon meal. Meat quality traits were measured, and no differences between the groups were found. Hence, these by-products could be considered as a valuable solution in Limousine bulls’ fattening periods and could be used to represent a key factor to improve cattle-feeding sustainability. ABSTRACT: Soybean meal is the most important protein source in beef cattle feeding. The research of alternative protein sources to replace soy use, avoiding negative effects on in vivo performance and on the product’s quality, is an important issue. In this context, cardoon represents a non-OGM resilient crop that can be cultivated in marginal lands for extracting its seed oil (utilized for biodiesel and biodegradable bioplastic production) and whose and the residual meal from its seed oil (utilized for biodiesel and biodegradable bioplastic production) could be a suitable by-product for animal feeding, due to its fairly high protein content. The aim of this study was to evaluate the feasibility of using cardoon meal as an innovative protein source during the Limousine bulls’ fattening period. Thirty-two bulls were divided into two groups and fed with a diet containing soybean meal (SG) or partially replacing soybean meal with cardoon meal as a protein source (CG), respectively. The feeding trial lasted about 11 months. Growth performances and meat physical–chemical traits were evaluated. No statistical differences in feed efficiency, average daily gain, or in the main meat quality indicators, as well as in fatty acid profiles were found among the groups. Therefore, cardoon meal could be considered as an alternative to soybean meal in fattening Limousine bulls in order to enhance the sustainability of the farming system.