Effect of sweet potato vines on performance parameters and some carcass characteristics of rabbits
According to Scapinello et al. (2003), alfalfa hay is the most commonly used fibre source in diets for rabbits in Brazil even though it is considered expensive and the crop management requires specifics such as increased soil fertility and drainage, pH close to neutral and deep soils. This justifies the search for alternatives to alfalfa, which may comprise up to 40% of the total cost of feed for rabbits.
Sweet potato (Ipomoea batatas) vines are common in Brazil. The tuberous root is popularly used in cooking and has recently started being used as raw material in fuel production (Gonçalves Neto et al., 2011). In 2012 alone, Brazil produced over 479 000 tons of sweet potatoes in an area totalling approximately 46 000 hectares. The sweet potato plant also has a highly branched root system with high capacity of land use, which makes it efficient in absorbing nutrients, which requires less fertilizer to be used (Santos et al., 2006).
Recent research has highlighted the importance of the use of agro‐industrial residues (Giordani Junior et al., 2014; Volpato et al., 2015), which are abundant in Brazil due to the country's intensive agricultural production. Researchers from different countries have studied the effect of sweet potato vines in animal nutrition (Tamir and Tsega, 2010; Nguyen et al., 2012; Lochmann et al., 2013) as a means of not only reducing the environmental impact of the production chain, but also lowering the final cost of the product.
Data concerning the inclusion of sweet potato vines in rabbit diets are scarce and insufficient in the literature. In this context, the objective of this study was to evaluate the weight gain, feed intake, feed conversion, carcass characteristics and metabolic parameters of the liver of rabbits fed diets containing different levels of sweet potato vines as a partial hay alfalfa substitute.