Growing pigs were used to assess the slaughter and carcass characteristics, organs and primal cut yields when fed diets supplemented with processed leaves of
Tithonia diversifolia
(wild sunflower) referred to as
Tithonia diversifolia leaf meal (TDLM). A 63-day feeding trial was conducted with commercially available male Large White growing weanling pigs on four experimental diets containing 19.0% crude protein and a digestible energy value of 2997 kcal/kg.
Tithonia diversifolia leaf meal (TDLM) progressively replaced soybeans at 10%, 20% and 30% inclusion levels in diets 2, 3 and 4, respectively. Carcass yields for pigs on 10% TDLM were similar (p>0.05) to the values obtained for pigs on the control diet without TDLM. Most other carcass parameters such as carcass length, chest width, trochanter width and leg length were similar (p>0.05) and variations where they existed were minimal. Slaughter traits such as live weight at slaughter, empty slaughter weight, dead weight and back fat depth were significantly better (p<0.05) for pigs on the control diet without TDLM inclusion at 20.2kg, 14.6kg, 19.1kg and 0.9cm, respectively. These values were closely followed by the values obtained for pigs on 10% dietary TDLM inclusion at 15.6kg, 11.5kg, 15.1kg and 0.5cm for live weight at slaughter, empty slaughter weight, dead weight and back fat depth, respectively. Poor values of empty slaughter weight, body mass index, dead weight and back fat depth were recorded for pigs on diets 3 (20% TDLM) and 4 (30% TDLM) ostensibly due to the low feed intake and subsequent poor weight gain and high feed conversion ratio. The above trend was repeated for offals and organs yields. However, reproductive organs were not adversely affected even at 30%. Most determined experimental pig primal cuts were within moderate ranges according to literature and also similar to values obtained for pigs on experimental control diet. Conclusively, pigs on 10% TDLM inclusion level had comparable slaughter/carcass traits, organs and primal cut yields with pigs on the control diet without TDLM and also with most reported values in existing literature. Growing pigs tolerated TDLM and in some cases surpassed the performances of pigs on conventional growing pig diets. Further research studies may be necessary to investigate the nutritional value of TDLM when more adequate processing techniques are employed to reduce its anti-nutrients.
