Pineapple stem by-product as a feed source for growth performance, ruminal fermentation, carcass and meat quality of Holstein steers

This experiment was conducted to determine the effects of pineapple stem by-product silage as a feed source in total replacement of Napier or corn silages on growth performance, feed intake and feed efficiency, ruminal fermentation, carcass characteristics and meat quality of Holstein crossbred steers. Forty-eight steers with an average age of 18 months (448.6 +/- 51.5 kg) were randomly allocated to three groups (one diet per group) in a completely randomized design. Steers were fed total mixed ration (TMR) containing a roughage-to-concentrate ratio of 20 : 80. The TMR diets contained Napier grass silage (nTMR), whole corn silage (cTMR) or pineapple stem silage (pTMR) and were offered ad libitum for six months. The results revealed that pTMR and cTMR diets resulted in a significantly higher weight gain than nTMR. These results were observed because pTMR and cTMR diets provided more N-free extract (NFE) total digestible nutrients (TDN) than nTMR diet, and the feed conversion efficiencies for pTMR and cTMR diets were higher than those of nTMR. Ruminal pH, ammonia-nitrogen and volatile fatty acid concentrations were not significantly different among dietary treatments. The carcass characteristics of steers fed cTMR and pTMR diets included significantly larger rib eye areas than steers fed nTMR, whereas meat quality was not affected by treatment. Additionally, the current research showed that pTMR diet provided the lowest feed cost per gain. The results suggest that pineapple stem by-product could be regarded as a potential feed source for reducing costs in cattle feedlots.