Effects of full fat rice bran and defatted rice bran on growth performance and carcass characteristics of growing-finishing pigs

G. A. Casas, M. F. Overholt, A. C. Dilger, D. D. Boler, and H. H. Stein

The objective was to test the hypothesis that increasing inclusion levels of full fat rice bran (FFRB) or defatted rice bran (DFRB) are not detrimental to growth or carcass characteristics, longissimus muscle (LM) quality, or fat quality when fed to growing-finishing pigs. A total of 224 barrows and gilts were randomly allotted to 7 treatments, with 4 pigs per pen and 8 pen replicates per treatment. Pigs had an average initial BW of 28.2 ± 4.1 kg and a 3-phase feeding program was used. A basal diet containing corn and soybean meal, 3 diets containing corn, soybean meal, and 10, 20, or 30% FFRB, and 3 diets containing corn, soybean meal, and 10, 20, or 30% DFRB were formulated within each phase. Daily feed allotments and pig BW at the start of the experiment and at the conclusion of each phase were recorded. On the last day of the experiment, 1 pig per pen was harvested and carcass characteristics, LM quality, and fat quality were determined. For the overall experimental period, no effects of dietary treatments were observed for average daily gain. However, average daily feed intake (ADFI) decreased (linear, P < 0.05) and gain to feed ratio (G:F) increased (linear, P < 0.05) for pigs fed diets with increasing concentrations of FFRB. In contrast, ADFI increased linearly (P < 0.05) and G:F decreased (linear, P < 0.05) as DFRB was included in the diets. There were no effects of dietary treatments on LM quality. The length of the bellies decreased (linear and quadratic, P < 0.05) as the inclusion of FFRB or DFRB increased in the diets. The concentration of crude fat in the adipose tissue of pigs increased linearly (P < 0.05) as the concentration of FFRB or DFRB increased in the diets. The concentration of saturated fatty acids in the adipose tissue of pigs fed diets containing FFRB decreased (linear, P < 0.05), whereas the concentration of polyunsaturated fatty acids (PUFA) increased (linear, P < 0.05). In contrast, addition of DFRB did not affect the concentration of fatty acids in adipose tissues. In conclusion, 30% FFRB included in diets for growing-finishing pigs may improve G:F without affecting carcass characteristics or LM quality with the exception that PUFA in adipose tissues will increase. However, inclusion of DFRB in diets for growing-finishing pigs will reduce G:F without affecting the LM quality or composition of adipose tissues.

2018. J. Anim. Sci. 96(6):2293–2309
https://academic.oup.com/jas/article-lookup/doi/10.1093/jas/sky145
DOI: 10.1093/jas/sky145