Fermented Cassava Residue Meal Improves Meat Quality by Regulating Muscle Fiber and Enhancing Lipid Metabolism in Huanjiang Mini-Pigs

This research investigated the effects of cassava residue meal (CRM) and fermented CRM (FCRM) on the growth performance, serum lipid indicators, carcass traits, and meat quality of Huanjiang mini-pigs. One hundred twenty Huanjiang mini-pigs with similar BW (body weight, 8.85 ± 0.64 kg) were divided into three dietary treatment groups: the CON group with a basal diet; the CRM group with a diet containing 5% CRM; and the FCRM group with a diet containing 5% FCRM. The feeding trial was conducted for 30 days. The findings revealed that dietary CRM and FCRM did not influence the growth performance and diarrhea rate of Huanjiang mini-pigs (<i>p</i> > 0.05). Dietary FCRM supplementation increased serum total cholesterol level compared to the CON group while decreasing serum cholinesterase level compared to the CON and CRM groups (<i>p</i> < 0.05). The level of serum low-density lipoprotein-cholesterol was higher (<i>p</i> < 0.05) in the CRM and FCRM groups in regard to the CON group. In addition, CRM and FCRM supplementation reduced (<i>p</i> < 0.05) the backfat thickness and carcass yield of Huanjiang mini-pigs. The meat quality analysis showed that dietary CRM and FCRM improved the meat quality by increasing the intramuscular fat content and redness (a*) value and decreasing the lightness (L*) value. Moreover, the <i>MyHC-IIx</i> expression in the <i>longissimus thoracis</i> (LT) muscle was upregulated (<i>p</i> < 0.05) in the CRM group, while <i>MYHC-IIb</i> expression displayed an increasing trend (<i>p</i> = 0.076) in the FCRM group relative to the CON group. The fatty acid composition in the LT muscle also revealed that the C20:0 level was lower in the CRM and FCRM groups, while the ∑SFA and ∑SFA/∑UFA were reduced (<i>p</i> < 0.05) in the FCRM group relative to the CON group. In summary, dietary CRM and FCRM supplementation improved the meat quality of Huanjiang mini-pigs without affecting growth performance and diarrhea rate. Notably, FCRM exhibited better effects on meat quality than CRM.