Effects of unconventional diets and unconventional low-protein diets during sow gestation on the growth performance, carcass traits, meat quality, and microbiota of offspring pigs

Abstract

This study evaluated long-term effects of replacing corn and soybean meal with wheat, broken rice, rice bran meal, rapeseed meal, and fermented distillers’ grains in gestating sow diets on offspring growing-finishing pigs’ growth performance, carcass traits, meat quality, and colonic microbiota. Thirty sows were assigned to corn-soybean meal (CON), unconventional ingredient (UCD), or unconventional low-protein diet (LP-UCD, 2 percentage points lower in CP). After weaning, 90 piglets (30 per group) were randomly allocated to pens (3 piglets/pen, 10 pens/group) and raised to approximately 120 kg body weight; growth data were recorded with pen as the experimental unit. At slaughter, 21 pigs (7/group) were sampled. Neither UCD nor LP-UCD affected overall growth performance, carcass traits, or meat quality of offspring. Compared to UCD, LP-UCD showed a lower feed-to-gain ratio at 8–25 kg ( P  < 0.05) but reduced average daily feed intake at 25–50 kg ( P  < 0.05). UCD had lower serum urea than CON ( P  < 0.05). LP-UCD had lower total protein, alanine aminotransferase, creatinine, and higher alkaline phosphatase, total cholesterol, and triglycerides than UCD ( P  < 0.05). LP-UCD tended to upregulate lipid metabolism genes like peroxisome proliferator-activated receptor delta. Colonic microbiota alpha/beta diversity did not differ. UCD increased the Firmicutes/Bacteroidota ratio vs. CON ( P  < 0.05). LP-UCD had higher Streptococcus and Coprococcus, and lower Anaerovibrio and Phascolarctobacterium vs. UCD ( P  < 0.05). In conclusion, gestational unconventional diets did not impair offspring growth or meat quality but were associated with alterations in metabolism, lipid-related gene expression, and microbiota composition. Notably, the unconventional low-protein diet showed potential to improve early feed efficiency.