Pre-Caecal Disappearance of Starch and Volatile Fatty Acid (VFA) Content in <i>Digesta</i> of <i>Caecum</i> of Growing Pigs Fed with Ripe Hulled Shredded Acorns in Their Diet

• Main Authors: Maria Grazia Cappai, Petra Wolf, Walter Pinna, Peter Rust, Josef Kamphues
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Agriculture
• Subjects: acorns; butyric acid; dietetic; fermentation; pig; valeric acid
• Online Access: https://www.mdpi.com/2077-0472/10/11/508

Physical properties and chemical composition of <i>caecum</i> chyme, with particular regard to starch pre-caecal disappearance and volatile fatty acid (VFA, C2-C5) content, were determined in 16 growing pigs fed raw acorns in the diet. Pigs were singly housed and divided into two experimental feeding groups (each <i>n</i> = 8). The control group was fed a conventional complete diet for pigs (pelleted; 890 g dry matter (DM)/kg, 435 g starch/kg DM, based on cereals and soybean extraction meal). The acorn-fed group was offered a combined diet, 70% of ripe whole shredded acorns (695 g DM/kg, 447 g starch/kg DM) and 30% of the control diet. After one week, all 16 animals were slaughtered, and contents of the caudal <i>ileum</i> and <i>caecum</i> were analyzed for dry matter, crude ash, and starch. Fresh <i>caecum</i> chyme was analyzed for VFA content and molar proportion of acetic, propionic, n-butyric, n-valeric acid were determined. VFA per kg of organic matter (OM) in the <i>caecum</i> differed significantly between groups (<i>p</i> = 0.047). Pre-caecal disappearance (pCD) of acorn native starch turned out to be high (>95%). Estimated VFA content in <i>caecum</i> in the acorn combined diet resulted in 8.72 g per kg of OM, and the relationship based on molar proportion between acetic:propionic:n-butyric:n-valeric acid was 1:0.2:0.1:0.04, which pointed to higher proportions of n-valeric acid when hulled shredded acorns are fed to pigs.