Modification of lipid fraction in ensiled high moisture corn

Abstract

The aim of this work is to study the changes of the lipidic fraction of ensiled high moisture corn (HMC). 11 maize hybrids were used, ensiled each in 3 mini experimental silos of 100 litres. For each hybrid 1 sample of fresh high moisture corn was obtained immediately after milling and 3 samples of ensiling HMC were kept after 2, 7 and 12 months. All samples were analysed for pH, dry matter, lactic acid, ammonia-N, ether extract, fatty acid composition and volatile fatty acids (VFAs). Ether extract of fresh high moisture corn was 35.7 g/kg dry matter (DM) and increased after 2 and 7 months of storage up to 39.4 g/Kg DM (P≤0.01); after 12 months it decreased to 38.1 g/kg DM (P≤0.01). Both saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) percentages decreased from 18.23% to 15.47% and from 24.84% to 23.57% respectively (before ensiling vs 12 months P≤0.01). Linoleic acid percentage increased from 55.34% to 59.44% (before ensiling vs 12 months P≤0.01). The linoleic acid content (g/kg of DM) increased on average from 19,1 before ensiling to 22.5 after 12 months of ensiling. These differences may affect the linoleic acid content of heavy pig diets when maize is used as HMC instead of corn meal.

Keywords

• Ensiled high moisture corn
• Lipid fraction
• Linoleic acid
• Heavy pig
• Fat quality