Corn is a cereal grain that is commonly used as a feed ingredient for swine diets due to its excellent palatability, and it can easily be grown on a wide range of environmental conditions. Conventional breeding of corn has generated a new variety (i.e., high-oil corn; Byron Seeds LLC, Rockville, IN), which is believed to contain more oil and crude protein (CP) than conventional corn. It is, therefore, possible that this high-oil corn may be comparable to other cereal grains and may serve as alternative to corn for pigs. However, there are at this point no data to demonstrate the nutritional value of high-oil corn. Therefore, an experiment was conducted to test the hypothesis that the standardized ileal digestibility (SID) of amino acids (AA) in high-oil corn is greater than in conventional corn.

Experimental design

Nine pigs (initial BW: 81.5 ± 5.9 kg) with a T-cannula installed in the distal ileum were allotted to a replicated 3 × 3 Latin square design with 3 diets and 3 periods. Therefore, there were 9 replicate pigs per treatment. Two diets contained high-oil corn or conventional corn as the only source of CP and AA. The last diet was a nitrogen-free diet that was used to determine the endogenous loss of AA from the pigs. Each experimental period lasted 7 d. The initial 5 d of each period was considered an adaptation period. Ileal digesta were collected on d 6 and 7 for 9 h using standard procedures. Diets and ileal digesta samples were analyzed for AA and Cr to calculate the apparent ileal digestibility (AID) of CP and AA in 2 sources of corn. The AID values were then corrected using the basal endogenous losses of CP and AA to calculate the SID values.

Results

The concentrations of crude protein and AA were greater in high-oil corn compared with conventional corn (Table 1). The SID of His, Ile, Leu, Lys, Phe, Thr, Val, Ala, Asp, Glu, and Tyr was greater (P < 0.05) in high-oil corn than in conventional corn (Table 2). The SID of CP, Arg, Met, Cys, and Ser also tended to be greater (P < 0.10) in high-oil corn than in conventional corn. Due to increased AA concentration and digestibility in high-oil corn, the concentrations of standardized ileal digestible AA in high-oil corn were greater (P < 0.05) than in conventional corn.

Key points

• High-oil corn contains more crude protein and AA compared with conventional corn.
• The SID of AA in high-oil corn was greater compared with conventional corn.
• Due to increased AA concentrations and digestibility in high-oil corn, high-oil corn contains more standardized ileal digestible AA than conventional corn.

Table 1. Crude protein and amino acid composition of high-oil corn and conventional corn, as-fed basis

Table 2. Apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in high-oil corn and in conventional corn^1,2

¹Data are least squares means of 9 observations per treatment.

²Values for SID were calculated by correcting the values for AID for basal ileal endogenous losses. Basal ileal endogenous losses were determined (g/kg of DMI) as CP, 20.27; Arg, 0.89; His, 0.19; Ile, 0.32; Leu, 0.48; Lys, 0.62; Met, 0.08; Phe, 0.29; Thr, 0.55; Trp, 0.09; Val, 0.41; Ala, 0.68; Asp, 0.78; Cys, 0.20; Glu, 0.94; Gly, 1.94; Ser, 0.55; and Tyr, 0.25.

³High-oil corn = Byron Seeds LLC, Rockville, IN.