Table 2. Standardized ileal digestibility (SID) of crude protein (CP) and apparent total tract digestibility (ATTD) of gross energy (GE) in feed ingredients fed to growing pigs

Item	Number of data1)	Average digestibility (%)
SID of CP
Rice	-	96.0
Corn	9	78.5
Soybean hulls	3	62.3
Wheat	-	89.4
Wheat bran	2	70.7
Palm kernel expellers	4	74.5
Copra meal	3	75.8
Cashew nuts	-	86.1
Rapeseed meal	11	72.8
Soybean meal	12	89.2
ATTD of GE
Rice	-	96.4
Corn	-	88.2
Soybean hulls	-	58.2
Wheat	-	86.8
Wheat bran	-	67.3
Palm kernel expellers	-	64.5
Copra meal	-	67.7
Cashew nuts	-	88.7
Rapeseed meal	-	64.9
Soybean meal	19	87.4

A total of 44 data for SID of CP in corn, soybean hulls, wheat bran, palm kernel expellers, copra meal, rapeseed meal, and soybean meal fed to growing pigs were obtained from 21 research papers and a total of 19 data for ATTD of GE in soybean meal fed to growing pigs were obtained from 9 research papers [8,11–33]. The values for SID of CP in rice, wheat, and cashew nuts, as well as the values for ATTD of GE in rice, corn, soybean hulls, wheat, wheat bran, palm kernel expellers, copra meal, cashew nuts, and rapeseed meal were determined by our research group as marked with hyphens.