Standardized total tract digestibility of phosphorus in cereal grains and coproducts fed to growing pigs

Abstract Text: The objective of this experiment was to determine the standardized total tract digestibility (STTD) of phosphorus (P) in 2 sources of cereal grain including barley and wheat and 9 sources of byproduct ingredient including almond meal, two different sources of corn gluten feed, corn gluten meal (CGM), lupin hull (LH), lupin kernel (LK), rice bran (RB), soybean meal, and wheat bran. Each ingredient was included to an experimental diet as a sole source of P. A P-free diet was formulated to estimate the basal endogenous loss of P. A total 12 diets were assigned to a 12 × 8 incomplete Latin square design with 12 barrows and 8 periods. Pigs with an initial BW of 46.7 ± 3.2 kg were individually housed in metabolism crates. Each period lasted 8 d consisted of 4-d adaptation and 4-d collection periods. Feces were collected based on the marker-to-marker method. Despite of the greatest concentration of P in RB, the STTD of P in RB was lower (P < 0.05) than CGM and LK (Table 1). Value for the STTD of P in LH was also lower (P < 0.05) than those in CGM and LK. In conclusion, the STTD of P in barley and wheat were not significantly different and these values were similar to values in cereal coproducts used in this experiment.

Table 1. Phosphorus (P) and standardized total tract digestibility (STTD) of P in 11 sources of oilseed meal fed to growing pigs (% as-fed basis, n = 8)

Item	P	STTD of P
Cereal grain
Barley	0.30	60.3ab
Wheat	0.30	63.9ab
Cereal coproduct
Almond meal	0.05	62.3ab
Corn gluten feed source 1	0.62	68.3ab
Corn gluten feed source 2	0.95	63.4ab
Corn gluten meal	0.24	75.7a
Lupin hull	0.17	51.3b
Lupin kernel	0.36	72.3a
Rice bran	1.73	53.3b
Soybean meal	0.62	66.1ab
Wheat bran	0.86	69.3ab
SEM		4.1
P-value		< 0.001

^a,bWithin a column, means without a common superscript letter differ (P < 0.05).

Keywords: Feedstuffs, Macromineral, Swine