Regression-derived phosphorus digestibility responses of broiler chickens to heat treatment of soybean meal and poultry meal

Comparison of different protein sources on the phosphorus digestibility of soybean meal for broiler chickens determined using the regression method

“…Concurrently, ileal digestibility and total tract utilization of DM linearly decreased when substituting cornstarch with soybean meal in all protein sources. These results are consistent with our previous studies ( Liu et al, 2014 ; Haetinger and Adeola, 2023 ).…”

“…The digestibility of P in soybean meal determined in diets with SBM as the only protein source, or with addition of casein, or PPI were 57.8, 63.2, and 58.8, respectively, with an average of 59.9%. These are similar to some previous reports of SBM P digestibility of 59% ( Rutherfurd et al, 2002 ), 55.3% ( Liu et al, 2013 ), 65.4% ( Babatunde et al, 2020 ), and distinct to other reports, such as 45% ( Rostagno et al, 2017 ), 45% ( Haetinger and Adeola, 2023 ), and reported values that ranged from 19 to 51% in a 17-station ring study reported by Rodehutscord et al (2017) . These differences may arise from different methodologies employed, the age of the birds, basal diet composition, or variations in soybean meal composition.…”

“…Additionally, the digestibility values reported by Mutucumarana et al (2015) were substantially higher than those determined in our study with similar methodologies (57.8 and 35.3%), which may be attributed to the different Ca:P ratio, longer length of the trial, or different age of birds (from 21 to 28 d) in their trial. The 3-day feeding period used in the present study is consistent with previous P digestibility trials ( Adekoya et al, 2021 ; Dilelis et al, 2021 ; Adekoya and Adeola, 2023 ; Haetinger and Adeola, 2023 ) designed to evaluate the P digestibility of a test ingredient and minimize confounding factors. One of such factors is physiological adaptation to low P diets that could increase P digestibility ( Li et al, 2015 ; Perryman et al, 2016 ) and was shown to significantly increase P digestibility when feeding test diets for 5 compared with 2 d ( Babatunde et al, 2019a , b ).…”

“…Regression analysis between the test ingredient-associated apparent ileal digestible P intake or total tract utilizable P intake in g/bird and the total P intake in g/bird was conducted using multiple linear regressions as described by Bolarinwa and Adeola (2012) and Haetinger and Adeola (2023) . Whereby each regression analysis consisted of 3 levels of soybean meal with 8 replicates per protein source for a total of 24 data points.…”

Ileal phosphorus digestibility of soybean meal for broiler chickens remains consistent across institutions in a collaborative study regardless of non-phytate phosphorus concentration in the pre-experimental starter diet

“…The current range from 43 to 46% P digestibility of soybean across institutions is considerably less variable than the 19 to 51% in the ring test ( Rodehutscord, 2017 ), which is attributable to more stringent standardization of protocols and fewer participants. Furthermore, these estimates are similar to some reported values in the literature of 45% ( Rostagno et al, 2017 ; Haetinger and Adeola, 2023 ), but lower than other reports that range from 55 to 65% ( Rutherfurd et al, 2002 ; Liu et al, 2013 ; Babatunde et al, 2020 ). Perhaps these discrepancies result from differences in bird management, diets, SBM P concentration, euthanasia procedure, or analytical methods.…”