Lay Summary The objective of this study was to determine effects of soybean hull inclusion on nutrient digestibility, nitrogen balance, and dietary energy value in growing gilts. Pigs were fed one of four dietary treatments with increasing levels of soybean hulls (0, 10%, 20%, 40%). Feed intake, was not different across dietary treatments, but body weight and average daily gain were lower as soybean hull inclusion increased. Apparent total tract digestibility (ATTD) of crude protein and nitrogen retention decreased as soybean hull inclusion increased in the diet. Fecal nitrogen excretion increased and urine nitrogen excretion decreased over time and as soybean hull inclusion increased. Dietary metabolizable energy (ME) content decreased as soybean hull inclusion increased. In conclusion, increasing dietary soybean hull inclusion to up to 40% increased fecal N output, decreased ATTD of N, decreased the ME value of the diet.
Mayer et al. (Fri,) studied this question.