Effect of millet and soybean hulls on nutrient and energy utilization in growing pigs. 1. Characterization of diets, growth performance and nutrient utilization
Hadorn, R.; Wenk, C.; Pfirter, H.P.
Journal of Animal Physiology and Animal Nutrition 75(1): 13-22
ISSN/ISBN: 0931-2439 Accession: 008539023
An experiment with growing pigs was conducted to examine the effects of various sources of dietary fibre in comparison to starch on growth performance and energy utilization. Twenty percent of a control diet (KO) was either replaced with wheat starch (20% STA), millet hulls (20% HI) or soybean hulls (20% SO). Sixteen male Large White castrates were housed in individual pens from 20.0 kg live weight (LW). The animals were fed a restricted diet. Just after slaughter at 95.3 kg LW, digesta samples were taken from different parts of the digestive tract. In comparison to diet KO, no differences could be seen in intake of digestible energy (DE) by the addition of wheat starch, whereas daily weight gain was lowered by 6%. No significant differences in growth parameters and DE content (average: 15.8 MJ/kg DM) were observed between diets KO and 20% SO. In diet 20% HI, DE content was lowered by 14% and DE intake also decreased. This resulted in a reduced daily weight gain and an impaired feed-conversion rate. Precaecal energy digestibility (d(E)) was significantly lowered by the content of total dietary fibre, whereas faecal excretion d(E) was influenced by the content of dietary fibre and its composition. The main fibre constituents influencing faecal excretion d(E) were insoluble hemicelluloses and lignin. It was concluded that differences in fibre utilization are mainly influenced by the processes in the digestive tract (mainly large intestine). Furthermore, pigs would be able to meet an important part of their energy requirements from microbial degradation of precaecally non-degradable nutrients in the large intestine, if lignin incrustation of insoluble hemicelluloses were not a limiting factor.