Method of using increasing levels of substitution of the basal diet by test feedstuffs in pig digestibility trials

Abstract

Two experiments were carried out to study the methodology of using increasing levels of substitution of the basal diet with fibrous test feedstuffs (sticky coffee hull -SCH) in digestibility trials with pigs. In Experiment 1, a digestibility trial was conducted using 30 crossbred barrows, allotted in a randomized block design. In Experiment 2, 42 growing and 42 finishing pigs were used, allotted in a completely randomized design, with six diets and seven replicates, with one animal per experimental unit. The six diets consisted of: a control diet, four diets using SCH ME values as obtained in Experiment 1 plus a diet using SCH ME value estimated by linear regression equation for 15% substitution. The digestibility study indicated that the use of increasing levels of substitution (7, 14, 21 and 28%) reduced SCH digestibility. ME values, as-fed basis, were 2,456, 2,377, 2,247 and 1,945kcal/kg. The overall results indicate that higher levels of substitution overestimate the energy value and that the method of increasing levels of substitution of the basal diet with feedstuffs test can be used to more accurately estimate the energy values of fibrous feedstuffs for pigs. For growing and finishing pigs respectively, up to 28% and 15% of sticky coffee hull can be used without impairing pig performance and economic feasibility.

Valorisation of Mediterranean agroindustrial by-products in pig production as feed and anaerobic co-digestion of slurry

“…Such differences between the in vitro (chapters 3 and 5) and the storage assays (chapters 4 and 6) can be explained by the differences in the diets designed for in vitro and storage assays and the variability observed in slurry production when animals are housed in commercial conditions (conventional pens). In the in vitro nutritional assays, the diets were designed to estimate the DE of the by-products tested by the regression or substitution method, usually conducted when testing fibrous byproducts (Piano et al, 2012;Bolarinwa and Adeola, 2012;. Under this methodology, the digestibility values from the different mixtures fed are regressed against the proportion of feedstuff included in the diets.…”