Project Number: 3625-31000-003-13
Project Type: Specific Cooperative Agreement

Start Date: Sep 26, 2008
End Date: Dec 31, 2009

Objective:
Determine how diet type (semipurified, standard, soy hulls, distillers grains, and pectin) affect the appearance or disapperance of inert markers (Ti and Cr) as pigs are switched between combinations of these diets, and determine the change in nutrient (energy, nitrogen, phosphorus) digestibility over time as diets are interchanged.

Approach:
Pigs will be fed 5 test diets for a period of 5 weeks prior to placement into individual pens. Pigs will then be adapted to the pens and fed the same diets for an additional 7 days. After this time period, pigs will be switched to each of the 5 diets (5 x 5 factorial) with each diet containing titanium as an inert marker. Pigs will have their feeders weighed daily and fecal matter obtained daily to measure Ti, energy, N, and P concentration for subsequent evaluation of nutrient digestibility over time. Following 14 days of collection, pigs will be returned to their initial diet (now containing chromium) to evaluate the disapperance of titanium in the initial feed as well as the appearance of Cr in the new feed (thus showing potential contamination between periods). All diets and fecal material will be analyzed for marker and nutrient concentration to evaluate nutrient digestion. All data will be analyzed using the GLM procedures of SAS with the two main factors being the initial and switched diets. This data is of critical value to the swine industry as feed grain (corn) prices are at historical highs and there is an abundance of higher fiber (reduced starch) corn co-products available for use by the swine industry. Yet, a thorough review of the literature has not shown clear evidence of the impact of diet switching on appearance of marker nor on the change in nutrient digestibility over time. Consequently, this type of methodology research is critical for the understanding on nutrient digestion in any future research on fibrous ingredients.