#07-172

Complete

Date Full Report Received

02/05/2009

Date Abstract Report Received

02/05/2009

Investigation

Institution:
Primary Investigator:

In North America, when energy is considered in formulation of swine diets, it is usually expressed as either digestible energy (DE) or metabolizable energy (ME). An energy system includes energy requirements and energy contributions of feedstuffs and diets, all expressed in the same units. However, DE and ME are energy systems that share important shortcomings: they systematically overvalue fibrous or high-protein feedstuffs and they systematically undervalue fats. These deficiencies in measurement of dietary energy are very important to the economics of pig production and there is, therefore, an increasing interest in using a system based on net energy (NE) of feed ingredients rather than DE or ME. It has been suggested that profits from pig production in North America would be improved by $2 to 3 per pig if diets were formulated based on a NE system rather than a DE or ME system. There are, however, no NE values for co-products from the dry grind ethanol industry such as distillers dried grains with solubles (DDGS) and high protein distillers dried grains with solubles (HP-DDG). The current research was, therefore, conducted to measure NE values in two sources of DDGS and in HP-DDG. The two sources of DDGS was a conventional DDGS (DDGS-CV) and a DDGS produced from uncooked corn (DDGS-BPX). The source of DDGS-CV that was used in this experiment had a greater concentration of fat then the DDGS-BPX that was used. The NE values were measured in growing as well as in finishing pigs to test the hypothesis that finishing pigs will be better able to digest the nutrients in DDGS than are growing pigs.

A total of 52 growing pigs (initial BW: 20.8 ± 2.06 kg BW) and 52 finishing pigs (initial BW: 87.2 ± 9.77 kg BW) were used in the experiment. Sixteen of the growing pigs and 16 of the finishing pigs were harvested at the start of the experiment to measure the initial body composition and the total energy concentration in the pigs. The remaining pigs were allotted to diets containing DDGS-CV, DDGS-BPX, or HP-DDG. Growing pigs were fed these diets for four weeks and finishing pigs were fed the diets for five weeks. At the end of the feeding period, all pigs were harvested and the body composition and the concentration of energy in the body were measured. By subtracting the amount of energy in the body at he start of the experiment, the energy retention during the experimental period could be calculated. By dividing this amount of energy by the total feed intake of the pigs during the experimental period, the amount of NE in each of the three ingredients could be calculated.

Results showed that for both growing and finishing pigs, growth performance were unaffected by dietary treatments. In growing pigs, no differences were observed in energy retention, and the NE of DDGS-BPX (1,596 kcal/kg), DDGS-CV (1,665 kcal/kg), and HP-DDG (1,783 kcal/kg) were not different. Finishing pigs fed the DDGS-CV diet had greater (P < 0.05) lipid gain than pigs fed the DDGS-BPX diet or the HP-DDG diet. The NE of DDGS-CV (2,718 kcal/kg) was also greater (P < 0.05) than the NE of DDGS-BPX (2,065 kcal/kg) and HP-DDG (2,291 kcal/kg). The average NE of DDGS-CV, DDGS-BPX, and HP-DDG was greater (P < 0.05) in finishing pigs than in growing pigs.

In conclusion, results of this research suggest that the NE for DDGS-CV, DDGS-BPX, and HP DDG is 1,665, 1,596, and 1,783 kcal/kg, respectively, for growing pigs, and 2,718, 2,065, and 2,291 kcal/kg, respectively, for finishing pigs.
The NE of DDGS is greater in finishing pigs than in growing pigs, and the greater the concentration of fat is in DDGS, the greater is the NE.

Contact information:
Principal Investigator and Title: Hans H. Stein, Associate Professor.
Institution: University of Illinois.
1207 W. Gregory Dr.
Urbana, IL 61801
Email: hstein@illinois.edu