Summary and Implications
A total of 120 weanling barrows were selected to represent the 10% lightest, median, and heaviest pigs at weaning (n=30 per weaning weight category). Eight pigs per weaning weight (WW) category were harvested as an initial slaughter group. The remaining 96 barrows were utilized in a 27-d growth and metabolism study, and harvested on d 33 or 34 post-weaning. At the completion of the experiment, pigs in each WW category were divided into the slowest, median, or fastest 33% average daily gain (ADG) category, yielding a nested design. Although average daily feed intake (ADFI) increased with increasing WW and ADG categories, feed efficiency (G:F) was not different. While tissue accretion rates varied due to WW and ADG category, the composition of gain was not affected. In conclusion, both WW and ADG affect the physiological development of pigs.
Iowa State University
Jones, Cassandra; Gabler, Nicholas; Patience, John F.; and Main, Rodger G.
"Irrespective of Differences in Weaning Weight, Feed Efficiency is
Not Different among Pigs with Varying Average Daily Gain,"
Animal Industry Report:
AS 657, ASL R2652.
Available at: http://lib.dr.iastate.edu/ans_air/vol657/iss1/76