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Relationship between feeding behavior and performance traits in boars
Feed accounts for over 60% of the cost of producing a market pig. Genetic variation exists for feed efficiency and it can be improved through selection. Feed efficiency or feed intake and growth are included in most selection programs; however, there is little known about how feeding behaviors can influence performance. Individual feed intake records from 895 Yorkshire, 685 Landrace, and 1588 Duroc boars were collected at a single finishing site using Osborne Feed Intake Recording Equipment (FIRE<sup>TM</sup>). Pigs were tested for 12 weeks from 75.7 (± 2.8) days old to 158.5 (± 3.0) days old. During the testing period, feed intake was recorded every other week on each pig, with the first 2 days discarded as the acclimation period and the other 5 days used to predict daily feed intake. While not on the FIRE feeders, pigs ate from a fence line feeder. For all three breeds, a greater amount of time spent in the feeder per day was correlated with poorer feed efficiency; the correlations (± SD) were 0.24 ± 0.06, 0.29 ± 0.07, and 0.26 ± 0.05, for Yorkshire, Landrace, and Duroc boars, respectively. The phenotypic correlations between feed intake per visit and feed efficiency ranged from 0.17 to 0.22 (P<0.05) for the three breeds. There was a positive correlation between average daily gain during the testing period and time spent in the feeder for all three breeds (0.08-0.12, P<0.05), but the magnitude was small. The amount of time spent in the feeder per day increased for the first three weeks after the pigs started the test, then declined for the remaining test period for all three breeds. Yorkshire boars spent the most time in the feeder at the beginning of the testing period, but spent the least time in the feeder after two weeks on-test compared to the other two breeds. The number of visits per day decreased throughout the testing period for Landrace and Duroc boars, while Yorkshire boars had a maximum number of visits per day half way through the testing period. Feed consumed per visit for all three breeds increased throughout the testing period. It was observed that Yorkshire boars had more visits per day to the feeder, but consumed less feed per day compared to Landrace and Duroc boars. Establishing how feeding behaviors influence boar performance can result in improved response in feed efficiency through both selection and feeding strategies.
Keywords:
feed intake, growth rate, swine