Feeding, foraging, and feather pecking behaviours in precision-fed and skip-a-day-fed broiler breeder pullets

Abstract

Broiler breeder chickens are feed-restricted to control growth and maximize chick production. Feed restriction creates welfare concerns as conventional skip-a-day feeding can increase activity levels and oral stereotypies during the rearing period. A precision feeding system has been developed to provide small meals to individual birds multiple times throughout a day when their BW is less than a target BW.Objectives of the current study were to investigate whether precision feeding affected: 1) restlessness in broiler breeder pullets, by comparing the prevalence of standing and walking to a flock fed every other day and 2) foraging frustration, by comparing foraging and stereotypic oral behaviours in precision-fed and skip-a-day-fed broiler breeders. Using a randomized complete block design, precision feeding and skip-a-day pens were each represented in 6 blocks (N=6) with 45 Ross 308 pullets per pen. Skip-a-day-fed pullets were fed at 10:30 am on alternating mornings. Live behaviour observations of pullets (15min per pen, 12 focal pullets) were conducted during morning (08:00–09:55) and afternoon (13:45–15:40) sessions once per week, from 10 to 21 weeks of age. Behaviours observed during instantaneous 1min scan sampling included: stand/walk, forage, sit, feather peck, dust-bathe, peck at wing-tag, pecking of the drinker, feeder, or pen wall, and ‘other’ behaviours. Means were reported as different when P<0.05. Feeder and pen wall pecking did not differ between treatments. Skip-a-day-fed pullets performed more stand/walk (6.15±0.05 vs. 5.69±0.05; F1,10=43.97; P<0.0001), forage (3.29±0.05 vs. 3.04±0.04; F1,10=15.37; P=0.0029), and feather peck (0.16±0.01 vs. 0.03±0.01; F1,10=58.31; P<0.0001) behaviours compared with precision-fed pullets, respectively. Precision-fed pullets performed more sitting (0.23±0.01 vs. 0.15±0.01; F1,10=20.15; P=0.0012) and drinker pecking (2.60±0.01 vs. 0.15±0.01; F1,10=39.11; P<0.0001) behaviours compared with skip-a-day-fed pullets, respectively. Feather pecking and foraging were not consistently inversely related, suggesting feather pecking in broiler breeders may have additional causal factors beyond re-directed foraging. An increase in drinker pecking suggests feeding motivation is still present in precision-fed flocks. In conclusion, compared with skip-a-day feeding, precision feeding appears to decrease, but not eliminate, feeding motivation in feed-restricted broiler breeder pullets.