Effects of environmental enrichment strategies on behavior and production performance of broiler breeder chickens reared at elevated temperatures

Enriched housing systems are embraced as better alternatives to bare housing systems for table egg laying hens. However, attention is presently turning to the meat type (broiler breeder) laying hens. Hence, this experiment investigated the effects of perch structures and sharp sand on behavior, physiology, and production performance of broiler breeder chickens reared under elevated temperatures. Two hundred and eighty eight broiler breeder females and 48 males (Cobb 500) at 21-weeks-old were assigned to their respective treatments in two different rooms. One room was maintained at 23°C to mimic a thermoneutral environment while the second room cycled between 23°C and 30°C to mimic a heat stressed environment. Each room had all four treatments and the treatments were replicated three times with 12 females and two males per replicate. The four treatments were sand (S), perch (P), a combination of sand and perch (SP), and control (C). Production performances (hen-day egg production, egg weights, floor eggs, fertility, and hatchability), Physiology (cortcosterone levels, heterophil/lymphocyte ratio), and behavior parameters were determined. The production data were analyzed using a completely randomized design (CRD) with repeated measures while the physiology and behavior parameters were analyzed using CRD split plot with sampling and a factorial in the whole plot. The results indicate that S and SP increased (P=0.0138) egg production. Enrichment S, P, and SP reduced the occurrences of floor eggs. HS environment increased (P=0.0435) bird’s corticosterone levels in broiler breeder males and tended to increase (P=0.07) female corticosterone levels. There was a trend (P=0.0792) for increased preening in the HS room. The birds in treatment P tended to preen more (P=0.0655) than those in S. The frequency of attempted mating was least (P=0.025) in treatment P. In the TN environment, broiler breeders reared in treatments S, SP, and C performed more (P=0.0029) completed mating than their counterparts in the HS room. The duration of sand use was higher (