Effects of Bird Age, Density, and Molt on Behavioral Profiles of Two Commercial Layer Strains in Cages

Abstract

Two commercial strains, Hy-Line W-36 and DeKalb XL, were moved to a laying house at 18 wk of age. They were housed 6 hens/layer cage at 2 densities (361 and 482 cm2/bird) with 2 replications each per strain/density combination. The high-density treatment contained 24 hens/replication and the low-density treatment contained 18 hens/replication for a total of 168 hens. Production parameters were measured during the first egg production cycle, the molt period, and the first 4 wk of the second lay cycle (20 to 68 wk of age). Behavioral observations were taken during 2 consecutive d at 26, 34, 43, 51, 62, 64, and 68 wk of age to examine behavioral patterns. Modified Hansen's tests were conducted concurrently to provide indication of the fearfulness levels of hens at the various stages of production. The production characteristics were similar for both strains. The hens kept at the higher density had lower (P < 0.01) hen-day production and (P < 0.05) daily egg mass. Appetitive behaviors were not affected by strain or density but were affected by the age of the hen and by molting. During the molt, feeding and drinking behavioral acts were fewer (P < 0.05) at 0.018 and 0.013 acts per bird/min, respectively, and standing behavior was highest. The results indicated that the frequencies of pecking inedible objects during the molt period were similar to the frequencies at 26 and 34 wk. Hens performed more acts of standing, and crouching and had lower frequency of movement during the molt. Those kept at a low density performed more movement acts. Feather pecking decreased as hens aged and increased when they molted but was not affected by strain or density. The frequency of aggression and submissive acts was significantly lower during the molt period. Behaviors were affected by strain, density, bird age, and molting; however, the patterns and number of aggressive acts did not increase to compromise the welfare status of the hens. Behaviors during the molt appeared consistent with mechanisms for conservation of body reserves.

Effects of a premolt calcium and low-energy molt program on laying hen behavior and heterophil-to-lymphocyte ratios

“…The time used by these hens in each respective posture and behavior is in agreement with previous laying hen behavioral research (Webster, 2000;Anderson et al, 2004). Therefore, any differences reported in the subsequent molt and postmolt periods could be attributed to the low-energy molt diets.…”

“…Webster (2000) and Biggs et al (2004;housed 3 hens/cage at 460 cm 2 /hen) reported no differences in aggressive pecking behaviors when comparing WM and FW molt treatments, but McCowan et al (2006) noted that cage pecking increased in hens (housed 3 hens/cage at 417 cm 2 /hen) assigned to an FW molt, and aggression increased in hens assigned to an FW and a non-FW molt during the molt period. Webster (2000), Anderson et al (2004), and Biggs et al (2004) reported in agreement across studies that FW birds did not show an increase in aggression, nonnutritive pecking, or sitting when compared with birds that still had access to a low-energy feed during molt. The 2 d of observations during molt were averaged before the final analysis because no difference was observed between observation days for each behavioral trait.…”

The effects of space allowance on egg yield, egg quality and plumage condition of laying hens in battery cages

“…Decreasing egg production was shown to be attributable to the reduced feeding area per hen, cannibalism (Hester and Wilson, 1986;Craig and Milliken, 1989;Lee and Moss, 1995;Süto et al, 1997;Sohail et al, 2001;Onbasilar and Aksoy, 2005;Jalal et al, 2006;Nicol et al, 2006) and stocking density (Adams and Craig, 1985). Anderson et al (2004) found out that the reduced cage stocking in Hy-Line W36 and Dekalb XL commercial layer genotypes decreased hen-day egg production. They reported a decrease in egg production from 82.3% to 77.4% because of reducing the cage stocking from 482 cm 2 to 361 cm 2 per hen.…”

“…A decrease in floor densities causes a reduction in egg production (EP), egg weight (EW) and feed intake (FI), an increase in mortality and feather pecking with poorer plumage scores (Bell, 1981;Roush et al, 1984;Anderson et al, 1989;Sandoval et al, 1991;Hester et al, 1996;Huber-Eicher and Sebö, 2001;Anderson et al, 2004;Onbasilar and Aksoy, 2005;Tauson, 2005;Jalal et al, 2006;Nahashon et al, 2006;Nicol et al, 2006). However, there is still a need to carry out further studies regarding egg production, egg quality, lower mortality and plumage damage of layers, as responses to reduced cage densities.…”

Enriquecimento ambiental para gaiolas convencionais de poedeiras em função de diferentes densidades de alojamento

“…, 1970;GROVER et al, 1972;CONNOR E BURTON 1975;CUNNINGHAM E OSTRANDER, 1981;CUNNINGHAM, 1982;CUNNINGHAM E OSTRANDER, 1982;ROUSH et al, 1984;CUNNINGHAM E GVARYAHU, 1987;CUNNINGHAM et al, 1987;CUNNINGHAM et al, 1988;ANDERSON et al, 2004;ON AŞILA E AKSOY, 2005;NAHASHON et al, 2006;DE MORAES GARCIA et al, 2015).…”