Effects of edible environmental enrichments during the rearing and laying periods in a littered aviary—Part 2: physical development of pullets and performance, egg quality, and carcass composition in laying hens

Abstract

Feather pecking and cannibalism are 2 major problems in laying hens' husbandry. Although additional environmental enrichment material ( EM ) supply is thought to lessen these problems, consistent evidences are lacking. This study examined the effects of EM supply (pecking stones and alfalfa bales) on biological performance, carcass composition, and animal losses in a littered housing system. 2,000 brown-egg and 2,000 white-egg layer hen pullets of the genetic strains Lohmann Brown classic and Lohmann Selected Leghorn classic, respectively, were reared separately in a 16-compartment aviary system until week 18. 1,320 remaining laying hens were then transferred to a 44-compartment laying stable (weeks 19–48). Both strains were tested under 4 treatment variants (n = 150–180 per strain and per variant): V1—no EM over the entire study period; V2—the rearing period with and the laying period without EM; V3—the rearing period without and the laying period with EM; V4—EM over the entire study period. Data on development, performance, egg quality, feed intake, EM consumption, animal losses, carcass composition, and economic traits were collected. Enrichment material supply during rearing (V2 and V4, both strains) was found to globally increase not only hens' relative gizzard mass ( P = 0.036) but also the cracked eggs' percentage (compared with V3; P = 0.008) and to decrease the body mass in weeks 6 ( P = 0.023) and 8 ( P = 0.023) and the uniformity in week 16 ( P = 0.011). Enrichment material provision during the laying period (V3 and V4, both strains) increased egg weights ( P = 0.028) and the mean body mass ( P = 0.036); however, continuous provision of EM (V4, both strains) increased the floor eggs' percentage ( P = 0.019). The EM supply did not affect mortality, loss of production days, losses due to skin and toe cannibalism, or the income over feed costs. However, the income over feed and enrichment costs of V1 hens was higher by 0.55 €/hen than that of V4 hens ( P = 0.022). Therefore, EM supply cannot be recommended as a measure to increase laying performance and reduce animal losses, but its positive effects on animal welfare should be considered.

Edible Environmental Enrichments in Littered Housing Systems: Do Their Effects on Integument Condition Differ Between Commercial Laying Hen Strains?

“…Hens reared with EM had lower body weights in weeks 8 and 16 compared to the CON, as already shown by [ 78 ]. Neither laying performance nor egg mass production increased with access to EM, as confirmed by recent studies [ 16 , 30 , 33 , 78 ]. In contrast to this study, [ 78 ] found higher egg weights in groups with access to pecking stones and alfalfa bales during the laying period.…”

“…Neither laying performance nor egg mass production increased with access to EM, as confirmed by recent studies [ 16 , 30 , 33 , 78 ]. In contrast to this study, [ 78 ] found higher egg weights in groups with access to pecking stones and alfalfa bales during the laying period. To our knowledge, no effect of EM provision in littered housing systems on albumen consistency as a trait of internal egg quality has been reported yet.…”

“…CON eggs showed higher HU values in comparison to EXP. Other studies that examined this context found no unidirectional effect of the EM variant [ 28 , 78 ]. Possible nutritional causes for the reduced albumen consistency when EMs are ingested can be discussed.…”

Environmental Enrichments in Laying Hen Production Systems with Emphasis on Welfare and Egg Quality

“…Schreiter et al (2020c) stated that egg albumen consistency in laying period decreased after rearing different genotypes (Lohmann Brown classic, Bovans Brown, Lohmann Selected Leghorn classic, and Dekalb White) in environments enriched with either pecking stones and alfalfa bales. Schreiter et al (2020b) observed that environmental enrichment with pecking stones and alfalfa bales material during rearing increased the percentage of cracked eggs in different laying hen genotypes (Lohmann Brown classic and Lohmann Selected Leghorn classic), and environmental enrichment during the laying period increased egg weights. However, when enrichment materials were continuously offered, the percentage of floor eggs increased in both genotypes.…”