Rearing cage type and dietary limestone particle size: II, effects on egg production, eggshell, and bone quality in Lohmann selected Leghorn-Lite hens

Abstract

We investigated effects of rearing cage type and dietary limestone particle size (LPS) on egg production, egg weight, eggshell, and bone quality in laying hens. The pullets were reared in conventional (CON; 20 chicks/cage, 270 cm²/chick) or furnished (FUR; 30 chicks/cage; 636 cm²/chick) cages and fed 3 LPS (fine, <0.595 mm; medium, 0.595 to <1.68 mm; and 1:1 mixture of F and M wt/wt) to 16 wk of age (woa). Pullets were transitioned to laying furnished cages and retained rearing treatment combination identities (n = 5, 20 hens/cage). Hens had free access to common commercial layer diet and water through to 40 woa. Eggs were recorded daily for calculation of hen day egg production (HDEP). Subsamples of eggs laid on the first day of 24, 28, 32, 36, and 40 woa were used for eggshell quality analyses. Two hens per cage were sacrificed on the last day of 24 and 40 woa for femur and tibia quality assessments. There was no interaction (P > 0.05) between rearing cage type and dietary LPS on response variables. At 19 and 20 woa, HDEP was higher (P < 0.01) for FUR than CON reared hens but was similar (P > 0.05) afterward. At 40 woa, FUR reared hens had higher (P < 0.05) body weight (BW), egg weight (EW), eggshell thickness, and eggshell weight and tended (P < 0.10) to have higher femur and tibia mineral density (BMD) and mineral content (BMC) than CON reared hens. Rearing dietary LPS had no effect (P > 0.05) on HDEP, BW, EW, and eggshell quality. Although, rearing dietary LPS did not affect (P > 0.05) femur and tibia BMD and BMC; at 24 woa, hens reared on medium LPS tended to have higher femur BMD (0.17 vs. 0.14 g/cm²; P = 0.079) and BMC (0.99 vs.0.78 g; P = 0.088) than hens reared on fine LPS. In conclusion, hens reared in furnished cages had better eggshell quality but had marginal effects on femur and tibia quality, whereas rearing dietary LPS had no effects on eggshell and bone attributes in hens.

Keywords: bone quality; egg production; eggshell quality; rearing housing; rearing limestone particle size.

Figure 1

The design of furnished layer cage (A) (source: Ford Dickson Inc., Mitchell, Ontario, Canada), and hens in the furnished cage during the study (B). Number labeling describes enrichment; 1 = Scratch mat/Litter mat, 2 = Perch, 3 = Curtained nest, 4 = Claw scratcher, 5 = Drinker and 6 = Litter delivery tube.

Figure 2

Effect of rearing cage type (A) and dietary limestone particle size (B) on the body weight of Lohmann LSL-Lite hens. For cages; conventional (CON) cage 76 cm × 71 cm × 46 cm; furnished (FUR) cage 239 cm × 80 cm × 75 cm outfitted with platforms and terraces. Limestone particle size; F, fine, <0.595 mm, F; medium, 0.595 to <1.68 mm, M; and 1:1 mixture of F and M wt/wt; FM.

Figure 3

Effect of rearing cage type on hen day egg production in Lohmann LSL-Lite hens. ∗∗ indicates P = <0.01. Conventional (CON) cage 76 cm × 71 cm × 46 cm; furnished (FUR) cage 239 cm × 80 cm × 75 cm outfitted with platforms and terraces.

Figure 4

Effect of rearing dietary limestone particle size on hen day egg production in Lohmann LSL-Lite hens. Dietary LPS (fine, <0.595 mm, F; medium, 0.595 to <1.68 mm, M; and 1:1 mixture of F and M wt/wt; FM). Abbreviation: LPS, limestone particle size.

Figure 5

Effect of rearing cage type on egg weight in Lohmann LSL-Lite hens. Conventional (CON) cage 76 cm × 71 cm × 46 cm; furnished (FUR) cage 239 cm × 80 cm × 75 cm outfitted with platforms and terraces.