Effects of stock density on the laying performance, blood parameter, corticosterone, litter quality, gas emission and bone mineral density of laying hens in floor pens

Abstract Icariin, a flavonol glycoside, is one of major active ingredients of the traditional Chinese medicine Herba epimedii. Icariin has been reported to successfully treat the osteoporosis of the rat. However, effects of icariin on the osteoporosis in caged laying hens are still unkown. This study present the effects of dietary icariin supplementation on the laying performance, the egg quality and the bone metabolism in caged laying hens. A total of 216 Lohmann pink-shell laying hens of 54-week-old from a commercial farm in the Hubei province of China were randomly assigned to 3 treatment groups with 6 replications per group and 12 birds per replication. The control group was fed a corn-soybean meal basal diet, and the experimental groups were fed basal diets supplemented with 500 and 2000 mg/kg icariin for 90 d. Layer performance responses, egg quality parameters, the bone mineral density and serum biochemical indicators were measured at the end of the experiment. Results showed that feed/egg ratio decreased as the supplied icariin level increased. The laying rate and the average egg weight were increased compared to the control group. However, no significant effect was observed on the egg quality. The bone mineral density of the tibia was measured by the dual-energy X-ray absorptiometry, indicating that icariin can increase the bone mineral density. Serum biochemical analysis showed that icariin decreased the level of alkaline phosphatase, tartrate-resistant acid phosphatase, osteocalcin and calcitonin. Our observations provided evidences that dietary supplementation of icariin increased the bone mineral density and improved the laying performance, and icariin can be used for the prevention of the osteoporosis in caged laying hens.

Download Full-text

Keel Bone Damage in Laying Hens—Its Relation to Bone Mineral Density, Body Growth Rate and Laying Performance

Animals ◽

10.3390/ani11061546 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1546

Author(s):

Christin Habig ◽

Martina Henning ◽

Ulrich Baulain ◽

Simon Jansen ◽

Armin Manfred Scholz ◽

...

Keyword(s):

Bone Mineral Density ◽

Growth Rate ◽

Bone Mineral ◽

Laying Hens ◽

Bone Fractures ◽

Body Growth ◽

Mineral Density ◽

High Performing ◽

Laying Performance ◽

Bone Damage

Keel bone damage is an important animal welfare problem in laying hens. Two generations of four layer lines, differing in phylogenetic background and performance level and kept in single cages or floor pens were weighed and scored for keel bone deformities (KBD) during the laying period. KBD, keel bone fractures (KBF) and the bone mineral density (BMD) of the keels were assessed post mortem. For BMD, relationships to laying performance and body growth were estimated. Caged hens showed more deformities, but fewer fractures and a lower BMD of the keel bone than floor-housed hens. White-egg layers had a lower BMD (0.140–0.165 g/cm2) and more KBD than brown-egg layers (0.179–0.184 g/cm2). KBF occurred more often in the high-performing lines than the moderate-performing ones. However, in the high-performing lines, BMD was positively related to total egg number from 18 to 29 weeks of age. The adult body weight derived from fitted growth curves (Gompertz function) had a significant effect (p < 0.001) on keels’ BMD. The study contributes to the understanding of predisposing factors for keel bone damage in laying hens. It showed that the growth rate has a rather subordinate effect on keels’ BMD, while the BMD itself greatly affects KBD.

Download Full-text