Influence of graded levels of calcium and vitamin K in the diets of laying hens during the growing phase and their effects on the laying phase

Abstract

The aim of this study was to evaluate the effect of dietary supplementation of vitamin K (vit K) and Ca in the diets of laying hens on bone and blood parameters and performance during the growing phase and the effects on the laying phase up to 32 weeks. The study utilized 120 Hy-Line W-36 pullets in the growing phase (13-18 weeks), 80 laying hens in the production phase (20-32 weeks), distributed in a completely randomized design in a 2 × 5 factorial arrangement, two levels of Ca (0.8 and 1.4%) and five levels of vit K supplementation (0, 2, 8, 16 and 32 mg/kg) with four experimental units. An experimental diet was fed during the growing phase, and the commercial diet was fed during the production phase and were analysed for biochemistry and bone variables at 18 and 32 weeks. In pullets, a significant interaction of levels of vit K and Ca was observed for total serum calcium (mg/dl), Seedor index, Ca in the bones (%) and medullary bone (%). Pullets at 18 weeks of age, receiving diets with 1.4% Ca, displayed a quadratic effect of vit K with better results for these variables with 17.86, 14.59, 14.48 and 16.80 mg/kg of vit K, respectively. For level 0.8% Ca no effect of vit K was observed. The treatments during the growing phase had no effect on egg production, performance and biochemistry serum until 32 weeks. Medullary bone (%), there was a significant interaction for 1.4% Ca and a quadratic effect for vit K, with greater medullary bone areas observed with 6.09 mg/kg vit K in the diet. Supplementation with vit K in a diet with 1.4% Ca during the growing phase allowed for an increase in the area of medullary bone at 18 weeks, which was maintained until 32 weeks.

An evaluation of bird weight and diet nutrient density during early lay on ISA Brown performance, egg quality, bone characteristics, and liver health at 50 weeks of age

“…The cortical thickness and medullary bone diameter were then measured at the breaking point using digital Vernier calipers with an accuracy of ± 0.01 mm. Bone density was measured as bone weight to bone length ( Souza et al, 2017 ), modified to 100 g/mm index where higher bone density is indicated by higher weight to length index. The broken bones were later used to determine the femur ash content.…”

A Comparison of Morphometric Indices, Mineralization Level of Long Bones and Selected Blood Parameters in Hens of Three Breeds

“…Bone diameter was measured at the middle of the shaft (horizontal plane). The Seedor index was calculated using the formula SI = bone weight (mg)/bone length (mm) to indicate the bone density (Souza et al, 2017). Percentage of dissected bones in relation to body weight was also calculated.…”

“…In turn, the humerus is pneumatized as a genetic adaptation to flight. Because these bones also differ in the degree of mineralization (Applegate and Liibum, 2002;Van Wyhe et al, 2012), the mechanical load acting on them, and the muscle attachment (Regmi et al, 2017), most studies concentrate on long bones (tibia, femur and humerus) as representative for skeletal health (Jendral et al, 2008;Van Wyhe et al, 2012;Souza et al, 2017).…”

Effects of dietary vitamin K3 supplementation on production performance, egg quality, vitamin K-dependent proteins, and antioxidant properties in breeding geese during the laying period

“…Vitamin K is involved in bone metabolism as a coenzyme of γ-carboxylase, enhancing bone formation, mineralization and the biosynthesis and activation of key bone proteins ( Zhang et al, 2003 ; Souza et al, 2017 ). OC, a marker of bone formation, is involved in bone mineralization ( Shen et al, 2021b ).…”