Performance of Hens Laying Eggs with Heavy or Light Shell Weight when Fed Diets with Different Calcium and Phosphorus Levels

Abstract

Hy-Line W36® hens, 56-wk-old, were used to study the response to changing dietary Ca and P levels of hens laying eggs with heavy (HSW) or light shell weight (LSW). Three diets were fed: control diet [3.9% Ca and .55% total P (P t )], low-Ca diet (2.2% Ca and .55% P t ), and high-P diet (3.9% Ca and .90% P t ). In Experiment 2, one half of hens previously fed the low-Ca diet were changed to a Ca-deficient diet (1.7% Ca and .55% P t ), and the others continued to receive the diet previously fed. Also, one half of the hens fed the high-P diet were changed to a high-Ca, high-P diet (4.4% Ca and .90% P t ), and the others continued to receive the high-P diet. The control hens continued to receive the control diet. Shell weight was determined, and feed intake and egg production (EP) were recorded. Calcium and P intake, and Ca utilization were calculated. Plasma Ca and P, tibia breaking strength, and bone ash were determined.In both experiments egg production and shell weight were significantly lower for hens consuming both low-Ca and Ca-deficient diets than hens fed the control diet. The adverse effect was greater for HSW hens than for LSW hens. Many of HSW hens ceased production when fed the Ca-deficient diet. Calcium utilization was greater for HSW than for LSW hens. Increasing P in the diet from .55 to .90% P t had no significant effect on SW or EP. Increasing Ca in the diet from 3.9 to 4.4% and P from .55 to .90% P, had no significant effect on either EP, SW, or feed intake. Bone breaking strength and bone ash were not affected by dietary treatments. Plasma Ca and P concentrations were higher in the LSW than HSW hens. (

Dietary calcium deficiency in laying ducks impairs eggshell quality by suppressing the process of shell biomineralization

“…Unexpectedly, there were few shell-less eggs observed during the depletion period because the frequency of ovulation was reduced. This observation is in accordance with previous reports in laying hens that dietary calcium deficiency decreased egg production (Nevalainen, 1969;de Bernard et al, 1980;Abdallah , 1993). It probably indicates an adaptable biological physiology of laying birds in response to calcium deficiency.…”

Calcium from limestone meal and grit in laying hen diets - effect on performance, eggshell and bone quality

“…This may suggest better Ca utilization in hens fed diets with partial substitution of LG for LF. A significant increase of Ca deposition in eggs was reported by Abdallah et al (1993) using higher Ca levels in the diet.…”

Níveis de fósforo disponível em dietas para codornas japonesas de 45 a 57 semanas de idade

“…Entretanto, para o teor de fósforo na tíbia, essa maximização ocorreu no nível de 0,42% Tabela 6 -Teores de cálcio, fósforo, magnésio e cinzas na tíbia e nas excretas de codornas japonesas alimentadas com dietas com diferentes níveis de fósforo disponível cálculo da relação Ca:P no tecido ósseo, percebeu-se que a mesma manteve-se entre 2,4:1 e 2,5:1 para os níveis de Pd testados, comprovando a capacidade dessas aves de regular a homeostase óssea, dos minerais cálcio e fósforo, por meio da atuação dos hormônios calcitonina e paratormônio durante a fase de postura, não se esquecendo também da importância da vitamina D 3 nessa regulação, uma vez que, no caso de deficiência dessa vitamina ou de seus metabólitos ativos, a primeira ocorrência é a hipofosfatemia e elevação da fosfatase alcalina. Esses resultados discordam dos relatos de Costa et al (2007), de que o nível de 0,46% de Pd na dieta é suficiente para proporcionar maior percentagem de cálcio no tecido ósseo, de Garcia et al (2000), Abdallah et al (1993) e Keshavarz & Nakajima (1993) de que os níveis de fósforo disponível não influenciam a porcentagem de cálcio nos ossos.…”