Alternative calcium source effects on commercial egg production and quality

K Pelícia,Ea Garcia,Abg Faitarone,C Móri,Da Berto,Mrs Scherer,Ja Dalanezi,Ab Molino

doi:10.1590/s1516-635x2007000200005

K Pelícia, Ea Garcia + Show 6 more

Open Access

https://doi.org/10.1590/s1516-635x2007000200005

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Abstract

This study aimed at verifying the possibility of replacing calcitic limestone by marine calcium in the diet of layers. A total number of 321 Hi-sex hens, with 40 weeks of age at the beginning of the experiment, was used. A completely randomized experimental design was applied, with 5 treatments (0, 15, 30, 45, and 60 % of calcitic limestone replacement by marine calcium source) and eight replicates of eight birds each. Treatments significantly affected specific gravity (p<0.05), with the inclusion of 60% marine calcium (T5) presenting the worst result as compared to T1, which included only calcitic limestone as calcium source. It was concluded that marine calcium can replace up to 45% of calcitic limestone with no effects on performance or egg quality.

Highlights

Calcium is very important for layers, as eggshell consists of 90% mineral matter, out of which 98% is composed of calcium carbonate (Mendonça Junior, 1993)
It was concluded that marine calcium can replace up to 45% of calcitic limestone with no effects on performance or egg quality
There were no statistical differences (p>0.05) among treatments as to mortality, egg production, egg weight, egg mass, feed intake, feed conversion ratio per dozen eggs and per kg eggs, and percentage of broken eggs, which are consistent with the results found by Kussakawa et al (1998), who did not find any effect of different combination of calcium sources on egg production, feed intake, or feed conversion ratio

Summary

Introduction

Calcium is very important for layers, as eggshell consists of 90% mineral matter, out of which 98% is composed of calcium carbonate (Mendonça Junior, 1993). According to Leeson & Summers (1997), the use of medullar bones for eggshell formation results in sudden loss of 2g of body calcium, and a calcium bone reserve must be build up before the production period. As well as particle size, solubility, and inclusion level influence eggshell quality (Faria 2002). Calcium absorption is related to several factors, such as vitamin D, protein, phosphates, free fatty acids, and zinc levels. Calcium source solubilization in the digestive tract is of utmost importance as, according to Bronner (1993), is essential, as calcium needs to solubilized in the digestive tract before being nutritionally used

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