Composição e solubilidade in vitro de calcários calcíticos de Minas Gerais

Abstract

RESUMOO experimento foi conduzido no Laboratório de Pesquisa Animal do Departamento de Zootecnia da Universidade Federal de Lavras -UFLA, em Lavras -MG, Brasil, com objetivo de avaliar as características físico-químicas de calcários calcí-ticos utilizados na alimentação de poedeiras. Foi utilizado um delineamento inteiramente casualizado, em esquema fatorial 4x5, sendo 4 calcários calcíticos extraídos em diferentes regiões de Minas Gerais (Ijaci, Barroso, Iguatama e Formiga) em 5 granulometrias padronizadas (0,15-0,30; 0,30-0,60; 0,60-1,20; 1,20-2,00 e 2,00-4,00 mm), totalizando 20 tratamentos, com 8 repetições. Os calcários foram encaminhados ao laboratório, onde se determinaram a composição mineral e a solubilidade in vitro determinada pelo método da perda de peso. Pela análise mineral dos calcários inferiram-se algumas diferenças numéricas, principalmente em elementos como ferro e manganês, além de detectar a presença de zinco e cobre em menor quantidade. Houve interação (P<0,01) entre os calcários e as granulometrias para a solubilidade in vitro dos calcários e todos os calcários apresentaram redução na solubilidade in vitro com o aumento da granulometria (P<0,01), porém, apresentando comportamento cúbico. O calcário de Barroso mostrou-se o mais solúvel (P<0,01) em todas as granulometrias e sua solubilidade in vitro foi superior a 12,5% na maior granulometria estudada (2,00-4,00 mm), o que representou uma taxa de solubilidade de 33,3% acima do valor determinado para o calcário de Formiga, que foi o menos solúvel (P<0,01) na mesma granulometria. Pelos resultados encontrados, verificou-se que a solubilidade in vitro não é influenciada unicamente pela granulometria em que o calcário se apresenta.Termos para indexação: Calcário, solubilidade, granulometria, cálcio, avicultura, poedeiras. ABSTRACTThe experiment was carried out at the Animal Research Laboratory the Department of Animal Science of the Federal University of Lavras -UFLA, in Lavras -MG, Brazil, with objective of evaluating the physical-chemistries characteristics of limestones used in the laying hens feeding. The experimental design was completely randomized in a 4x5 factorial arrangement, being four limestones extracted in different areas of Minas Gerais (Ijaci, Barroso, Iguatama and Formiga) in five particle size standardized (0.15-0.30, 0.30-0.60, 0.60-1.20, 1.20-2.00 and 2.00-4.00 mm), amounting twenty treatments, with eight replications. The limestones were directed to the laboratory where was determined the mineral composition and the in vitro solubility, certain for the method of the weight loss. The mineral analysis of the limestones, indicated some numerical differences mainly in elements as iron and manganese, besides detecting the presence of zinc and copper in smaller amount. There was interaction (P<0.01) among the limestones and the particle size for the in vitro limestones solubility and all the limestones presented reduction in the in vitro solubility with the particle size increase (P<0.01), however, presenting cubic response. The Ba...

Alternative calcium source effects on commercial egg production and quality

“…Calcitic limestone GMD was 0.18mm, whereas marine calcium GMD was 0.4mm, and therefore it was expected that limestone would promote better results, particularly as to egg weight and eggshell weight, as demonstrated by Guinote & Nys (1991). However, our results are consistent with those of Fassani et al (2004), who worked with limestone GMDs between 0.15 and 0.60 mm, and did not observe differences in limestone intake, limestone intestinal retention, or in vitro solubility. It must be noted that the limestone particle sizes used by Fassani et al (2004) are similar to those found for calcitic limestone and marine calcium used in the present study.…”

“…However, our results are consistent with those of Fassani et al (2004), who worked with limestone GMDs between 0.15 and 0.60 mm, and did not observe differences in limestone intake, limestone intestinal retention, or in vitro solubility. It must be noted that the limestone particle sizes used by Fassani et al (2004) are similar to those found for calcitic limestone and marine calcium used in the present study. This is important as limestone with lower solubility, which is found in limestone with larger particles, increases calcium intestinal retention, thereby improving eggshell quality, as observed by Guinote & Nys (1991).…”

“…This is important as limestone with lower solubility, which is found in limestone with larger particles, increases calcium intestinal retention, thereby improving eggshell quality, as observed by Guinote & Nys (1991). On the other hand, Fassani et al (2004), working with particle sizes of 2.00-4.00 mm found different limestone intake, limestone intestinal retention, and in vitro solubility.…”

“…On the other hand, Makled & Charlés (1987) found improved apparent egg density due to the association of calcium sources. The different results found in other studies are related to the chemical composition and to the physical characteristics of different calcium sources (Fassani et al 2004). Roland (1986), Rao et al (1992), and Cheng & Coon (1990) carried out studies to evaluate optimal particle size of calcium sources in terms of performance and egg quality.…”

Adding agregado calcáreo and Conchuela in diets of broilers and its effect on production

“…Pero, para ser absorbido, primero tiene que ser solubilizado, el tiempo de soluvilización depende de la fuente de calcio y del tamaño de partícula (Saunders-Blades et al, 2009). Por ello, Fassani et al (2004) sostienen que la variación en la composición química, solubilidad in vitro, biodisponibilidad y granulometría son importantes para la selección de fuentes de calcio en la alimentación animal, siendo la solubilidad un factor principal, porque está relacionada con la biodisponibilidad y absorción intestinal. Mediante la presente evaluación se determinará la influencia de la adición de dos fuentes de calcio sobre los parámetros productivos de pollos de carne de la línea Cobb 500.…”