Effect of the levels of calcium and particle size of limestone on laying hens

Abstract

-This experiment was conducted to evaluate the effect of levels of calcium (Ca) and particle size of limestone (LS) for laying hens. It was used 216 Dekalb White laying hens at 25 to 49 weeks of age in a completely randomized design in a 3 × 2 factorial arrangement, composed of three levels of calcium (3.92, 4.02 and 4.12%) and two particle sizes of limestone (thin -0.60 mm; and thick -1.00 mm), resulting in 6 treatments with six replicates of six birds. There was no significant effect of levels of calcium and limestone particle size neither of the interaction calcium × particle size for feed intake, egg weight, specific gravity, shell thickness, shell percentage, Haugh unit, calcium and phosphorus digestibility and percentage of digestive tract. Production, mass, conversion by mass and conversion by egg dozen had their best results with 4.12% of calcium in the diet. Percentage of gizzard and feed intake observed at 3:00 p.m. improved as limestone granulometry improved from 0.60 to 1.00 mm. There was an interaction effect among calcium level and limestone granulometry for breaking strength of tibia, bone density, length of the small intestine and feed intake at 6:00 a.m.; 9:00 a.m., 12:00 p.m., 6:00 p.m. and 9:00 p.m., respectively. It is recommended the addition of 4.12% of calcium and limestone in the thick granulometry (1.00 mm) for a better performance of commercial laying hens. More studies are needed to elucidate the mechanisms involved in the alteration of nutritional behavior of laying hens in response to changes in the levels of calcium and in the granulometry of limestone in the rations.Key Words: bone strength, egg quality, performance Efeito dos níveis de cálcio e da granulometria do calcário para poedeiras comerciais RESUMO -O experimento foi realizado para avaliar o efeito dos níveis de cálcio (Ca) e da granulometria do calcário (GC) para poedeiras comerciais. Foram utilizadas 216 poedeiras da linhagem Dekalb White de 25 a 49 semanas de idade em um delineamento inteiramente casualizado, em esquema fatorial 3 × 2, composto de três níveis de cálcio (3,92; 4,02 e 4,12%) e duas granulometrias do calcário (fina -0,60 mm; e grossa -1,00 mm), que resultaram em seis tratamentos, com seis repetições de seis aves. Não houve efeito significativo dos níveis de cálcio e da granulometria do calcário nem da interação nível de cálcio × granulometria do calcário para o consumo de ração, o peso dos ovos, a gravidade específica, a espessura da casca, a porcentagem de casca, a unidade Haugh, a digestibilidade de cálcio e fósforo e a porcentagem do trato digestório.A produção, massa, conversão por massa e conversão por dúzia de ovos tiveram seus melhores resultados com 4,12% de cálcio na dieta . A porcentagem de moela e o consumo de ração observado às 15 h melhoraram com o aumento na granulometria do calcário de 0,60 para 1,00 mm. Houve efeito da interação entre nível de cálcio e granulometria do calcário para a resistência à quebra da tíbia, a densidade óssea, o comprimento do intestino delgado e o consumo de...

Free-choice Feeding of Three Different Dietary Calcium Sources and their Influence on Egg Quality Parameters of Commercial Layers

“…According to Pizzolante et al, (2009), coarse limestone produced less cracked eggs. In contrast, a study conducted by de Araujo et al, (2011), revealed that no effect due to limestone particle sizes on egg weight, egg dozen conversions, shell thickness, egg shell ratio and Haugh Unit. Pelicia et al, (2009) showed that in vitro solubility of limestone decreased with increasing particle size and no significant effect of particle size distribution on egg production, egg weight and feed intake of layers.…”

Calcium particle size and feeding time influence egg shell quality in laying hens

“…Calcium (Ca) is a key mineral in laying hens, particularly during the laying period (Araujo et al, 2011). Dietary Ca is one of the primary factors affecting egg shell quality and shell strength (William, Horacio, Paulo, Luis, & Marcelo, 2006).…”

“…Particle size of calcium sources in layers' diets is an important factor affected calcium bioavailability. Acknowledging this importance, the identification of the Ca bioavailability of different sources and also the ideal Ca particle size (generally limestone) in laying hens have been received great interest by researchers for a long time (Araujo et al, 2011;De Witt, Kuleile, Van der Merwe, & Fair, 2008;Ekmay & Coon, 2011;Guinotte & Nys, 1991;Guo & Kim, 2012;Koreleski & Šwiątkiewicz, 2004;Lichovnikova, 2007;Pavlovski, Vitorović, Lukić, & Spasojević, 2003;Pelicia et al, 2011;Saunders-Blades, MacIsaac, Korver, & Anderson, 2009;Skřivan, Marounek, Bubancova, & Podsedníček, 2010).…”

Digestibility of calcium in feed ingredients and requirements of digestible calcium for growing pigs

“…In laying hens, the effect of particle size on the digestibility of Ca is variable (Scheideler 1998;Araujo et al 2011), but in pigs, a particle size between 0.10 and 0.54 mm does not affect the relative bioavailability of Ca (Ross et al 1984). Recently, it was also reported that a particle size between 200 and 1125 microns does not affect the ATTD or STTD of Ca in Ca carbonate included in phytate-containing diets based on corn and potato protein isolate (Merriman and Stein 2015).…”