Avaliação da qualidade da casca dos ovos provenientes de matrizes pesadas com diferentes idades

Abstract

RESUMOFoi realizado um estudo sobre qualidade da casca dos ovos incubáveis provenientes de matrizes pesadas com diferentes idades, por meio da avaliação da relação entre peso da casca e peso do ovo e análises de peso específico, espessura, porosidade, resistência e microscopia eletrônica. Os dois tratamentos foram definidos pela idade da matriz, sendo considerados ovos de matrizes novas  33 semanas  e de matrizes velhas  63 semanas. Os ovos de matrizes com 33 semanas foram mais leves, e o número de poros por cm 2 foi menor que o de ovos das aves mais velhas. Ovos de aves com 63 semanas apresentaram menor percentual de casca em relação ao peso do ovo, menor peso específico e menores resistência e espessura da casca. A proporção das membranas da casca em relação à sua espessura total foi maior nas matrizes mais novas. Concluiu-se que ovos de matrizes velhas têm qualidade de casca inferior aos ovos das matrizes novas e que as membranas da casca nos ovos de matrizes novas desempenham papel relevante em sua estrutura.Palavras-chave: incubação, matrizes pesadas, qualidade de casca do ovo ABSTRACT We conducted a study on eggshell quality from Cobb® broiler breeders at different ages by assessing the relationship between eggshell weight and egg weight and analysis of specific weight, thickness, porosity, strength and electron microscopy. Both treatments were defined by broiler breeder age, considering eggs from young breeders (33 weeks) and eggs from old breeders (63 weeks). It was observed that eggs from breeders at 33 weeks have lower weight and number of pores per cm

Age influence on quality of shell and penetration in bacterial laying lightweight eggs

“…Eggs from laying hens aged 62 and 51 weeks show larger weight than the ones from hens aged 39 and 21, respectively. This data agrees with findings by Barbosa et al (2012) and Trindade et al (2007), which reported larger EWs as the bird aged. According to Almeida et al (2006), this is due to the production of larger ovarian follicles, which determine the production of eggs with large yolks, thereby increasing the ratio of yolk weight and egg weight.…”

“…Table 2, the bird's age influenced significantly (P≤0.05) the number of pores in the shell (NP), with older birds showing higher NP by cm 2 than younger ones. Similar data have been found in the studies of Barbosa et al (2012). Pore size, however, suffered no influence (P>0.05) from bird's age (Table 3).…”

“…Age influence (P≤0.05) over SP was observed, with eggs from younger birds showing higher values for this parameter than the ones from birds aged 62 weeks, corroborating Barbosa et al (2012). As reported by Valente (2011), as the bird ages, the SP does not increase in the same proportion as the EW, since the amount of calcium mobilized for shell formation, regardless of age progression, remains the same, with only a lower rate of calcium carbonate deposition by area unit and, thereby, a lower SP.…”

“…The eggshell works as natural packaging to internal components by acting as a physical barrier, hampering pathogenic penetration and excessive water loss (Barbosa et al, 2012).…”

“…In this context, eggs for human consumption with shells of inferior quality are more likely to be contaminated by microorganism, representing a higher risk to consumer health (Carvalho and Fernandes, 2013;Mazzuco and Bertechini, 2014).…”