Características físicas dos ovos e dos pintos de corte sobre o período de nascimento e qualidade dentro da janela de eclosão
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Data
2019-10-18
Autores
Thimotheo, Mariana [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Eclodibilidade e qualidade dos pintos e duração da incubação são importantes no processo de incubação de ovos, e podem ser influenciados pelas características físicas dos ovos. No Capítulo 1 é apresentada uma abordagem teórica sobre o tema. No Capítulo 2 foi analisado a qualidade incubatória de ovos leves e pesados de matrizes de corte, dentro do intervalo de peso de ovo comercialmente incubável, considerando a dinâmica de nascimentos, a eclodibilidade e a qualidade geral dos pintos e ao longo da janela de eclosão, considerando incubação dos ovos até 504h (padrão dos incubatórios) e 529h (real). Para isso, ovos férteis com 56-61g (leves) e com 65-71g (pesados) de matrizes de corte Cobb foram incubados a 37,5ºC e 60% de UR, com giro a cada hora. Pintos e ovos foram analisados de acordo com o período de nascimento (precoce, intermediário e tardio: 472-485h, 485-512h e 512,5-529h de incubação, respectivamente), em ambos os pesos de ovos. Os resultados mostraram eclodibilidade similar para ovos leves e pesados até 504h e até 529h (65,8% e 86,7%; 70,7% e 87,9%; respectivamente), e aumentou de 17% e 20%, respectivamente, de 504h para 529h. Ovos pesados apresentaram janela de eclosão mais curta (2,5h para 504h de incubação e 6,6h para 529h de incubação) e maior concentração de nascimentos de pintos intermediários que os ovos leves. Pintos de ovos leves apresentaram melhor qualidade devido à menor incidência de problemas de alantoide e atividade. Pintos precoces de ovos leves apresentaram a melhor qualidade comparada aos demais pintos do mesmo peso de ovo e aos pintos dos ovos pesados. De acordo com os resultados, ovos leves apresentam maior qualidade incubatória no que se refere à qualidade dos pintos, enquanto os ovos pesados apresentam maior qualidade incubatória quando se considera janela de eclosão e sincronismo na eclosão. Tais resultados mostram que aumento da produção de pintos precoces deve ser meta a ser alcançada pelos incubatórios. No Capítulo 3, foi estudado se características físicas dos pintos e dos ovos (leves e pesados) determinam o período de nascimento de pintos dentro da janela natural de eclosão. Para isso foi adotado o mesmo protocolo de incubação e delineamento experimental utilizado no Capítulo 2. Os resultados mostraram que pintos precoces apresentam maior tamanho de bico e são provenientes de ovos com maior tamanho de câmara de ar. Tais resultados mostram, pela primeira vez na literatura, relação do período de nascimento dos pintos dentro da janela de eclosão com o tamanho da câmara de ar e do bico. Eles sugerem a possibilidade do tamanho do bico ser levado em consideração em futuros estudos de seleção genética para aumentar a produção de pintos precoces, o que parece interessante uma vez que há a possibilidade de aves com maior tamanho de bico apresentarem maior ingestão de alimentos e, consequentemente, menor período de crescimento.
Hatchability and chick quality, and incubation duration are important for the egg incubation process, and they may to be influenced by physical characteristics of the eggs. Chapter 1 presents a theorical approach on this theme. Chapter 2 compared the quality for incubation of light and heavy eggs from broiler breeders, within the egg weight interval recommended for incubation based on birth dynamics, hatchability, and general quality of the chicks and chick quality throughout hatch window until 504h and 529h. For this, fertile light (56-61g) and heavy (65-71g) eggs from broiler breeders were incubated at usual conditions (37.5ºC, 60% RH, egg turning each hour until 18º day). Physical characteristics of eggs and chicks were analyzed according to birth period (early, intermediate and later: 472-485h, 485-512h e 512.5-529h of incubation, respectively). The results showed similar hatchability for light and heavy eggs until 504h and 529h (65.8% and 86.7%; 70.7% and 87.9%; respectively), as well as a 17% and 20% increase in the hatchability, respectively, from 504h to 529h. Heavy eggs presented a shorter hatch window and a higher rate of intermediate chicks compared to light eggs. Chicks from light eggs had better quality compared to other chicks due to low occurrence of alantoic cord and low activity. Thus, light eggs presented better quality for incubation resulting of better chick quality, whereas heavy eggs had good quality for incubation because their short hatch window and simultaneous higher hatch synchronism. These results show higher production of early chicks should be preconized by hatcheries. In Chapter 3, the relation of the physical characteristics of the eggs and newly hatched chicks with the birth period within the hatch window was analyzed. The egg incubation was realized following the same procedure used in Chapter 2. Early chicks had longer beak and hatched from eggs containing larger air chamber than intermediate and later chicks. These results show, by the first time in the literature, a relation between incubation duration and beak and air chamber size. They suggest beak length should be considered in genetic selection studies to increase the production of earlier chicks, and this is very interesting once broilers presenting greater beak size may have higher feed intake and, consequently, shorter growth period before slaughter.
Hatchability and chick quality, and incubation duration are important for the egg incubation process, and they may to be influenced by physical characteristics of the eggs. Chapter 1 presents a theorical approach on this theme. Chapter 2 compared the quality for incubation of light and heavy eggs from broiler breeders, within the egg weight interval recommended for incubation based on birth dynamics, hatchability, and general quality of the chicks and chick quality throughout hatch window until 504h and 529h. For this, fertile light (56-61g) and heavy (65-71g) eggs from broiler breeders were incubated at usual conditions (37.5ºC, 60% RH, egg turning each hour until 18º day). Physical characteristics of eggs and chicks were analyzed according to birth period (early, intermediate and later: 472-485h, 485-512h e 512.5-529h of incubation, respectively). The results showed similar hatchability for light and heavy eggs until 504h and 529h (65.8% and 86.7%; 70.7% and 87.9%; respectively), as well as a 17% and 20% increase in the hatchability, respectively, from 504h to 529h. Heavy eggs presented a shorter hatch window and a higher rate of intermediate chicks compared to light eggs. Chicks from light eggs had better quality compared to other chicks due to low occurrence of alantoic cord and low activity. Thus, light eggs presented better quality for incubation resulting of better chick quality, whereas heavy eggs had good quality for incubation because their short hatch window and simultaneous higher hatch synchronism. These results show higher production of early chicks should be preconized by hatcheries. In Chapter 3, the relation of the physical characteristics of the eggs and newly hatched chicks with the birth period within the hatch window was analyzed. The egg incubation was realized following the same procedure used in Chapter 2. Early chicks had longer beak and hatched from eggs containing larger air chamber than intermediate and later chicks. These results show, by the first time in the literature, a relation between incubation duration and beak and air chamber size. They suggest beak length should be considered in genetic selection studies to increase the production of earlier chicks, and this is very interesting once broilers presenting greater beak size may have higher feed intake and, consequently, shorter growth period before slaughter.
Descrição
Palavras-chave
Bico, Câmara de ar, Duração da incubação, Eclodibilidade, Período de nascimento