1677 - PHYSIOLOGY, ENDOCRINOLOGY, AND REPRODUCTION...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1677 PHYSIOLOGY, ENDOCRINOLOGY, AND REPRODUCTION 2010 Poultry Science 89 :1677–1683 doi: 10.3382/ps.2009-00386 Key words: genetic line , embryo physiology , hatching event , juvenile growth ABSTRACT Broiler performance is known to be re- lated to embryonic developmental parameters. How- ever, strain or genotype differences with regard to embryo physiological parameters and juvenile growth have received little attention. A total of 1,200 hatch- ing eggs produced by Cobb and Ross broiler breeders of the same age were studied. At setting for incubation and between 66 and 130 h of incubation, egg resonant frequency (RF) was measured as an indicator of em- bryonic development. Also, eggs were weighed before setting and at d 18. From d 10 to 18 of incubation, remaining albumen was weighed. During the last days of incubation, hatching events such as internal pipping (IP), external pipping, and hatch were monitored ev- ery 2 h. Hatched chicks were recorded and weighed. At IP stage, gas partial pressures in the egg air chamber were measured. Hatched chicks were reared for 7 d and weighed. Results indicate that RF of Ross eggs were lower than those of Cobb eggs ( P < 0.01) and start- ing time point of RF decrease occurred earlier in Cobb eggs than in Ross eggs. Relative egg weight loss up to 18 d of incubation was lower in Cobb than in Ross ( P < 0.05). At IP, partial pressure of CO 2 was higher in Cobb than in Ross ( P < 0.05) with shorter incuba- tion duration in Cobb. Between 6 and 60 h posthatch, heat production was higher in Cobb than in Ross ( P < 0.05). At 7 d posthatch, Cobb chicks were heavier than Ross chicks ( P < 0.05). It is concluded that Cobb and Ross embryos-chicks have different growth trajectories leading in different patterns of growth resulting from differences in physiological parameters. Comparison of Cobb and Ross strains in embryo physiology and chick juvenile growth K. Tona ,* 1 O. M. Onagbesan ,† B. Kamers ,‡ N. Everaert ,‡ V. Bruggeman ,‡ and E. Decuypere ‡ * Laboratory of Poultry Sciences, Faculty of Sciences, University of Lome, B.P. 1515 Lome, Togo; † Department of Animal Physiology, University of Agriculture, P.M.B 2240 Abeokuta, Nigeria; and ‡ Laboratory for Physiology, Immunology and Genetics of Domestic Animals, Department of Biosystems, Katholieke Universiteit Leuven, 3001, Belgium INTRODUCTION During the past 5 decades, intensive selection in broil- ers has focused on posthatch growth rate and feed con- version to achieve increased meat yield. But, all broiler strains do not have similar physiology or development trajectories, or both. Posthatch performance is known to be related to embryonic developmental parameters (Tona et al., 2003a). Similarly, the effects of incubation conditions, egg storage conditions, and age of breeders on embryonic parameters are well known (O’Dea et al., 2004; Tona et al., 2004). However, strain or genetic line differences with regard to embryo physiological param- eters and juvenile growth have received little attention.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

1677 - PHYSIOLOGY, ENDOCRINOLOGY, AND REPRODUCTION...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online