In ovotemperature manipulation influences embryonic motility and growth of limb tissues in the chick (Gallus gallus)

Abstract

SUMMARY The chick embryo, developing in the egg, is an ideal system in which to investigate the effects of incubation environment on the development of the embryo. We show that raising the temperature of the eggs by just one degree,from 37.5°C to 38.5°C, during embryonic days (ED) 4–7 causes profound changes in development. We demonstrate that embryonic movement is significantly increased in the chicks raised at 38.5°C both during the period in which they are at the higher temperature but also 4 days after their return to the control temperature. Concomitant with this increase in embryonic activity, the embryos raised at higher temperature grow to significantly heavier weights and exhibit significantly longer leg bones (tibia and tarsus)than the controls from ED12 onwards, although mineralization occurs normally. Additionally, the number of leg myonuclei is increased from ED12 in the embryos raised at the higher temperature. This is likely to promote greater leg muscle growth later in development, which may provide postural stability to the chicks posthatch. These changes are similar to those seen when drugs are injected to increase embryonic activity. We therefore believe that the increased embryonic activity provides a mechanism that can explain the increased growth of leg muscle and bone seen when the eggs are incubated for 3 days at higher temperature.

Increasing the incubation temperature between embryonic day 7 and 10 has no influence on the growth and slaughter characteristics as well as meat quality of broilers

“…There is either a direct effect by influencing molecular steps necessary for the proliferation and differentiation of myoblasts, or an indirect by general stimulation of the metabolism and the in-ovo movement of the embryo, as postulated by Hammond et al (2007). The present results showing no difference of the broiler growth and slaughter characteristics are difficult to discuss because already published investigations differed in the analysed poultry species, the treatment conditions and the time of sampling.…”

“…Other publications that increased the incubation temperature at a similar period during embryogenesis disagree with the present results. Maltby et al (2004), Yahav et al (2004a and Hammond et al (2007) showed that the increased temperature has an positive effect on the post-hatch muscle development (e.g. BW or MFN).…”

“…A main advantage is that the embryonic development can be easily manipulated. Different endogenic factors with an impact on the avian embryogenesis have been investigated including the oxygen concentration (LeonVelarde and Monge, 2004;Chan and Burggren, 2005; -E-mail: Carsten.Werner@tiho-hannover.de Mortola and Labbe, 2005), the light colour (Rozenboim et al, 2003;Halevy et al, 2006) or the temperature around the brooding eggs (Christensen et al, 2001;Gauly et al, 2001;Von Blumroder and Tonhardt, 2002;Maltby et al, 2004;Tonhardt et al, 2004;Yahav et al, 2004a and2004b;Lourens et al, 2005;Collin et al, 2007;Hammond et al, 2007;Piestun et al, 2009). Direct manipulations include the in-ovo injection of growth hormones or factors (e.g.…”

“…embryonic day (ED) 4 to 7, ED 8 to 12, ED 8 to 10, ED 16 to 18) and sampling times before and after hatch of the animals (e.g. ED 18, 4 day, 25 day and 35 day post-hatch) (Maltby et al, 2004;Yahav et al, 2004a and2004b;Collin et al, 2007;Hammond et al, 2007;Piestun et al, 2009). Considering these publications -especially of this Maltby et al (2004) who showed that higher incubation temperatures between ED 9 and 12 in turkeys increases the MFN, the aim of this study was to investigate, how a higher incubation temperature between ED 7 and 10 -an important period of primary (embryonic) and secondary (foetal) myotube formation (Miller and Stockdale, 1986) -influences muscle development and/or structure in broiler post-hatch.…”

Advances in research on the prenatal development of skeletal muscle in animals in relation to the quality of muscle-based food. I. Regulation of myogenesis and environmental impact

“…A regime of 38.58C caused an increased myonuclear and fibre number in ST, along with a delay in differentiation (Maltby et al, 2004). In chickens, Hammond et al (2007) have shown that Rehfeldt, Te Pas, Wimmers, Brameld, Nissen, Berri, Valente, Power, Picard, Stickland and Oksbjerg these small temperature manipulations alter muscle cellularity, possibly through an effect on in ovo movement activities (higher temperatures produced sustained increases in movement). Werner and Wicke (2008) reported that increased temperature (38.58C) between embryonic days 7 and 10 of incubation positively influenced the post-hatch muscle development in cocks, but not in hens.…”