Short cold exposures during incubation and postnatal cold temperature affect performance, breast meat quality, and welfare parameters in broiler chickens

Abstract

Cold stimulations during egg incubation were reported to limit the occurrence of ascites in broilers subjected to cold temperature after 14 d of age. However, data are lacking on the impacts of such strategy in case of cold temperature conditions at start. This study aimed to evaluate the effects of incubation and posthatch cold challenge on performance, breast muscle integrity, and meat processing quality in broiler chickens. Ross 308 eggs were incubated under control temperature (I 0 , 37.6°C) or subjected to 15°C during 30 min on day 18 and 19 of incubation (I 1 ). Chicks from each group were reared in floor pens either at standard rearing temperature (T 0 ), from 32°C at 0 d to 21°C at 21 d of age, or exposed to colder rearing temperature (T 1 ), from 29°C at 0 to 21°C at 21 d of age. All birds were then kept at 21°C until slaughter (day 40), when body weights ( BW ), feed conversion ratio ( FCR ), breast muscle yield, meat processing quality, and the occurrences of meat defects, hock burns, and pododermatitis were recorded. No significant impact of incubation conditions on hatchability was observed. At day 40, BW was more under T 1 than under T 0 conditions, with T 0 females (but not males) presenting more BW after I 1 than after I 0 conditions. In the whole period, T 1 chickens presented lower FCR than T 0 chickens and higher breast meat yields at day 40. The occurrence of white striping was more in I 1 T 1 males than in all other groups, except for the I 0 T 1 males. Hock burns were more frequent in I 1 T 1 males than in all females and I 0 T 0 males, whereas the occurrence of pododermatitis was lower in T 0 males than in other groups. Despite some positive effects of I 1 incubation on growth after starting under low ambient temperature, this study reveals the limits of such strategy concerning chicken health and welfare, demonstrating that early thermal environment is a major component of the quality and sustainability of chicken meat production.

Embryonic Thermal Manipulation Affects Ventilation, Metabolism, Thermal Control and Central Dopamine in Newly Hatched and Juvenile Chicks

“…2 0.5 ± 0.08 ns 14 days-old NA (pg/µg) ♀ 11.4 ± 2.6 8.5 ± 1.0 8.9 ± 1.4 ns ♂ 7.5 ± 0.9 6.7 ± 0.9 7.8 ± 0.8 ns compensate their growth later on after periods of growth delay caused by cold (Mortola, 2009). Likewise, Nyuiadzi et al (2020) observed that males exposed to a lower incubation temperature presented a higher body mass under cold exposure during rearing, while females incubated in a cold temperature have greater growth at normal post-hatching temperatures. These effects of cold incubation on BM are possibly a result of hormonal differences between sexes in the very early embryo development and in the early growth phases (Dainat et al, 1991;Kocamis et al, 1998;Bello et al, 2014;Nyuiadzi et al, 2020).…”

In ovo injection of black cumin (Nigella sativa) extract on hatching and post hatch performance of thermally challenged broiler chickens during incubation

“…Several attempts have been made to improve the thermo-tolerance of chickens to adapt to heat stress conditions such as heat acclimation, including the use of thermal conditioning ( Yahav and Hurwitz 1996 ; Yahav and Plavnik, 1999 ; Willemsen et al., 2010 ; Nyuiadzi et al., 2020 ). During the last few days of incubation, chicken embryos grow faster, and their rate of nutrient utilization increases ( Elwan et al., 2019 ).…”

The Role of Incubation Conditions in the Onset of Avian Myopathies

“…Recently, Nyuiadzi et al (2020) reported slightly less white striping occurrence at D40, when Ross 308 chicken embryos from 36-wk-old breeders, incubated at constant 37.6 • C (99.68 • F) and 70% RH were exposed to 15 • C and 81% RH for 30 minutes at days 18 and 19. This treatment also had improvements in final body weight (37 grams) compared to the control, but no effects on feed efficiency, carcass and cut up part yields, or meat quality.…”

“…The environmental conditions post-hatch may affect the responses of hatchlings to incubation treatments. The treatment reported by Nyuiadzi et al (2020) was a short cold exposure that could occur when transferring eggs from setters to hatchers. As far as brooding conditions are adequate, it seems reducing embryo metabolic heat during this period (ED18 and ED19) is positive to reduce white striping.…”

“…It remains to be evaluated the effects of appropriate stepdown temperatures in the hatchers, as eggshell temperature raises due to embryo metabolic heat production. The reduction in machine temperature is a common practice in single-stage incubation (Boleli et al, 2016), but not used in multi-stage machines or the experiment reported by Nyuiadzi et al (2020).…”