Vitamin C prevents the effects of high rearing temperatures on the quality of broiler thigh meat

Abstract

We investigated the effects of incubation temperatures and vitamin C injections into eggs (treatments: 37.5ºC, 39ºC, 39ºC+vitamin C) on resultant chick pectoralis major and sartorius muscle fiber hypertrophy, as well as their effects on the quality of breast and over-thigh meat of broilers reared under cold, control, or hot temperatures. Incubation at 39ºC increased the shear force and reduced meat redness in breast meat (P < 0.05). Vitamin C prevented these high temperature incubation effects [shear force (kgf cm(-2)): 37.5ºC = 2.34, 39ºC = 2.79, 39ºC+vitamin C = 2.44; redness: 37.5ºC = 2.64, 39ºC = 1.90, 39ºC+vitamin C = 2.30], but reduced water content (37.5ºC = 74.81%, 39ºC = 74.53%, 39ºC+vitamin C = 69.39%) (P < 0.05). Cold rearing temperatures increased breast meat redness (a*: cold = 2.78, control = 2.12, hot = 1.98), while hot rearing temperatures reduced the muscle fiber area (cold = 5.413 μm(2), control = 5.612 μm(2), hot = 4.448 μm(2)) (P < 0.05) without altering meat quality (P > 0.05). Hot rearing temperatures increased the cooking loss (cold = 30.10%, control = 33.66%, hot = 37.01%), shear force (cold = 3.05 kgf cm(-2), control = 3.43 kgf cm(-2), hot = 4.29 kgf cm(-2)) and redness (a*: cold = 4.63, control = 3.55, hot = 3.20) in the over-thigh meat of broilers from eggs incubated at 37.5ºC, increasing the area of muscle fibers, while cold rearing temperatures diminished cooking loss and shear force, reducing the muscle fiber area (P < 0.05). Incubation at 39ºC and 39ºC+vitamin C prevented the effects of hot and cold rearing temperatures, by diminishing and increasing the muscle fiber area, respectively.

Poultry Egg Incubation: Integrating and Optimizing Production Efficiency

“…Egg water loss depends of eggshell porosity , given by its pore number, diameter, length, and shape. Therefore, it is higher in eggs laid older breeders or larger eggs from a same breeder age incubated at high temperatures and/or low relative humidity levels (Morita et al, 2009(Morita et al, , 2010Sgavioli et al, 2015). Although the velocity of the air on the egg surface has no direct effect on water loss (Meijerhof & van Beek, 1993), as previously mentioned in this review, it allows continuous conductive-convective heat dissipation, and therefore, indirectly influences egg water loss.…”

“…It was demonstrated that eggshell temperature increases from the second third of incubation at 36-39°C incubation temperature (Sgavioli et al, 2015;Almeida et al, 2016;. This increase is related with the greater metabolic heat production by the fetus during this high growth rate phase (Lourens et al, , 2007.…”

“…As mentioned above, according to the laws of thermodynamics, heat is transferred between the eggs and the incubation environment down a thermal gradient, i.e., always from the warmer to colder region. Under optimal incubation temperature (around 37.5-37.8ºC), eggshell temperature remains lower than the setter room temperature during the first week, starts to increase in the second week, and it is higher than the setter room temperature during the last week of incubation (French, 2007;Sgavioli et al, 2015). This indicates that eggs incubated under those temperatures need to gain heat in the beginning and to lose it during the last week of incubation, respectively.…”

“…This shows that the embryo is able to react to minor temperature fluctuations inside the egg, and that it attempts to regulate its internal temperature within a very narrow range (Tzschentke & Nichelmann, 1997). Based on these findings, studies were carried out to assess the effects of incubation temperature on embryo temperature, thermal manipulation during incubation, and in-ovo injection of the anti-stress nutrients, such as vitamin C, as means to induce possible thermal adaptation of poultry during rearing or to promote phenotypic changes to meet specific objectives (Sgavioli et al, 2013(Sgavioli et al, , 2015Ferreira et al, 2015;Almeida et al, 2016;Morita et al, 2016 a,b).…”

“…The main objectives are to increase chicken thermo tolerance during rearing or to modulate commercially important characteristics, such as immune response, fat deposition, etc. ( Joseph et al, 2006;Walstra et al 2010;Ipek et al, 2014;Almeida et al, 2015;Ferreira et al, 2015;Sgavioli et al, 2015;. Researchers have applied different types of thermal manipulation, in terms of intensity, frequency, duration, and embryonic development period (Tables 1-3).…”