Carcass and meat quality traits, and urinary cortisol variation was studied in 96 barrows assigned to the following treatments: feed texture (FT; mash vs. pellets), meal frequency (MF; 2 vs. 5 meals per day) and fasting time (F; 4, 14 and 24h) according to a 2×2×3 factorial design. Pigs fed mash, receiving feed five times a day and fasted for 24h before slaughter had lower carcass dressing yield (P<0.001). A higher (P<0.05) bruise score was found on carcasses from pigs fasted for 14 and 24h and fed either pelleted or mashed feed five times per day. The pH(u) value in the Longissimus muscle increased (P<0.05) with increasing fasting time, whereas in the Adductor muscle it was higher (P<0.05) in pigs fed with pellets in two meals per day and fasted for 24h. Urinary cortisol tended to be higher in pigs fasted for 14h compared to those fasted for 4 (P=0.10) and 24h (P=0.06). The results of this study show a significant influence of pellet feeding on carcass yield in fasted pigs, while the effects of pre-slaughter fasting time on meat quality traits were limited.
"Besides caloric intake, meal frequency has been regarded as an additional factor able to affect BW and composition in man (Schwarz et al., 2011). The few studies on this subject in growing pigs have provided somewhat conflicting results on BW and fat gains (O'Hea and Leveille, 1969; Allee et al., 1972; Faucitano et al., 2006). Meal frequency did not alter the absorption and digestibility of energy and amino acids in pigs (Ruckebusch and Bueno, 1976, Chastanet et al., 2007). "
[Show abstract][Hide abstract] ABSTRACT: Ingested dietary nutrients and feed energy are partitioned among tissues to sustain body growth. Based on the respective costs of the various metabolic pathways allowing use and storage of feed energy into cells, it may be theorized that daily meal frequency could affect growth, body composition or feed efficiency. This study aimed to determine the effects of daily meal frequency on nutrient partitioning, tissue metabolism and composition, and growth performance. Young growing pigs (30 kg BW) were offered a same amount of feed either in two (M2, n = 15) or twelve (M12, n = 16) meals per day during a 3-week interventional period. Animals fed twice a day had an accelerated weight gain (+6.4%, P < 0.05) and exhibited a greater G:F (+4%, P = 0.03) than animals fed twelve meals per day during this period. Basal plasma concentrations of glucose, lactate, triglyceride, urea and leptin were lower (P < 0.001) in M2 pigs than in M12 pigs. Meal frequency also changed (P < 0.001) the time-course profiles of plasma concentrations of glucose, insulin and lactate in response to meal ingestion. A greater rise and a sharper fall in plasma glucose and insulin levels were observed in M2 pigs compared with M12 pigs. In both groups, similarities were observed in the postprandial time-courses of plasma concentrations of insulin and of alpha-amino nitrogen (used as a measure of total AA). Despite these metabolic responses, tissue lipids, glycogen content, and enzyme activities participating to energy metabolism in muscle and liver were similar (P > 0.10) in both groups at the end of the trial. Percentage of perirenal fat in the body and depth of dorsal subcutaneous fat tissue were not affected by meal frequency, but kidney weight was lower (-18%, P < 0.001) in M2 pigs than in M12 pigs. Altogether, the less frequent daily meal intake improves the conversion of feed into weight gain, without marked modifications of tissue composition in young pigs.
"If we take the NAO index to be a climate and ice cover proxy indicator (Vinje 2001; Hurrell et al. 2003; Bader et al. 2011), this indicates that the bears are under higher levels of physiological stress during years with less ice cover and thus less easy access to seals. Increased cortisol levels have been associated with fasting in a number of mammal species, including humans (Ward et al. 1992; Faucitano et al. 2006), although reported results are not always consistent between sex and age classes (Faucitano et al. 2006; Bennett et al. 2012). With regards to polar bears, Hamilton (2007) found that the length of sea ice coverage and fasting was the strongest determinant of serum cortisol levels in Hudson Bay bears, in contrast to which Chow et al. (2011) found no difference in serum total cortisol concentrations between individuals in feeding and fasting states. "
[Show abstract][Hide abstract] ABSTRACT: Polar bears are heavily dependent on sea ice for hunting sufficient prey to meet their energetic needs. When
the bears are left fasting, it may cause a rise in the levels of the stress hormone cortisol. Cortisol is the major corticosteroid hormone in most mammals, including polar bears. Production and regulation of this stress hormone are vital for the body as it is part of a myriad of processes, including in relation to metabolism, growth, development, reproduction, and immune function. In the present study, we
examined the correlation between East Greenland polar bear hair cortisol concentration (HCC), a matrix that
reflects longer-term hormone levels, and the fluctuations of the North Atlantic Oscillation (NAO) index, a large-scale climate phenomenon applied as a proxy for sea ice extent in the Greenland Sea along the coast of East Greenland. In doing so, a significant positive correlation (r = 0.88; p = 0.0004) was found between polar bear hair cortisol and the NAO, explaining 77 % of the variation in HCC observed between years over the period 1989–2009. This result indicates that interannual fluctuations in climate and ice cover have a substantial influence on longer-term cortisol levels in East Greenland polar bears. Further research
into the implications and consequences inherent in this correlation are recommended, preferably across multiple polar bear populations.
"Thus, although cortisol is necessary for normal physiological function, chronic elevations have a negative impact on muscle and immune cell function and bone metabolism (Kraemer et al., 2005). While the serum concentration of cortisol has been used as a reliable indicator of stress levels (Carrasco, Panea, Ripoll, Sanz, & Joy, 2009), it has also been measured in skeletal muscle (Shaw, Trout, & McPhee, 1995), hair (Kalra et al., 2007), saliva (Foury et al., 2005), and urine (Faucitano et al., 2006). "
[Show abstract][Hide abstract] ABSTRACT: The effect of muscle cortisol concentration on muscle fiber characteristics and technological and sensory quality of pork was investigated. With the exception of the percentage of type IIA fibers, muscle fiber characteristics were not associated to cortisol levels. However, muscle cortisol concentration was positively associated with muscle pH(24h) (r = 0.23, P<0.05) and negatively associated with drip loss (r = -0.49, P<0.001), lightness (r = -0.24, P<0.05), shear force (r = -0.25, P<0.05), and texture profile analysis-hardness (r = -0.35, P<0.01). Additionally, the water-holding capacity of meat samples was affected by cortisol levels, with lower cortisol concentrations associated with less tender samples. These results indicate that the concentration of cortisol in the muscle is related with meat quality as well as the sensory quality of cooked pork.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.