Serum neuropeptide Y (NPY) and leptin concentrations in pigs selected for components of efficient lean growth

Serum profile of metabolites and hormones in obese (Iberian) and lean (Landrace) growing gilts fed balanced or lysine deficient diets

“…Weiler et al (1998) also found higher IGF-1 levels in European wild boars as compared to Large White in spite of the greater growth potential of the latter, but cortisol level was much lower in Large White boars. Differences on serum concentrations of leptin were not unexpected, as Iberian and Landrace breeds strongly differ in body type and because differences in peripheral concentrations of leptin have been previously reported to exist between swine breeds differing in growth and carcass characteristics at 110 kg BW (Berg et al, 2003) and between different genetic lines of Large White pigs at 90 kg BW (Cameron et al, 2003), although no differences were found at 34 kg BW (Berg et al, 2003). The breeds we have compared are more extreme in terms of body composition than those compared in the aforementioned studies and, consequently, differences in body composition are of greater magnitude, which could explain the marked differences in serum leptin among Iberian and Landrace gilts found in the present study.…”

Genetic relationships of body composition, serum leptin, and age at puberty in gilts12

“…Literature estimates of leptin concentration were scarce and generally at fixed time points. Cameron et al (2003) estimated heritability of leptin in Large White pigs between 0.05 and 0.46 during different phases (30 to 90 kg) of a feed test. Generally, greater heritability estimates were observed at the end of the feed test.…”

Leptin concentration in blood and its hypothalamic binding are poorly related with amount of fat and growth rate in pigs

“…From the animal breeding point of view, leptin has arisen as an important hormone which can regulate the pig growth rate and time of fattening, beside its possible action on final meat quality (leptin diminishes fat storage). Cameron et al (2003) even stated that in the pig breeding practice "...leptin concentration in blood could be used as a physiological predictor of genetic merit if there were significant responses to selection". The results obtained in this study indicate that not only there are differences in daily body gains and in the fat content between the investigated breeds, but also in these groups leptin concentration in blood and leptin binding in the hypothalamus is different.…”

“…Under experimental conditions it decreases feed intake (Barb et al, 1998;Velkoska et al, 2003). The amount of the produced and secreted leptin may depend on hormonal and nutritional factors (Zhang et al, 1994;Saladin et al, 1995;Cameron et al, 2000Cameron et al, , 2003McNeel et al, 2000). This substance informs the central nervous system about the metabolism of the fatty tissue and the amount of stored lipids (Campfield et al, 1995;Meister, 2000).…”

“…Some authors investigated leptin concentrations or the expression of mRNA for leptin and its receptors in the pig and tried to describe their role during growth, fattening, and gestation (Guay et al, 2001;Berg et al, 2003;Cameron et al, 2003). Simultaneously, there are only scanty data presenting leptin binding to its receptors in animals (Margetic et al, 2002), and no data about leptin binding in pig tissues.…”