Leptin as an indicator for carcass composition in farm animals

Abstract

The function of leptin in livestock species has been intensively studied during recent years. Due to the associations between plasma leptin concentrations and body fat, leptin could be used as an indicator for the in vivo evaluation of carcass composition in breeding programs. This review specifically discusses leptin mRNA expression in several fat tissues, the relationship between plasma leptin and body fat and the influence of fasting on this association. It also refers to the limitations of the use of plasma leptin concentrations as a predictor for selection purposes in breeding animals. Furthermore, single nucleotide polymorphisms in the leptin gene have some effects on carcass traits and the leptin gene is considered to be a candidate gene for a marker-assisted selection. However, these results are very inconsistent across various populations and need to be confirmed in future studies before leptin can be used efficiently in breeding programs and management.

Genetic correlations among carcass cross-sectional fat area ratios, production traits, intramuscular fat, and serum leptin concentration in Duroc pigs

“…They concluded that early leptin concentrations were not at all or only slightly associated with BF, plasma leptin concentrations immediately before slaughter correlated more strongly with this fat characteristic. Altmann and von Borell (2007) inferred from a review of numerous studies that estimation of body fat at slaughter based on leptin concentration in early life provides little information. For that reason, the potential for use of plasma leptin as a selection tool in breeding programs is limited because the leptin concentration is related to the fat accumulation at the point of measurement.…”

“…Jiang and Gibson (1999) reported a lack of association between polymorphisms of the leptin gene and adiposity within 4 breeds of pigs exhibiting high and low BF. The associations between carcass characteristics and specific leptin gene polymorphisms are often population-specific and vary across studies, although the polymorphisms have been demonstrated to be functional (Altmann and von Borell, 2007). Further study is necessary to clarify these associations.…”

“…Berg et al (2003) reported that no relationship was found between the serum leptin concentration and marbling in LM in pigs. Because of the reduced leptin expression in IMF and its low fraction of total body fat, it is unlikely that IMF tissue contributes considerably to the plasma leptin concentration (Altmann and von Borell, 2007). Different lipid metabolism was suggested from the result that genetic correlations of same fatty acids among different fatty tissues of innerlayer and outer-layer subcutaneous fat, intermuscular fat, and IMF decrease as the anatomical distance of the fat tissues increases.…”

The usefulness of leptin measurements and ultrasound fat thickness for assessment of body fat reserves of Awassi lambs

“…On the other hand, Kumar et al (1998) reported that the expression of leptin mRNA in omental, perirenal and subcutaneous fat tissue was similar in lambs. The level of leptin gene expression may reflect considerable differences among adipose tissues and the reason is not known yet why the leptin expressions are various in different fat depots (Altmann and von Borell 2007). In the light of these findings it can be concluded that leptin is not a strong predictor but it offers an opinion and on the other hand, BW and UFT were not the predictors for omental fat in male Awassi lambs.…”

“…Therefore, fat tail cannot be considered as a simple body fat and it cannot be reflected in serum leptin level. Additionally, regional variations in fat deposition can affect serum leptin level (Altmann and von Borell 2007). In other words, every fat tissue cannot affect the serum leptin level.…”