Selection against abdominal fat percentage may increase intramuscular fat content in broilers

Abstract

Excessive abdominal fat content (AFC) has negative impacts on feed efficiency and carcass quality. Unlike AFC, intramuscular fat content (IMFC) could be a favourable trait, which has a positive impact on meat quality. To meet consumers' needs, a long-term goal of broiler breeders is to decrease AFC and improve the IMFC simultaneously. The current study was designed to investigate the relationship between AFC and IMFC and to compare IMFC, including the pectoral major muscle fat content (PIMFC) and intramuscular fat content of leg muscle (LIMFC), between two broiler lines divergently selected for abdominal fat percentage over 17 generations. The results showed that there was a significant difference in PIMFC and LIMFC between the two lines in all five generation populations used. The birds in the lean line had significantly lower AFC but higher PIMFC and LIMFC than the birds in the fat line. We also detected differences in the liver fat content (LFC) between the two lines and the results showed that birds in the fat line had significant higher LFC than birds in the lean line. Our results indicated that a desirable broiler line with higher IMFC but lower AFC could be obtained by genetic selection.

Evaluation of Bone Marrow Adipose Tissue and Bone Mineralization on Broiler Chickens Affected by Wooden Breast Myopathy

“…The extraordinary muscle development of modern broilers is going together with increased adipose tissue, predominantly fat adhered to mesentery, along the intestine from the pylorus to the colon (Wang et al, 2007; Leng et al, 2016). Published studies have identified several genes connected with adiposity in chickens, which may help to regulate the excessive accumulation of fat in the gastrointestinal tract (Bourneuf et al, 2006; Bornelöv et al, 2018).…”

Identification of differentially expressed genes and pathways between intramuscular and abdominal fat-derived preadipocyte differentiation of chickens in vitro

“…A higher growth rate induces larger fiber diameters and lower IMF deposition, which severely deteriorates the quality of meat [4, 5]. However, the overemphasis on selection for a rapid growth rate leads to excessive fat accumulation, especially AbF accumulation [6]. Excessive fat is often discarded as waste [6–8].…”

“…However, the overemphasis on selection for a rapid growth rate leads to excessive fat accumulation, especially AbF accumulation [6]. Excessive fat is often discarded as waste [6–8]. Reducing the levels of AbF and increasing the levels of IMF have therefore become a major breeding goals in the chickens industry [6, 9].…”

“…Excessive fat is often discarded as waste [6–8]. Reducing the levels of AbF and increasing the levels of IMF have therefore become a major breeding goals in the chickens industry [6, 9].…”

“…Zhou et al found that dietary supplementation with 3% conjugated linoleic acid (CLA) decreased AbF accumulation but increased IMF content [21]. Leng et al indicated that a desirable broiler line with high IMF content but low AbF content could be obtained by genetic selection [6]. This may be because AbF deposition and IMF deposition are subject to different regulatory mechanisms.…”