Correlated Responses to Selection for Increased Intramuscular Fat in a Chinese Quality Chicken Line

Abstract

The correlated response in traits encompassing meat quality, carcass, sexual maturity, egg production, and egg quality traits arising from selection for increased intramuscular fat (IMF) content of breast muscle were investigated in the fifth generation of a selection experiment including a line (F) selected for increased IMF and a randombred control line (C). The results showed that breast muscle IMF content in the F line (4.25%) was significantly higher (P < 0.001) than that in the C line (3.80%) after 5 generations of selection. The same trend was observed in IMF content in thigh muscle (20.03 vs. 19.41%, P < 0.05). The shear force of breast muscle in the F line was lower than that in the C line (1.82 vs. 2.12 kg, P < 0.01), whereas increases occurred in BW (P < 0.05), carcass weight (P < 0.05), breast muscle weight (P < 0.001), breast muscle percentage of live weight (P < 0.05), abdominal fat weight (P < 0.001), ovarian weight at 90 d of age (P < 0.05), and egg weight (P < 0.05) in the F line, relative to the C line. Age at first lay in the F line was 4.84 d earlier than that in the C line (P < 0.001). No differences were found between the 2 lines (P > 0.05) in the following traits: drip loss, meat color (L*, a*, and b*), carcass percentage, thigh muscle weight, thigh muscle percentage, abdominal fat percentage, first egg weight, egg number (until 43 wk), Haugh units, shell thickness, and egg shape. The results of the present study demonstrated that selection for breast muscle IMF leads to desirable changes in meat quality, carcass, sexual maturity, and egg production traits.

Dietary L-arginine supplementation reduces abdominal fat content by modulating lipid metabolism in broiler chickens

“…We also found that the abdominal fat content expressed as the percentage BW was significantly (P , 0.02; Table 3) lower with the 0.25% and 1.00% L-Arg treatments compared with the control, whereas they did not differ significantly from each other. IMF is one of the major factors that affects meat quality because of its effects on other traits such as the flavor, juiciness and tenderness of meat (Zhao et al, 2007). The abdominal fat tissue grows faster compared with other fat tissues (Butterwith, 1989) and it reaches its maximum rate of growth at 42 days of age (Havenstein et al, 2003).…”

“…The right breast muscles were removed from the sternum, minced after removing any obvious fat, and stored at 2208C. The IMF of the breast muscle was determined in triplicate, according to the method described by Zhao et al (2007), and expressed as the percentage total fat (dry weight). Blood samples were collected using a 5-ml anticoagulant syringe (Shanghai K & G International Co. Ltd, Shanghai, China) via the wing vein, centrifuged at 48C and 5900 3 g for 10 min to obtain the plasma, and stored in 1.5-ml Eppendorf tubes at 2708C until analysis.…”

Effects of caponization on growth performance, carcass composition and meat quality of males of a layer line

“…Increased IMF is generally associated with decreased shear values and thus with improved meat tenderness. Zhao et al (2007) reported that an increase of IMF resulted in a significant decrease of shear values in chickens. A negative correlation between IMF and shear values has also been found in pigs (Van Laack et al, 2001) and sheep (Okeudo and Moss, 2005).…”

The Expression of Can and Camk is Associated with Lipogenesis in the Muscle of Chicken

“…Twelve birds were sacrificed per week at 4, 8, and 16 weeks of age, and the thigh muscles were collected. The right thigh muscles collected from the 12 birds sacrificed each week were stored at −20°C to determine intramuscular fat (IMF) content by ether extraction in a Soxhlet apparatus (Zhao et al, 2007), which was expressed as a the percentage of muscle weight (on dry matter basis). The left thigh muscles collected from the same birds were stored at −80°C for RNA extraction.…”

“…It is generally accepted that intramuscular fat (IMF) content is an important indicator of meat quality (Zhao et al, 2007;Choi & Kim, 2009;Hocquette et al, 2010). The problems of meat quality, such as sensory characteristics, tenderness and physical attributes, are related to fat accumulation in broilers.…”