Chicken Abdominal Fat Research Articles

Identification of Ava I Polymorphisms in the Third Intron of GH Gene and Their Associations with Abdominal Fat in Chickens

Growth hormone (GH) plays a diverse role in animals together with other hormones of somatotropic axis. In the current research, chicken GH (cGH) as a candidate gene affecting carcass traits was investigated in the chickens from 2 local chicken breeds [Mountainous Black-Bone (Wugu) and Caoke chicken] in the Sichuan province, 1 pure line of a quality chicken (Sanhuang chicken) from the Guangdong province, and commercial crossbreds. The RFLP method was used to identify polymorphisms of the cGH gene. Three restriction enzyme polymorphic sites were detected in the cGH gene. Sequence alignment from GenBank revealed 2 mutations in the third intron of the cGH gene, which were identified by the Ava I enzyme. Two novel Ava I polymorphic sites were genotypied in 240 chickens from the above-mentioned chicken populations. One EcoR V polymorphic site, the previously reported polymorphism, was also detected in these populations. Significant differences in allelic and genotypic frequencies among all the chicken populations were observed. In Ava I polymorphic sites, allele A2 and B1 had higher frequencies than allele A1 and B2, respectively. In EcoR V polymorphic sites, the frequency of allele N2 was higher than that of allele N1. Associations of polymorphisms of the cGH gene with carcass traits were analyzed by using a GLM procedure. Significant associations were found between Ava I genotypes or combined genotypes and abdominal fat weight and abdominal fat percentage (P ≤ 0.05). The allele A2 and B1 had a beneficial effect on increasing the live BW, breast muscle weight, and breast muscle percentage while decreasing the abdominal fat weight, abdominal fat percentage, and s.c. fat thickness. No significant associations were observed between EcoR V genotypes and carcass traits. In conclusion, the cGH gene may be a potential marker affecting the abdominal fat trait of chickens.

Abdominal fat pad mass reduction by in ovo administration of anti-adipocyte monoclonal antibodies in chickens

The effect of in ovo administration of antiadipocyte monoclonal antibodies (MAb) on growth and adipose tissue development in chickens was investigated. In Trial 1, 60 fertilized eggs from layer-type chickens were injected into allantoic circulation with different amounts of MAb against chicken adipocyte plasma membranes (0, 0.05, 0.1, 0.2, and 0.4 mg) on Day 15 of embryogenesis. In Trial 2, 180 fertilized broiler eggs were injected into allantoic circulation with 0.2 mg MAb on Day 15 of embryogenesis. In Trial 1, high doses (0.2 and 0.4 mg) of MAb in in ovo injection reduced (P < or = 0.05) abdominal fat pad weight without affecting total body weight at 42 d of age. Only the highest dose (0.4 mg) significantly reduced hatch rate. In Trial 2, adipose tissue (pectoral, femoral, and abdominal), major organ (heart, liver, and spleen), and total body weights at 14 d of age were not affected by in ovo injection. Hatch success rate of eggs was not significantly different among treatments. However, by 6 wk of age, in ovo injection of MAb significantly reduced (P < or = 0.05) abdominal fat pad weight by more than 28%. This relative fat pad mass reduction occurred without affecting femoral or pectoral fat tissues. Total body weight and feed intake were not affected among treatments. Our experiments demonstrated for the first time that in ovo administration of anti-adipocyte MAb on Day 15 of embryogenesis reduced the chicken abdominal fat pad mass by 42 d of age without affecting growth or body weight.

Contribution of lipoprotein lipase to differences in fatness between broiler and layer-strain chickens.

The growth of abdominal fat in chickens from broiler and layer-strains up to 10 weeks of age was measured and compared with changes in plasma very low density lipoprotein (VLDL) concentration and tissue lipoprotein lipase activities. The growth of abdominal fat in broilers was much more rapid than in layer-strain chickens. Plasma VLDL concentrations in the two strains were similar up to 5 weeks of age but thereafter concentrations tended to be higher in broilers. Plasma VLDL concentrations in both strains were much lower than those necessary for maximum lipoprotein lipase activity. The lipoprotein lipase activity of abdominal fat increased much more rapidly in broilers than in layer-strain chickens. In both strains the pattern of its increase relative to body weight was similar to that of abdominal fat. Differences in the lipoprotein lipase activity of abdominal fat between strains were attributed to differences in both activity/adipocyte and number of adipocytes. They were reduced or abolished if activity was expressed relative to tissue weight, or to its content of DNA or protein. The results strongly suggest that the greater lipoprotein lipase activity of the abdominal fat pad in broilers is an important factor in its rapid growth.

In Vivo Prediction of Abdominal Fat in Chickens Using Plasma Urea Nitrogen Changes

The dilution of urea infused into the venous system was measured in 16 Leghorn and 77 broiler chickens. The changes in plasma urea nitrogen and a variable referred to as “urea space” were very poor predictors of carcass fat as estimated by abdominal fat.