Evaluation of a Specific Gravity Method for Estimating the Total Carcass Fat of New York-Dressed Broiler Chickens

Abstract

Four trials were conducted to determine the applicability of a specific gravity method to estimate total New York-dressed carcass fat. Specific gravity values were compared to abdominal fat pad measurements, and total carcass moisture and fat values. Carcasses were produced over a very wide range of total carcass fat, from 6.5 up to 18.8%, by feeding one of five test diets with calorie-to-protein ratios ranging from 61 to 260. Total carcass fat was estimated on each New York-dressed carcass using specific gravity and abdominal fat pad weight. Each carcass was then ground, homogenized, and analyzed for total moisture and total fat. Results indicated that total carcass moisture had the best correlation with total analyzed carcass fat (r = -.95). Abdominal fat pad percent and weight resulted in the next best correlations (r = +.92 and r = +76, respectively), while specific gravity resulted in the poorest correlation (r = -.73). The low correlation value for specific gravity is thought to be due primarily to entrapped air in the lungs and air sacs of the New York-dressed carcasses. (

Safety of use of colouring agents in animal nutrition - Part III: ß-apo-8’-carotenal, ethyl ester of ß-apo-8’-carotenoic acid, lutein, zeaxanthin and concluding remarks

“…Damron et al (1990) used different Tagetes products (meal, extracts, oleoresins) with free or saponified xanthophylls in broiler diets and observed a better pigmenting efficiency for free lutein than for saponified lutein or lutein/zeaxanthin mixtures. In contrast, Fletcher et al (1986) observed significantly better skin and shank pigmentation in broilers with a saponified marigold product. Calafat et al (2005) used canthaxanthin and paprika oleoresins in combination with Tagetes for broiler skin pigmentation and observed a higher colouring efficiency for the combination of canthaxanthin with Tagetes.…”