The Effect of Diet on Liver Glycogen and Body Composition in the Chick

Abstract

Experiments were conducted to study the effects of diet on liver glycogen and body composition in the three-week-old chick. When percent protein and percent lysine were varied, liver glycogen concentration declined significantly as protein and lysine increased, 32.6 vs. 19.4 mg/g for the 14 and 35% protein diets, respectively. Carcass fat decreased and carcass moisture increased in a pattern similar to glycogen as protein and lysine increased in the diets. When seven levels of lysine were fed in isocaloric, isonitrogenous diets, glycogen content was not significantly different in any of the treatments. Liver glycogen was highest at the lowest energy level when dietary energy was increased and protein held constant. Carcass fat varied with the energy level but was also influenced by the amino acid balance. The data suggest that percent carbohydrate to percent fat ratio in the diet (both calculated) is an important factor affecting glycogen, but more research is needed to determine the mechanisms controlling the glycogen content of the liver.

Effects of Varying Dietary Protein and Energy Levels on Growth Rate and Body Fat of Broilers

“…Kondra et al (1962) found that high protein diets produced less abdominal fat when fed to broilers. Similar observations were made by Seaton et al (1978) and Reid and White (1978). Kubena et al (1974b) and Griffiths et al (1977) noted that caloric restriction during the early life of the broiler reduced the amount of abdominal fat at market age.…”

“…Griffiths et al (1977) reported that the amount of abdominal fat in male broilers exposed to early caloric restriction was reduced when the protein-calorie ratio of the diet was lowered. Seaton et al (1978) conducted work showing that carcass fat decreased and moisture increased as the percent protein and lysine in the diet increased. Reid and White (1978) reported that body protein was a linear function of body weight, with carcass fat increasing as the protein level of the diet decreased.…”

Changes in ghrelin mRNA level, plasma growth hormone concentration and performance in different dietary energy and protein levels in broiler chicken

“…The low protein diet decreased carcass and breast percentage during different periods and thigh percentage at 21 days of age (van Nguyen and Bunchasak, 2005;Smith and Pesti, 1998;Attia et al, 2001). The significant effect of energy levels on abdominal fat is similar to the previous study of Seatton et al, (1978) and Attia et al, (1998) found an increasing carcass fat with elevation of energy levels.…”

Analysis of Liver Glycogen in Chicks

“…Thus, liver homogenates may be stored frozen for later analyses provided they are thawed rapidly and analyzed immediately. Our findings for frozen tissue are similar to those of Cleland and Bannister (1979) who found no glycogen decrease after storage at -21 and -70 C. The range of liver glycogen levels reported here are similar to those found by Cleland and Bannister (1979), Seaton et al (1978), Raheja and Linsheer (1978), and Huff et al (1979). As noted by others (Cleland and Bannister, 1979), a large bird to bird variation in glycogen content was found within treatment groups.…”

“…Glycogen content of chick liver is known to vary considerably with diet (Seaton et al, 1978;Raheja and Linsheer, 1979;Rosebrough et al, 1978). In caged chicks where pecking orders have been established, the variation in rates of feeding may cause variations in levels of liver glycogen.…”