Effect of Dietary Crude Fiber on Endogenous Dry Matter and Nitrogen Excretion in Cockerels

GEORGIEVA, V., S. CHOBANOVA, N. TODOROV and D. PAVLOV, 2014. Effect of dietary crude fiber on endogenous dry matter and nitrogen excretion in cockerels. Bulg. J. Agric. Sci. 20: 903-908 The experiments were carried out with 10 cecectomisеd cockerels for each diet. They are force fed by method of Sibbald (1986) with nitrogen free diets of pure nutrients and with sunflower meal with different crude fiber and crude protein content. The endogenous excretion of nitrogen was established by quantity excreted when cockerels are kept without feeds (fasting), by extrapolation (regression) of excretion when fed nitrogen free diet with different level of cellulose, by feeding nitrogen free diet, and extrapolation (regression) when cockerels are fed sunflower meal with different protein and crude fiber content. The endogenous nitrogen was 1.69, 1.73, 1.78, and 1.80 g respectively. The differences between data obtained by different methods are not significant (P > 0.05). There are tendency for increasing endogenous nitrogen excretion with increasing pure cellulose or crude fiber in diets. Endogenous dry matter excretion was 8.00 g in fasting cockerels, 9.26 g by extrapolation nitrogen free diets with different cellulose level, and 9.61 g by extrapolation diets with sunflower meal (SFM) with different crude protein, and crude fiber content. Differences between different methods are not significant (P>0.05). Although there is some impact of type of fiber, differences are small. However, the results with fasting bid tend to be lower. Part of the observed small difference was probably due to the incomplete digestibility of dietary mineral supplements in diets with pure nutrients and in SFM, and partly on increased secretions and raw (desquamation) of epithelial cells, which are not reabsorbed completely. Therefore, level of insoluble feed fiber in diet is not expected to be serious obstruction to establish basic value for endogenous nitrogen excretion in practical diet with normal fiber content.