Incorporation of endogenous urea nitrogen into the amino acids of bacterial protein in the rumen of goats fed diets with various protein levels
Journal Title: Journal of Animal and Feed Sciences - Year 2013, Vol 22, Issue 4
Abstract
The aim of the study was to investigate the effect of different levels of protein in a diet on the incorporation of endogenous urea nitrogen (EUN) into individual amino acids (AA) of the ruminal bacteria of goats fed a low- (LP), medium- (MP), or high-protein diet (HP) in a 3 × 3 Latin square design. Three Alpine goats of about 35 kg body weight fitted with cannula into the rumen and catheter into the jugular vein were fed three isoenergetic diets containing 11% (LP), 13% (MP), or 16% (HP) crude protein in dry matter. The goats were infused for 6 days continuously with an 15N urea solution into the jugular vein. Ruminal bacteria were hydrolysed with 6M HCl. Next, butyl derivatives of free bacterial AA were obtained using HCl in butanol, then N-acylated using trifluoroacetic acid anhydride and analysed by gas chromatography using a mass-selective detector. The concentration of urea in plasma was 178, 356 and 667 mg · l–1 in goats from groups LP, MP and HP, respectively. 15N-excess during the infusion of labelled urea was significantly higher (P < 0.05) in the vast majority of AA of ruminal bacteria from goats fed the LP diet in comparison with goats fed the HP diet. Therefore, the level of protein in the diets affects the incorporation of EUN into bacterial AA. With the LP diet, EUN was incorporated mostly into glutamic acid, isoleucine and arginine, while in the case of the HP diet, into glutamic acid and arginine, as well as methionine. Regardless of the level of nitrogen in the diets, the incorporation of 15N into proline was very low. Irrespective of the dietary nitrogen level, EUN appears to be predominantly used for synthesis of glutamic acid in ruminal bacteria.
Authors and Affiliations
J. P. Michalski, J. Kowalczyk, M. Czauderna, W. Litwin
Keywords
Related Articles
- EP ID EP73001
- DOI -
- Views 127
- Downloads 0
Genetic parameters estimation and breeding values prediction for linear described traits in the Old Kladruber horse
Genetic parameters estimates and breeding values for 36 conformation traits repeatedly observed over 16 years with a linear description of the type were evaluated for 977 Old Kladruber horses. The genetic parameters were...
Postprandial oxidative losses of dietary leucine depend on the time interval between consecutive meals: a model study with rats
Postprandial oxidative losses of egg white-bound [1-13C]-leucine were studied as 13C recovery in the breath of rats in relation to different time intervals between two meals. Male Wistar rats (n = 48; 68.3 ± 5.9 g) divid...
The effect of particle size of full-fat rapeseed and of multi-carbohydrase enzyme supplementation on nutrient digestibility and performance in broilers
The aim of the study was to investigate the effect of the particle size of full-fat rapeseed and of multi-carbohydrase enzyme supplementation on chicken performance. The experiment was conducted with 480 male broiler chi...
Response of Shami goats and kids to variable levels of soyabean or sunflower oils in diets
A study was conducted to determine the effect of feeding soyabean or sunflower oil to lactating Shami goats on milk production, composition and fatty acid profile. Goats (n=125), 2 to 4 years of age and 55 to 60 kg livew...
Plant extract enhanced ruminal CLA concentration, in vitro
The effect of adding plant extracts to ruminal fluid on the formation of conjugated linoleic acid (CLA) isomers and on fermentation parameters was evaluated. Initially, fifteen plant extracts at two levels (1 and 2 mg ·...