The detoxification of ammonia occurs mainly through conversion of ammonia to urea in the liver via the urea cycle and glutamine synthesis. Congenital portosystemic shunts (CPSS) in dogs cause hyperammonemia eventually leading to hepatic encephalopathy. In this study, the gene expression of urea cycle enzymes (carbamoylphosphate synthetase (CPS1), ornithine carbamoyltransferase (OTC), argininosu...

Five experiments were conducted to determine the true digestible Trp (dTrp) requirement of nursery pigs. Treatments were replicated with four or five pens of five or six pigs each. Pigs were weaned at 21 (Exp. 1, 2, and 5) or 19 d (Exp. 3 and 4), and fed common diets for various times and then experimental diets for 8 (Exp. 1), 13 (Exp. 2 and 3), or 14 d (Exp. 4 and 5). Experiment 1 (160 pigs, ...

We conducted two experiments evaluating the lysine requirement of 91- to 113-kg gilts. Gilts (PIC L326 x C-22) with initial body weights of 42 (Exp. 1) or 39 kg (Exp. 2) were blocked by weight in a randomized complete block design. Experiment 1 included 105 gilts, with seven gilts per pen and five replications (pens) per treatment. Experiment 2 included 125 gilts, with eight gilts per pen and f...

BACKGROUND Like several other parasites, Teladorsagia circumcincta secretes or excretes urea, but neither the rate of efflux nor the possible metabolic sources of the urea has been considered. METHODS Parasites were maintained by passage through sheep. Urea efflux was measured using phenol/hypochlorite after treatment with urea aminohydrolase. The kinetics of creatine amidinohydrolase and arg...

The sequence of the gene for beta-lactamase I from Bacillus cereus 569/H has been redetermined. Oligonucleotide-directed mutagenesis has been carried out, and the effects of the changes on the ampicillin-resistance of Escherichia coli TG1 expressing the mutant genes have been studied. Lysine-73, close to the active-site serine-70 and a highly-conserved residue, has been converted into arginine....

The effect of varying dietary lysine supply from low to adequate levels on amino acid partitioning across splanchnic tissues was investigated in growing barrows prepared with permanent indwelling catheters placed in the carotid artery, portal vein and hepatic vein. Pigs (32.9 (SD) 1.4 kg) were fed either a lysine-deficient diet (L1; n=9) or a lysine-adequate diet (L2; n=7) according to a comple...

l-lysine is an essential amino acid required for nutrition of animals and humans. It has to be present in food and feed, which, in many cases, is realized by supplementation of the feed-stuffs with pure lysine. The high importance of lysine in nutrition has stimulated intensive research on the lysine biosynthetic pathways and their regulation and the search for microorganisms capable of over-pr...

Although previous studies have shown that virtually the entire carbon skeleton of dietary glutamate (glutamate-C) is metabolized in the gut for energy production and amino acid synthesis, little is known regarding the fate of dietary glutamate nitrogen (glutamate-N). In this study, we hypothesized that dietary glutamate-N is an effective nitrogen source for amino acid synthesis and investigated...

A total of 163 sows were used in a study to determine the requirement for total sulfur amino acids (TSAA), relative to lysine, during lactation. All experimental diets were cornsoybean meal-based and formulated to contain 0.88% true ileal digestible (TID) lysine (0.97% total lysine). The experimental diets contained 0.37% L-lysine HCl, with other crystalline amino acids added to ensure that TSA...

The effects of 20 amino acids and two amides were studied on the flowering of a photoperiodically insensitive duckweed, Lemna paucicostata LP6. Alanine, asparagine, aspartate, cystine, glutamate, glutamine, glycine, lysine, methionine, proline, serine, and threonine induced flowering under a photoperiodic regime of 16 hours light and 8 hours darkness. Among these, glutamate and aspartate were f...