title: Effects of graded levels of lysine and excess arginine and threonine on young pigs fed practical diets.
abstract: Three experiments were conducted to estimate the lysine requirement of the weanling pig and the effects of excess arginine and threonine on that estimate. Feeding 1.15% dietary lysine in Exp. 1 and 1.20% in Exp. 2 maximized feed efficiency and resulted in the lowest plasma urea N values. Adding .15% threonine to the diets in Exp. 2 did not affect (P greater than .10) performance of the pigs, but increased (P less than .01) plasma urea N and decreased (P less than .01) plasma lysine concentrations. Supplemental arginine (.22%) did not affect performance of the growing pigs in Exp. 3, but it increased (P less than .01) plasma urea N. Pigs fed a corn-soybean meal diet utilized feed more efficiently (P less than .05) than those fed a corn-fish meal-dried whey diet. The most likely cause for this response was that the corn-soybean diet contained more lysine (.82%) than expected, whereas the corn-fish meal-dried whey diet had close to the expected content of lysine (.72%). From these results, it was concluded that the lysine requirement of the weanling pig fed practical diets is at least 1.15 or 1.20% of the diet. Also, added arginine or threonine did not adversely affect the performance of pigs.
mesh_terms: D000601:Amino Acids, Essential / Q000097:blood; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D001806:Blood Urea Nitrogen; D001835:Body Weight; D008239:Lysine / Q000008:administration & dosage / Q000378:metabolism*; D009751:Nutritional Requirements; D013552:Swine / Q000254:growth & development / Q000378:metabolism*; D013912:Threonine / Q000008:administration & dosage / Q000494:pharmacology*; D014886:Weaning
chemical_list: D000601:Amino Acids, Essential; D013912:Threonine; D001120:Arginine; D008239:Lysine