title: Long-term feeding effects of dietary protein levels on egg production, immunocompetence and plasma amino acids of laying hens in subtropical condition.
abstract: The objective of this study was to determine the effect of protein levels on production performance, immune response, liver triglyceride and plasma amino acids profile of laying hens during 21-48 weeks of age. Two groups of commercial hens (Babcock B-308) were fed with diets with different crude protein levels (14% and 18% CP). The high protein diet (18% CP) significantly increased production performance, essential amino acid intake, spleen weight (% of body weight), ND-titre (haemagglutination-inhibition test), serum albumin (g/dl), serum alpha-globulin and plasma essential amino acids (except histidine) and decreased liver triglyceride (mg/g liver) in relation to the low protein diet (14% CP). In long-term effect, therefore, this study suggested that adequate dietary condition of amino acids, particularly methionine and branch-chain amino acids is necessary for sustaining normal immunocompetence and achieving maximum production performance.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Kasetsart University, Banngkok, Thailand.
authors.forename: K
authors.initials: K
authors.lastname: Poosuwan
authors.forename: C
authors.initials: C
authors.lastname: Bunchasak
authors.forename: C
authors.initials: C
authors.lastname: Kaewtapee
mesh_terms: D000375:Aging; D000596:Amino Acids / Q000097:blood*; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000097:blood* / Q000276:immunology / Q000502:physiology*; D002980:Climate; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000494:pharmacology*; D004334:Drug Administration Schedule; D005260:Female; D010058:Oviposition / Q000187:drug effects*; D013696:Temperature
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins