title: Effects of increasing dietary L-carnitine on growth performance of weanling pigs.
abstract: Four experiments were conducted to evaluate the effects of supplementing graded levels (0 to 100 ppm) of L-carnitine to the diet of weanling pigs on growth performance during a 34- to 38-d experimental period. A fifth experiment was conducted to determine the effects of addition of L-carnitine to diets with or without added soybean oil (SBO) on growth performance. In Exp. 1, 128 pigs (initial BW = 5.5 kg) were allotted to four dietary treatments (six pens per treatment of four to six pigs per pen). Dietary treatments were a control diet containing no added L-carnitine and the control diet with 25, 50, or 100 ppm of added L-carnitine. In Exp. 2, 3, and 4, pigs (4.8 to 5.6 kg of BW) were allotted to five dietary treatments consisting of either a control diet containing no added L-carnitine or the control diet with 25, 50, 75, or 100 ppm of added L-carnitine. All diets in Exp. 1 to 4 contained added soybean oil (4 to 6%). There were seven pens per treatment (four to five pigs per pen) in Exp. 2, whereas Exp. 3 and 4 had five and six pens/treatment (eight pigs per pen), respectively. In general, dietary carnitine additions had only minor effects on growth performance during Phases 1 and 3; however, dietary L-carnitine increased (linear [Exp. 1], quadratic [Exp. 2 to 4], P < 0.03) ADG and gain:feed (G:F) during Phase 2. The improvements in growth performance during Phase 2 were of great enough magnitude that carnitine addition tended to increase ADG (linear, P < 0.10) and improve G:F (quadratic, P < 0.02) for the entire 38-d period. In Exp. 5, 216 weanling pigs (5.8 kg of BW) were allotted (12 pens/treatment of four to five pigs per pen) to four dietary treatments. The four dietary treatments were arranged in a 2 x 2 factorial with main effects of added SBO (0 or 5%) and added L-carnitine (0 or 50 ppm). Pigs fed SBO tended (P < 0.07) to grow more slowly and consumed less feed compared with those not fed SBO, but G:F was improved (P < 0.02). The addition of L-carnitine did not affect (P > 0.10) ADG or ADFI; however, it improved (P < 0.03) G:F. Also, the increase in G:F associated with L-carnitine tended to be more pronounced for pigs fed SBO than those not fed SBO (carnitine x SBO, P < 0.10). These results suggest that the addition of 50 to 100 ppm of added L-carnitine to the diet improved growth performance of weanling pigs. In addition, supplemental L-carnitine tended to be more effective when SBO was provided in the diet.
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater 74078, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Rincker
authors.forename: S D
authors.initials: SD
authors.lastname: Carter
authors.forename: D E
authors.initials: DE
authors.lastname: Real
authors.forename: J L
authors.initials: JL
authors.lastname: Nelssen
authors.forename: M D
authors.initials: MD
authors.lastname: Tokach
authors.forename: R D
authors.initials: RD
authors.lastname: Goodband
authors.forename: S S
authors.initials: SS
authors.lastname: Dritz
authors.forename: B W
authors.initials: BW
authors.lastname: Senne
authors.forename: R W
authors.initials: RW
authors.lastname: Fent
authors.forename: L A
authors.initials: LA
authors.lastname: Pettey
authors.forename: K Q
authors.initials: KQ
authors.lastname: Owen
mesh_terms: D000375:Aging / Q000502:physiology; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn; D002331:Carnitine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D011897:Random Allocation; D013024:Soybean Oil / Q000008:administration & dosage; D013552:Swine / Q000254:growth & development*; D014886:Weaning; D015430:Weight Gain / Q000187:drug effects
chemical_list: D013024:Soybean Oil; D002331:Carnitine