title: Evaluation of standardized ileal digestible lysine requirement of nursery pigs from seven to fourteen kilograms.
abstract: Four experiments were conducted to determine the standardized ileal digestible (SID) Lys requirement of pigs (Sus scrofa) from 7 to 14 kg. In Exp. 1, 294 pigs (6.8 kg BW) were used in a 28-d growth trial with 7 pigs per pen and 7 pens per treatment. Treatment diets were fed from d 0 to 14, and a common diet was fed from d 14 to 28. The 6 SID Lys levels tested were 1.15, 1.23, 1.30, 1.38, 1.45, and 1.53%. The diets were corn- and soybean-meal [Zea mays L. and Glycine max (L.) Merr.] based, with 10% spray-dried whey, 4.5% fish meal, and contained 3.37 Mcal of ME/kg. From d 0 to 14, ADG increased (quadratic, P < 0.001) as SID Lys increased from 1.15 to 1.30% with no further increase at greater levels. Gain:feed increased (linear, P < 0.001) with increasing SID Lys. Experiments 2 to 4 were 14-d growth trials with diets containing 1.22, 1.32, 1.42, 1.52, or 1.62% SID Lys. Diets were corn- and soybean-meal based with 3.45 Mcal of ME/kg. Soybean meal and lactose were constant in all diets at 30 and 7% of the diet, respectively. In Exp. 2, 840 pigs (7.6 kg BW) were used, with 24 pigs per pen and 7 pens per treatment. Increasing SID Lys from 1.22 to 1.42% increased (quadratic, P < 0.01) ADG and G:F with no further improvement observed in pigs fed the 1.52 or 1.62% SID Lys diets during d 0 to 14. In Exp. 3, 1,260 pigs (8.5 kg BW) were used with 42 pigs per feeder (2 pens per feeder) and 6 feeders per treatment. Increasing dietary Lys increased (quadratic, P < 0.02) ADG and G:F with the greatest response observed as SID Lys increased from 1.22 to 1.32% and, then, slight improvements with 1.42 and 1.52% during d 0 to 14. In Exp. 4, 770 pigs (7.4 kg BW) were used with 22 pigs per pen and 7 pens per treatment. Increasing SID Lys increased (quadratic, P = 0.05) ADG with pigs fed 1.32 and 1.42% SID Lys diets having the greatest BW gains during d 0 to 14. Increased SID Lys decreased (linear, P < 0.001) ADFI and increased (linear, P < 0.001; quadratic, P = 0.02) G:F. In conclusion, results of these experiments indicate that the 1998 NRC Lys recommendations (e.g., 1.19% SID Lys for 5 to 10 kg pigs) are less than required for optimal growth for 7 to 14 kg pigs. One-slope straight broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.30% for ADG and 1.37% for G:F, or at least 3.86 and 4.18 g SID Lys/Mcal ME, respectively. Quadratic broken-line analysis indicated that the SID Lys requirement for optimal growth was at least 1.37% for ADG and 1.54% for G:F, or at least 4.19 and 4.92 g SID Lys/Mcal ME, respectively.
authors.affiliation: Department of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan 66506, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Nemechek
authors.forename: A M
authors.initials: AM
authors.lastname: Gaines
authors.forename: M D
authors.initials: MD
authors.lastname: Tokach
authors.forename: G L
authors.initials: GL
authors.lastname: Allee
authors.forename: R D
authors.initials: RD
authors.lastname: Goodband
authors.forename: J M
authors.initials: JM
authors.lastname: DeRouchey
authors.forename: J L
authors.initials: JL
authors.lastname: Nelssen
authors.forename: J L
authors.initials: JL
authors.lastname: Usry
authors.forename: G
authors.initials: G
authors.lastname: Gourley
authors.forename: S S
authors.initials: SS
authors.lastname: Dritz
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary; D007082:Ileum / Q000502:physiology*; D008239:Lysine / Q000378:metabolism*; D009751:Nutritional Requirements; D013552:Swine / Q000254:growth & development / Q000502:physiology*
chemical_list: D008239:Lysine