Libal G W, Uttecht D J, Hamilton C R
Department of Animal and Range Sciences, South Dakota State University, Brookings 57007-0392, USA.
J Anim Sci. 1997 Feb;75(2):417-22. doi: 10.2527/1997.752417x.
Large White x Landrace primiparous and multiparous sows (n = 115) were used to evaluate the tryptophan needs of lactating sows fed diets supplemented with crystalline lysine to contain .75% lysine. Sows were fed 1.8 kg of their allotted diets from d 110 of gestation until parturition and then were allowed ad libitum access to diets analyzed to contain either .12 (n = 58) or .17% (n = 57) tryptophan during a 21-d lactation. Diets were created by crystalline tryptophan and lysine additions to a corn-soybean meal basal diet that contained .12% tryptophan. Tryptophan level in the lactation diet did not affect number or weight of pigs at 21 d (P > .10). Sows fed .17% tryptophan were heavier at d 21 of lactation than those fed .12% tryptophan (P = .09) due to less weight loss during the 21-d lactation (P = .09). Feed intake was greater (P < .05) for sows fed .17% tryptophan than for sows fed .12% tryptophan. A reference diet analyzed to contain .11% tryptophan and .63% lysine was fed to an additional 11 sows only as a baseline for measuring plasma urea nitrogen and amino acids. Plasma tryptophan concentrations were higher (P < .05) for sows fed .17% tryptophan than for sows not fed added L-tryptophan. Among sows fed the low-tryptophan diets, sows fed the reference diet (.60% lysine) had higher (P < .05) plasma phenylalanine and valine concentrations than sows fed .75% lysine. Diet did not affect plasma concentrations of any other essential amino acid (P > .10). Plasma urea N levels were lower (P = .11) for sows fed the diet supplemented with tryptophan. Lactating sows allowed ad libitum access to diets containing .75% lysine benefited from higher feed intake and lower weight loss when dietary tryptophan levels were increased from .12 to .17%.
选用大白猪与长白猪的初产和经产母猪（n = 115），来评估在日粮中添加结晶赖氨酸使赖氨酸含量达到0.75%的泌乳母猪对色氨酸的需求。母猪从妊娠第110天至分娩期间饲喂1.8千克分配给它们的日粮，然后在21天的泌乳期内自由采食分析含0.12%（n = 58）或0.17%（n = 57）色氨酸的日粮。日粮通过向含0.12%色氨酸的玉米 - 豆粕基础日粮中添加结晶色氨酸和赖氨酸来配制。泌乳日粮中的色氨酸水平对21日龄时仔猪数量或体重没有影响（P > 0.10）。由于在21天泌乳期内体重损失较少（P = 0.09），采食含0.17%色氨酸日粮的母猪在泌乳第21天时比采食含0.12%色氨酸日粮的母猪体重更重（P = 0.09）。采食含0.17%色氨酸日粮的母猪采食量高于（P < 0.05）采食含0.12%色氨酸日粮的母猪。另外11头母猪仅采食一种分析含0.11%色氨酸和0.63%赖氨酸的对照日粮，作为测定血浆尿素氮和氨基酸的基线。采食含0.17%色氨酸日粮的母猪血浆色氨酸浓度高于（P < 0.05）未添加L - 色氨酸的母猪。在采食低色氨酸日粮的母猪中，采食对照日粮（赖氨酸0.60%）的母猪血浆苯丙氨酸和缬氨酸浓度高于（P < 0.05）采食含0.75%赖氨酸日粮的母猪。日粮对任何其他必需氨基酸的血浆浓度没有影响（P > 0.10）。采食添加色氨酸日粮的母猪血浆尿素氮水平较低（P = 0.11）。当日粮色氨酸水平从0.12%提高到0.17%时，自由采食含0.75%赖氨酸日粮的泌乳母猪受益于更高的采食量和更低的体重损失。
