Qi K, Lu C D, Owens F N
E. (Kika) de la Garza Institute for Goat Research, Langston University, OK 73050.
J Anim Sci. 1993 Jun;71(6):1579-87. doi: 10.2527/1993.7161579x.
Castrated male goat kids (20 Alpine, 12 Angora) were individually fed isonitrogenous and isoenergetic diets containing 2.28% N and S (added as CaSO4) at either .11 (basal), .20, .28, or .38% of dietary DM. Sulfate supplementation during the 8-wk growth trial quadratically increased ADG (P < .05) and tended to increase quadratically the DMI (P < .07) of goats, with a peak value for the .20% S diet. Even when analyzed using DMI as a covariate, ADG was quadratically increased (P < .05) by added S. Sulfate supplementation linearly increased (P < .001) S intake, fecal S output, and S retention. Sulfate supplementation tended to increase quadratically (P < .06) the blood plasma concentration of L-lactate. However, sulfate supplementation did not significantly affect (P > .10) plasma sulfate, plasma cystine, ruminal ammonia N concentrations, or purine N content of isolated ruminal bacteria. Sulfate supplementation quadratically increased (P < .05) fractional N retention. Urinary output of uric acid increased quadratically (P < .01) with S supplementation, presumably reflecting ruminal bacterial protein synthesis. Calculated by regression, the optimal dietary S content for maximum ADG was .22% S (N:S = 10.4:1), for maximum DMI it was .24% S (N:S = 9.5: 1), for maximum N retention it was .23% (N:S = 9.9: 1), and for maximum absorbed N retained it was .22% (N:S = 10.4:1). These results support the current estimate of the S requirement of goats for growth (N:S = 10:1).
去势公山羊羔（20只阿尔卑斯山羊，12只安哥拉山羊）分别饲喂含氮和硫量相同且能量相等的日粮，氮含量为2.28%，硫（以硫酸钙形式添加）含量分别为日粮干物质的0.11%（基础日粮）、0.20%、0.28%或0.38%。在为期8周的生长试验中，补充硫酸盐使山羊的平均日增重呈二次曲线增加（P < 0.05），且干物质采食量也有呈二次曲线增加的趋势（P < 0.07），其中以硫含量为0.20%的日粮达到峰值。即使以干物质采食量作为协变量进行分析，补充硫仍使平均日增重呈二次曲线增加（P < 0.05）。补充硫酸盐使硫摄入量、粪便硫排出量和硫保留量呈线性增加（P < 0.001）。补充硫酸盐使血浆L - 乳酸浓度有呈二次曲线增加的趋势（P < 0.06）。然而，补充硫酸盐对血浆硫酸盐、血浆胱氨酸、瘤胃氨氮浓度或瘤胃分离细菌的嘌呤氮含量无显著影响（P > 0.10）。补充硫酸盐使氮保留率呈二次曲线增加（P < 0.05）。补充硫后尿酸的尿液排出量呈二次曲线增加（P < 0.01），这可能反映了瘤胃细菌蛋白质的合成。通过回归计算，使平均日增重最大的日粮最佳硫含量为0.22%硫（氮:硫 = 10.4:1），使干物质采食量最大的为0.24%硫（氮:硫 = 9.5:1），使氮保留量最大的为0.23%（氮:硫 = 9.9:1），使吸收氮保留量最大的为0.22%（氮:硫 = 10.4:1）。这些结果支持了目前对生长山羊硫需求量的估计（氮:硫 = 10:1）。
