Department of Animal Science, Texas A&M University, College Station, TX 77843.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad354.
Pigs with intrauterine growth restriction (IUGR) have suboptimum growth performance and impaired synthesis of glycine (the most abundant amino acid in the body). Conventional corn- and soybean meal-based diets for postweaning pigs contain relatively low amounts of glycine and may not provide sufficient glycine to meet requirements for IUGR pigs. This hypothesis was tested using 52 IUGR pigs and 52 litter mates with normal birth weights (NBW). At weaning (21 d of age), IUGR or NBW pigs were assigned randomly to one of two nutritional groups: supplementation of a corn-soybean meal-based diet with either 1% glycine plus 0.19% cornstarch or 1.19% L-alanine (isonitrogenous control). Feed consumption and body weight (BW) of pigs were recorded daily and every 2 or 4 wks, respectively. All pigs had free access to their respective diets and clean drinking water. Within 1 wk after the feeding trial ended at 188 d of age, blood and other tissue samples were obtained from pigs to determine concentrations of amino acids and meat quality. Neither IUGR nor glycine supplementation affected (P > 0.05) feed intakes of pigs per kg BW. The final BW, gain:feed ratio, carcass dressing percentages, and four-lean-cuts percentages of IUGR pigs were 13.4 kg, 4.4%, 2%, and 15% lower (P < 0.05) for IUGR pigs than NBW pigs, respectively. Compared with pigs in the alanine group, dietary glycine supplementation increased (P < 0.05) final BW, gain:feed ratio, and meat a* value (a redness score) by 3.8 kg, 11%, and 10%, respectively, while reducing (P < 0.05) backfat thickness by 18%. IUGR pigs had lower (P < 0.05) concentrations of glycine in plasma (-45%), liver (-25%), jejunum (-19%), longissimus dorsi muscle (-23%), gastrocnemius muscle (-26%), kidney (-15%), and pancreas (-6%), as compared to NBW pigs. In addition, dietary glycine supplementation increased (P < 0.05) concentrations of glycine in plasma and all analyzed tissues. Thus, supplementing 1% of glycine to corn-soybean meal-based diets improves the growth performance, feed efficiency, and meat quality of IUGR pigs.
患有宫内生长受限（IUGR）的猪生长性能不佳，甘氨酸（体内最丰富的氨基酸）合成受损。用于断奶后猪的常规玉米和豆粕日粮中甘氨酸含量相对较低，可能无法为 IUGR 猪提供足够的甘氨酸以满足其需求。本研究使用 52 头 IUGR 猪和 52 头具有正常出生体重（NBW）的同窝仔猪进行了验证。在断奶（21 日龄）时，将 IUGR 或 NBW 仔猪随机分配到两个营养组之一：在玉米-豆粕日粮中添加 1%甘氨酸和 0.19%玉米淀粉或 1.19% L-丙氨酸（等氮对照）。分别每天和每 2 或 4 周记录一次猪的采食量和体重（BW）。所有猪均自由采食各自的日粮和清洁饮用水。在 188 日龄结束的饲养试验后 1 周内，从猪身上获得血液和其他组织样本，以确定氨基酸浓度和肉质。IUGR 或甘氨酸补充均未影响（P＞0.05）每公斤 BW 猪的采食量。IUGR 猪的最终 BW、增重：采食量比、胴体出肉率和四瘦肉切块率分别比 NBW 猪低 13.4 公斤、4.4%、2%和 15%（P＜0.05）。与丙氨酸组相比，日粮甘氨酸补充增加了（P＜0.05）最终 BW、增重：采食量比和肉色值（红色评分），分别增加了 3.8 公斤、11%和 10%，同时减少了（P＜0.05）背脂厚度 18%。与 NBW 猪相比，IUGR 猪的血浆（-45%）、肝脏（-25%）、空肠（-19%）、背最长肌（-23%）、腓肠肌（-26%）、肾脏（-15%）和胰腺（-6%）中的甘氨酸浓度较低（P＜0.05）。此外，日粮甘氨酸补充增加了（P＜0.05）血浆和所有分析组织中甘氨酸的浓度。因此，在玉米-豆粕日粮中补充 1%的甘氨酸可改善 IUGR 猪的生长性能、饲料效率和肉质。
