Department of Animal Science, Iowa State University, Ames, IA 50011, USA.
Department of Veterinary Diagnostic and Production Medicine, Swine Medicine Education Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad151.
The objective of this study was to investigate the effects of dietary metabolizable energy (ME) level and the ratio of linoleic acid:α-linolenic acid (LA:ALA) on the growth performance, lipid metabolism, circulatory and joint inflammatory status, and synovial fluid proteome of grow-finish pigs. A total of 224 pigs (BW = 41.5 ± 6.1 kg; PIC Genus 337 × 1050, Hendersonville, TN) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) ME dietary treatment with a high (23:1) or low (12:1) LA:ALA in a 2 × 2 factorial arrangement. Diets were fed across three 28-d phases. Pigs were housed either four barrows or four gilts per pen. Blood samples were collected on days 0, 21, 42, and 84. Synovial fluid was collected from the hock and carpus joints on days 0 and 84. Liver and adipose tissue samples were collected on day 84. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with pen as the experimental unit and energy level, essential fatty acid ratio, sex, phase, and their interactions as fixed effects. Compared to LE, HE increased days 28, 56, and 84 body weight (BW; P = 0.005). For the overall period, HE increased average daily gain (ADG) compared to LE (P < 0.001) and improved feed efficiency (P = 0.001), while LE increased feed intake compared to HE (P < 0.001). Gilts receiving diets with low LA:ALA had similar final BW to barrows receiving a low LA:ALA at days 28, 56, and 84 (P = 0.024), resulting from improved overall days 0-84 ADG compared to gilts receiving the high LA:ALA (P = 0.031). In the liver, HE decreased the mRNA abundance of acetyl CoA carboxylase (ACACA; P = 0.004), cluster of differentiation 36 (P = 0.034), and tended to decrease fatty acid synthase (FASN; P = 0.056). In adipose tissue, HE decreased ACACA (P = 0.001) and FASN (P = 0.017). Plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNFα) were reduced on day 84 compared to day 0 (P ≤ 0.014). In the hock and carpus synovial fluid, LE tended to reduce CRP and TNFα (P ≤ 0.096). Hock and carpus synovial fluid CRP were also reduced on day 84 compared to day 0 (P = 0.001). Age of the pig impacted serum and hock synovial fluid protein abundance, but not energy level, LA:ALA, or their interactions (P < 0.05). To conclude, the high and low LA:ALA ratios utilized in this study can be fed at varying energy levels without impacting growth. Additionally, LA:ALA ratios can differentially impact the growth of barrows and gilts.
本研究旨在探讨饲粮代谢能（ME）水平和亚油酸：α-亚麻酸（LA：ALA）比例对生长育肥猪生长性能、脂代谢、循环和关节炎症状态以及滑液蛋白质组的影响。共选用 224 头体重为（41.5±6.1）kg 的 PIC Genus 337×1050 猪（田纳西州亨德森维尔），随机分为 ME 水平高（3.55 Mcal/kg；HE）和低（3.29 Mcal/kg；LE）组和 LA：ALA 比例高（23：1）和低（12：1）组，每个处理 4 个重复，每个重复 4 头公猪或 4 头母猪。试验共分为 3 个 28d 阶段，猪饲养在每个栏舍 4 头公猪或 4 头母猪。分别于 0、21、42 和 84d 采集血液样品，0 和 84d 采集跗关节和腕关节滑液样品。84d 时屠宰猪，采集肝脏和脂肪组织样品。数据采用 PROC MIXED（SAS 9.4）软件作为重复测量数据进行分析，以栏舍为试验单位，以能量水平、必需脂肪酸比例、性别、阶段及其互作为固定效应。与 LE 相比，HE 增加了 28、56 和 84d 的体重（BW；P=0.005）。整个试验期，与 LE 相比，HE 提高了平均日增重（ADG；P＜0.001）和饲料效率（P=0.001），而 LE 提高了采食量（P＜0.001）。低 LA：ALA 饲粮组母猪的终末 BW 与低 LA：ALA 饲粮组公猪相似，在 28、56 和 84d 时差异显著（P=0.024），这是由于母猪整个 0-84d 的 ADG 提高，高于高 LA：ALA 饲粮组母猪（P=0.031）。在肝脏中，HE 降低了乙酰辅酶 A 羧化酶（ACACA；P=0.004）、分化群 36（P=0.034）的 mRNA 丰度，并且有降低脂肪酸合酶（FASN；P=0.056）的趋势。在脂肪组织中，HE 降低了 ACACA（P=0.001）和 FASN（P=0.017）的表达。与 0d 相比，84d 时血浆炎症标志物 C 反应蛋白（CRP）和肿瘤坏死因子-α（TNFα）显著降低（P≤0.014）。在跗关节和腕关节滑液中，LE 降低了 CRP 和 TNFα（P≤0.096）。与 0d 相比，84d 时跗关节和腕关节滑液中 CRP 显著降低（P=0.001）。猪的年龄影响血清和跗关节滑液蛋白质的丰度，但不受能量水平、LA：ALA 或其互作的影响（P＜0.05）。综上所述，本研究中使用的高和低 LA：ALA 比例可以在不同的能量水平下使用，而不会影响生长性能。此外，LA：ALA 比例可以不同程度地影响公猪和母猪的生长性能。
