J Anim Sci. 2017 Dec;95(12):5485-5496. doi: 10.2527/jas2017.1785.
Sows are usually restricted fed during pregnancy to maximize their reproductive efficiency, which may predispose sows to a state of hunger. However, an objective measurement of hunger status has not been established. In the present study, we examined the correlation of plasma hormones and NEFA and selected the best predictors for hunger status using pregnant gilts. Three different levels of feed intake (0.5, 1.0 and 2.0 × maintenance energy intake [0.5M, 1.0M and 2.0M, respectively]) were imposed from Day 28 to 34 of gestation to create different hunger statuses in pregnant gilts. Plasma hormones related to energy homeostasis and NEFA were analyzed to quantify their response to different levels of feed intake. A total of 18 gilts (197.53 ± 6.41 kg) were allotted to 1 of 3 dietary treatments using a completely randomized design. Results showed that BW change, ADG, and G:F from Day 28 to 34 of gestation were higher ( < 0.01) for gilts on the 2.0M feeding level than for gilts on the 0.5M feeding level. Plasma acyl ghrelin concentrations showed a relatively flat pattern during the 24-h period. Plasma acyl ghrelin and NEFA concentrations and areas under the curve (AUC) were greater ( < 0.05) in gilts on the 0.5M level of feed intake than in those on the 2.0M level of feed intake. No differences were observed among the 3 feeding levels in terms of plasma glucagon-like peptide 1 and leptin concentrations. Additionally, consumption time for 1.82 kg feed on Day 35 of gestation was longer ( < 0.01) in gilts fed the 2.0M level of feed intake from Day 28 to 34 of gestation than in those on the 0.5M level of feed intake. Simple linear regression results showed that the AUC of acyl ghrelin was the best predictor for consumption time ( = 0.82), whereas the AUC of NEFA was the best predictor for BW ( = 0.55) or backfat change ( = 0.42) from Day 28 to 34 of gestation. In conclusion, our data suggested that a relative flat pattern existed in pregnant gilts in terms of the diurnal plasma profile of acyl ghrelin and that the level of feed intake of pregnant gilts was negatively correlated with plasma concentrations of acyl ghrelin and NEFA, which, in turn, were negatively associated with feed consumption time. The AUC of acyl ghrelin and NEFA seemed to be the best predictors for hunger status of pregnant gilts.
母猪通常在怀孕期间被限制采食量，以最大限度地提高其繁殖效率，这可能使母猪处于饥饿状态。然而，目前还没有建立饥饿状态的客观衡量标准。在本研究中，我们研究了血浆激素和非酯化脂肪酸（NEFA）的相关性，并使用妊娠母猪选择了饥饿状态的最佳预测因子。从妊娠第 28 天到第 34 天，母猪分别接受了三种不同的采食量（0.5、1.0 和 2.0×维持能量摄入量[0.5M、1.0M 和 2.0M]），以在妊娠母猪中产生不同的饥饿状态。分析了与能量平衡和 NEFA 相关的血浆激素，以量化它们对不同采食量水平的反应。总共 18 头母猪（197.53±6.41kg）被完全随机设计分配到 3 种饮食处理中的 1 种。结果表明，与 0.5M 采食量组相比，2.0M 采食量组的母猪在妊娠第 28 天至第 34 天期间的 BW 变化、ADG 和增重/采食量比更高（<0.01）。24 小时内，母猪血浆酰基 ghrelin 浓度呈相对平坦的模式。与 2.0M 采食量组相比，0.5M 采食量组的母猪血浆酰基 ghrelin 和 NEFA 浓度以及曲线下面积（AUC）更高（<0.05）。3 种采食量水平之间，母猪血浆胰高血糖素样肽 1 和瘦素浓度无差异。此外，与 0.5M 采食量组相比，从妊娠第 28 天至第 34 天接受 2.0M 采食量的母猪在妊娠第 35 天的饲料消耗时间更长（<0.01）。简单线性回归结果表明，酰基 ghrelin 的 AUC 是消耗时间的最佳预测因子（=0.82），而 NEFA 的 AUC 是 BW（=0.55）或背膘变化（=0.42）的最佳预测因子。从妊娠第 28 天至第 34 天。总之，我们的数据表明，妊娠母猪的酰基 ghrelin 昼夜血浆谱存在相对平坦的模式，并且母猪的采食量水平与血浆酰基 ghrelin 和 NEFA 浓度呈负相关，而血浆酰基 ghrelin 和 NEFA 浓度又与饲料消耗时间呈负相关。酰基 ghrelin 和 NEFA 的 AUC 似乎是妊娠母猪饥饿状态的最佳预测因子。
