Large variability in body composition is observed in pigs fed and raised in similar conditions. Part of this variation might be explained by the feeding behaviour of pigs, given its effect on metabolic hormones associated with energy regulation and protein metabolism. The objective of this study was to elucidate this relationship by examining body composition with a new index describing feeding behaviour in finishing pigs. Feeding behaviour and body composition information on 138 pigs during the last 28 d of the finishing phase from three trials were used. For each pig, the sum of the areas between the observed relative cumulative feed intake and the regression line for the evolution of relative feed intake over time was used to calculate the new feeding behaviour index. This index quantifies the irregularity of feed intake (IIFI) by integrating different components of feeding behaviour into a single measurement. Body lipids and protein composition were estimated by dual X-ray densitometry at the beginning (day 1) and end of the finishing phase (day 28). The relationship of IIFI with performance and body composition variables was examined using correlation tests and factor analysis within each dataset. In datasets where IIFI was correlated with body composition, linear models were used to quantify the contribution of IIFI to the total variation of body composition. Weak to moderate correlations (r = ±0.31 to ±0.44; P < 0.05) of IIFI with body composition and performance variables were found only in datasets 1 and 2. However, in dataset 2, IIFI was also correlated with daily feed intake (r = - 0.54; P < 0.001). Irregular feeding behaviour is associated to increased proportion of protein (PdDG) and decreased proportion of lipids (LdDG) in body gain. However, IIFI only accounted for 8% to 14% and 10% to 12% of the total variation of PdDG and LdDG in datasets 2 and 1, respectively. Additionally, factor analysis showed that the number of meals and IIFI had high loadings in a factor separate from factors associated with body composition or performance, suggesting that body composition and performance are independent of feeding behaviour. In conclusion, factors other than feeding behaviour might be involved in modulating body composition of finishing pigs fed ad libitum.

在类似条件下饲养和饲养的猪中观察到身体成分的巨大差异。考虑到猪的进食行为对与能量调节和蛋白质代谢相关的代谢激素的影响，这种变化的部分原因可能是猪的进食行为。本研究的目的是通过使用描述育肥猪摄食行为的新指数检查身体成分来阐明这种关系。使用了来自三项试验的 138 头猪在育肥阶段最后 28 天的饲养行为和身体成分信息。对于每头猪，观察到的相对累积采食量与相对采食量随时间演变的回归线之间的面积总和用于计算新的采食行为指数。该指数通过将饲喂行为的不同组成部分整合到单一测量中来量化采食量的不规则性 (IIFI)。在开始阶段（第 1 天）和结束阶段（第 28 天），通过双 X 射线密度测定法估计身体脂质和蛋白质组成。在每个数据集中使用相关性测试和因子分析来检查 IIFI 与性能和身体成分变量的关系。在 IIFI 与身体成分相关的数据集中，线性模型用于量化 IIFI 对身体成分总变化的贡献。弱到中等相关性（在每个数据集中使用相关性测试和因子分析来检查 IIFI 与性能和身体成分变量的关系。在 IIFI 与身体成分相关的数据集中，线性模型用于量化 IIFI 对身体成分总变化的贡献。弱到中等相关性（在每个数据集中使用相关性测试和因子分析来检查 IIFI 与性能和身体成分变量的关系。在 IIFI 与身体成分相关的数据集中，线性模型用于量化 IIFI 对身体成分总变化的贡献。弱到中等相关性（r  = ±0.31 至 ±0.44；仅在数据集 1 和 2 中发现 IIFI 与身体成分和性能变量的P < 0.05。然而，在数据集 2 中，IIFI 也与每日采食量相关（r  = - 0.54; P< 0.001)。不规律的进食行为与蛋白质 (PdDG) 比例增加和脂质 (LDDG) 比例降低有关。然而，IIFI 仅分别占数据集 2 和数据集 1 中 PdDG 和 LdDG 总变异的 8% 至 14% 和 10% 至 12%。此外，因子分析表明，进餐次数和 IIFI 在与身体成分或表现相关的因素分开的因素中具有高负荷，这表明身体成分和表现与喂养行为无关。总之，除饲喂行为之外的其他因素可能会影响育肥猪随意饲喂的身体成分。