Universidade Técnica de Lisboa, Portugal.
Int J Biol Sci. 2012;8(2):214-27. doi: 10.7150/ijbs.8.214. Epub 2012 Jan 1.
During the finishing phase of bovines, large amounts of subcutaneous and visceral fats are deposited leading to production inefficiencies with major impact on meat quality. A better understanding of the cellularity features of the main fat depots could provide strategies for adipose tissue manipulation. This study assessed the effect of feeding diets with distinct forage to concentrate ratios on the cellularity of two fat depots of beef cattle and their implications on the fatty acid profile. Thus, two phylogenetically distant Portuguese bovine breeds, Alentejana and Barrosã, were selected. The results did not show differences in subcutaneous fat deposition nor in visceral fat depots partitioning. Plasma adipokines concentration failed to show a consistent relationship with fatness, as leptin remained constant in all experimental groups, whereas interleukin-6 was influenced by breed. Fat depot seems to determine the area and number of adipocytes, with larger adipocytes and a lower number of cells in subcutaneous fat than in mesenteric fat. Neither breed nor diet influenced adipocytes area and number. The contents of total fatty acids, partial sums of fatty acids and conjugated linoleic acid isomeric profile were affected by breed and fat depot. The incorporation of saturated fatty acids (SFA), trans fatty acids, polyunsaturated fatty acids (PUFA) and branched chain fatty acids (BCFA) was higher in mesenteric fat depot, whereas subcutaneous fat depot had greater percentages of monounsaturated fatty acids (MUFA). In addition, SFA and MUFA proportions seem to be breed-related. In spite of the less relevant role of diet, the percentages of PUFA and BCFA were influenced by this factor. Under these experimental conditions, the effect of fat depot on cellularity and fatty acid composition prevails over breed or diet, as reinforced by the principal component analysis.
在牛的育肥阶段，大量的皮下和内脏脂肪沉积，导致生产效率低下，对肉质有重大影响。更好地了解主要脂肪沉积的细胞特征，可以为脂肪组织的操纵提供策略。本研究评估了不同饲粮中粗饲料与精饲料比例对牛肉牛两种脂肪沉积的细胞特性及其对脂肪酸谱的影响。因此，选择了两个在进化上相距较远的葡萄牙牛品种，阿连特茹和巴罗萨。结果表明，皮下脂肪沉积和内脏脂肪沉积没有差异。血浆脂肪因子浓度与肥胖没有一致的关系，因为所有实验组的瘦素都保持不变，而白细胞介素-6受品种影响。脂肪沉积似乎决定了脂肪细胞的面积和数量，与肠系膜脂肪相比，皮下脂肪的脂肪细胞更大，数量更少。品种和饲粮都不影响脂肪细胞的面积和数量。总脂肪酸含量、脂肪酸部分总和和共轭亚油酸异构体谱均受品种和脂肪沉积的影响。饱和脂肪酸（SFA）、反式脂肪酸、多不饱和脂肪酸（PUFA）和支链脂肪酸（BCFA）在肠系膜脂肪沉积中的含量较高，而单不饱和脂肪酸（MUFA）在皮下脂肪沉积中的含量较高。此外，SFA 和 MUFA 的比例似乎与品种有关。尽管饲粮的作用不那么重要，但 PUFA 和 BCFA 的比例受这一因素的影响。在这些实验条件下，脂肪沉积对细胞特性和脂肪酸组成的影响超过了品种或饲粮，这一点得到了主成分分析的支持。
