Vicente Fernando, Santiago Carme, Jiménez-Calderón José D, Martínez-Fernández Adela
Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA),Villaviciosa (Asturias),Spain.
J Dairy Res. 2017 Aug;84(3):254-263. doi: 10.1017/S0022029917000383.
This Research Paper addresses the hypothesis that is possible to identify the type of feed used for dairy cows by means of the analysis of milk composition and the fatty acid profile of milk fat. Sixteen dairy farms were monitored during 1 year with quarterly visits between summer 2014 and spring 2015. Rations varied throughout the year due to annual dynamic change of forage production, forage rotation, variation of nutrient requirements according to physiological state of the animal, etc. The ingredients of the rations were analysed by cluster identifying five feeding systems based on the main ingredient of the diet: grazing, maize silage, grass silage, dry forage and concentrate. Milk composition could explain up to 91·3% of the total variability among feeding systems, while fatty acid profile could explain only up to 61·2% of total variability. However, when the sum of types of fatty acids and their ratios are taken, up to 93·5% of total variability could be explained. The maize silage system had the greatest milk yield, protein, solid non-fat and urea proportions, as well as the highest proportion of saturated fatty acid and lowest concentration of trans11 18 : 1, cis9 18 : 1 and 18 : 3 n3. Principal component analysis distinguishes the maize silage system from other feeding systems, both from milk composition and milk fatty acid profile. Concentrate system overlapped partially with the grazing, grass silage and dry forage systems. The latter systems had the highest concentrations of cis9 18 : 1, trans11 18 : 1 and 18 : 3, but there was no clear differentiation among them.
本研究论文探讨了一种假设，即通过分析牛奶成分和乳脂肪的脂肪酸谱来确定奶牛所使用的饲料类型是可行的。在2014年夏季至2015年春季期间，对16个奶牛场进行了为期1年的监测，每季度进行一次走访。由于牧草产量的年度动态变化、牧草轮作、根据动物生理状态的营养需求变化等因素，全年的日粮有所不同。根据日粮的主要成分，通过聚类分析日粮成分，确定了五种饲养系统：放牧、玉米青贮、牧草青贮、干饲料和精饲料。牛奶成分能够解释不同饲养系统间高达91.3%的总变异性，而脂肪酸谱仅能解释高达61.2%的总变异性。然而，当考虑脂肪酸类型及其比例的总和时，可解释高达93.5%的总变异性。玉米青贮系统的牛奶产量、蛋白质、非脂固形物和尿素比例最高，饱和脂肪酸比例也最高，但反式11 18:1、顺式9 18:1和18:3 n3的浓度最低。主成分分析从牛奶成分和牛奶脂肪酸谱两方面将玉米青贮系统与其他饲养系统区分开来。精饲料系统与放牧、牧草青贮和干饲料系统部分重叠。后几种系统中顺式9 18:1、反式11 18:1和18:3的浓度最高，但它们之间没有明显差异。
